FOOT-AND-MOUTH DISEASE AND ZOONOSES CONTROL

III INTER-AMERICAN MEETING ON

FOOT-AND-MOUTH

DISEASE AND

ZOONOSES CONTROL

PAN AMERICAN HEALTH ORGANIZATION

Pan American Sanitary Bureau, Regional Oflice of the

WORLD HEALTH ORGANIZATION

1971

III INTER-AMERICAN MEETING ONFOOT-AND-MOUTH DISEASEAND ZOONOSES CONTROL

(Buenos Aires, Argentina, 14-17 April 1970)

Scientific Publication No. 218

PAN AMERICAN HEALTH ORGANIZATIONPan American Sanitary Bureau, Regional Office of the

WORLD HEALTH ORGANIZATION525 Twenty-Third Street, N.W.Washington, D.C. 20037, U.S.A.

1971

CONTENTS

Address by the Director of the Pan American Sanitary Bureau,Dr. Abraham Horwitz ........................................... v

Address by the Executive Director of the Inter-American DevelopmentBank, Mr. Ildegar Pérez Segnini ................... i.............. viii

Address by the Secretary of State for Agriculture and Livestock ofArgentina, Dr. Lorenzo A. Raggio .................................. xiii

FINAL REPORT .................................................... 1

PART 1. BASES FOR A FOOD AND NUTRITION POLICYIN THE AMERICAS

Participation of the Agricultural Sector-Juan F. Yriart ................ 27The Responsibility of the Health Sector in Planning and Conducting Na-

tional Food and Nutrition Policies-Roberto Rueda-Williamson ....... 34

PART II. FOOT-AND-MOUTH DISEASE VACCINES

Use and Experiences with Frenkel-Type Vaccine-Jacob G. van Bekkum ........................................... 47

Tissue Culture Vaccines (BHK) in Foot-and-Mouth Disease Control-John B. Brooksby ............................................... 52

Studies on Live Virus Vaccines for Foot-and-Mouth Disease-Carlos A. Palacios ............................................... 58

Accidents and Reactions Observed in Foot-and-Mouth Disease Vaccina-tions-Manfred W. Mussgay ...................................... 78

New Vaccines and Future Prospects in Foot-and-Mouth Disease Immuni-zation-Jerry J. Callis ........................................... 84

PART III. HEALTH ASPECTS OF THE IMPORT AND EXPORTOF ANIMALS AND ANIMAL PRODUCTS INTENDED

FOR CONSUMPTION

Present Status of the Production and Consumption of Animal Products inthe Hemisphere and Prospects in the Next Ten Years-José J. Cañón.. 93

Health Problems Involved in the Import and Export of Foodstuffs ofAnimal Origin-Fernando Quevedo ................................ 106

Disease Problems Associated with the Import and Export of Animal Prod-ucts Intended for Consumption-Teodorico Terry .......... ....... 119

Need for Uniform Animal Health Guidelines and Regulations Governingthe Import and Export of Animals Intended for Consumption andBreeding-H. O. Konigshófer .................................. 123

Present and Future Problems Associated with the Import and Export ofAnimals and Animal Products, and Their Effect on the Economic Devel-opment of Countries-Ernest E. Saulmon ........................... 131

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iv Contents

ANNEXES

1. Epidemiological Surveillance of Foot-and-Mouth Disease-RobertoGoic Martinic and Victor H. Moscoso ........................... 139

2. List of Participants ............................. 142

, ADDRESS BY THE DIRECTOR OF THEPAN AMERICAN SANITARY BUREAU

DR. ABRAHAM HORWITZ

We tend nowadays to talk in terms of decades rather than of centuries, suchis the speed and range of events in the modern world. We are also betterinformed than in the past, and hence we make bold to predict the future withgreater assurance. That during the 1960's events of vast significance took placewhich have left their mark on the Americas is an indisputable fact. There arethose who raise the query whether the political declarations and the enterprisesto which they gave rise attained their object, in other words, whether the out-come was a success or a failure. It might seem wishful thinking to try to changethe face of a continent in a single decade; but it is perfectly reasonable to tryto alter radically the course of events in the countries belonging to that conti-nent, and this is in fact what has happened. Not only have people becomeaware; there have been achievements which justify the optimism felt in somequarters in regard to the 10-year period beginning with the present year.

With regard to the prevention and cure of disease, vital and health statisticsreveal steady progress, in spite of the notable underregistration of morbidityand mortality. There is likewise a sense of realism which is prompting Govern-ments, professionals, and experts of public and private services to make pro-ductive use of the human and material resources at their disposal. Notwith-standing the political and social ups and downs-which are to be expected, sincehigher income brings higher aspirations-we are confident that this trend willcontinue to benefit an increasing number of human beings in this Hemisphere.

The forecasts made concerning the feeding of the world population from thisyear onward are therefore not surprising. The introduction of high-yield,improved varieties of wheat, corn and rice, resistant to disease and highlyresponsive to the action of fertilizers, gives grounds for an optimistic view ofthis grave problem, as a result of this so-called "green revolution." If the trendshould spread, some predict that it is not the production of food that will be themajor problem but its distribution and preservation to ensure proper consump-tion and utilization. This is a matter of proper organization and administrationof a series of complex mechanisms in individual countries and communities.It may be pertinent to recall that there are those who hold that the most seriouscrisis of our time is the institutional crisis. They maintain that the traditionalinstitutions have been unable so far to adapt themselves to the speed of changein human beings. The institutions established now and in the future must givecareful thought to ways and means of satisfying vital needs which are a featureof a more just society, and these needs include nutrition.

There can be no efficient organization which is not the outcome of a rationalpolicy. To draw up such a policy for food and nutrition in the Americas hasbecome a pressing need. Prevention and treatment of the ravages of malnutri-

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vi Addresses

tion and other deficiency diseases is a hopeless task without a knowledge offood availability and quality, and the organization of food production withoutregard for the health and sickness requirements of the inhabitants, as well astheir economic needs, would appear to be equally futile. The dissociation offunctions created artificially by men does not exist in nature; we can thereforeunderstand why agriculture and health specialists are convinced today that theymust take joint action and pursue a single policy for the common good. TheMinisters of Health have favored this policy. They have also favored the estab-lishment of a Nutrition Data Retrieval and Analysis Center for the countriesof the Americas. This information would be useful for the formulation, execu-tion, and evaluation of programs for the production, consumption, import, andexport of protective and energy-giving foods. The Government of the Republicof Argentina has expressed interest in having the headquarters of this under-taking in its territory, and is sponsoring a project on the subject with thecollaboration of the United Nations Food and Agriculture Organization andour own Organization. It is noteworthy that agrometrics has not yet attainedthe same degree of development in Latin America as biometry. In other words,demographic and vital and health statistics, and procedures for analyzing them,are more widely and more frequently used than statistics on agriculture andlivestock-raising. The scheme in question might well have the immediate effectof inducing Governments to organize or extend their services for collecting andeffectively using data connected with their agricultural policies.

We look forward during the present meeting to a wide-ranging debate on thiswhole complex question, in the course of which the Ministers of Agriculture ortheir representatives will no doubt enlighten us concerning the feasibility, or thepresent status, whichever applies, of the process of providing the populationwith the minimum balanced diet. This is, of course, a multisectoral and multi-disciplinary operation, and there are traditions and conventions which are noteasy to bypass; but we cannot remain unmoved in the face of a mortality ratein children under 5 years which represents 44 per cent of all deaths in LatinAmerica and the Caribbean area. Malnutrition contributes in large measureto this death rate and helps to increase it.

An important component in this whole problem is the loss of essential pro-teins through diseases in certain animal species. But it is a matter of evengreater concern when these diseases are transmitted to men. I should like toexpress to the Government of Argentina, on behalf of the Pan American HealthOrganization and the World Health Organization, our profound gratitude formaking it possible to establish the Pan American Zoonoses Center as a success-ful going concern. In response to Resolution VIII of your II Meeting held inRio de Janeiro in May 1969, you will be hearing the report of the Special Mis-sion which so far has visited 15 countries in the Hemisphere to seek your viewson regional extension of the activities of the Center. Everyone is agreed as tothe need for controlling the zoonoses in cattle, reducing infection in humanbeings, and increasing the protein intake of vulnerable groups. This impliesan intensification of the education and training programs, and of research andadvisory services to Governments, all with a view to reducing the incidenceof these problems. It is gratifying to note the readiness of the Inter-AmericanDevelopment Bank and the International Bank for Reconstruction and Devel-

Abraham Horwitz vii

opment (World Bank) to consider applications for credits for livestock promo-tion, including zoonoses control.

The other items on your agenda merely corroborate the great significance ofthe present meeting. I should like to make special mention of the panel onvaccines for foot-and-mouth disease control, the mere mention of which indi-cates its tremendous practical importance. I should like once again to thankthe Government of Brazil, on behalf of the Organization, for the excellentfacilities it has provided for the Pan American Foot-and-Mouth Disease Centersince its inception. Since it is financed today by Governments, its program andbudget will come up for discussion at one of the working sessions.

A second panel will discuss health and food problems connected with importsand exports of animals and animal products. Here again, the mere mention ofthe subject reveals its implications for nutrition and for the economy. I amsure that the debates will suggest lines of action which public and privatebodies, as well as the international organizations, will endeavor to put intopractice. This is our feeling in regard to all the resolutions which you see fitto adopt here. They will enable us to make our contribution to the well-beingand the development of the Hemisphere.

We propose to set up at the Headquarters of the Organization a departmentto handle relations between health and agriculture, which have taken on aspecial importance in the Americas and are a matter of great concern to us.The justification for this new departure will be more patent to the extent thatGovernments formulate and implement a food and nutrition policy. We shallthus be better able to direct and organize the cooperation of the Pan AmericanHealth Organization in dealing with problems which by their nature and theconsequences that derive from them are among the most vital.

Nothing seems impossible today in the Americas; this is the most positivelesson to be drawn from what has occurred during the 1960's. Albert Camusexpressed this, much more poetically, when he said that we must mend whathas been torn, we must make justice once more conceivable in a manifestlyunjust world, we must give a new meaning to happiness for peoples poisonedby the unhappiness of our times. No doubt it is a superhuman task; but thefact is that what are described as superhuman tasks can be and are accom-plished by men in the fullness of time.

ADDRESS BY THE EXECUTIVE DIRECTOR OF THEINTER-AMERICAN DEVELOPMENT BANK

MR. ILDEGAR PÉREZ SEGNINI

It is my great privilege to bring you greetings from the Inter-AmericanDevelopment Bank-from its Board of Executive Directors and more particu-larly from its President, Felipe Herrera, who until the very last moment hadbeen hoping to be present personally at this important meeting. This turnedout to be impossible because of commitments in connection with the preparationof the forthcoming meeting of the Board of Governors of the Bank, which isabout to open in Punta del Este, Uruguay. He has asked me to assure you ofhis personal interest in the purposes and objectives which bring us togetherhere, and of his firm conviction that the development of the countries of ourHemisphere and the well-being of its inhabitants are bound to be enhancedby the implementation of the conclusions and recommendations that emergefrom this meeting.

For three years running-thereby establishing a noteworthy tradition-thePan American Health Organization has brought together the Ministers ofAgriculture and senior government experts of our countries for joint discussionof problems relating to foot-and-mouth disease and other livestock diseases,realizing as it does that they affect all the countries, directly or indirectly, andcall for comprehensive solutions likewise based on joint action.

The Inter-American Development Bank has attended all these meetings,voicing the opinion of its member countries, fully appreciative of the problemsinvolved, and working with others for their solution.

I should like to thank the Pan American Health Organization for its kindinvitation, and indeed to thank all of you for this excellent and timely oppor-tunity to express the interest and concern of IDB in regard to the discussionswhich take place here and to assure you of its firm intention to support thetechnical measures and decisions adopted. We regard the present meeting ashighly important. We feel that it could be invaluable for this Hemisphere,many of whose problems and difficulties could be overcome if we could confirmour decision to face them in a comprehensive, united fashion.

Action by IDB in the Agriculture and Livestock-Raising Sector

The economy of our countries continues to be based essentially on agricultureand livestock-raising. It is this sector that has primary responsibility for pro-viding the wherewithal to feed a growing population, while at the same time itconstitutes a fundamental source of employment. Nevertheless, serious short-comings have restricted its development, and unless we succeed in giving it thebenefit of the latest technological advances, we shall face the serious difficulties

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Ildegar Pérez Segnini ix

already hinted at by the international organizations concerned with food andagricultural development.

During the 10 years since its inception, IDB has made a substantial contribu-tion to the valiant efforts of the Latin American countries to improve theiragriculture. No doubt its concern in this direction explains the fact that thefirst two loans of the Fund for Special Operations earmarked a considerableportion of the financing for development programs in this sector.

Now that we have reached the end of our first decade, we have encouragingresults to show, with an agricultural portfolio which is the highest in IDB,representing 24.3 per cent of the total. Up to 31 December 1969, IDB'scontribution to the achievement of progress in the Hemisphere amounted to$3.5 billion, of which $834 million represent assistance in introducing improvedtechniques into agriculture. To appreciate this contribution fully, let us recallthat every dollar lent by IDB mobilizes two dollars of the domestic resourcesof the different countries, likewise for agriculture. As a result of this collabora-tion, 6.5 million persons have seen their living conditions improved, and1.5 million hectares have been added to the cultivated areas or have increasedtheir productivity. The activities reflected in these figures show that the Inter-American Development Bank continues to be the public organ which hascontributed most to agricultural financing in Latin America.

Appreciable indirect contributions have also been made by way of road-building and rural housing, support for the teaching of agronomy or veterinarymedicine and for rural health programs.

The close relationship between health and agriculture and the active andcooperative participation of these sectors in a food and nutrition policy for theAmericas will be examined at this meeting. IDB has likewise given its supportto health programs. This field, along with education and other fields, has beengiven special attention by our President, Felipe Herrera, who was awarded theBronfman Prize by the American Public Health Association in recognition ofhis work for the protection of public health in Latin America.

The complexity of the agricultural sector, in the development of which non-human factors are frequently involved, makes its financing subject to specialproblems and features which IDB has helped to resolve in conjunction with thevarious countries. The traditional fields of financing such as agricultural orirrigation credits have been given attention, but as these programs have devel-oped others have arisen which likewise need encouragement, so that we findourselves financing new items such as the marketing of agricultural and live-stock products or animal health programs involving foot-and-mouth diseasecontrol.

Importance of Animal Health in Livestock Development

Livestock-raising has received something like $72 million in direct loans, or8.6 per cent of the whole of the agricultural portfolio. At the same time, IDBhas helped to finance other projects which indirectly benefit livestock-raisingor which imply livestock development programs, to the tune of approximately$47 million, making the total IDB contribution under this heading approxi-mately $119 million.

The experience gained with livestock projects indicated the need to give

x Addresses

thought not only to the quality of livestock and to feeding and management,but particularly to animal health.

Losses caused by foot-and-mouth disease, estimated at some $500 million,are not the only factor which worries individual countries and seriously affectsthe economy of the Region. In quite a few of the Latin American countries wefind a decline of more than 30 per cent in livestock production as a consequenceof infectious and parasitic diseases. If these diseases are to be controlled, theymust be combated at all levels-the farm, the country, or in the case of diseaseswith a marked tendency to spread, such as foot-and-mouth disease, even at theregional or continental level.

A control process not carried out at the level of the entire region affected isas useless as it is costly. It is this technical need which gives foot-and-mouthdisease and other animal health campaigns their status as a multinationalintegration program. This has been IDB's approach ever since it made its firstloans for foot-and-mouth disease control to Paraguay and Chile in 1968 andto Argentina in 1969, totaling $15.6 million.

In a recent report on the livestock situation in the Region, the EconomicCommission for Latin America points out the favorable prospects and the veryextensive possibilities of zonal integration and complementation for the coun-tries of the Latin American Free Trade Association. But it also points out thatthe countries must unify and coordinate their activities, improve their researchand technical assistance services, and undertake joint action against foot-and-mouth disease, the endemic nature of which in the South American countries ishampering sales of meat in certain international markets.

Significance of the Action Taken against Foot-and-Mouth Disease and theImprovement in Animal Health

With the effective assistance of the countries of the Region, of the PanAmerican Health Organization, and particularly the Pan American Foot-and-Mouth Disease Center, as well as other bodies, IDB has given vigorous sup-port to a campaign to combat this and other livestock diseases. In additionto the foot-and-mouth disease campaigns in Argentina, Chile, and Paraguaynow under way with the financial support of the Bank, Bolivia has in prepara-tion a health project which will include campaigns against foot-and-mouthdisease, brucellosis, and paralytic bovine rabies. Brazil has already placedbefore the Bank a project, now at an advanced stage of discussion, covering asa first stage the control of foot-and-mouth disease in seven Brazilian stateswhere livestock production is most heavily concentrated. The program willmake use of the experience acquired in the campaigns in Rio Grande do Sul andother states. Colombia, with the help of the Pan American Foot-and-MouthDisease Center, has just completed an animal health program including thecontrol of this disease and of brucellosis. Ecuador is due to conclude in thesecond half of 1970 an animal health project for the organization of which itobtained a technical assistance loan from the Bank on a contingent repaymentbasis. Peru, with technical advice from the Foot-and-Mouth Disease Centerand technical assistance from IDB, is hoping to complete the formulation ofits project in the first half of 1970 and to be in a position to submit it for

Ildegar Pérez Segnini xi

financing. Uruguay is using preinvestment funds to prepare a foot-and-mouthdisease, hydatidosis, and brucellosis project to supplement its current cam-paign. Venezuela is likewise completing the formulation of a project for ahealth campaign.

Thus, in response to the recommendations and the strategy approved atprevious meetings, IDB has pledged full support to this program, and theprospects are favorable, since all the countries of South America have projectsof this nature either in progress or at an advanced stage of preparation.

Toward a Solution of Animal Health Problems

It is an undoubted fact that the measures aimed at livestock promotion willall fail to achieve real results or will be seriously and constantly in jeopardyunless the livestock diseases, especially foot-and-mouth disease, are broughtunder control or eradicated. The meat deficit in Latin America also means ashortage of proteins, an essential element in human nutrition; this calls urgentlyfor sustained, systematic action at the regional level with a view to increasingthe livestock population, the main source of this valuable element.

The experience of the campaigns now under way-the outcome of criteriaand guidelines for the preparation and study of projects formulated with thehelp of the individual countries, the Pan American Health Organization, andvarious scientific centers to which recourse has been had-leads us to believethat this target is feasible. We have the means of attaining it; all we need isthe will to do so.

The Bank is prepared to support these programs resolutely as part of thepolicy it has established, and it looks to the individual countries to proceed withthe preparation of soundly-designed programs based on proper technical adviceand with due attention given to multinational considerations and the efficientuse of technological and scientific resources. There will be a need for sustainedand constant effort, for effective coordination between countries, financingbodies and technical centers, for a continuing evaluation of results, as well asfor efficient institutions endowed with adequate resources and technical per-sonnel, the active participation of stockmen and farm workers, good-qualityvaccines in sufficient quantities, and other factors of like importance. Use willhave to be made of the permanent advisory services of the Pan AmericanHealth Organization, the Pan American Foot-and-Mouth Disease Center, FAO,scientific centers, and other assistance; and it will be necessary to strengthenscientific institutions such as the Foot-and-Mouth Disease Center, to help themwith their research, to promote an interchange of technical information, and toencourage multinational and regional coordination.

The Inter-American Development Bank will continue to work in closecooperation with the Ministers for the elimination of foot-and-mouth diseaseand other livestock diseases. It is reassuring to see you assembled here onceagain, with the same firm resolve, evaluating the progress you make and adopt-ing appropriate decisions to confirm proposals and to detect or rectify mistakes.The Bank is happy to be present here and it will continue to attend wheneverit considers this necessary, since its raison d'étre is and will continue to be toserve the countries of the Hemisphere.

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Finally, I should like to send a greeting and say a word of thanks to theArgentine people and Government for their hospitality and for the facilitiesgiven us. They will assist us in conducting our discussions and provide anatmosphere propitious for fruitful resolutions.

ADDRESS BY THE SECRETARY OF STATE FORAGRICULTURE AND LIVESTOCK OF ARGENTINA

DR. LORENZO A. RAGGIO

The Government of the Republic of Argentina wishes to express, through me,the honor it feels in welcoming its eminent visitors from the sister republics ofthe Americas and those countries of Europe that will share our concern topresent a united front in the fight against some of the factors causing theinadequate food intake in many parts of the world.

My country is anxious that all of you should feel at home here in these work-ing sessions, in the knowledge that you have the fellow-feeling of all theArgentine citizens, who are genuinely interested in learning the results of yourdeliberations, begun two years ago under the auspices of the Pan AmericanHealth Organization and continued today at this III Meeting. It is evidentthat this sentiment is shared by all your countries, since they have sent toattend this meeting the outstanding figures in one or another aspect of health,agriculture, and the economy.

The demand for more and more food, both to meet the spiraling growth ofthe population and to improve the standard of living of the new peoples joiningthe community of nations, is increasing at a prodigious rate everywhere in theworld. We have a tremendous responsibility, as chiefs of technical bodies whichtake the lead in obtaining this food, not only to meet the internal needs of ourcountries, but to help as far as we can in the solution of the problem at theworld level.

The extent to which we can do so is determined in a sense by the naturalconditions and the geographic area of our countries, and also by a concernto improve quality and intensify production capacity.

Here is where our great responsibility begins, where the unquestionable goalof our duty lies-in the acquisition of agricultural technology with a view tohigher productive capacity and the safeguarding of this production throughthe adoption of the necessary preventive measures to ensure that pests anddiseases do not destroy the whole or part of it.

The diseases affecting livestock are today taking a considerable toll of theanimal population in terms of head of cattle and tonnage of meat and deriva-tives lost. I need not quote the figures on the cost which this represents; thestatistics at the disposal of all of us are a reliable indication that, except foroccasional fluctuations, the percentage level of livestock production is falling,even though the over-all quantities may appear to indicate the contrary.

There is daily evidence to show that countries which hitherto could boast ofself-sufficiency in food production are today faced with the imminent prospectof having to call upon other producing countries to make up their deficit. Inthe face of this prospect we cannot remain impassive, otherwise we incur the

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charge of willful negligence. That is why the community of effort we are build-ing up through these meetings is not a mere pious hope, but a very positivemeans of coordinating the technical efforts of the countries and the internationalorganizations to achieve a precise and positive goal.

We must also remember that countries like ours, anxious to advance in thedirection of industrialization so as to achieve a standard of living in keepingwith the possibilities of modern technology and science, must do everythingpossible to increase and sustain food production. This will not only enable usto keep our manpower efficient, healthy, and physically vigorous, but will alsoprovide an exportable balance to help satisfy the needs of other countries andat the same time allow us to meet the costs which this industrialization involves.

We must also remember that the livestock producers are aware of the vitalrole they play in this world crusade against hunger, and they have the right toinsist that the agencies in charge of the economic policy of the various countriesdevote their efforts to legislation which will allow them to earn a fair remunera-tion and thus make it possible for them to continue to share the responsibilitiesof the health campaigns with their Governments.

The official bodies should devote their best efforts to planning and organizingthese campaigns, not only with a deep concern for health but with a genuinepractical outlook. This will encourage producers to redouble their efforts,expending on this task their enormous traditional stock-in-trade of knowledgeof livestock exploitation and plowing back their profits in the interests ofincreased production.

Although it will be a basic issue in the papers to be read here, I feel I shouldmention the tremendous concern felt in countries such as Argentina, which aretraditional livestock producers, about the disease which plays most havoc withproduction, namely, foot-and-mouth disease.

The campaigns against this disease have been in progress for some years, andit is evident that considerable progress has been made. This is borne out clearlyin my own country by the figures, which show that out of a total of 404,000livestock establishments subject to control, with an approximate total of50 million head of cattle and 40 million sheep, the number of foci recorded in1969 was 1,957, many of them consisting of a single animal. Moreover, we havesucceeded in eradicating the disease from a large section of the territory,covering practically the whole of Patagonia.

But although progress has been made in this direction, the very fact that thedisease is still with us brings us within the health legislation of the importercountries, which considerably restricts our exports.

Argentina, like other Latin American countries, has never denied the exis-tence of foot-and-mouth disease, a disease brought into our Continent fromoutside, but we do feel that recognition should be given to the vigorous cam-paigns we are waging. In its plans for the next five years, Argentina proposesto invest approximately 200 million pesos (US$50 million), including a loanfrom the Inter-American Development Bank, and we also have the strong sup-port of the producers. We hope to achieve control of this disease and thus tobe able to look forward confidently to its final eradication.

Before concluding, I should like to make special mention of the Pan Ameri-can Health Organization together with its subsidiary agencies, the Pan Ameri-can Foot-and-Mouth Disease Center and the Pan American Zoonoses Center,

Lorenzo A. Raggio xv

which have done such admirable work in ensuring that technical activities atthe expert level in our countries constantly enjoy the benefit of advisory ser-vices. They have likewise organized training courses for laboratory techniciansand maintained a vigorous interchange with technical offices of the Govern-ments; and in their laboratories the two Centers have studied and solved manyproblems arising in individual countries and in regional groups of countries.

That these meetings are sponsored by the Pan American Health Organizationis an eloquent comment on the continuing concern about the health problemsaffecting the countries of the Americas.

I repeat, gentlemen, please feel at home here, and I trust that your work willbe fruitful and your efforts crowned with success.

FINAL REPORT OF THE MEETING

FINAL REPORT

The III Inter-American Meeting, at the Ministerial Level, on Foot-and-Mouth Disease and Zoonoses Control was held at the San Martin Theater inthe city of Buenos Aires, Argentina, from 14 to 17 April 1970. The meetingwas convened by the Director of the Pan American Sanitary Bureau pursuantto Resolution XIX 1 approved by the Directing Council of the Pan AmericanHealth Organization at its XVII Meeting, and Resolution XV 2 of the II Inter-American Meeting on Foot-and-Mouth Disease and Zoonoses Control.

OFFICERS

The heads of delegations met on 14 April to elect the officers of the meeting.The following were elected:

President: Dr. Lorenzo A. Raggio, Secretary of State for Agricultureand Livestock (Argentina)

Vice-Presidents: General Jorge Barandiarán PagadorMinister of Agriculture and Fisheries (Peru)

Hon. Lionel M. RobinsonMinister of Agriculture, Land and Fisheries (Trinidadand Tobago)

Dr. Abraham Horwitz, Director of the Pan American Sanitary Bureau,served as Secretary ex officio.

PARTICIPANTS

The following Governments were represented at the meeting: Argentina,Barbados, Bolivia, Brazil, Chile, Colombia, Costa Rica, Cuba, DominicanRepublic, Ecuador, El Salvador, France, Guatemala, Guyana, Honduras,Jamaica, Mexico, Kingdom of the Netherlands, Nicaragua, Panama, Paraguay,Peru, Trinidad and Tobago, United Kingdom, United States of America,Uruguay, and Venezuela. The Government of Canada sent an official observer.Observers from the following international organizations were also present:Inter-American Development Bank, International Bank for Reconstruction andDevelopment, United Nations Development Program, United Nations Chil-dren's Fund, Inter-American Institute of Agricultural Sciences, InternationalOffice of Epizootics, and Food and Agriculture Organization of the UnitedNations.

1 Official Document PAHO 82, 74-76.2 Scientific Publication PAHO 196, 16.

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PLENARY SESSIONS

Dr. Abraham Horwitz, Director of the Pan American Sanitary Bureau,opened the meeting and in his address referred to the importance of the preven-tion and cure of animal diseases as a means of improving the food supply andnutrition of the peoples of the Americas. He stressed that one immediateconsequence of the agreement concluded by the Ministers of Health 3 to estab-lish a Nutrition Data Retrieval and Analysis Center would be to encouragethe organization or expansion of the services devoted to the compilation anduse of data relating to the agricultural policies of the Governments. Moreover,recognizing the need for specialists in the fields of agriculture and health towork closely together, the Organization proposed to establish at its Head-quarters a department charged with coordinating all matters relating to thoseactivities. Dr. Horwitz then reviewed briefly the agenda and stressed the impor-tance of all the topics for the health and the economy of the countries.

Next, Dr. Lorenzo A. Raggio, Seeretary of State for Agriculture and Live-stock of Argentina, welcomed the participants and expressed the hope that themeeting would contribute to the solution of problems arising from the extra-ordinarily fast growth of the world demand for food. He extended his wishesfor the success of the meeting and stressed the need to establish closer bondsof cooperation between the countries and the international organizations con-cerned with animal health problems in the Hemisphere.

At the first plenary session, Mr. Juan F. Yriart, Regional Representativefor Latin America and Assistant Director-General of the Food and AgricultureOrganization, spoke on "The Role of the Agricultural Sector," under the topic"Bases for a Food and Nutrition Policy in the Americas." He described theexisting collaboration between his Organization and the Pan American HealthOrganization, which work together to improve the relationship between agri-cultural production and food and nutrition. He enumerated certain fundamentalmeasures that could be adopted by the Governments of the countries to increasethe production and supply of food, and strongly urged that a veritable crusadeof human solidarity be launched to improve nutrition among the peoples.

Dr. Roberto Rueda-Williamson, Regional Adviser in Nutrition of the PanAmerican Sanitary Bureau, presented a paper on "The Responsibility of theHealth Sector," as the second part of the above-mentioned topic. He drewattention to the seriousness and magnitude of malnutrition and other deficiencydiseases in large groups of population in Latin America, and to their adverseeffects on the economic and social development of the countries. He gavespecial emphasis to the need for multisectoral action-encompassing health,agriculture, and education plans-in order to formulate and implement a soundnational food and nutrition policy in each country.

In connection with this topic, the Representative of Colombia presented adraft resolution on food availability and consumption indexes, and the Repre-sentative of Peru submitted another draft resolution on national food andnutrition policies.

At the second plenary session, Mr. Ildegar Pérez Segnini, Executive Directorof the Inter-American Development Bank, referred to the Bank's activities inthe agricultural and livestock sector of Latin America, and particularly to the

3 Official Document PAHO 89, 40.

Final Report 5

importance of animal health to livestock development. He reviewed thefinancial assistance granted not only for foot-and-mouth disease control cam-paigns in Argentina, Chile, and Paraguay and for the preparation of similarcampaigns in other countries, but also for programs against other zoonosesof economic and social importance such as brucellosis, rabies, hydatidosis,and tuberculosis. Lastly, he recommended that the countries draw up well-conceived animal health programs, which should be supported by suitabletechnical advice and take into account multinational aspects.

Following this address, the Representative of Paraguay expressed hiscountry's appreciation for the aid it had received from the Inter-AmericanDevelopment Bank for the development of its foot-and-mouth disease controlprogram, and presented a draft resolution requesting the Bank to help financedemonstration and training programs at the Pan American Foot-and-MouthDisease Center. The Representative of Brazil also presented a draft resolutiondealing with international cooperation in animal health programs.

The second part of this plenary session was devoted to country reports on thestatus of vesicular diseases and to the prevention and control activities underway. Following the order of registration of speakers, reports were submittedby the following participants and countries: Dr. Teodorico Terry Elejalde(Peru), Dr. Lautaro Gómez Ramos (Chile), Dr. Ezelino Arteche (Brazil),Dr. Gabriel Baraya (Colombia), Dr. José Luis Roca García (Bolivia), andDr. Pablo T. Quinteno Pinzón (Panama).

The first speaker at the third plenary session (15 April) was Dr. RamónRodríguez, Head of the Department of International Affairs of the Universityof Chile, who presented the report of the Scientific Advisory Committee on the"Research Program of the Pan American Foot-and-Mouth Disease Center andthe Pan American Zoonoses Center." He expressed the Committee's satisfactionat the progress made in the field of research, which had attained a trulyacademic level, and stressed that the activities of both Centers, adequatelycoordinated with the national universities, would be an important factor thatwould benefit the countries and the international organizations. He pointed outthat both Centers are in a unique position to give research training in connec-tion with animal health problems common to the Americas, and asserted thatthe activities carried out by the Centers cannot be substituted by individualaction.

Following that statement, the Representative of Peru presented a draftresolution, which was unanimously approved.

Next, Dr. Enrique García Mata presented the "Report on Zoonoses Controlas an Integral Part of Agriculture and Livestock Development and the Role ofthe Pan American Zoonoses Center," containing the findings of the studyentrusted by PASB to the speaker, in conjunction with Drs. Juan T. Bowlerand Rubén Lombardo, pursuant to Resolution VIII 4 of the II Inter-AmericanMeeting on Foot-and-Mouth Disease and Zoonoses Control. He reviewed thecurrent status of the principal animal diseases in the Americas, examinedtheir economic effects, and summarized the views expressed during his inter-views with Ministers and Government officials with reference to the mostimportant problems in their respective countries and the advice and assistancethey would like to receive from the Pan American Zoonoses Center. Finally,

4 Scientific Publication PAHO 196, 12-13.

6 Final Report

he stressed the need for granting increased financial assistance to the Centerin view of the growing demands made on it by the problem of animal diseasesin the Americas.

The Representatives of Costa Rica, Paraguay, the United States of America,and Venezuela commended both the report and the Pan American ZoonosesCenter on its work. The Representative of Colombia presented a draftresolution on the future programs and financing of the Center, which wasadopted by 18 votes in favor, none against, and 3 abstentions.

During the second part of the session the draft resolutions presented at thesecond plenary session were put up for discussion and, there being no comments,were voted on and unanimously approved.

Dr. Mário Fernandes, Director of the Pan American Foot-and-MouthDisease Center, then presented the proposed program and budget estimates forthe Center for 1971 and the provisional drafts for 1972 and 1973. After variouscomments and explanations, the Representative of Brazil submitted a draftresolution, which was unanimously adopted.

At the fourth plenary session, in the absence of the President and of bothVice-Presidents, the Hon. Robert J. Jordan (Guyana) was elected ProvisionalPresident. The session was devoted to reports on the status of vesicular diseasesand other zoonoses presented by the following Representatives: Mr. RubénEspinosa R. (Ecuador), Hon. Robert J. Jordan (Guyana), Dr. Carlos H.Aguilar Avila (Honduras), Dr. Leonard V. Butcher (Trinidad and Tobago),Dr. Amador P. Nita (Kingdom of the Netherlands), Dr. Humberto Olmos(Venezuela), Dr. Cedric L. Bent (Jamaica), Dr. Nelson Magallanes Pastorino(Uruguay), Dr. Malcolm B. Proverbs (Barbados), Dr. José Luis Solano Astúa(Costa Rica), Mr. Ricardo R. Granada Pineda (El Salvador), Dr. Juan F.Urguizú Gutiérrez (Guatemala), Dr. Parisio Pineda Ayala (Paraguay), Dr.Gustavo Reta Pettersson (Mexico), Dr. Frank Mulhern (United States ofAmerica), Dr. Luis María Cuevas (Dominican Republic), Dr. Jorge Borsella(Argentina), Dr. John Reid (United Kingdom), Dr. Albert E. Lewis (Canada),and Dr. Louis R. Perpere (France).

After concluding his presentation, the Representative of the Kingdom of theNetherlands submitted a draft resolution on the cooperation rendered by theFood and Agriculture Organization of the United Nations (FAO), which wasunanimously adopted.

The fifth plenary session (16 April) discussed the topic assigned to PanelA: "Vaccines for Foot-and-Mouth Disease Control."

Dr. Jacob G. van Bekkum, Director of the Amsterdam Central VeterinaryInstitute (Kingdom of the Netherlands), in presenting his paper on "Use andExperiences with Frenkel-Type Vaccine," referred to the excellent resultsobtained in his country with one yearly application of that vaccine to cattle,and the enforcement of strict supplementary animal health measures, includingthe slaughter of diseased or contaminated cattle. He stated that over 50 millionvaccinations had been applied in his country since 1953, and that not a singleoutbreak of foot-and-mouth disease had been recorded in the past two years.

Dr. John B. Brooksby, Director, Animal Virus Research Institute of Pirbright(United Kingdom), then discussed the topic "Tissue Culture Vaccines (BHK)in Foot-and-Mouth Disease Control." He reviewed the advantages of cell

Final Report 7

lines in virus cultures for the production of vaccines and drew attention to theirimportance when planning large-scale vaccination campaigns.

In presenting the third topic, "Study of Live Virus Vaccine against Foot-and-Mouth Disease," Dr. Carlos A. Palacios, Director of the VeterinaryResearch Center (Venezuela), summarized the history, results, and prospectsof these types of vaccines, and referred particularly to the research workcarried out in Venezuela and at the Pan American Foot-and-Mouth DiseaseCenter.

The next speaker was Professor Manfred W. Mussgay, President, FederalResearch Institute for Animal Virus Diseases of Tubingen (Federal Republicof Germany), who presented the topic "Accidents and Reactions Observed inFoot-and-Mouth Disease Vaccinations." In his concluding remarks he calledattention to the fact that the studies made in the Federal Republic of Germanyshowed that allergic postvaccinatal reactions were infrequent; consequently,while such reactions can occasionally pose some problems, this should not bea deterrent to the use of the vaccines to control the disease, particularly inview of the fact that there are technical means available, if needed, to reducethose reactions.

Panel A discussions closed with the presentation by Dr. Jerry J. Callis,Director of the Plum Island Animal Disease Laboratory (United States ofAmerica), on "New Vaccines and Future Prospects in Foot-and-Mouth DiseaseImmunization." He emphasized the research under way to improve inactivatedvaccines by testing new inactivants and adjuvants and by virus concentrationand purification techniques. He also referred to the possibilities of interferon incontrolling the disease.

A discussion followed during which questions, views, and information wereexchanged by the Representatives of Argentina, Colombia, Jamaica, UnitedKingdom, United States of America, and Uruguay, at the end of which threedraft resolutions were presented. All three resolutions-one presented by Chileon foot-and-mouth disease vaccines, and two presented by Venezuela on thestrengthening of animal health services and application of health measuresin the control of foot-and-mouth disease-were unanimously approved.

The sixth plenary session opened with a report on Cuba, presented by Dr.Pedro Roca. Following this, the meeting proceeded with the discussion of thetopics assigned to Panel B: "Health Aspects of the Import and Export ofAnimals and Animal Products for Consumption," which included papers byDrs. José J. Cafiñón, Director of the Joint FAO/ECLA Agricultural Division;Fernando Quevedo, of the Pan American Zoonoses Center; Teodorico TerryElejalde, Assistant Director for Animal Health, Ministry of Agriculture andFisheries (Peru); H. Kónigshófer, of the Food and Agriculture Organizationof the United Nations (presented by Dr. Frank J. Peritz, Regional Veterinarianof FAO), and Ernest E. Saulmon, Director, Animal Health Division, Agricul-tural Research Service, Department of Agriculture (United States of America).

In his report on the "Present Status of the Production and Consumptionof Animal Products in the Hemisphere and Prospects in the Next Ten Years,"Dr. Cañón stressed the need for considering livestock problems with a broadoutlook and for solving them through soundly conceived interdisciplinaryaction. During the presentation of the second topic, "Health Problems Involvedin the Import and Export of Foodstuffs of Animal Origin," Dr. Quevedo called

8 Final Report

attention to the need for Latin American countries to adopt measures at thehemispheric level and to standardize food control methods in order to increasetheir exports and meet the growing demands of importers with regard to quality.

In referring to "Disease Problems Associated with the Import and Exportof Animal Products Intended for Consumption," Dr. Terry made some interest-ing remarks on the movement of cattle for consumption and recommended thatmultinational programs be carried out for the control of communicable andparasitic diseases.

Dr. Peritz presented the topic "Need for Uniform Animal Health Guidelinesand Regulations Governing the Import and Export of Animals Intended forConsumption and Breeding," and Dr. Saulmon presented the paper entitled,"Present and Future Problems Associated with the Import and Export ofAnimals and Animal Products, and Their Effect on the Economic Developmentof Countries." Both speakers concurred on the need for joint efforts to exchangeknowledge and attain goals that will be reflected in the economic developmentof the Hemisphere. The importance of the concepts contained in these papersled Dr. Carlos Ruíz Martínez, President-Counselor, National Council ofAgricultural Research, International Office of Epizootics (OIE), to review theactivities of that organization in the field of international legislation; he thencalled attention to the International Animal Health Code, and expressed hiswarmest congratulations to the Pan American Sanitary Bureau for its work inthis field.

Next, Dr. Roberto Goic Martinic, Chief, Field Advisory Services, PanAmerican Foot-and-Mouth Disease Center, presented the topics "Epidemiolog-ical Surveillance of Foot-and-Mouth Disease" and "Reference Guide forEvaluation of Foot-and-Mouth Disease Control Programs." He stated thatprobably during the current year a definitive system of epidemiological sur-veillance of vesicular diseases would be established in the Americas, and thatthis Guide was a valuable contribution to the evaluation of the progress andresults of foot-and-mouth disease prevention and control campaigns.

Finally, Dr. Boris Szyfres, Director of the Pan American Zoonoses Center,presented the topic, "Epidemiological Surveillance of Rabies." He reviewedthe work carried out by the Center in this field and also drew attention to theneed to increase the production of vaccines and exercise stricter quality control.

During this session, several draft resolutions were examined and unanimouslyapproved.

At the seventh plenary session (17 April), the Minister of Agriculture andFisheries of Peru, General Jorge Barandiarán Pagador, reported that in April1971 the VI Meeting of Ministers of Agriculture of the Americas, sponsored bythe Organization of American States, would be held in Lima. He would there-fore be pleased if the Pan American Sanitary Bureau would consider thepossibility of holding the IV Inter-American Meeting on Foot-and-MouthDisease and Zoonoses Control in that city. The Representative of Nicaraguasupported the proposal and the Representative of Uruguay requested that it beapproved by acclamation. However, the Technical Secretary of the Meeting,Dr. Pedro Acha, requested that the Pan American Sanitary Bureau be per-mitted to consult with the Organization of American States since the holdingof two meetings of different organizations might create certain inconveniences.

The Final Report was then read and approved unanimously without change.

Final Report 9

The Technical Secretary explained that the Director of the Bureau had hadto return to Washington unexpectedly for reasons beyond his control and hadrequested him to greet the representatives on his behalf and to present hisregrets for having to be absent from the closing session. Speaking for theDirector, he expressed appreciation for the collaboration rendered by the con-sultants, as well as for the valuable participation of the Ministers and repre-sentatives, and requested that they send to the Headquarters of the Organiza-tion any and all suggestions they deemed necessary with reference to themeeting. Lastly, he especially thanked the Government of Argentina for itscooperation, which had made it possible to hold the discussions without diffi-culty and had led to their complete success.

The meeting was closed by General Barandiarán Pagador, who, on behalfof his country, thanked the representatives for having elected him Vice-President, and on behalf of all the representatives, thanked the Government ofArgentina for their many courtesies. After praising the work of the Pan Ameri-can Health Organization in behalf of the countries of the Hemisphere, hestated in closing: "The great significance of this meeting can be seen in theimportant topics selected for consideration, the valuable analysis made of thestatus of problems vital to the Hemisphere, and the resolutions adopted, basedon a realistic approach to the activities that should be undertaken or accel-erated in the field of animal health for the benefit of economic and socialdevelopment of the countries."

RESOLUTIONS APPROVED

The following resolutions were approved in plenary sessions:

Resolution I

Vote of Thanks to the Scientific Advisory Committee

THE III INTER-AMERICAN MEETING,

Considering the importance of the scientific and technological activitiesof the Pan American Foot-and-Mouth Disease Center and the Pan AmericanZoonoses Center to the understanding and control of these diseases;

Bearing in mind the variety of functions and the skills of the professionalstaff of the Centers;

Having made a thorough appraisal of the report of the Scientific AdvisoryCommittee on the work of the two Centers; and

Recognizing the excellent scientific qualifications of the members of theCommittee,

RESOLVES:

1. To express its satisfaction with the comprehensive in-depth analysis con-tained in the report on the activities and achievements of the Centers.

2. To call attention to the recommendations for broader, more complex future

10 Final Report

endeavors in research, technical assistance, and training in problems relating tothese diseases.

3. To express its appreciation to the Scientific Advisory Committee for itsefforts, as reflected in this annual analysis, and to support its recommendations.

(Approved at the third plenary session,15 April 1970)

Resolution II

Program and Future Financing ofthe Pan American Zoonoses Center


Having studied the Report on Zoonoses Control as an Integral Part of Agri-culture and Livestock Development and the Role of the Pan American ZoonosesCenter, which contains the results of a study. requested in Resolution VIII ofthe II Inter-American Meeting;

Aware of the serious danger caused by the major zoonoses to human andanimal health, as well as their harmful effect on economic growth and thedevelopment of the livestock industry;

Recognizing the essential role of the Pan American Zoonoses Center ineducation, research, and advisory services for the purpose of assisting theGovernments in promoting, expanding, and improving national programs tocontrol and prevent zoonoses;

Having taken note of the recommendations of the Scientific Advisory Com-mittee of the Pan American Zoonoses Center concerning the need for expandingits activities to provide broader services for zoonoses control on a regionalbasis, which will require additional financial support from Governments and theUnited Nations Development Program;

Noting the favorable reception accorded the mission of Drs. Juan T. Bowler,Enrique García Mata, and Rubén Lombardo and the support expressed by therespective Ministries of Agriculture for continuing and expanding the workof the Center; and

Bearing in mind the importance to the future of the Center, as a regionalproject, of obtaining an extension of the support of the United Nations Devel-opment Program, as well as of providing increasing financial support within theregular budget,

RESOLVES:

1. To express appreciation to the members of the mission for their valuableservices and excellent report.

2. To approve the program recommendations contained in the report, inwhich Governments are requested to give special attention to programs forcontrol and prevention of brucellosis, rabies, bovine tuberculosis, and hydatido-sis, as well as the recommendations on the activities of the Center in education,research, and advisory services.

Pinal Report 11

3. To support a proposal to the United Nations Development Program forextension of financial assistance to the Center as a regional project and torequest the Pan American Health Organization to collaborate with the Govern-ments in the submission of the proposal.

4. To recommend to the XVIII Pan American Sanitary Conference that itapprove an additional appropriation of $300,000 for 1971 to meet the require-ments of the Center as presented in Document RICAZ3/14, in the understand-ing that the Ministries of Agriculture of the Governments of the Organizationwill increase their financial support in accordance with the scale of assessments.


Resolution III

Food Availability and Consumption Indexes


Taking into account that although food balance sheets constitute importantover-all indicators of the food situation, many Latin American countries do notprepare them regularly, or these contain incomplete or inaccurate data;

Considering that the setting of goals for availability of food for humanconsumption will make it possible to give biological orientation to the plansfor food production, imports, and exports; and

Considering that food consumption surveys carried out in different specificpopulation groups, classified according to various criteria (geographic, socio-economic, biodemographic), make it possible to determine the actual consump-tion of food by the population,

RESOLVES:

1. To recommend to the Governments that they make a special effort toprepare and publish the food balance sheets annually on the basis of reliabledata, and to adjust future goals for availability of food for human consumptionin accordance with the nutritional needs of the population.

2. To recommend to the Governments that they conduct periodic food andnutrition surveys in order to determine the magnitude and characteristics ofthe nutritional problems and food consumption levels in the different strataand specific groups of the population and to ascertain the progress made inthe fields of food and nutrition in Latin American countries.


12 Final Report

Resolution IV

National Food and Nutrition Policies


Considering that food and nutrition problems are widely prevalent in LatinAmerica and have an adverse effect on health, education, agriculture, and theeconomy, thereby hindering the development of the countries;

Bearing in mind that food and nutrition problems are caused by a numberof complex factors involving different sectors of economic and social develop-ment; and

Considering that food and nutrition programs call for the implementation ofcoordinated, simultaneous intersectoral plans responding to a definite foodand nutrition policy,

RESOLVES:

1. To recommend to the Governments that they formulate and implementnational food and nutrition policies, organizing for this purpose technical com-mittees or groups at the national planning level, which would assume theresponsibility of formulating, encouraging, coordinating, and evaluating thedevelopment of those policies.

2. To recommend to the countries that they include food and nutrition pro-grams in their respective sectoral plans for agriculture, economy, health, andeducation.

3. To request the Pan American Sanitary Bureau, the Food and AgricultureOrganization of the United Nations, and the United Nations Children's Fundto promote in all the countries of Latin America the formulation and develop-ment of national food and nutrition policies, to which end it is suggested thaia standing committee of these organizations be established, which would formu-late and coordinate the activities of the proposed plan.


Resolution V

Assistance of the Inter-American Development Bankfor the Pan American Foot-and-Mouth Disease Center


Considering that the control of foot-and-mouth disease in South Americadepends on the correct application of the most efficient techniques for themanufacture, control, and application of vaccines;

Bearing in mind the increasing demand for specialized personnel to developthe foot-and-mouth disease control programs envisaged in the Hemisphere;

Final Report 13

Recognizing the accelerated progress of foot-and-mouth disease control tech-niques and the need to put them into practice promptly;

Considering that the Pan American Foot-and-Mouth Disease Center operatesas a regional reference, education, and training organization for the countries;and

Considering that with the Center's existing facilities and equipment it is notpossible to develop techniques and methods for the production of various typesof vaccines on a basis comparable to private industry, nor can their quality becontrolled on a large scale,

RESOLVES:

To request the Inter-American Development Bank to supplement its firmsupport to the countries in their foot-and-mouth disease control programs bygranting the Pan American Foot-and-Mouth Disease Center the financial as-sistance required to establish a demonstration unit for the control of foot-and-mouth disease. This unit would be devoted primarily to training personnel ofthe Hemisphere in industrial production of various types of vaccines andquality control systems; field methods of application of vaccines; and tech-niques for evaluating foot-and-mouth disease control programs.


Resolution VI

International Cooperation in Animal Health Programs


Recognizing that an essential funetion of international organizations in thehealth, economic, and agricultural fields is to achieve increased coordinationand development of the animal health programs in the Hemisphere;

Aware of the importance and magnitude of foot-and-mouth disease controlprograms, for which financial assistance is made available by internationalcredit institutions, particularly the Inter-American Development Bank;

Bearing in mind the wishes expressed by the representatives of Governmentsat this meeting, as set forth in the report of the Special Mission of PAHO(Document RICAZ3/14), that national zoonoses control programs be initiated,particularly for brucellosis, tuberculosis, and bovine rabies, with financialassistance from international credit agencies; and

Considering that this effort to promote animal health programs should besupported by the most efficient technical coordination at the multinationallevel,

RESOLVES:

1. To express its gratitude to the Inter-American Development Bank for thefinancial support it is granting to the countries to enable them to carry outtheir foot-and-mouth disease control campaigns, and for its decision to extend

14 Final Report

this support to the control of other animal diseases such as those mentioned,which cause serious economic and social problems to the countries of theHemisphere.

2. To recommend to countries which are in the planning stage of nationalcampaigns against foot-and-mouth disease and other animal diseases that theyconsider the possibility of supplementing the financing of these campaigns bymaking use of the credit facilities afforded by the Inter-American Develop-ment Bank.

3. To request the Pan American Health Organization to prepare, as soonas possible, standard techniques applicable, at the multinational level, to theprograms for the control of the principal zoonoses, particularly brucellosis.

4. To request the Pan American Health Organization and the Food andAgriculture Organization of the United Nations, as well as other regionalorganizations, to provide all possible technical assistance to the countries forthe development and coordination of their campaigns against foot-and-mouthdisease and other zoonoses.


Resolution VII

Program and Budget Estimates of thePan American Foot-and-Mouth Disease Center

for 1971 and Provisional Draft for 1972


Bearing in mind the serious and harmful repercussions of foot-and-mouthdisease in the affected countries on nutrition, the livestock industry, and eco-nomic progress, and the constant threat to countries free of the disease;

Recognizing that the Pan American Foot-and-Mouth Disease Center playsan essential and effective role in the struggle to control and prevent the disease;

Having made a detailed study of the program and budget estimates for 1971and the provisional draft for 1972;

Noting that the program continues along the lines approved but withincreased emphasis on technical assistance and training in support of nationalprograms for control and prevention;

Recognizing that the Scientific Advisory Committee pointed out that thequality of the proposed programs would make it possible to meet the expandedservices requested by the countries, and recommended that these activitiesreceive adequate financial support;

Noting further that the proposed budget increases are modest and that themajor portion will be required to meet increasing costs,

RESOLVES:

1. To express its full support to the Pan American Foot-and-Mouth DiseaseCenter and the program which it is carrying out.

2. To reaffirm the need for the Center to continue and increase its activities

Final Report 15

to provide the Governments with personnel training and technical advisoryservices essential for the planning, execution, and coordination of national andregional programs for the prevention and control of foot-and-mouth disease.

3. To emphasize the importance of the Center's applied research programson the laboratory and field aspects of foot-and-mouth disease and the signifi-cance of these programs to the technical assistance provided to the countriesin order to achieve ultimate control and prevention of the disease.

4. To recommend to the XVIII Pan American Sanitary Conference that itgive favorable consideration to the approval of the proposed program andbudget estimates of the Center for 1971 as set forth in Document RICAZ3/7.

5. To recognize that the provisional draft of the program and budgetestimates for 1972 include activities that are scientifically and operationallysound, which will make it possible to provide vital assistance to the countries,and that the draft will be subject to further study in 1971 by the IV Inter-American Meeting on Foot-and-Mouth Disease and Zoonoses Control and bythe Executive Committee and the Directing Council of the Pan AmericanHealth Organization.

(Approved at the third plenary session15 April 1970)

Resolution VIII

Cooperation with the Food and Agriculture Organizationof the United Nations


Considering that the countries of Latin America are making special effortsto develop their livestock programs and to ensure the acceptability of theirproducts in foreign markets; and

Considering that the Director-General of FAO has repeatedly demonstratedhis interest in obtaining technical and scientific resources from outside theRegion to strengthen the development of these programs,

RESOLVES:

To recommend to the Director of the Pan American Sanitary Bureau that hestudy the best possible means to take advantage of FAO's offer, which willbenefit the countries in the Region.

(Approved at the fourth plenary session15 April 1970)

Resolution IX

Foot-and-Mouth Disease Vaccines


Considering that foot-and-mouth disease vaccines are fundamental and in-dispensable for the success of campaigns against the disease;

16 Final Report

Realizing the great importance of research on new techniques for the pro-duction of vaccines and of the development of such techniques in order toobtain an increasingly effective product at a low cost;

Bearing in mind that, whatever the technique used in their production, foot-and-mouth disease vaccines are delicate biological products that requirespecial care in their preservation until they are used; and

Emphasizing the need for and significance of using standardized biologicalsfor vaccine production and effective quality control,

RESOLVES:

1. To recommend to the Governments that they adopt the necessary mea-sures to ensure that vaccine-producing laboratories are equipped with adequatefacilities and properly trained personnel to guarantee the production of aneffective vaccine.

2. To request the Pan American Foot-and-Mouth Disease Center to intensifyits research work on the development of new techniques for the productionand control of vaccines, and to cooperate with national laboratories or institutesengaged in research in this field.

3. To recommend to the countries that, as a fundamental element of theirfoot-and-mouth disease control programs, they establish official laboratoriesand services for controlling the production and efficacy of every batch ofvaccine, as far as possible, including the distribution and application phases.

4. To request the Pan American Foot-and-Mouth Disease Center that, incollaboration with the Governments, it establish a commission for the prepara-tion and adoption of standardized regulations and techniques for vaccinequality control that will be acceptable to animal health authorities of theHemisphere.

(Approved at the fifth plenary session,15 April 1970)

Resolution X

Strengthening of Animal Health Services


Considering that foot-and-mouth disease and zoonoses control calls for theorganization of veterinary medical services capable of making administrativedecisions and taking action; and

Recognizing the need for strengthening official animal health services in orderto place them on a level compatible with such responsibility,

RESOLVES:

1. To recommend to the countries that they give to the animal healthservices of their respective Ministries of Agriculture the hierarchical positioncommensurate with the importance of the problems under their responsibility.

2. To recommend furthermore that such services be provided with the

Final Report 17

stability, adequate financing, and administrative flexibility necessary for theefficient development of programs of prevention and control of foot-and-mouthdisease and other animal diseases.


Resolution XI

Application of Health Measures in theControl of Foot-and-Mouth Disease


Considering that foot-and-mouth disease control programs are at varyingstages of development in most countries of South America and in the prepara-tory phase in others;

Bearing in mind the need for obtaining a high degree of immunity in theanimal population exposed to risk of the disease;

Recognizing that the success of the programs depends not only on systematicvaccination of the animals but also on the strict and proper application ofanimal health control measures; and

Bearing in mind that health problems are common in some border areas andcan extend into other areas,

RESOLVES:

1. To recommend to the Governments that during each stage of vaccinationagainst foot-and-mouth disease they endeavor to immunize as many animalsas possible.

2. To recommend to the Governments that they establish supervision sys-tems that will enable them to suitably check vaccinations made by privatepersons or by personnel employed in the official program.

3. To recommend to the foot-and-mouth disease control authorities that theyintensify the enforcement of animal health control measures designed to preventthe spread of the disease.

4. To request the countries to coordinate their foot-and-mouth disease con-trol programs in border areas, with the cooperation of the Pan American HealthOrganization, through the Pan American Foot-and-Mouth Disease Center.


Resolution XII

International Trade in Animals and Animal Products


Bearing in mind that international trade in animals and animal products forhuman consumption is an economic factor of maj or importance to the countriesof the Americas;

18 Final Report

Considering the increase in intraregional and interregional trade in animalsand animal products resulting from the expansion of livestock developmentprograms;

Recognizing that foot-and-mouth disease and other zoonoses are an obstacleto the development of such trade;

Considering the need for having uniform standards and criteria for healthregulations in the different countries, in order to facilitate the solution ofproblems relating to international trade; and

Bearing in mind that the Regional Technical Animal Health Commission(Argentina, Bolivia, Brazil, Chile, Paraguay, and Uruguay) and the Interna-tional Regional Organization for Health in Agriculture and Livestock (Panama,the Central American countries, and Mexico) have already taken steps tostandardize import and export regulations,

RESOLVES:

1. To recommend to the Governments that they intensify their efforts toachieve the standardization and coordination of rules, regulations, and controlprocedures for the import and export of animals and animal products.

2. To request the Pan American Health Organization, through the PanAmerican Zoonoses Center and the Pan American Foot-and-Mouth DiseaseCenter, to promote international coordination in this field, with the cooperationof the United Nations Food and Agriculture Organization and the regionalanimal health organizations, by providing personnel training and technicalassistance to the countries.

3. To recommend to the Governments that they support and sponsor periodicmeetings of animal health authorities, for the purpose of making a constantreview and evaluation of health problems that affect intraregional and interre-gional trade in animals and animal products. For these meetings, it would beadvisable to have the participation of the agencies of the Latin AmericanCommon Market.

(Approved at the sixth plenary session,16 April 1970)

Resolution XIII

Food Hygiene


Realizing that contaminated food products of animal origin cause serioushealth problems in the Hemisphere resulting in an unfavorable effect on proteinsources in a region where protein deficiencies already constitute a majorconcern;

Considering the importance of intra- and interregional trade in food ofanimal origin, and the need to facilitate it through the use of standard proce-dures and techniques that permit adequate control of such foods;

Bearing in mind the increasing importance and requirements of health regula-

Final Report 19

tions in the countries relative to international commerce in animals and animalproducts for human consumption; and

Considering that for the organization of efficient food control services it isnecessary to have adequate numbers of specialized professionals in micro-biology, food technology, and hygiene,

RESOLVES:

1. To recommend to the Pan American Health Organization that it promotethe coordination of activities developed by the national agencies in the fieldof food control, with a view to establishing uniform criteria for control ap-plicable to the domestic and international food commerce.

2. To recommend to the countries that they prepare and enforce codes ofsanitary procedures governing the production, processing, storage, transporta-tion, and distribution of food.

3. To request the Pan American Zoonoses Center that, as part of its ex-panded program, it include gradual increases in advisory services to thecountries and the training of professional personnel in the fields of micro-biology and food hygiene.

4. To recommend to the universities and other scientific centers of thecountries of the Hemisphere that they increase their food science training pro-grams for personnel at all levels.


Resolution XIV

Epidemiological Surveillance of Foot-and-Mouth Disease


Considering the report presented by the Pan American Foot-and-MouthDisease Center (Document RICAZ3/17) on the activities carried out in theinter-American epidemiological surveillance program for foot-and-mouth dis-ease that is being implemented pursuant to Resolution 1 5 of the II Inter-American Meeting on Foot-and-Mouth Disease and Zoonoses Control;

Bearing in mind that the success of this program will depend largely on thecooperation it receives from the governmental organizations responsible forobtaining the information and promptly submitting it to the Center forcompilation and subsequent distribution; and

Recognizing that it is necessary to have the highest degree of cooperationbetween the countries and the Center in reporting the cases of the disease inorder to obtain the information that will permit the control and prevention offoot-and-mouth disease in the Hemisphere,

RESOLVES:

1. To request the Pan American Foot-and-Mouth Disease Center to intensifyits activities for improving the inter-American system of epidemiological sur-veillance of foot-and-mouth disease.

5 Scientific Publication PAHO 196, 8.

20 Final Report

2. To recommend to the countries that they establish a reporting and sta-tistical service as part of their foot-and-mouth disease control programs, witha view to extending it to all animal health activities.

3. To recommend to the countries that they give their strongest possiblesupport to the development of those services to enable the most rapid collection,analysis, and distribution of the basic information required for the epi-demiological surveillance of foot-and-mouth disease.

4. To request the Pan American Foot-and-Mouth Disease Center to consider,among its future activities, the possibility of holding a meeting of specialistsin animal disease reporting to examine the methods currently used and theprogress being made in foot-and-mouth disease control.

(Approved at the sizcth plenary session,16 April 1970)

Resolution XV

Reference Guide for Evaluating Foot-and-MouthDisease Control Programs


Having considered the "Reference Guide for Evaluating Foot-and-MouthDisease Control Programs" (Document RICAZ3/15), prepared by the PanAmerican Foot-and-Mouth Disease Center pursuant to Resolution XIII 6 of theII Inter-American Meeting on Foot-and-Mouth Disease and Zoonoses Control;and

Bearing in mind that the Guide contains the basis for evaluating thedevelopment and results obtained in foot-and-mouth disease campaigns andthe measures that are indispensable for the planning of future activities in thecontrol of this disease, at both the national and multinational levels,

RESOLVES:

1. To recommend to the countries that they establish an evaluation unit assoon as possible within the structure of their national foot-and-mouth diseasecontrol services, and that this unit apply the procedures and indicators out-lined in the above-mentioned Guide.

2. To recommend to the Pan American Foot-and-Mouth Disease Center thatit organize a meeting of the officials responsible for the evaluation units citedabove for the purpose of reviewing and analyzing the results of experienceobtained in applying the Reference Guide.


6 Ibid., pp. 15-16.

Final Report 21

Resolution XVI

Epidemiological Surveillance of Rabies


Considering the report presented by the Pan American Zoonoses Center onthe operation of an epidemiological surveillance service for rabies in the Ameri-cas pursuant to Resolution VII 7 of the II Inter-American Meeting on Foot-and-Mouth Disease and Zoonoses Control;

Recognizing that this report contains up-to-date epidemiological informa-tion on rabies which is indispensable for carrying out efficient programs forthe prevention and control of the disease;

Bearing in mind the economic importance of bovine rabies and the need forhaving available as much epidemiological information as possible in orderto determine more precisely the magnitude of the losses and to promote abetter development and evaluation of control programs;

Realizing that it is necessary to improve case-reporting systems and thecollection and shipment of samples to laboratories, and to have a larger numberof diagnostic laboratories located in strategic areas of the affected countries; and

Bearing in mind that in various countries the cases reported include boththose diagnosed clinically and those diagnosed by laboratory methods only,

RESOLVES:

1. To express its satisfaction at the establishment by the Pan AmericanZoonoses Center of an epidemiological rabies surveillance service for the Ameri-cas, recognizing its usefulness for rabies control programs, both in the field andin the laboratory.

2. To recommend to all the Governments of the Americas that they par-ticipate in this important disease-reporting system by forwarding rabies infor-mation regularly to the Pan American Zoonoses Center.

3. To recommend the installation, expansion, or improvement of laboratoriesfor diagnosing rabies, according to the needs of each country.

4. To recommend to the countries that they improve their rabies-reportingsystem, including the collection and shipment of samples to laboratories.

5. To request the countries to report all cases of bovine rabies whetherdiagnosed clinically or by laboratory methods.

6. To recommend that the Pan American Zoonoses Center continue andexpand its service of epidemiological surveillance of rabies, and examineperiodically its development and gradual improvement with the Governments.


7 Ibid., p. 12.

22 Final Report

Resolution XVII

Control of Vaccines against Bovine Rabies


Bearing in mind that vaccination against bovine rabies is an essential weaponin the fight against the disease and that its value depends on the quality of thevaccine used;

Recognizing the desirability of standardizing the methods of quality controlfor rabies vaccine used in various countries, and for improving and coordi-nating research in methods used in field and laboratory tests; and

Considering the need to submit each batch of vaccine for examinationby official control methods for potency, innocuity, and purity, according tostandard requirements,

RESOLVES:

1. To recommend that the countries establish a systematic method of controlover vaccines against bovine rabies, both domestic and imported, adopting thenecessary measures so that the official control services will have an adequatesupply of trained personnel, equipment, and resources to control these examina-tions.

2. To request that the Pan American Zoonoses Center, in addition to provid-ing training, reference services, and biologicals through its expanding programs,cooperate with the countries in the verification and periodic standardization oflaboratory tests for the control of vaccines against bovine rabies as well as inevaluating the efficacy of the vaccine under field conditions.


Resolution XVIII

Education and Training


Considering the interest shown by the Governments in the development andconduct of campaigns against foot-and-mouth disease, brucellosis, tuberculosis,bovine rabies, and other zoonoses;

Bearing in mind that the implementation and development of such cam-paigns entail heavy investments by the Governments and the internationalcredit organizations, as well as the support and backing of technical andadministrative structures that will permit the effective control of these diseases;and

Recognizing the need to increase the number of trained professional per-sonnel required for the various stages of the implementation of animal healthprograms in the Americas,

Final Report 23

RESOLVES:

1. To recommend to the countries that they intensify the training of per-sonnel at all levels to assure the successful development of animal healthcampaigns.

2. To request the Pan American Health Organization to consider the pos-sibility of increasing its cooperation with the countries in the training ofveterinarians in the planning, administration, and evaluation of animal healthprograms.


Resolution XIX

Equine Encephalomyelitis


Considering that the reports presented by the representatives of severalcountries reveal the frequent appearance of cases of equine encephalomyelitis;

Recognizing that the disease has spread to various countries of Central andSouth America and has caused fatal cases among human beings; and

Bearing in mind that epizootic outbreaks among horses can cause extremelyhigh losses,

RESOLVES:

To recommend to the Pan American Health Organization that it appoint aworking party to examine this problem, consider possible solutions, and proposeaction to be taken.


Resolution XX

Technical Assistance in EquineEncephalomyelitis and Vesicular Stomatitis


Considering that the zoonoses cause serious economic losses in importantgeographic areas, with serious risks of spread of the disease and public healthhazards, such as occur in the case of equine encephalomyelitis;

Bearing in mind that in addition to causing economic losses, other diseasesinterfere with the development of control and eradication programs for foot-and-mouth disease, thereby hindering the detection of the disease, such asoccurs with vesicular stomatitis,

24 Final Report

RESOLVES:

To request the Pan American Foot-and-Mouth Disease Center and the PanAmerican Zoonoses Center, in close cooperation with other international agen-cies, to provide technical assistance to the affected countries in order to studyessential aspects such as epidemiology, vector identification, and reservoirs, andcarry out vaccine production for the control and/or eradication of the above-mentioned diseases.


Resolution XXI

Vote of Thanks to the Government of Argentina


Bearing in mind the wholehearted collaboration of the Government ofArgentina in the holding of the present meeting, and the generous supportand active participation of that Government in its organization, which con-tributed in great measure to the successful outcome of its deliberations,

RESOLVES:

To express its thanks to the Government of Argentina for its cooperation inthe conduct of this III Inter-American Meeting on Foot-and-Mouth Diseaseand Zoonoses Control.


PART I

BASES FOR A FOOD AND NUTRITIONPOLICY IN THE AMERICAS

PARTICIPATION OF THE AGRICULTURAL SECTOR

MR. JUAN F. YRIART *

I wish first to extend to the delegates thewarmest greetings from the Director-General of FAO, Mr. Addeke H. Boerma,and his best wishes for the success of thismeeting.

I would also like briefly to explain myown presence at the meeting. The PanAmerican Health Organization and FAOhave always maintained close relations toensure that both are duly informed of eachother's activities in the field of animalhealth in Latin America. These relationshave been strengthened and coordinatedduring recent months. I had the honor ofjoining FAO at an opportune time and havebeen able to work closely with the Director-General in strengthening our links with theinstitutions of the Inter-American Systemto effect closer coordination and collabora-tion or joint action in activities of commoninterest to all of us.

As far as cooperation with the PanAmerican Foot-and-Mouth Disease andZoonoses Centers is concerned, a numberof personal contacts have taken place be-tween the Directors as well as the tech-nicians of the two Organizations to coordi-nate our activities and determine the mostefficient manner for FAO to attract re-sources from outside the Hemisphere tosupport PAHO projects in these fields. Ibelieve that I can say, without fear of con-tradiction, that we are reaching a level ofconsultation and coordination that is nearly

* Assistant Director-General of the Food andAgriculture Organization of the United Nations,Regional Representative for Latin America.

27

free from duplication and overlapping ofeffort, and instead we are seeing comple-mentary action and mutual support.

Livestock Development in Latin America

Before dealing with the subject of foodand nutrition I would like to define ourOrganization's interest in livestock prob-lems, in relation to which the control offoot-and-mouth disease and other zoonosesis a principal consideration.

FAO, with the goodwill of the Govern-ments, is concentrating its efforts withinfive areas of action: development of high-yielding varieties of basic food crops;filling the protein gap; war on waste;mobilization of human resources for ruraldevelopment; and improving the foreignexchange situation.

Livestock merits a high priority in ourLatin American programs, and in particularas it relates to these areas of concentration.The protein deficit and the war on wasteare especially relevant in our livestock pro-grams. The losses we suffer from epizootics,for example, not only constitute waste offood for domestic consumption, but alsorepresent a loss to the foreign trade sectorof many countries.

The FAO Regional Office for LatinAmerica has adopted a new working pat-tern in order to more effectively assist theGovernments in the multidisciplinary studyof livestock development problems. In theintegrated and global approach, now em-

28 Food and Nutrition Policy

ployed, problems of animal production andhealth, marketing, financing, internationalcommerce, etc., can be effectively dealt withat the request of, and in cooperation with,the various Governments so as to help themformulate their livestock policies and todefine their needs for technical and finan-cial assistance.

I would also like to remind you that inAugust 1970 here in Buenos Aires, we shallhold the Second Ad Hoc Consultation onMeat and Poultry within the framework ofour Committee on Commodity Problems. Asin the case of the First Consultation held atour Headquarters in 1969, the problem ofinternational markets will be analyzed witha view to considering possible mechanismswhich FAO could establish to collaboratewith Governments in regulating the tradein meat.

Livestock Production and Food andNutrition Policies

The subject of meat production links usclosely with the work of PAHO in strivingto improve the relationship between foodand nutrition in the various countries. Dur-ing this last year a new link has been forgedbetween our two Organizations for thatpurpose.

In accordance with FAO's Constitution,the programming of livestock productionmust take into consideration the food andnutrition requirements of mankind. Con-versely, we cannot consider the needs forfood and nutrition without also taking intoconsideration the programming of livestockproduction. The interest that PAHO has inthe problems of livestock production, givenits responsibilities in the field of food andnutrition, is the link that unites us. I be-lieve that the meeting we held in 1969 atthe expert level, and which UNICEF andECLA also attended, fully demonstrated the

new spirit of collaboration between PAHOand FAO. This also explains why the Di-rector of PASB wished to draw to your at-tention the topic "Bases for a Food andNutrition Policy in the Americas," and whyhe has honored me by asking me to placethis subject before you. The attention weshall give to these problems during the com-ing days will be one more step in a programof action which we shall follow up withsubregional meetings to consider food andnutrition policies for groups of countries.

I should like to add that I have beenassociated with the Pan American Foot-and-Mouth Disease and Zoonoses Centerssince their establishment, and it has alwaysbeen a source of satisfaction for me to workwith institutions of the Inter-American Sys-tem. This, and the affectionate respect Ihave held for Dr. Horwitz, arouses deepfeelings as I now consider the responsibili-ties facing me in working toward strength-ening the cooperation between our twoOrganizations in order to offer to the Gov-ernments and their peoples effective assist-ance in solving some of their more pressingproblems.

Latin America is facing serious and pro-found problems which can, and do, affectthe biological picture of its human re-sources. These are demonstrated by thehigh rate of infant mortality and morbidity,attributable in great part to the prevalenceand incidence of undernourishment andmalnutrition throughout vast sectors of thepopulation. This is particularly apparent inthose zones characterized by high demo-graphic growth and low economic develop-ment and has direct repercussions on humanproduction capacity, with a consequent in-crease of social and political tensions.

If careful note is taken of the future foodrequirements of Latin America, in the lightof the rates of economic development andpopulation growth, it is readily apparent

Participation of the Agricultural Sector 29

that a most difficult period lies ahead. Thisimpending crisis can be avoided only if ur-gent and adequate measures are promptlytaken in the sectors of production, market-ing, and consumption of foodstuffs. Thesemeasures should be embodied in an inte-grated policy which, on a short-term basis,would overcome the more acute phases ofthe problem, without losing sight of thelonger-term necessity of integrating thefood and nutrition objectives at the govern-mental decision-making levels and in thenational plans for social and economicdevelopment.

In this brief analysis of the nutritionproblems facing Latin America, it is alsonecessary to comment on the current demo-graphic situation in order to more effec-tively analyze and evaluate the urgent con-tinental problems relating to the supply andconsumption of foodstuffs. This is a pre-requisite for policy formulations.

Food and Demographic Growth

As you undoubtedly know, in LatinAmerica there are more than two hectaresof farmland available for each person,whereas in Europe the figure is 1.3 hectaresand in Asia only 0.4. In addition, LatinAmerica possesses great areas of undevel-oped but potentially productive lands. Un-fortunately, this otherwise favorable situa-tion is offset by the low productivity of boththe land and agricultural labor. This isreadily illustrated by the statistics of agri-cultural production using wheat as an indi-cator. In Latin America approximately 350kilograms of wheat are produced per hec-tare, whereas in the United States 880 kgare produced. As to productivity per capita,we find the gap between the regions evengreater: the figure is 300 per cent higher inthe United States than in Latin America.Such is the situation in which Latin Ameri-

can agriculture finds itself. During thedecade of the '60s, over-all production inLatin America has grown at a cumulativeannual rate of 2.2 per cent per capita,which is considerably below the 4 per centlevel considered as optimum for agriculturalpolicy and proposed for the Region.

The accelerated rate of population growthin Latin America, the highest of any regionin the world, makes this picture even morebleak. As a result of a combination of highbirth rates and declining mortality rates, itnow amounts to 3 per cent per annum. Atthis rate the population will be doubledwithin the next 20 years.

As a consequence of the prevailing lowagricultural productivity and accelerateddemographic growth, the availability offoodstuffs within the Region as a whole canat best be considered as barely adequate inboth quantity and quality. This is so not-withstanding the abundance of natural re-sources. Of the two, the qualitative situa-tion is more critical than the quantitative.For example, whereas the current supply ofcalories is 20 per cent above its pre-warlevel, the supply of animal proteins hasdeclined by a like amount.

Thus, given the demographic forecastsfor Latin America during the next 30 years,it will be necessary to double the total sup-ply of foodstuffs and nearly triple the pro-duction of animal proteins in order tosatisfy the projected demand and attainadequate nutritional targets.

This calls for bold efforts in reorientingand reorganizing livestock and fish produc-tion. Changes and innovations that willimprove the productivity of agriculturalresources are essential. More rational usemust be made of the land, taking advantageof the current advances in science and tech-nology. All this must be done within co-hesive and comprehensive food and nutri-


tion policies and should be included in thegeneral development plans.

Analysis and Evaluation of the CurrentLatin American Position in the Light of theEstablishment of National Policies forFood and Nutrition

At the Eighth FAO Regional Conference(Viña del Mar, Chile, 1965), where thebasic principles of agricultural developmentwere reviewed, the consensus was that theprimary objective of livestock programsshould be to satisfy the nutritional require-ments of the various sectors of the popula-tion. Nevertheless, this objective has notbeen realized so far and even as a policydoes not appear to be included in the agri-cultural programming in the Region. There-.fore, I believe it expedient to present someideas and points of view dealing with theaims and objectives that such policiesshould attain during the next few years.

1) The. majority of Latin Americancountries have prepared sectoral plans forthe development of agriculture as integralparts of national development plans butwithout, unfortunately, giving nutrition ob-jectives the priority they deserve. Conse-quently, the opportunity exists to reconsiderthis aspect and formulate lines of actionthat will increase the quantity and improvethe quality of food for human consumptionand result in a more satisfactory intake ofenergy-giving and protective foods.

2) At a time when policies and plans foragrarian reform and land settlement are be-ing promoted, food and nutrition considera-tions should be included in their technicalprograms to ensure an improvement in theproductive capacity of the beneficiaries.

3) Given the inflationary process existingin many countries of the Region, as well asthe levels of economic development, Gov-

ernments should take strict measures toavoid a deterioration of the relationshipsbetween food prices and personal income,and also between food prices and othercommodity prices, with the object of al-lowing for an adequate as well as a morebalanced diet. The price relationships ofenergy-giving and protective foods shouldbe given special attention in order to en-courage more balanced and adequate dietsand thus better enable the individual todevelop to his full mental and physicalpotential.

4) It is estimated that approximately25 per cent of the economically active popu-lation in Latin America is unemployed, andthat hardly 25 per cent of the land classifiedas suitable for the production of foodstuffsis under cultivation. Furthermore, it is alsoknown that manufacturing installations areworked at about half of their capacities.From this we can conclude that the re-sources, both human and physical, areavailable which could be used for develop-ment and the elimination of undernourish-ment among our peoples. It is thus obviousthat not only are there economic, social,and human justifications for our winningthe food and nutrition battle within theRegion, but we also have the potentialresources with which to do so.

5) One of the most effective means ofincreasing the availability of foodstuffs isthe application of new concepts and tech-nology. This will not only help to decreasehigh losses of foodstuffs, which in somecountries amount to 30 per cent of totalproduction, but will also create reservesthat can be used for the enhancement ofnutritional value, improved marketing andprice policies, and better distribution. Atthe same time, foreign trade policies shouldbe carefully reviewed to ensure that importsbenefit the population's nutritional status

Participation of the Agricultural Sector

and that exports do not drain the country ofhighly nutritious foods.

Thus, because of the prevailing con-ditions in Latin America, it is urgent thatcohesive interdisciplinary policies and ac-tions be formulated to cope with the situ-ation. That is to say, it is essential toestablish rational food and nutrition policiesthat will serve the needs of all strata ofsociety.

The aforementioned technical meeting ofFAO and PAHO, held in May 1969 with theparticipation of UNICEF and ECLA, wascalled for the purpose of establishing guide-lines for the formulation and execution offood and nutrition policies in the LatinAmerican countries. After considerabledeliberation and a discussion of govern-mental measures connected with selectiveproduction of foods, marketing, and con-sumer guidance, as well as the technicaland institutional aspects of the problem, themeeting agreed to define food and nutritionpolicy as a complex of measures that wouldcontribute to the optimum nutritional statusof the whole population through an ade-quate supply of food and accompanied byinduced changes in consumption patterns.Such a policy should be included as anintegral part of the national social and eco-nomic development plans, and should beexecuted by means of coordinated sectoralprograms.*

We are thus able to see the manner inwhich food and nutrition policy at the na-tional and regional levels is closely tied inwith the general problem of underdevelop-ment, and that the effectiveness of suchpolicies is dependent upon the degree towhich the structural causes of underdevel-opment and the low efficiency in the produc-tion of foodstuffs are dealt with.

* Elements of a Food and Nutrition Policy inLatin America. Scientific Publication PAHO 194.Washington, D. C., 1970.

Consequently, we can also see the neces-sity of reviewing and developing some fun-damental measures that can be put intoaction by the Governments of Latin Amer-ica to expand the production and the supplyof foodstuffs. In this manner, the planningprocess involves not only the formulationof plans but also putting them into action.

Among the measures to be taken intoconsideration are the following:

* Economic and social stimulus for theprocessing and marketing of foodstuffs inorder to ensure their widest possible dis-tribution, and when necessary use of pricecontrols to safeguard the interests of thelower-income groups; promotion of a desir-able balance of trade between exported andimported foodstuffs; and recourse to tax andprice incentives when necessary.

* Investments and the financing of pro-grams related to the extension of industrialand agricultural credits and the creation ofsocial infrastructure for the production,marketing, and distribution of foodstuffs.

* Application of technology for the re-orientation of livestock and fishery researchand their respective extension services;particular attention should be given to thestudy and promotion of those foodstuffsnutritionally important in habitual diets.

Such measures, within national food andnutrition policies, will facilitate the pro-duction and distribution of a more adequatesupply of foodstuffs. Nevertheless, the pic-ture would be incomplete unless, at thesame time, food consumption targets werealso fixed. In order to do this, it is necessaryto take into account demographic patternsand inereases; recommended daily intakeper person for each group of foods; datafrom surveys of food consumption anddietary habits; and available supplies ofenergy-producing and protein foodstuffs,both animal and vegetable. On the basis

31


of such studies, a comparison can be madebetween the data on availability of foodsand the findings of food consumptionsurveys in the different socioeconomicgroups, in order to determine whether thereis a sufficiency, an oversupply, or a deficit ofthe various types of foods, at both thenational and the zone levels.

Targets in regard to the availability andconsumption of foodstuffs, which must serveas the basis of any food and nutritionpolicy, are dependent on the followingvariables:

a) Production and consumption trendsfor foodstuffs and the forecasts over a givennumber of years.

b) Forecasts of demographic growth aswell as distribution of population and vari-ations in family size.

c) Forecasts of income growth and itsrelation to the consumption of foodstuffs.

d) Relationships of prices within the dif-ferent groups of foodstuffs and betweenthese and other consumer goods.

The methodology to be employed in thistype of analysis is that in common usage ingeneral planning activities and thus is thedirect responsibility of the national plan-ning offices. In order to assure a balance inthe planning process, close cooperation mustexist between the nutrition specialists andthose charged with planning national live-stock development. Executing the plan willinvolve decisions being made at the govern-mental level, which will be embodied inspecific projects with adequate financing.

The private sector, with its potentialresources of capital, organization, and pro-ductive capacity, also has an important roleand should be involved in this process. Thefulfillment of the aims and objectives setwithin a food and nutrition policy requiresa minimum technical and administrativestructure staffed by specialized and well-

trained personnel in the field of humannutrition and closely associated with thenational planning agency. At the sametime, it is necessary to strengthen the foodand nutrition units in the principal executiveagencies that are directly involved in thisfield, particularly those in the ministries ofhealth, agriculture, and education. Althoughsignificant advances along these lines havebeen made, the efforts have been unisectoraland much remains to be done to completethis essential infrastructure in most of ourministries of agriculture and education.FAO is keenly interested in offering tech-nical assistance to the Latin AmericanGovernments to aid them in implementingthese vital proj ects.

I may have gone into too much detail inanalyzing some of the factors involved inthe establishment of food and nutritionpolicies in Latin America. Nevertheless,my interest is to demonstrate the need toapproach the problem in a planned, coor-dinated, and interdisciplinary manner. Thisis the only sure way of ensuring concreteaction to cope with the problems of thesupply and consumption of foodstuffs. Thisis imperative in both nutritional and humanterms; for mankind's betterment is the pur-pose of all our activities and we accept thefact that all share the birthright of anadequate and balanced diet. I firmly believethat our Governments, together with publicand private organizations, should give over-riding importance to the achievement ofthis goal.

Food and Nutrition Policy in the Decade ofthe '70s

I do not believe I am mistaken in fore-casting that during the seventies, at thedecision-making levels of the Latin Amer-ican Governments and among the varioussocioeconomic bodies, high priority will be

Participation of the Agricultural Sector

given to the struggle against undernourish-ment and malnutrition as an integral ele-ment of the social and economic develop-ment programs. During the decade that hasjust ended, FAO, through the Freedom fromHunger Campaign, as well as the PanAmerican Health Organization, the WorldHealth Organization and others, havealready provided a strong stimulus in thisdirection. Now we must consolidate ourefforts, mobilizing national and interna-tional resources to integrate food and nutri-tion objectives into the development plansin order to effect a more rational employ-ment of all the factors destined to achievethat end.

In order to contribute to the attainmentof this objective, FAO and PAHO, in asso-ciation with the Argentine Government,plan to set up a Nutrition Data Retrievaland Analysis Center for Latin America.The role of the Center will be to:

1) Collect, analyze, and interpret datarelating to the availability of food and thenutritional status of the population.

2) Offer advice to Governments on theformulation of food and nutrition policy.

3) Develop effective methodologies andprocedures, and train various categories of

national personnel to execute food andnutrition programs suited to national, sub-regional, and regional conditions.

We also hope to continue to hold LatinAmerican meetings on food and nutritionpolicies with the cooperation of UNICEFand the participation of ECLA, so thatthose directly concerned with agriculture,health, education, economics, and planningmay benefit from a mutual exchange ofideas and experiences in this wide field anddevelop adequate policies for the future.

Before closing I would like to appeal toall the Governments of Latin America, andin particular to those present here at thismeeting, to unite in the undertaking of acrusade for the attainment of higher levelsof food and nutrition for our peoples; acrusade that will enable us to more fullyappreciate the present and future needs ofour fellowmen as they relate to a modernsociety wherein a minimum of well-beingand the basic necessities of food, health, ndproductive work are assured. In such acommunity can a spirit of humanism oper-ate alongside and together with science andtechnology for the well-being of the in-dividual and the community as a whole.

33

THE RESPONSIBILITY OF THE HEALTH SECTOR INPLANNING AND CONDUCTING NATIONAL FOOD

AND NUTRITION POLICIES

DR. ROBERTO RUEDA-WILLIAMSON *

Malnutrition and Social and EconomicDevelopment

Although malnutrition and other defi-ciency diseases have been very prevalent inlarge segments of the population in LatinAmerica for several centuries, it is only inthe last 10 years that international agenciesand the Governments have become fullyaware of the size and importance of nutri-tion problems. Thus, the Declaration of thePresidents of the Americas, signed at Puntadel Este, Uruguay, in 1967, stated that oneof the goals of the continental policy ofeconomic and social development would bethe improvement of the nutritional condi-tions of the population.

To bring out the importance of thisDeclaration some preliminary considera-tions are in order concerning the obstaclesthat nutrition problems put in the way ofthe economic and social progress of develop-ing and industrializing countries.

Many studies have shown that there is adirect correlation between substandard nu-tritional status in the individual and his lowresistance to disease. Protein-calorie mal-nutrition in children completely changestheir defense mechanisms, the result beingthat malnourished infants are not only morefrequently attacked by infectious diseasebut are also more subject to complications

* Regional Adviser in Nutrition, Pan AmericanSanitary Bureau.

or secondary diseases, and their convales-cence is more prolonged. This explains whyprotein-calorie malnutrition in children iscoupled with high mortality and morbidity,especially in those under 5 years of age.They are a very vulnerable group becauseof their high nutritional needs stemmingfrom their rapid growth and the key pe-riods of nutritional and environmental ad-aptation through which they are passing.

It is therefore not surprising that vitalstatistics in the Region show that mortalityin children under one year of age is five to10 times higher than it is in developedcountries; and that mortality in the 1-4years group, which is most directly relatedto protein-calorie malnutrition, is 10 to 30times higher than in the industrializedcountries. Furthermore, preliminary datafrom the Inter-American Investigation ofMortality in Childhood, sponsored byPAHO, show that in a great many instancesprotein-calorie malnutrition is the underly-ing or associated cause of death in childrenunder 5 years of age, even though deathcertificates do not explicitly say so.

However, these figures do not fully ex-press the seriousness of the nutrition prob-lem in Latin America. From the standpointof the educational and economic develop-ment of the countries of the Region, thegrave consequences of malnutrition in thechildren who survive its harmful effects areperhaps its most serious aspect. It has been

34

Responsibility of the Health Sector 35

shown that malnutrition in children is es-sentially characterized by a lag in the nor-mal processes of physical growth and de-velopment, frequently coupled with mentalretardation. The malnourished child ceasesto grow normally because he lacks the es-sential raw materials for the formation ofhis tissues; he is inactive, tires easily, andmanifests changes in his psyche, becomingirritable and apathetic. The malnourishedchild does badly in school, is less receptiveto teaching, and makes less progress thanwell-fed children who pay greater attentionto the teacher. There is good reason tobelieve that malnutrition is in part respon-sible for poor scholastic performance inunderdeveloped countries.

Finally, nutritional status has a specificeffect on the capacity of the individual forphysical work, both with respect to its dura-tion and its intensity. The human organismis frequently compared to a machine thatneeds fuel and continuing repair of its tis-sues and organs to ensure that it functionscorrectly; however, that fact is even morefrequently forgotten. The association be-tween nutrition and health, on the one hand,and work, on the other, is not a new idea;but only in recent years have serious ob-servations been made confirming that un-doubted correlation. In Germany, Indo-china, Costa Rica, and other countriesstudies of miners and agricultural and con-struction workers have shown that it ispossible to achieve a significant increase inthe output of workers and in productivityrates by adding to their deficient diet thecalories and nutrients necessary to make itbalanced and adequate in terms of their age,the climate in which they live, and theactivity they perform.

If to these observations we add the syner-gistic relationship between malnutrition andinfection, which results in a higher preva-lence of diseases in malnourished popula-

tions and thus in the loss of thousands ofhours of work due to illness, the impact ofmalnutrition and illness on productivityrates in a country and consequently on itseconomy is even more obvious. A recentstudy on health manpower in Colombia,made by the Association of Medical Schools,in cooperation with the Ministry of PublicHealth (1), showed that workers lose 96million days a year as a result of illness;assuming an average wage of 20 pesos aday, this absenteeism represents a financialloss of about 2 billion pesos, or approxi-mately US$100 million a year-a figure thatwould represent US$1 billion in terms of theminimum salary in the United States. Inaddition, there is the high cost of medicalcare, the loss in the efficiency of the worker,the residual disability, and the years of lifelost by premature death.

What has been said above shows that ahigh level of nutrition and health in theagricultural and the industrial worker ofLatin America will help increase productionin that area, and also that programs tocontrol malnutrition and disease should notbe regarded as expenditures but highlyprofitable investments.

The above-mentioned observations andstudies also clearly demonstrate the closeinterdependence between nutrition, health,and the social and economic development ofthe country and establish the fact that mal-nutrition and other nutritional diseases af-fect not only the health sector but also theeducational and agricultural sectors and theeconomy in general.

I should now like to add a few considera-tions on the place of the various factorscausing malnutrition in the different devel-opment sectors, in order to indicate whatthe bases should be for preventive activi-ties in the field of nutrition in the countriesof the Region.


Determining Factors in Malnutrition

The specific objectives of programs toprevent malnutrition might be summarizedas follows: to make sufficient food availablefor the whole population; to ensure that theentire population consumes foods that sat-isfy its nutritional needs; to prevent dis-eases that may interfere with the utilizationor cause excessive loss of nutrients. How-ever, this very simple picture, which in-cludes the three components of the epi-demiological constellation of deficiencydiseases-agent, environment, and host-becomes much more complicated when wetake a closer look at the determining factorsrelated to the availability, consumption,and use of foodstuffs.

The availability of foodstuffs at the locallevel depends on a number of favorablecircumstances connected with agriculturalproduction, such as quality of the soil,water, climate, rainfall, irrigation, land ten-ure patterns, seeds, animal and vegetablediseases, fertilizers, breeds of animals, kindand quality of animal feeds, agriculturalmechanization, credit systems, manpowerskills in these fields, etc. Furthermore, theproductivity of human beings is directlyrelated to their nutritional status and theirhealth, which accounts for the low outputof industrial and agricultural workers inareas where malnutrition is widespread.

Animal diseases cause a substantial lossof foodstuffs of animal origin, which areprecisely those that have the highest nutri-tional value. Losses are calculated on thebasis of the destruction of meat, milk, eggs,or in net production losses directly due todisease. It has been calculated that in LatinAmerica the loss in animal products due tocattle diseases exceeds 35 per cent of thetotal production (2). Among these diseases,foot-and-mouth disease and certain zoono-ses such as rabies, brucellosis, bovine tuber-

culosis, and hydatidosis are responsible forthe loss of thousands of tons of animal pro-tein, a loss that seriously aggravates themalnutrition problem in Latin America andalso impedes livestock development in thecountries.

Proper control of animal diseases couldbring about a significant increase in theavailability of animal protein in relation tothe present rates of production. Pertinentstudies have estimated that this increasemight be as much as 4.4 grams of animalprotein per day per capita in the countriesof the Region (2) ; this would be the equiva-lent of a 50 per cent increase in the presentsupply of animal protein for the Region,which, according to FAO, is 9 grams perperson per day (3). This meeting will heara full report on the control of zoonoses asan integral part of agricultural develop-ment, prepared by a PAHO mission, includ-ing estimates of the animal protein lossesdue to livestock diseases and their impacton the economies of the countries.

There are other factors involved in theavailability of foodstuffs, namely, those re-lating to various links in the food chainfrom producer to consumer. They includethe warehousing, storage, processing, andpackaging of foodstuffs as well as transpor-tation and distribution to the local marketor to the corner shop.

An adequate level of consumption of foodby each and every one of the members of afamily or of a community also depends onanother set of factors of an economic orsociocultural nature. On the one hand, capi-tal and levels of employment and salariesdetermine the purchasing power of a familyunit; and on the other, food customs andhabits, beliefs and taboos relating to food,and health and child-rearing practices de-termine individual and family preferencesand feeding practices, that is to say, thecharacteristics of individual diets, both in


quantity and quality, and the extent towhich they satisfy nutritional requirements.

Adverse sociocultural factors connectedwith food and nutrition more frequentlyaffect the most vulnerable groups of thefamily, i.e., children under 5 years of age,pregnant women, and nursing mothers; thismeans that although a family may haveenough food, this fact may not be reflectedin good infant feeding, since taboos andcultural blocks often prevent them fromreceiving the foods eaten by the adultmembers.

Finally, there are a number of factorsthat determine the correct utilization of thefoods consumed and the losses of certainnutrients. Infectious and parasitic diseasesare determining factors in malnutrition, forthey result not only in a loss of nutrientsbut also in a loss of appetite, and frequentlypatients are subjected to food restrictionsby reason of ignorance or incorrect foodpatterns and practices. Furthermore, as hasbeen mentioned, malnutrition reduces thedefenses of the organism against diseasesand establishes a vicious circle due to thissynergistic action.

It is therefore evident that a number ofthe development sectors of a country aredirectly affected by the' nutrition problemsof its population, and also that the factorsgiving rise to such problems are situatedespecially in the economic, agricultural,health, and educational sectors. There isthus a twofold reason for stating that if wewish to prevent and successfully controlmalnutrition and other deficiency diseaseswe must undertake coordinated multisec-toral programs aimed at eliminating thevarious determining factors.

National Food and Nutrition Policies

The United Nations-being fully awareof the need for multisectoral activities andprograms to solve the nutrition and food

problems of the countries-has undertaken,through PAHO/WHO, FAO, and UNICEF,to promote and offer technical and financialassistance for the organization and opera-tion of applied nutrition programs in vari-ous countries. These programs are definiteefforts to coordinate the sectors of economicand social development that are more di-rectly responsible for the solution of foodand nutrition problems. Although the de-velopment of applied nutrition programshas been slow and has encountered thedifficulties inherent in a shortage of trainedpersonnel, they have been initiated as pilotprojects in small areas and subsequentlyconverted into larger-scale programs whoseexpansion and consolidation have beenachieved through intersectoral coordination.Applied nutrition programs have been underway in eight countries of the Region for fiveor more years, and their area of operationhas been progressively extended; programsare also being organized in two other coun-tries. However, it has now become neces-sary to view the problem from a broaderstandpoint.

If we examine the food and nutrition pro-grams conducted in Latin America, we seethat in the past they have not been the out-come of national policies. In the last 10years, however, the countries have becomeaware of the need to establish and imple-ment a clearly-defined national food andnutrition policy as a basis for coordinatingsectoral plans, and they have accepted thefact that coordinated efforts make it possi-ble to tackle all the various aspects of theproblem at the same time, and thus obtainmore than a piecemeal solution.

A food and nutrition policy has been de-fined as the formulation and implementa-tion of a set of measures that ensure anoptimum nutritional status for the wholepopulation through an adequate supply offoods and the necessary changes in con-


sumption patterns. This policy must beestablished as an integral part of the na-tional plans for economic and social de-velopment and be carried out through co-ordinated sectoral programs. Each countrymust be encouraged to set up a multidisci-plinary technical committee, situated at thehighest administrative level in the nationalplanning office, to assume responsibility forestablishing a food and nutrition policy.

The technical committee on food and nu-trition policy should comprise representa-tives of the sectoral planning offices of thevarious ministries or government depart-ments that are directly or indirectly re-sponsible for planning and executing spe-cific projects in this field. It should beresponsible not only for the formulation ofa national food and nutrition policy but alsofor studying material, manpower, and finan-cial resources for the simultaneous conductof coordinated activities. This group wouldhave to supervise the initiation and institu-tion of the measures established and recom-mend the necessary administrative decisionsfor ensuring that they are correctly orga-nized and executed and for periodicallyevaluating the progress made.

The execution of the national food andnutrition policy is the responsibility of thedifferent sectoral agencies involved. Eachis responsible for executing that part of theprogram which directly concerns it. Amongthese agencies are the national planningoffice; the ministries of agriculture, health,and education; agricultural research, agrar-ian reform, industrial development, credit,agricultural marketing, and food technologyagencies; associations of producers; agen-cies regulating food standards and retailprices; universities and middle-level train-ing centers; and finally, the institute ofnutrition or the technical group specializingin nutrition, generally under the authorityof the ministry of public health. The com-

ponents of a food and nutrition policy inLatin America were discussed by an expertgroup that met in Washington, D.C., in 1969under the auspices of PAHO/WHO andFAO (4).

Responsibility of the Health Sector

Let us now look at the responsibility ofthe health sector in planning and conduct-ing a national food and nutrition programin a given country.

Planning the program. As is well known,the first stage of planning is the diagnosisof the situation. With respect to the healthand nutrition situation, this diagnosis isbased primarily on three indicators: the netavailability of food for human consumption,the actual consumption of food in the vari-ous socioeconomic strata, and the nutri-tional status of the population. The netavailability of food is expressed in termsof per-capita amount of each of the variousgroups of foods (cereals, meats, fats, vegeta-bles, fruits) and also the caloric and proteinvalue of each of them individually and asa whole. To obtain this information, foodbalance sheets and pertinent demographicdata are used. However, food balance sheetsreflect only the apparent consumption anddo not enable us to ascertain the actualconsumption of food, that is, the actualamount ingested by individuals of differentpopulation groups or strata. To overcomethis drawback, systematic surveys of theconsumption of food in specific populationgroups classified according to different cri-teria (geographic, socioeconomic, biodemo-graphic, etc.) must be made. These studiesare the responsibility of the nutritionists ornutritionists-dietitians who are members ofthe health team.

The availability and consumption of foodin a country, as established by means of


food balance sheets and consumption sur-veys, must be compared with the nutritionalneeds of the population in the light of therecommended daily intake of calories andnutrients for the country concerned; thoserecommended standards must, of course, beestablished by the nutrition experts of thehealth team, using appropriate methods andprinciples.

On the basis of these recommendations, itwill be possible to evaluate the results of theconsumption surveys and determine whetheror not the various groups have sufficientnutrients. Food consumption targets canthen be established; that is, the amount offood necessary to enable the population tosatisfy its caloric and nutrient needs. Theyare established, taking into account thepopulation structure in each country, thedaily per-capita recommended calorie andnutrient intakes, the average caloric andnutrient content of each group of foods, theavailability of foods in each country, re-gional consumption and food-habit surveys,the desirable distribution of the caloric con-tribution by source, as well as the relativecontribution of energy and protein foods bysource. Food consumption targets are a use-ful reference point for agricultural andeconomic planners, who, in the light thereofand taking other factors into consideration,can establish a clearly defined policy gov-erning food production, importation, andexportation; and imports and exports, re-gardless of their origin, must be adjusted tothat policy. The comparison and analysisof the above-mentioned data calls for co-ordinated and joint efforts by the nutritionexperts of the health sector and the expertsin economics and agriculture.

I have already pointed out that the per-capita availability of foods in a country isan average value and thus does not reflectactual consumption by different socio-economic sectors of the population or their

nutrition problems. Therefore, to make amore accurate diagnosis of the problems,nutrition surveys that include data on foodconsumption must be conducted, as well assurveys on dietary habits and chemical andbiological analyses that indicate the nutri-tional status of the population.

Virtually all the countries of the Regionhave been able to make a basic diagnosisof the food and nutrition program, for whichpurpose PAHO has provided consultant ser-vices. Furthermore, through the researchcarried out by the Institute of Nutrition ofCentral America and Panama (INCAP)and by the Caribbean Food and NutritionInstitute, which is also supported by FAO,and through collaborative or individualstudies made in various countries, PAHOhas helped to ascertain the prevalence qfnutritional diseases as well as their extentand characteristics. As a result of studieson protein-calorie malnutrition, nutritionalanemias, hypovitaminosis A, and endemicgoiter, which have provided informationsupplementary to that derived from nutri-tion surveys in the countries, it has beenpossible to give better guidance to nutritionprograms.

As soon as the food and nutrition situa-tion in a country has been diagnosed, thetechnical groups belonging to the sectors in-volved must prepare coordinated sectoralplans of operations after first determiningthe resources available in each sector-in-stitutional, material, economic, technical,legislative, etc.-for conducting activities,projects, and programs aimed at the com-mon objective of ensuring the optimumnutritional status for the population of thecountry.

Conduct of the program. In each multi-sectoral program, the health sector shouldundertake specific activities in line with thenational food and nutrition policy of thecountry.


General health activities. Public healthagencies and organizations conduct twotypes of activities through the generalhealth services. The first are those thathelp to improve the population's nutritionalstatus but that cannot be regarded as beingspecifically for that purpose. They includeactivities for the restoration of health un-dertaken in hospitals, health centers, andoutpatient departments; general preventiveand curative activities aimed at protectionof mothers and children, such as prenatalcare programs, education on nutrition dur-ing pregnancy and lactation; care of thenewborn; care in delivery and the post-partum period; family counseling on thespacing of children and family planning;preventive and curative health services forinfants and preschool-age children; schoolhygiene programs; adult hygiene programsincluding screening for diabetes, control ofobesity, and investigation of other diseasesrelated to nutrition; and finally, environ-mental sanitation activities of fundamentalimportance to the nutritional status of theindividual and the community. Among thelast-mentioned activities special mentionmay be made of the prevention of water-borne diarrheal diseases by means of in-house water connections, proper sewage andgarbage disposal, improved housing, peri-odic spraying of houses with insecticides inareas where malaria or Chagas' disease isendemic, rodent control, since rodents helpto reduce the availability of foodstuffs, andmeasures to prevent the contamination andinfestation of foods and reduce the food-borne infections.

Specific nutrition activities. To thesegeneral activities must be added the secondgroup, more specific to nutrition, which arepart of a health program and therefore car-ried out by health personnel at the national,intermediate, or local level.

I have already mentioned how the health

sector shares at the national level with othersectors the responsibility for establishmentof a national food and nutrition policy ineach country. The health sector must ac-tively assist in formulating a national nutri-tion program in line with that policy; itmust ensure that the necessary funds areassigned to it from its own budget; and itmust also play a key role in coordinatingand promoting economic and technical as-sistance, multilateral and bilateral, incor-porating it into the national nutrition pro-gram and thus avoiding separate programsthat frequently lead to incomplete utiliza-tion of existing resources.

The national nutrition program, the gen-eral object of which is to achieve an opti-mum nutritional status for the whole poplu-lation, has the following specific objectives:to develop manpower for nutrition; to pro-mote the availability and proper consump-tion of protein-rich foods; to conduct nutri-tion education and food supplementationprograms for the most vulnerable popula-tion groups (pregnant women and nursingmothers, children under 5 years of age,school-age children); to ensure the nutri-tional rehabilitation of children with ad-vanced malnutrition; to establish and im-plement food and nutrition regulations andstandards; to undertake research on nutri-tion problems in order to correctly orientprograms designed to solve them; and ingeneral, to help formulate and implementthe national food and nutrition policy.

It is up to the health sector at the na-tional level to inform the highest govern-mental decision-making levels of the extentand importance of the nutrition problemsaffecting the population, so as to ensure thatnutrition programs are given the prioritythey deserve in the country's social andeconomic development plans.

At this level, the health sector must alsogive advice on and assist in the establish-


ment of procedures, regulations, techniques,teaching programs, food standards, andhandbooks for operating various servicesrelated to food and nutrition, whether inthe health, education, or agricultural sector.

The research and teaching programs inthese fields must also be coordinated anddirected by the nutrition groups of thehealth sector. In Latin America the train-ing of personnel specialized in nutrition(nutritionists and nutritionists-dietitians)is of very special importance, since thepresent shortage of such professional per-sonnel is one of the factors that has limitedthe expansion of programs.

Some activities of nutrition programsmust be incumbent on the health authoritiesat the central level; for example, requestsfor multilateral or bilateral technical oreconomic assistance for food supplementa-tion programs and the subsequent distribu-tion of equipment or food supplies to inter-mediate or local levels; the conduct ofnationwide nutrition education programsthrough radio, television, or the press; thepreparation of publications and distributionof educational material to be used at thelocal level.

At the intermediate level the health sec-tor is responsible for the formulation andintra- and intersectoral coordination of thenutrition program for the province or stateand for administering and directly super-vising it. Intersectoral coordination enablesmaximum use to be made of the technicaland economic resources available and si-multaneous complementary activities to becarried out.

The health team at the intermediate levelplans the nutrition component in the healthplan; defines the part to be played by eachmember of the technical team in nutritionactivities; gives advice to and supervises thelocal and district level; and adapts national

standards for the conduct of nutrition pro-grams to local conditions.

At the local level it is responsible for theexecution of food and nutrition programs.These are carried out through health ser-vices, elementary schools, and agriculturalextension agencies. These services are thebasic structures through which the com-munity receives direct attention from theprofessional and auxiliary personnel incharge of the various activities of the pro-gram in their particular sector. These ac-tivities are described in the PAHO publica-tion dealing with nutrition activities at thelevel of the local health services (5).

In the area of health the basic opera-tional units are the districts, the centers,and the health posts. The nutrition activi-ties they conduct include the diagnosis ofthe problem in individuals and in the com-munity, the promotion of a good nutritionalstatus, specific protection against nutri-tional diseases, and treatment of nutritionaldeficiences.

The diagnosis comprises the study of in-dicators of nutritional problems such asvital statistics, anthropometric values,cliniconutritional and food surveys, as wellas of the causative factors.

The promotion of a good nutritional sta-tus includes educational activities for per-sons benefiting from the services and for thecommunity in general; promotion of andassistance in activities to increase the avail-ability and consumption of food with a highnutritional value; encouragement of earlyparticipation in maternal and child healthprograms; promotion of intersectoral co-ordination at the local level; and trainingof nursing auxiliaries in food and nutrition.

Specific protection activities include pe-riodic supervision of the health of vulner-able groups and counseling with respect tofeeding; the supply of iron to pregnantwomen and of vitamin A, iodine, and other


nutrients in areas where their deficiency isendemic; food supplementation programs,high priority being given to the most vul-nerable groups; promotion of the increasingconsumption of traditional foodstuffs richin proteins, new protein mixtures, andenriched foods.

The treatment of nutritional diseases in-cludes hospitalization of advanced cases ofmalnutrition, organization and operation ofnutrition rehabilitation centers, treatmentof anemia and vitamin deficiencies, andperiodic supervision of children undergoingrehabilitation.

In the education sector the basic operat-ing unit is the elementary school. The schoolnutrition program includes five correlatedand complementary activities: teaching ofbasic ideas about food and nutrition as partof the regular elementary curriculum; op-eration of a school dining room; organiza-tion and operation of a school garden, schoolcooperative, and school nutrition club.

In the agricultural sector the local basicoperating unit is the agricultural extensionservice. Through this service agriculturalengineers, veterinarians, and intermediate-level personnel promote and provide guid-ance in the conduct of agricultural and live-stock projects aimed at increasing produc-tion and the availability of foodstuffs, ori-enting their consumption, and improvingeconomic and living conditions. The agri-cultural team gives technical assistance tofarmers as well as specialized services suchas supervised credit, supply of seeds andimproved varieties; it organizes them intogroups and gives them informal training inagriculture and animal husbandry, prepara-tion and storage of foods, nutrition, hygiene,and home economics, including training invarious types of handicrafts to enable themto improve the financial conditions of theirfamilies.

The responsibility of the health sector in

these community programs carried out bythe education and agriculture sectors is pri-marily the food and nutrition training ofschoolteachers and home economists andexpert advisory services in the organizationand conduct of school and rural nutritionprograms.

Conclusions

A rapid review of the components of thenational food and nutrition program andespecially of the responsibility of the healthsector in conducting it at the national, inter-mediate, and local levels leads to the follow-ing general conclusions which are consideredof major importance for this meeting:

1. Nutritional diseases are one of themajor obstacles to the acceleration of theeconomic and social development of LatinAmerica.

2. To ensure the whole population theoptimum nutritional status, each countrymust formulate and implement a clearlydefined food and nutrition policy, wherebythe availability, consumption, and use offood is brought into line with the needs ofthe population.

3. To implement the national policy, it isnecessary to conduct a national food andnutrition program made up of sectoral pro-grams included in the health, education, andagricultural plans.

4. As part of the national food and nutri-tion program, it is necessary for the agricul-tural and health sectors to undertake jointactivities to control animal diseases, pri-marily the zoonoses which greatly reducethe availability of protein foods essentialfor the population of the Hemisphere.

5. Programs undertaken by the countriesof the Region to control malnutrition anddisease must be given a high priority as partof economic and social development plans

Responsibility of the Health Sector

and must be considered as highly productiveinvestments.

6. To extend the coverage and increasethe effectiveness of the national food and

nutrition program in the country, it is es.sential to make maximum use of govern-mental health, agricultural, and educationservices and resources.

BIBLIOGRAPHY

(1) Colombian Association of Medical Schools.Study on Health Manpower and Medical Educa-tion in Colombia. Washington, D. C., Pan Ameri-can Health Organization, 1967.

(2) Pritchard, W. R. "Increasing Protein Foodsthrough Improving Animal Health." In Propectsof the World Food Supply, A Symposium. Wash-ington, D. C.: National Academy of Sciences, 1966.

(3) Food and Agriculture Organization of the

United Nations. The State of Food and Agricul-ture. Rome, 1964.

(4) Pan American Health Organization. Ele-ments of a Food and Nutrition Policy in LatinAmerica. Scientific Publication 194. Washington,D. C., 1970.

(5) Pan American Health Organization. Activi-dades de nutrición en el nivel local de un serviciogeneral de salud. Scientific Publication 179. Wash-ington, D. C., 1969.

43

PART II

FOOT-AND-MOUTH DISEASEVACCINES

USE AND EXPERIENCES WITH FRENKEL-TYPE VACCINE

DR. JACOB G. VAN BEKKUM *

The Frenkel vaccine as we know it nowwas developed in the years after the SecondWorld War (1).

The method is based on older observa-tions by Maitland and Maitland, whichshowed that vaccinia-virus would multiplyin fragments of tissue kept in survival sus-pended in a fluid medium. To grow foot-and-mouth disease virus in vitro, Frenkelused epithelium harvested from the tonguesof slaughter cattle. The development ofantibiotics made it possible to apply thisprinciple on a large scale. The tissue iscollected shortly after slaughter. It is har-vested by peeling off the epithelium afterthe tongue has been fixed on a drum and isthen collected in a buffer solution. If main-tained at refrigeration temperature, it willremain suitable for use for one or moredays. The virus multiplies only in the deepepithelium layers, but the presence of non-producing hornified tissue does not seem toaffect the multiplication process adversely.Epithelium from both susceptible and im-mune cattle has been found suitable forlarge-scale virus production, although in thelatter case the quantity of seed virus neededto infect the cultures may be larger.

At first the tissue, which was collected inthe form of cell sheets, was cut into smallfragments prior to cultivation. This step isnow in most instances omitted.

Virus culture takes place in stainless steelcontainers with a useful content of 30 to

* Director, Central Veterinary Institute, Amster-dam, The Netherlands.

47

100 liters. Seed virus may be obtained bycattle passage and subsequent adaptationby a few transfers in Frenkel or other cul-tures. Up to now all virus strains testedhave been found to multiply sufficiently inthe Frenkel system, although some may givebetter antigen yields and more potent vac-cines than others.

Different types of culture vessels havebeen developed, but the principle is alwaysthe same. The tissue is kept in suspensionby stirring during incubation at about37°C., while oxygen or an oxygen-nitrogenmixture is led through the fluid. This aera-tion serves two purposes, i.e., to supply oxy-gen to the actively metabolizing tissue andto remove the CO2 formed in the course ofthe process.

The culture medium is usually a Tyrodebuffer, supplemented with amino acids, vita-mins, etc. The solutions used in differentlaboratories may vary with regard to theirglucose, bicarbonate, and amino-acid con-tents.

Antibiotics are used in all instances, buthere again different producers may use vari-ous mixtures on account of differences in thebacterial flora encountered and experienceswith allergic reactions after vaccination.Cultures reach their maximum yield 20 to24 hours after seeding, depending on thevirus strain used. According to our experi-ence, both epithelium and culture fluid con-tain large quantities of virus and shouldtherefore be collected. Cultures are har-vested by grinding up the tissue; remaining

48 Foot-and-Mouth Disease Vaccines

tissue fragments are removed bytion; and a bacteria-free suspenEtually obtained by centrifugatio:or treatment with chloroform. Icarried out carefully, need notpreciable losses. Sterile viruscan be kept at refrigerator temIseveral weeks and may in the ntested for virus type, virus conteetc.

Vaccine is prepared by adsor]virus on aluminum hydroxide artion with formaldehyde at 25-processes employed in differentmay vary, e.g., in the dry mattethe aluminum hydroxide, the coof formaldehyde, and the duratof inactivation. In many instanis added.

The final dosage in which theemployed may vary from 1 totype. A reduction of the volumeasily obtained by separating theto which the antigen is adsorbesupernatant fluid.

The innocuity and potency teFrenkel vaccines are those enother foot-and-mouth disease vthe routine innocuity test, thelingual injection of susceptiblgenerally preferred. The potenmay be done in cattle, but for mtories the technique is too exroutine use.

Frenkel vaccines have been i,Netherlands since 1952. Initiall,A and O were used. In 1953 1added and an annual vaccinacattle was introduced.

In May 1967 the Dutch livesttion showed the following comp¢

CattleSwineSheep

No. of animals

3,970,0003,920,000

560,000

centrifuga- The country's total surface area is 32,600sion is even- km2 . The cattle are of the dairy type, keptn, filtration, in herds averaging 25 head. The averageFiltration, if farm is about 14 hectares. A complete regis-lead to ap- tration of the cattle is maintained, the ap-suspensions paratus for which is in the hands of theperature for farmers' organizations.neantime be The annual vaccination is carried out bynt, sterility, administering one dose of trivalent vaccine

to all cattle more than 4 months old in aption of the 10-week period in the spring. Vaccinationnd inactiva- is carried out by veterinary surgeons and is-26°C. The not compulsory. Unvaccinated stock canlaboratories only be sold for slaughter. In practice aboutr content of 99 per cent of the animals aged more than)ncentration 4 months are vaccinated.ion and pH The policy not to vaccinate young calveslces saponin is based on laboratory evidence (2). Cows

that have received several doses of vaccinee vaccine is excrete large quantities of antibodies with) 10 ml per their colostrum. When taken up by their.e is usually calves in the first one or two days of life,e hydroxide, these antibodies will protect the calvessd, from the against the disease, but they also prevent

an effective vaccination. The four-month!sts used for period is an average; some calves may benployed for expected to respond earlier to vaccination,accines. As although young stock do not immunize asintradermo- readily as adult cattle.le cattle is Since Frenkel vaccine first came into useicy test too in the Netherlands in 1953, a number ofany labora- minor changes have been made in the pro-pensive for duction process. The foot-and-mouth dis-

ease control policy applied in the field alson use in the underwent repeated modifications.y only types The vaccine at first was used in a 15 mltype C was dose per type. This has since been reducedtion of the to 5 ml, and a further reduction to about

1.5 ml is in preparation. Other changes tookock popula- place in the production process itself. Virusosition: culture is done in vessels with an effective

volume of about 40 liters. As antibiotics weNo. oj farms usually employ penicillin, neomycin, and

162,000 chloromycetin. The present need, equiva-95,00024,000 lent to 5 to 6 million trivalent cattle doses

Frenkel-Type Vaccine 49

per year, is covered by processing about130,000 cattle tongues, or 3,500 kgs of tissue.

In general, the policy should be to adaptthe vaccine as far as possible to the field byusing field strains for antigen production.Since a general vaccination policy was in-troduced in Holland in 1953, such a change-over had to be made only once. This isprobably due to the high level of immunityof the cattle population, which reduces viruscirculation to a negligible level and thusprevents the development of variant strains.

Cattle that have repeatedly been vac-cinated may also develop an immunity tovirus strains that differ appreciably fromthose incorporated in the vaccine. This was,for instance, shown in the course of the 1967outbreak, when cows that had received sev-eral annual doses of 02-vaccine provedresistant to challenge with the O0-strain.

Some specifications of the vaccine now inuse are the following: Vaccines are pre-pared monovalently and contain at least10 .-3 mouse ID50 of virus per dose and type.The aluminum hydroxide content of thefinal product is 2 per cent dry matter. In-activation is carried out for 48 hours at apH of 8.2 with a formaldehyde concentra-tion of 0.03 per cent. Vaccines of the abovecomposition are routinely tested for in-nocuity by intradermolingual injection intosusceptible cattle. Immediately after prepa-ration no infective virus can be detected inthem by this route. The batch size is usually2,000 liters, 400,000 doses. The potency testis done by measuring a PD5 0 in groups of15 cattle, two weeks after vaccination. Thenumber of PD50 per 5 ml dose varies be-tween 6 and 15. In 1967, 1,500 importedsusceptible cattle were used for the in-nocuity and potency testing of about 15 mil-lion monovalent cattle doses. This numberis reduced as other control techniques be-come available.

The routine control measures employed in

the field consisted up to 1955 of mass vac-cination supported by the routine veteri-nary police measures. In that year a slaugh-ter policy was introduced, and all vac-cinated cattle showing foot-and-mouth dis-ease symptoms, as well as unvaccinatedcattle, sheep, and swine found on infectedfarms, were removed and destroyed.

This program has proved effective, as thefollowing figures show, and has since beenadopted in a number of other Europeancountries.

Foot-and-mouth disease incidence inthe Netherlands

Year

1951195219531954195519561957195819591960196119621963196419651966196719681969

No. of cases(farms) reported

20,7507,654

30834484747763

1835,4702,103

1461,4262,193

196Oo

In the period between 1961 and 1967 thedisease occurred mainly in pigs. This causeda number of secondary cases in cattle, whichvaried in different years. In the winter epi-zootic of 1966-1967 cattle were involved inabout 10 per cent of the outbreaks. As arule only unvaccinated calves or youngstock that had been vaccinated only oncewere affected. This was the reason fortaking additional measures.

Prior to 1967 there existed a supplemen-tary vaccination program for young stockwhich were moved in the autumn. Its re-


sults were rather incomplete, and only about15 per cent of the individuals of the agegroups at risk were treated. In 1967 a gen-eral autumn vaccination of all cattle thathad not previously been vaccinated or hadreceived only a single dose of vaccine wasintroduced.

Laboratory investigations have providedfurther information on the effect of foot-and-mouth disease vaccination on the re-sistance of cattle against the disease.

Cattle develop virus neutralizing anti-bodies after vaccination. Following admin-istration of a single dose of vaccine, theserum antibodies attain a maximum valueafter three to four weeks. The titer thendrops off, but reaches a stable level afterthree to four months, which is maintainedfor a long period (3). The duration of theimmunity that develops after one vaccina-tion is not more than four to six months,when intradermolingual challenge is used.Repeated vaccination is therefore judged anessential part of any long-term programusing these vaccines.

Every annual revaccination results in anincrease of the serum antibody level (4).These antibodies persist for many years,even when vaccination is not continued.Such repeatedly vaccinated cattle have asolid immunity against both field exposureand infection by intradermal inoculation asoften practiced in the laboratory.

There is a clear-cut relationship betweenthe serum titer and resistance to infectionin both animals vaccinated recently andthose vaccinated long ago (5). The levelsof antibody necessary for 50 per cent pro-tection against generalization after intra-dermolingual challenge are, however, dif-ferent for both groups. Nearly all cattledevelop tongue lesions if this challenge iscarried out nine or more months after vac-cination but they will not develop gen-eralized lesions. Experience shows that such

animals will not develop disease when ex-posed under field conditions.

A slaughter policy now constitutes anessential part of the foot-and-mouth diseasecontrol programs in most West Europeancountries. When such a method was firstused in the Netherlands, there was no infor-mation with regard to the occurrence ofvirus carriers. As a consequence, only in-dividuals showing clinical symptoms wereslaughtered. We know now that manycattle that remain clinically normal afterexposure may become virus carriers, but upto the present these have not been known tocause new outbreaks of the disease.

Carriers have been found as late as twoyears after infection, but the condition isessentially self-limiting (6). After the1965-1966 type C outbreak, the last virusisolations from carriers were made in 1968.Since April 1967 the country has been freeof clinical foot-and-mouth disease, althoughthe last 0° carriers from the 1966-1967 out-breaks only became negative in the courseof 1968. Especially late carrier viruses havebeen found to differ markedly from isolatesrecovered from outbreaks.

Since 1953 more than 50 million Dutchcattle have been vaccinated with Frenkelvaccine. These were mainly valuable pro-duction stock. In this period the vaccineproved its efficacy and innocuity. Everyyear a few cases of anaphylactic reactionsof the immediate type are reported. Theseare usually mild and respond readily totreatment with antihistamine preparations.Losses are less than one per million.

In the Netherlands as well as in variousother European countries, control of thedisease is based on annual vaccination ofthe cattle. These programs are supportedby a slaughter policy and the application offurther police measures, such as quarantine,disinfection, etc.

Sheep are not routinely vaccinated. The

Frenkel-Type Vaccine 51

vaccination of this species poses no partic-ular problems, and only a fraction of thevaccine dosage used for cattle is needed toafford a satisfactory level of protection.

From 1961 onward a series of outbreaksoccurred which mainly affected pigs. Insome years these became quite extensive.Initially they were combated only bystamping out and by the application ofpolice measures, as experience indicatedthat the normal vaccines had a low efficacyin swine.

In 1961-1962 more than 300,000 pigswere destroyed in the course of a singleeradication campaign. As this policy provedexpensive and it often took a long time toattain the objective of eradication, vacci-nation was finally resorted to.

Most satisfactory results were obtainedby vaccinating all pigs in endangered zones.Preferably vaccines with three or moretimes the antigen content used for cattlewere employed. Such vaccines give pigs areasonably good protection against contactexposure, which is, however, of a short dura-tion. The results obtained in the field aregenerally better than one would deducefrom laboratory evidence.

Aluminum hydroxide adsorbed antigensare quite effective in pigs when adminis-

tered repeatedly, as can occasionally bedone in breeding stock. The immunity soobtained in sows may be sufficient to givepassive immunity to their offspring for twoor more months (7).

The problems related to the protection ofpigs against foot-and-mouth disease are notspecific for a given vaccine. New vaccinescontaining antigens emulsified in oil havebeen reported by several authors to give aprotection of longer duration than alum-inum hydroxide adsorbed antigens; but withsuch vaccines the protection given to theswine population as a whole will not bemore than three or four months, as theaverage life immunity in swine is not morethan six months.

Protection of the individual farm ispossible but demands an almost continuousvaccination. The application of such apolicy to the whole swine population wouldprove too costly.

It should be realized that foot-and-mouth disease in pigs is often secondary tothe disease in cattle. There are severalexamples of the disappearance of the diseasefrom swine after the outbreaks in cattle hadbeen brought under control. As far as weknow, pigs do not become virus carriers.

BIBLIOGRAPHY

(1) Frenkel, H. S. "Research on Foot-and-Mouth Disease III: The Cultivation of the Viruson a Practical Scale in Explantations of BovineTongue Epithelium." Amer J Vet Res 12:187, 1951.

(2) van Bekkum, J. G. "A Serological Analysisof the Results of the Dutch Foot-and-MouthDisease Program." Bull Office Int Epizoot 54:372,1960.

(3) van Bekkum, J. G., C. H. Dale, and R. C.Fish. "Immunogenic Studies in Dutch Cattle Vac-cinated with Foot-and-Mouth Disease Vaccinesunder Field Conditions I: Neutralizing AntibodyResponses to 0 and A Types." Amer J Vet Res24:77,1963.

(4) Fish, R. C., J. G. van Bekkum, R. P. Leh-mann, and G. N. Richardson. "Immunologic Re-sponses in Dutch Cattle Vaccinated with Foot-

and-Mouth Disease Vaccines under Field Condi-tions: Neutralizing Antibody Responses to O, Aand C Types." Amer J Vet Res 30:2115, 1969.

(5) van Bekkum, J. G., R. C. Fish, and I. Na-thans. "Immunologic Responses in Dutch CattleVaccinated with Foot-and-Mouth Disease Vac-cines under Field Conditions: Neutralizing Anti-body Responses and Immunity to O, A and CTypes." Amer J Vet Res 30:2125, 1969.

(6) Straver, P. J., P. H. Bool, A. M. J. M. Claes-sens, and J. G. van Bekkum. "Some Properties ofCarrier Strains of Foot-and-Mouth Disease Virus."Arch Ges Virusforsch (in press).

(7) Nathans, I. "Vaccinatie van Varkens Te-gen Mond-en Klauwzeer." Thesis, University ofUtrecht, 1965.

TISSUE CULTURE VACCINES (BHK) INFOOT-AND-MOUTH DISEASE CONTROL

DR. JOHN B. BROOKSBY *

The advantages of a cell line for thecultivation of virus for vaccine productionare well known. With modern methods ofcell storage, a constant supply of a uniformhost cell is available for regular routineproduction of virus. This host cell can besubjected to rigorous tests to prove theabsence of adventitious viruses; it will givereproducible results; and from the practicalpoint of view it means that the producingunit is free from the difficulties frequentlyfound in arranging the supply of materialfrom slaughterhouses. To be satisfactory,however, the cell line must multiply readilyto a high cell concentration; it must be fullysusceptible to the virus and must producevirus to a high titer. Moreover, the cellproducts must have no adverse effects onthe inoculated animal either in possibletumor production or in the production ofanaphylactic effects. Criticism of the BHKcell for foot-and-mouth disease vaccineproduction is centered mainly on these lasttwo points, because in all other respects thecell is clearly very efficient for vaccineproduction.

Our present knowledge suggests thatthese two points of criticism can be met.Extensive experiments have failed to showproduction of tumors by anything otherthan the intact BHK cell, and then only inthe homologous species, the hamster. Evenliving cells implanted in domestic animals

* Director, Animal Virus Research Institute,Pirbright, England.

have never given rise to any oncogenieeffect. As far as the cells being a source ofallergen is concerned, the situation at pre-sent is that reaction to BHK protein canbe produced in the same way as to manyother constituents of the vaccine, but theproblem can be overcome largely by achange of inactivant used in the vaccine.Further studies on purification of the prod-uct may also be of value in this direction.

The purpose of this paper is to describethe present situation in regard to BHK-derived vaccines, indicating the progressthat has been made since the susceptibilityof the cell was established in 1962 byMowat and Chapman and the first demon-strations of its usefulness in vaccine produc-tion were made by Capstick et al. and byMowat et al. in the same year. Observationson the usefulness of the cell have been madein many European countries, the highestrate of commercial production in Europehaving been achieved in Italy (Nardelli,1969).

This paper does not propose to go intodetail on the methods of virus productionand vaccine formulation but rather to dis-cuss the principles involved. Details are inany case available in a number of publica-tions (see Bibliography).

Cell and Virus Production

BHK cells can be stored indefinitely in amaster bank. Sufficient cells have been laid

52

BHK Vaccines

down in this to provide directly for thenext 30 years and for a further period byderivation from any one of these seeds,which are held in liquid nitrogen at-196°C. For routine runs, productionbanks at -70°C with larger quantities ofcells are held, and revival from storage forproduction from these takes from four tosix weeks. Cascade systems of vessels arearranged so that cell culture in increasingvolume can be carried out in entirely closedsystems. Extensive quality controls aremaintained on cells for cell size, growth,growth rate, chromosome number, virussusceptibility, and screening for myco-plasma and for microbial contamination.

The method of choice for cultivation ofcells is in suspension culture, and the linederived by the workers at Pirbright is avail-able for this purpose. New lines can bederived from cells hitherto grown in mono-layer, but the initial line appears to be themost satisfactory of those which have beenderived.

An alternative method of proceeding tocell cultivation is by growing seed in sus-pension culture and transferring into mono-layer rolling bottles. Very high cell con-centrations can be achieved in the rollingbottle system, which does not require quitethe sophisticated equipment needed for sus-pension cell culture work. Nevertheless,suspension cell equipment is much moreconvenient in operation, requiring less laborand less space. The cell density achievedin suspension cultures is now 3 x 106cells/ml or greater.

Virus Production

Seed virus for BHK vaccine productionis usually satisfactory if the field strain ispassaged in BHK-21 monolayer cells for3-6 passages, then transferred to suspensionculture. There is thus no question of the

strain having been subjected to a long seriesof passages which might modify it in someway. In suspension culture, the virus/cellinput ratio is now normally something of theorder of 1:10 or 1:100, but a ratio of 1:1000has been satisfactory when tested. The cul-ture period may vary with the strain,although in general it is about 48 hours.Maximum virus titers will be reachedearlier than the time at which the virusshould be harvested, and it has been thepractice to harvest at a point betweenmaximum virus titer and maximum comple-ment-fixing titer. The virus culture is thenfiltered to remove cell debris in two stages,through a prefilter of pure cellulose and thenthrough a nitrocellulose membrane with apore diameter of 0.2,a.

Virus Inactivation and Formulation ofVaccine

Virus inactivation is by 0.05 per centacetylethylenimine for 30 hours at 26°C.Each cattle dose contains 5 mgm of saponin.

Safety Testing of Vaccine

The safety testing of the BHK vaccine iscarried out before the saponin adjuvant isadded. The subject has recently beeninvestigated by Anderson et al., and it hasbeen demonstrated that the most efficientmethod is by the inoculation of large vol-umes onto monolayer tissue cultures. Thismethod is more sensitive than the use ofcattle for the detection of possible failure ofthe inactivation procedure. Acetylethyleni-mine inactivation is free from the terminaltail in the inactivation curve that accom-panies inactivation with formalin.

Vaccine for field use at the present time,however, is also tested by inoculation of thetongues of cattle in the same manner as foraluminum hydroxide Frenkel vaccines.

53


Potency of BHK Vaccines

Table 1 presents an example of data on50 per cent protective dose determinationof a vaccine prepared in the manner de-scribed. This method of determination ofvaccine potency by the dilution techniquehas been employed as standard at Pirbrightfor the experimental evaluation of vaccines.Throughout these tests, various laboratorytests are employed in parallel. These includecomplement-fixation tests on total comple-ment-fixing antigen and on the 25 nmantigen; serum tests on the sera of cattlewhich have been vaccinated, taken at thepre-exposure stage; and finally, guinea pigprotection tests using the same vaccine toimmunize guinea pigs. For the purposesof this table, the complement-fixing anti-gen content is the total antigen and, ofcourse, is diluted out in proportion to thevaccine dilution given. The serum titers areon color tests; a significant titer in terms ofprotection is of the order of 1:45. Thehigher titers produced are approaching those

which would be given in convalescentanimals. Reaction is assessed on the basisof protection against the appearance ofsecondary lesions. As can be seen in thetable, a number of animals are protectedeven against the development of clinicalreactions on the tongue after intradermalchallenge, but this is less reproducible thanthe demonstration of secondary lesions onthe feet. This has been chosen as a realisticendpoint which compares more with contactchallenge and therefore possibly with asevere field exposure.

Table 2 presents the data, including thosefrom Table 1, for six typical batches ofvaccine produced in the same way. Thenumber of PD5 0 per dose of vaccine wasestimated at 21-28 days after vaccinationand can be seen to be much above theminimum requirement of 6 PD50 per dose.The total complement-fixing units per doseof vaccine are not precisely correlated withthe number of PD,, per dose and wouldappear to vary from strain to strain. Theantibody titers refer to those of the groups

TABLE 1-Results of an experiment to determine the potency for cattle of a type C (strain Norville)vaccine prepared with antigen produced in BHK deep suspension culture and with saponin as adjuvant.

No. protectedSteer Vaccine CF antigen Prechallenge Clinical reaction afterNo. dilution content serum titer i/d tongue challenge No. vaccinated

Tongue and feetTongue and feetTongue and feetTongue only

NilNilTongue onlyTongue only

Tongue onlyNilNilNil

NilNilTongue onlyNil

HH 52HH 53HH 54HH 55




1:641:641:641:64

1:161:161:161:16

1:41:41:41:4

1:11:11:11:1

0.8 cfu0.8 cfu0.8 cfu0.8 cfu

3.1 cfu3.1 cfu3.1 cfu3.1 cfu

12.5 cfu12.5 cfu12.5 cfu12.5 cfu

50 cfu50 cfu50 cfu50 cfu

1:81:221:661:22

1:20481:20481:1281:90

1:7081:7081:7081:512

1:81921:56001:1781:4096

1/4

4/4

4/4

4/4

PD.; value = 40.6 per 2 ml vaccine dose.

cfu = complement fixing unit.

BHK Vaccines 55

TABLE 2-The response of cattle to BHK-produced antigens formulated with saponin 5 mgm/doseas adjuvant and given by subcutaneous injection.

Total cfu per 2 mldose vaccine

210150130130130

Harvested as 90Diluted for vac-cine test to 50

No. of PDso per 2 mldose vaccine i/dtongue challenge21-28 days post-

vaccination

>3027

>64416

40.6(equiv. to 73 forundiluted harvest)

Peak antibody titers (C.M.I.)prior to challenge from

groups of cattle given thefield dose of vaccine

1:5951:2951:4571:537

1:2818

C.M.I. = Cells metabolic inhibition.

of animals receiving the field dose of un-diluted vaccine. It is clear that the responsein all these cases has been completelysatisfactory.

Table 3 shows the laboratory results onfive vaccines given to swine. In this case theadjuvant was the water-in-oil emulsion, andthe vaccine was given by subcutaneousinjection. In this instance we do not havechallenge results, and the estimate of pro-tection is given by the pig antibody titersof groups of 10 pigs or more up to 28 dayspostvaccination. Challenge results exist inthe laboratory for groups of pigs up to ninemonths after vaccination and are extremelygood.

Field Use of BHK Vaccines

Although Pirbright was responsible forpioneer work in developing BHK vaccines,the pilot plant at the Institute was not

TABLE 3-The response of swine to BHK-pro-duced antigens formulated as primary water-in-oilemulsions and given by subcutaneous injection.

Total cfu Peak antibodyper 2 ml titers (C.M.I.) up

dose to 28 days p.v.Type Strain vaccine mean from 10 pigs

01 Swiss 1/66 117 1:645A. Iraq 24/64 200 1:346A5 Eystrup 108 1:851C 997 200 1:186SAT-2 Ken. 3/57 60 1:457

converted from Frenkel production until1967; since that time the program has cen-tered on research into methods of BHKvaccine production. Vaccine from the Insti-tute has therefore been issued only forrelatively minor field trial studies, the mainproduction capacity being employed in theproduction of Frenkel-type vaccine againststrains of virus exotic to Europe. Workingin a building adjacent to the Institute,however, the Wellcome Foundation has de-veloped and applied the BHK productiontechnique, and in many of its overseaslaboratories it has carried it through to ahigh level of production. I am indebted tothe Wellcome Foundation for the informa-tion in Table 4, which sets out the use ofBHK vaccines in a number of areas duringthe last four or five years. As can be seen,there has been considerable production inthis period, and there is no question thatthe vaccine has now passed the experimentalstage. There are no data which can supportin a fully scientific manner the claim thatthe vaccine is efficient, but it appears tohave met with general acceptance, and insome areas where campaigns have beenperhaps a little more closely supervised,notably in Kenya, there has been gratifyingevidence of the failure of the virus to spreadfrom surrounding areas into areas in whichvaccination has been carried out. In view of

Type

0101A5A5A.C

Strain

BFS 1860Swiss 1/6EystrupEystrupEystrupNorville

Foot-and-Mouth Disease Vaccines

TABLE 4-The field use of BHK Vaccines. (Data from the Wellcome Foundation)

Country Vaccine

Brazil BHK formalinMonolayer 1965-1968Suspension 1967-1970

Uruguay BHK Frenkel mixture(50-50) formalinBHK suspension cells

grown in bottles

Spain BHK formalin, nowAEI, suspension cells

Kenya BHK formalin, nowAEI, suspension cells

Botswana BIIK AEI suspensioncells

Adjuvant

Aluminum hydroxide

Vaccination Duration of Number of dosesRegime campaign applied

3 times yearly 3 years 2-20 million perannum

Aluminumhydroxide 3 times yearly 5 years Up to 8 millionSaponin per annum

-- -- 2 years -

Aluminum hydroxideSaponin


2 times yearly, 2 years 11/2 million cattlethen annually have had 3 doses

Annually 4 years 300,000 doses perannum

the paper to be given at this meeting by Dr.Mussgay, it may be appropriate to mentionthat reports of anaphylactic reactions fol-lowing vaccination have been limited toeight farms in Brazil, none in Uruguay,none in Spain, a limited number in Kenya,and none in Botswana. Apart from theWellcome experience, the major use ofBHK-produced vaccine has been in Italy.In 1969 Nardelli described the productionprocesses in use at the Institute at Brescia.There the procedure depends on the growthof seed cells in suspension and the transfer-ence of these cells to rolling bottles. Thegroup at Brescia has continued to developsuspension culture, but its main productionremains in the rolling bottle monolayer. Inrecent years several million doses have beenprepared annually and used in northern

Italy. Although some cases of anaphylaxishave been reported, they are not considerednumerous enough to interfere with thesuccessful use of the vaccine.

Conclusion

The production of BHK vaccine is arelatively simple process, and the applica-tion of the vaccine in the field has not givenrise to greater problems than are usuallyassociated with new immunizing agents.BHK vaccines produce as good an immu-nity as earlier foot-and-mouth disease vac-cines. Because of the production advantagein having cells readily available, BHK vac-cine should be given most serious considera-tion when plans are made for increasedfoot-and-mouth disease vaccine production.

BIBLIOGRAPHY

(1) Anderson, E. C., P. B. Capstick, G. N.Mowat, and F. B. Leech. "In vitro Method forSafety Testing of Foot-and-Mouth Vaccines."J Hyg (Camb) 68:159-162, 1970.

(2) Capstick, P. B., R. C. Telling, W. G. Chap-man, and D. L. Stewart. "Growth of a ClonedStrain of Hamster Kidney Cells in SuspendedCultures and Their Susceptibility to the Virus ofFoot-and-Mouth Disease." Nature (London) 195:1163, 1962.

(3) Capstick, P. B., R. C. Telling, and A. J.

Garland. "Utilization and Control of BHK Cellsin Inactivated Foot-and-Mouth Disease VaccineProduction. In Proceedings, lOth InternationalCongress of the Permanent Section of Microbio-logical Standardization, Prague, 1967.

(4) Capstick, P. B., A. J. Garland, W. G. Chap-man, and R. C. Masters. "Factors Affecting theProduction of Foot-and-Mouth Disease Virus inDeep Suspension Cultures of BHK-21 Clone 13Cells." J Hyg (Camb) 65:273, 1967.

(5) Mammerickx, M. and J. Leunen. "Indus-

56

BHK Vaccines 57

trial Culture of BHK 21 Cells at the National In-stitute for Veterinary Research, Brussels." BullOffice Int Epizoot 65:337, 1966.

(6) Mowat, G. N., J. B. Brooksby, and T. W. F.Pay. "Use of BHK 21 Cells in the Preparation ofMouse Attenuated Live Foot-and-Mouth DiseaseVaccines for the Immunization of Cattle." Nature(London) 196:655, 1962.

(7) Mowat, G. N. and W. G. Chapman. "Growthof Foot-and-Mouth Disease Virus in a Fibroblas-tic Cell Line Derived from Hamster Kidneys."Nature (London) 194:253, 1962.

(8) Polatnick, J. and H. L. Bachrach. "Produc-tion and Purification of Milligram Amounts ofFoot-and-Mouth Disease Virus from Baby Ham-ster Kidney Cell Cultures." Appl Microbiol 12:368, 1964.

(9) Rivenson, S. and M. Segura. "Multiplica-ción del virus aftoso en cultivos en frascos rotantesde la línea celular BHK 21 de rifión de hámster."Revista de Investigaciones Ganaderas 18:293, 1963.

(10) Telling, R. C. and R. Elsworth. "Sub-merged Culture of Hamster Kidney Cells in aStainless Steel Vessel." Biotechn Bioengin 7:417,1965.

(11) Ubertini, B., L. Nardelli, S. Barei, G. Pa-nina, and E. Lodetti. Report of the Meeting ofthe Research Group, Standing Technical Com-mittee, European Commission for the Control ofFoot-and-Mouth Disease. Rome: Food and Agri-culture Organization, 1970.

(12) Ubertini, B., L. Nardelli, S. Barei, G. Pa-nina, and E. Lodetti. "Controlli di efficacia su bo-vini di vaccini antiaftosi monovalenti e trivalentipreparati con virus da cellule BHK." Atti dellaSocietá Italiana della Scienza Veterinaria 22:895,1968.

(1S) Ubertini, B., L. Nardelli, A. Dal Prato, G.Panina, and S. Barei. "BHK 21 Cell Cultures forthe Large-Scale Production of Foot-and-MouthDisease Virus." Zentralblatt für Veterinármedizin,Reihe B., 14:432, 1967.

STUDIES ON LIVE VIRUS VACCINESFOR FOOT-AND-MOUTH DISEASE

DR. CARLOS A. PALACIOS *

Background

The research carried out in Europe on theadaptation of foot-and-mouth disease virusto embryonated eggs following Peragallo'sdescription in 1937 was confirmed by Trauband Schneider in 1948. Skinner's discoveryconcerning the susceptibility of sucklingmice in 1951, and the work of Gillespie in1954, describing the technique of adaptingthe virus to day-old chicks, established theinitial guidelines for new studies in theAmericas and throughout the world. Thesestudies demonstrated that through the tech-nique of continuous passage of the foot-and-mouth disease virus through different hosts(such as embryonated eggs, suckling andadult mice, rabbits of various ages, day-oldchicks, and tissue cultures), strains of viruscan be produced that can be used as modi-fied live vaccines for cattle, owing to theirlow pathogenicity and high immunogenicity.

The first reports of these studies andthe use of modified live virus vaccines tocombat foot-and-mouth disease in SouthAmerica were published by Rubino andTortorella in 1940 (cited by Palacios, 7, 8).Between 1933 and 1939, foot-and-mouthdisease viruses were submitted to a seriesof passages in guinea pigs. The test ani-mals showed only slight pathogenicity andgood immunity in laboratory tests. Thesame viruses were then submitted to pas-sages in sheep in order to obtain sufficient

* Director, Veterinary Research Center. Min-istry of Agriculture and Livestock, Maracay, Vene-zuela.

quantities to carry out field experiments.On various farms in Uruguay, 7,300 headof livestock were vaccinated. Only 30 ani-mals (0.4 per cent) showed any post-vaccinal reactions. In 20 of the 27 experi-ments, adequate protection resulted. Theconclusions of this study indicate that con-tagiousness was not present and that themodified virus likewise showed a notablereduction in pathogenicity for sheep.

The bibliographic researches of Bachrach(1968), Palacios and collaborators (1966),and Palacios (1968) give a historical de-scription of almost all the scientific worksprepared on this subject.

Application of the Live Virus Vaccine inVarious Parts of the World

The principal countries in which thelarge-scale application of the modified livevirus vaccine has been studied in relationto various types of foot-and-mouth diseaseviruses (A and O Vallée, C Waldmann,SAT-1, SAT-2, and Asia-1) are Israel,Kenya, South Africa, Transvaal, South-West Africa, Guyana, Brazil, Colombia,Ecuador, Chile, and Venezuela.

Israel

Kemron, cited by Bachrach (2) andPalacios (7, 8), reports that using live virusvaccines of the Asia-1 type modified in em-bryonated eggs, he was successful in con-

58

·Studies on Live Virus Vaccines 59

trolling the spread of the disease to non-infected areas from 8-10 days after theapplication of the vaccine. No undesirablepostvaccinal reactions were observed amongthe 86,000 head of cattle involved.

In more limited experiments, Kemron andGoldsmit found that vaccination with thetype of virus mentioned produced a 100 percent immunogenic response. They also ob-served that a considerable difference existedin responses according to the differentgroups of animals and that the older theanimal, the better the response. They re-ported that following a booster dose at14 months, there was a significant increasein the level of antibodies.

The importance of subtypes is pointedout by Bachrach (2) when he states thatin 1965 Kemron's modified A,, vaccine wasineffective against subtype A22. A residualpathogenicity formerly unnoticed in thevaccine was observed; it produced lesionsin the teats of the udders of pedigreedFriesian animals, leading to secondarymastitis.

Kenya

Galloway (6) reports on the use of livevirus vaccine of the modified Rho-1 strainbelonging to the SAT-2 type. Vesicularmaterial received in Pirbright in July 1960confirmed that an outbreak occurring dur-ing the previous month in the NanyukiDistrict in Kenya belonged to the SAT-2type. This was the first time that this typeof virus had appeared outside of the na-tive reserves and it produced a great dealof anxiety among officials and farmers. Itwas believed that the infection had beenintroduced by game animals from theMukogodo Reserve. Two infection fociwere established and an intensive vaccina-tion program was carried out around them

and on all farms in the populated area ofNanyuki. Some cattle from the native re-serves were also vaccinated. In all, about80,000 animals were inoculated. In additionto the native Boran breed and its crosseswith Friesian, Ayrshire, and Guernsey, vac-cinated animals came from a large numberof pure breeds such as Guernsey, Friesian,and Red Poll. Following vaccination, therewas no sign of spread of the infection.

Reports on postvaccinal reactions indi-cated that these were very benign in charac-ter and limited to approximately 10 per centin the European breeds and their crosseswith the autochthonous breeds. Reactionswere much less pronounced in animals ofthe Boran breed, amounting to a mere 2 percent. Galloway confirms that out of a herdof 500 Guernseys, 12 animals showed themost extensive and severe lesions producedby the use of this type of vaccine. He alsopoints out that in a farm in the middle of afocus, where 1,003 cattle had been vaccin-ated, one animal was found to have severelesions three days after vaccination; uponexamination of the vesicular material, it wasfound that the virus had no subtype relationwith the virus used in the vaccine. The au-thor believes that this observation is ex-tremely interesting, since certain severereactions may be erroneously attributed tothe vaccination, when they are really due toan infection with wild virus.

Subsequently, it was shown that the fieldvirus was a different subtype from that usedin the vaccine, but even under these circum-stances it was possible to limit and controlthe spread of the SAT-2 virus by applica-tion of the modified live virus vaccines.

South Africa

Galloway, using modified live virus vac-cine of the Rho-1 strain belonging to the

Vaccines for Foot-and-Mouth Disease Control

SAT-2 type, reports on its application inSouth Africa in an area comprising 80,580cattle. An outbreak of foot-and-mouth dis-ease had been raging in the central zone ofthis area for about three weeks, and wasshowing a pronounced tendency toward ex-pansion.

A wide sanitary cordon was establishedand the cattle were fire-branded to stoptheir irregular movements; in addition, anintensive vaccination campaign coveringclose to 44,000 head of cattle was carried outin the area surrounding the focus. Resultsindicate that out of the 44,000 head vacci-nated in the area not initially infected, only320 (0.7 per cent) contracted the disease;18,000 of these cattle were administered asecond dose when cases of foot-and-mouthdisease were noticed in certain farms amongcattle that had been vaccinated six to eightweeks earlier. Within 25 days of the seconddose, there was a reduction and total disap-pearance of these cases. The infected zonehad a population of about 43,600 animals,of which 7,954 were vaccinated. Field ex-posures were conducted on these animalsand it was established that 66 per cent ofthe unvaccinated animals and 37 per centof the vaccinated animals contracted thedisease in the center of the focus.

The results also indicate that althoughthe strain of the virus that was present inthe field belonged to a different subtype, itwas possible to control the rapid spread ofthe disease. This categorically proves theextraordinary value of the modified livevirus vaccine even under such adverse con-ditions as those in which it was adminis-tered in this case.

Transvaal

Martin and Edwards (cited by Palacios,7) report that during a field experiment inTransvaal that involved using a live virus

vaccine modified by passage in mice (Rho-1of SAT-2/1 type) and that included 3,400vaccinated cattle, very slight lesions wereobserved in only 0.35 per cent of the ani-mals. These researchers did not observeabortions or other reactions that might havebeen attributed to the vaccine. Althoughthe animals were vaccinated without dis-tinetion to sex or age, the virus apparentlydid not spread to the unvaccinated cattleused as controls. Experiments carried outby the same team (cited by Bachrach, 2)show that this modified live virus vaccineproduced a 91 per cent immunity to itshomologous virus in cattle and gave partialprotection to an additional 7 per cent. Intwo experiments carried out with Afri-kander and Cebu Kenya cattle vaccinatedwith the Rho-1 strain (SAT-2/1) intra-muscularly and intradermolingually and ex-posed to the field virus SAT-2/2 and SAT-2/3, it was observed that 70 per cent of the3,400 Afrikander animals (SAT-2/2) and63 per cent of the 2,000 Cebu Kenya cattle(SAT-2/3) were protected. These experi-ments indicate that the modified virusesused would be capable of conferring a highdegree of protection from foot-and-mouthdisease viruses to adult animals, provided,of course, that the field strain employed didnot differ in its antigenic structure from theRho-1 strain.

South-West Africa

Galloway describes a large outbreak offoot-and-mouth disease diagnosed in Pir-bright in July 1961 as belonging to theSAT-1 type. This was the first outbreakdiagnosed in South-West Africa (with theexception of a few along the borders of thecountry) which affected livestock districtsin the central region having highly suscepti-ble populations. The hope that sanitarymeasures and field exposures might control

60

Studies on Live Virus Vaccines 61

the disease, as had occurred on other occa-sions, prevented them from consideringvaccination until more than a month afterthe initial outbreak. By this time, the num-ber of farms affected had increased con-siderably, complicating the epidemiologicalpicture of the infection of game animals.Because of the grave danger of the spreadof the disease, a good deal of anxiety wasgenerated in neighboring countries, espe-cially in South Africa, which was importingsome 250,000 to 300,000 cattle on the hooffrom South-West Africa.

When vaccination with the RV11 modi-fied strain was begun, almost two monthshad passed since the initial outbreak andmore than 170 farms had been affected.There was an average of 20 new cases dailyand this figure promised to soon reach 30or 40 a day. For initial control of the epizo-otic, 678,000 doses of modified live virusvaccine were used; in the area borderingaround the zone vaccinated with modifiedlive virus, 2,630,000 doses of inactivatedvaccine were administered. In spite of thetremendous difficulties met with during thevaccination campaign-such as farms withan area of 6,000 to 7,000 hectares, the im-possibility of bringing together all the ani-mals for vaccination, the persistent drought,the spread of the virus by wild animals, theimplementation of field exposures, and thedifference between the subtypes of the vac-cine and the field virus (a difference estab-lished by cross-immunization tests in cattle)-a protection of 90 per cent was achievedwith the modified live virus vaccines in theareas nearest the outbreak and of 95 percent with the inactivated vaccine in theareas surrounding that in which the modi-fied live virus vaccines were used.

Dr. J.H.B. Viljoen, Deputy Director ofthe Veterinary Services of South-WestAfrica, in an interesting document presentedto the International Office of Epizootics in

1964 (9), reports on the campaign againstfoot-and-mouth disease carried out in hiscountry. He states that some 4,490,645doses of inactivated and modified vaccineswere used on cattle, sheep, and goats on atotal of 4,798 farms. Of these, some1,237,000 doses were modified virus vac-cines, used particularly for cattle and goats.This was the most extensive campaign tobe realized anywhere in the world with thistype of vaccine at that particular time(1961-1962). Dr. Viljoen points out thatthe sanitary control measures implementedincluded the construction of a 2.59 m barrierto control the movement of animals. Thismeasure, however, was only effective in cer-tain areas, while in others it was useless,possibly because it was constructed verynear the known zones of infection. Thewriter also emphasized the importance ofwild animals in the spread of this epidemicand the use of field exposures, which hadbeen useful on other occasions to controloutbreaks of foot-and-mouth disease incombination with animal health measures.

The inactivated vaccine was used in theperipheral zone and the modified live virusvaccine near the affected area. Althoughthere were gaps in the immunization, thefight against the disease was completelysuccessful owing to a repetition of the vac-cination several times in necessary cases.The epizootic was halted and the diseasewas completely eliminated in the latter partof 1962. Proofs were obtained that the useof vaccines on infected farms interruptedthe course of the disease.

Certain cases of neuromuscular distur-bances in sheep, which circumstantial fieldtests attributed to the application of themodified virus vaccine SAT-1, were dis-covered. The practice of field exposures,still used in highly contaminated areas, isto be condemned in the fight against foot-and-mouth disease, owing to the impossi-


bility of containing or isolating all suscepti-ble animals, particularly game animals. Itis believed that the field exposures put intopractice since 1931 have increased the infec-tiousness of the SAT types of the foot-and-mouth disease virus among game animals.

Guyana

In September 1961 an outbreak of foot-and-mouth disease (type A Vallée virus)occurred in the Rupununi savanna. Tenthousand doses of inactivated vaccine wereadministered in the affected zone and 5,000cattle were vaccinated with a modified livevirus vaccine (67th passage of the strain oftype A,4 Cruzeiro) in the central area ofthe outbreak. This measure was taken afterpreliminary testing of this vaccine with20 cattle, which showed no postvaccinaleffects. Eight hundred of the 5,000 animalsvaccinated were individually observed with-out any reaction whatsoever being discov-ered.

The modified live virus vaccine, both byitself and in combination with inactivatedvaccine, gave the vaccinated cattle excellentprotection. Not only did it prevent thespread of the disease, but until the present-eight years later-not a single outbreak offoot-and-mouth disease attributed to type AVallée has been discovered.

In 1969 Guyana experienced a new out-break of foot-and-mouth disease diagnosedas belonging to the type O Vallée virus.

Brazil

The headquarters of the Pan AmericanFoot-and-Mouth Disease Center is locatedin this country, and the following is a sum-mary of the most important studies carriedout by that institution and the BiologicalInstitute of Sáo Paulo. Also included are

some of the studies conducted jointly withthe Veterinary Research Center in Vene-zuela, particularly as regards the study andapplication of modified live virus vaccinesfor type A Vallée virus.

In results obtained with the 66th and67th passages in rabbits of a type C Wald-mann virus (Cunha et al., cited by Palacios,7, 8) a low degree of pathogenicity (3/96)and good immunity (91/106) in cattle wasobserved. In contrast, all swine inoculatedcontracted generalized foot-and-mouth dis-ease (10/10) and seven of the animals died.While there was no contagiousness amongthe cattle, it was quite high among theswine.

Other studies were conducted on survivaland carriers of this modified type C virus(utilized in a bivalent vaccine with type AVallée virus, avianized). In these studies,type C Waldmann virus was recovered inalmost all the cattle vaccinated, and insome contacts, in various organs and tissues.These observations led to other experimentsto study the biological characteristics ofthis virus. Preliminary results indicate thatsome of the viruses isolated from carriers(submitted to three serial passages in suck-ling mice) produced relatively high titersin cattle, accompanied by generalized andvesicular lesions (5/8).

Cattle inoculated with vaccine virus andviruses isolated from postvaccinal reactionscould transmit and produce serious vesicu-lar foot-and-mouth disease lesions in swinecontacts; swine inoculated with the samevirus samples and showing serious lesionsdid not, however, infect the two cattle thatwere kept in contact with them (Bernalet al., Augé de Mello et al., cited by Pala-cios, 7, 8).

At the Pan American Foot-and-MouthDisease Center, Bernal and collaboratorsare studying new strains of type C Wald-mann virus, subtype C,, modified in em-

____62


bryonated eggs and cell cultures at lowtemperatures. So far, results are encourag-ing since they show extremely low patho-genicity for swine and cattle, good im-munity for cattle, and partial immunityfor swine.

The results of studies by Bernal et al.(cited by Palacios, 7, 8) with O Camposstrain (type O Vallée, subtype O0) modifiedby serial passages in 14-day-old embryo-nated eggs reveal that pathogenicity de-creases progressively, while good immunityis maintained for bovines, even at the 99thpassage.

Using data obtained at the 67th, 80th,and 92nd passages of the A Cruzeiro strain(type A Vallée, subtype A24) in 14-day-oldembryonated eggs (3) Cunha et al. andPalacios (cited by Palacios, 7, 8) indicatethat the pathogenicity of this virus forhighly susceptible cattle (from zones free offoot-and-mouth disease in Venezuela, Co-lombia, Ecuador, and Chile) was 16/32 forthe virus at the 67th passage, 13/32 at the80th passage, and 16/104 at the 92nd pas-sage. At the last level, pathogenicity wasvery low, and in susceptible cattle from anepidemic zone (Brazil) it was even lower:4/18 and 0/66 for the 67th and 92nd pas-sages, respectively. Good immunity was ob-tained in all cattle vaccinated, even whenthe trial inoculation was effected with anantigenically dissimilar virus (subtypes A18

and A 9g). There was no indication of thespread of the infection from vaccinatedcattle to susceptible contact animals. Thisvirus still maintains a high pathogenicityfor swine at the 113th passage. In a limitedexperiment with sheep, no postvaccinal re-actions were observed at the 92nd passageand the animals were immune.

Duration of immunity in 1- to 2-year oldcattle inoculated with a monovalent vac-cine (strain A24 Cruzeiro, passage 92).Eighty cattle were used in this study, de-

scribed in the reports of the Pan AmericanFoot-and-Mouth Disease Center (8). Theywere divided into four groups and giventhe following treatment:

I. One dose of vaccine (30 cattle).II. Two doses of vaccine at an interval

of 30 days (22 cattle).III. Two doses of vaccine at an interval

of 240 days (16 cattle).IV. Cattle not vaccinated and in contact

(12 cattle).

Of all the animals vaccinated for the firsttime, only one presented a benign postvac-cinal reaction. After revaccination no signsof pathogenicity were detected.

In Group I, which received only one doseof vaccine, the following was observed:

Ten cattle showed complete immunity bythe 30th day; six out of 10 showed im-munity by the 120th day; and five out of 10also showed immunity by the 180th day. Inthis last test four contact animals (withoutvaccination) presented generalized lesions.All four control animals of each experimentreacted and presented generalized lesions.

The curve of antibody levels is repre-sented by the arithmetic mean of the indicesobtained from the animals used in the chal-lenge test, which decreases after 30 days,staying close to the immunity level con-sidered to be acceptable up to the sixthmonth.

The cattle of Group II, tested sevenmonths after revaccination, showed goodimmunity (8/8), while the four controlsgeneralized. In the test performed one yearafter revaccination, seven out of nine vac-cinated animals remained immune, while thefour controls, as well as the unvaccinatedcontact animals, contracted the disease.

Regarding the cattle of Group III, allshowed immunity (7/7) 210 days after re-vaccination, while the unvaccinated con-tacts and the four controls presented gen-


eralized lesions. An identical result wasobtained one year after revaccination in thetest performed with eight vaccinated ani-mals.

In Group II the antibody level stayedabove the indicative limit of protection upto seven months after revaccination, dimin-ishing slowly until the 12th month of thistest.

Regarding the antibody level, it is inter-esting to point out that, by coincidence,two curves with marked differences werefound referring to the animals used in thechallenge test of Group III. One, relatingto animals challenged in the 15th month,stayed well above the immunity line; thesecond one, relating to cattle that were chal-lenged in the 20th month, stayed below thesame line. Both groups reacted very well torevaccination in the eighth month andstayed above this line up to 20 months,when this test was finished.

Duration of immunity in calves inocu-lated with a monovalent vaccine (strain ACruzeiro, passage 92). The experiment wascarried out in 187 calves (3-6 months ofage) submitted to two different treatments(report of the Pan American Foot-and-Mouth Disease Center cited by Palacios,8).

Group I: 83 calves vaccinated threetimes, intramuscularly, at 30-day intervals.

Group II: 79 calves vaccinated fourtimes; the first three doses at seven-dayintervals and the fourth dose, 90 days afterthe first.

A third group of 16 calves were kept ascontact controls without vaccination. Theimmunity tests were performed by theinoculation of homologous virus and bystudying the seroprotection indices in suck-ling mice.

The results of postvaccinal reactionsshowed that 3 per cent of the vaccinatedcattle presented benign lesions.

Regarding the immunity measured by theserum antibodies, there was a pronouncedincrease in the arithmetic mean in the twogroups of vaccinated calves.

In both groups the arithmetic mean ofthe sera studied remained the same up to the12th month, very near to the line establishedas indicative of protection.

In Group I it was observed that the anti-body levels were at or above the 1.7 line forthe sixth and eighth month, thus coincidingwith the results of the challenge tests. Atthe test performed at the 12th month, sevenout of the eight cattle used showed antibodyindices below 1.5, which could explain thediscrepancy between the arithmetic mean ofthe antibody level of all the remaining ani-mals and the challenge test, which showedonly a 1/8 protection level.

In Group II the curve of antibody levelsand the challenge test were closely related.

In Group III (unvaccinated calves) theantibody levels were never above 1.7, andin the challenge tests all cattle were un-protected.

Use of bivalent vaccines. An experimenton the duration of immunity in cattle re-vaccinated with modified A Vallée and CWaldmann virus seems to indicate thatimmunity lasts up to 360 days, indepen-dently of the time between vaccination andrevaccination, whether this is a 30- or a 180-day period.

Experiments carried out at the PanAmerican Foot-and-Mouth Disease Centerand the Veterinary Research Center inVenezuela seem to indicate that bivalentvaccines do not present a cumulative effectof pathogenicity nor a decrease in the im-munogenic properties of the virus used.

Carriers and survival of some modifiedlive virus in vaccinated cattle. Esophago-pharyngeal material from cattle vaccinatedand revaccinated with modified live virus

64


(A avianized and C lapinized) at differentintervals (30 and 180 days), as well as asmall non-vaccinated group left in contact,were studied for virus isolation throughinoculation of suckling mice and cultures ofBHK-21, C-13 cells, and their typing bycomplement fixation.

The data obtained indicate that, althoughthere was a tendency for the number of car-riers to be reduced (which after the firstvaccination was 16/32 for the group revac-cinated in 30 days and 15/49 for the re-vaccinated group in 180 days), it was pos-sible to isolate the virus up to the 270 daysafter vaccination (1/49) and apparentlyrevaccination at 30 or 180 days did not in-crease the number of carriers.

The virus isolated in all cases was CWaldmann, with the exception of a case atthe 90th day and another at the 240th day,in which virus A Vallée was isolated.

In experiments performed in order tostudy three virus isolation methods-inocu-lation of swine, suckling mice, and tissueculture-the data obtained show that suck-ling mice and BHK cells seem to be moresusceptible than swine and that it wasnecessary to use these two methods becauseotherwise it would have been impossible toisolate virus from three or four out of thenine known positive cases.

Some of the calves coming into contactwith animals inoculated with bivalent vac-cine utilized in this experiment (1) becamecarriers for 180 days. It must be pointedout, however, that this occurred only withtype C Waldmann. Another interesting ob-servation made during these studies was theapparent absence of any reciprocal relation-ship between the concentrations of anti-bodies and the isolation of virus from carrieranimals. Augé de Melo also reports in hisstudy that he succeeded in isolating typeC Waldmann virus from unvaccinatedcalves born of cows immunized during the

gestation period and after the birth of theyoung with trivalent modified live virusvaccines which included the type C Wald-mann lapinized strain. The antibody levelsof these animals were always below 1. Theresults obtained with the C Waldmann virusdescribed above, which illustrate the re-cuperation of pathogenicity of the C virus,its prolonged persistence in carriers, in or-gans and in tissues, and its contagiousnesswithout clinical signs in cattle and withlesions in swine, led to the elimination ofthis strain from later research and its com-plete rejection for field use. The shortcom-ings of this virus stand out particularlywhen compared to A Vallée virus, Cruzeirostrain, which, insofar as carriers are con-cerned, could only be detected in two ani-mals at 90 and 240 days and which wasapparently absent in the organs and tissuesutilized in the survival studies. Moreover,in various studies carried out by the PanAmerican Foot-and-Mouth Disease Center,this virus has shown no contagiousness forcattle (both adults and young) or swine.

Table 1 shows the pathogenicity resultingfrom the application of monovalent andpolyvalent vaccines to cattle in the field.This information was gathered by detailedexamination of groups of vaccinated ani-mals, as well as by the observation of theseanimals to determine which of them showedclinical symptoms of the disease.

A great variety of postvaccinal vaccina-tion responses resulted. This variety is ex-plained by the variables existing in thecattle utilized with respect to breeds, ages,state of immunity, etc. Apparently, thenumber of cattle showing reactions does notincrease considerably with the polyvalentvirus. In other words, the latter does notappear to produce cumulative pathogenic-ity. Cunha et al. and Palacios et al. dis-covered that the effectiveness of the poly-valent modified live virus vaccines is not


TABLE 1-Pathogenicity resulting from the application of monovalent and polyvalent live virus vac-cines against foot-and-mouth disease in cattle in Brazil.

ReaetorsVaccinated

Year Virus/modification cattle Individual a General b

Monovalent vaccinesO/Colll0/E52-65A/E67A/E920/Co67

Polyvalent vaccinesA/E92 O/ColllA/E92 C/Co67A/E92 O/E106 C/Co67

a All the cattle were carefully examined to detect reactions in the mouth, feet, and so forth.b Field observation to detect any animal which could be clinically affected.

inferior to that of the respective monovalentvaccines.

Observations of a small group of youngcattle during a natural foot-and-mouth dis-ease outbreak in one of the farms whereprevious experiments had been carried outrevealed an obvious antigenie difference be-tween O strain modified in rabbits and thesame strain modified in chick embryos. Atthe end of nine months, the former stillprotected 40 per cent (5/13) of the inocu-lated animals; the latter protected 70 percent (9/13). The 70 per cent immunitylevel was similar to that observed in a groupof cattle that had contracted the diseasenine months earlier (15/24).

The Biological Institute of Sáo Paulo,Brazil, has carried out research with threemodified viruses in monovalent and poly-valent vaccines corresponding to types Aand O Vallée and C Waldmann, all modifiedby passages in embryonated eggs (L. Pusti-glione et al., cited by Palacios, 8).

From 1964 to 1966, type A monovalentvaccine was applied on 120 dairy farms with30,000 head of cattle formerly vaccinatedwith inactivated vaccines. The seroprotec-tion indexes were 3.5 to 4.5 over an eight-month period. In 1966 and 1967, bivalent(A and O) and trivalent (A, O, and C)vaccines were administered to 15,000 cattle.

No adverse postvaccinal effects were ob-served and not a single case of foot-and-mouth disease was reported. Antibody con-centrations are being studied.

Colombia

Foot-and-mouth disease has been presentin Colombia in 1950, when an epizootic ofO Vallée virus affected Venezuela and sweptfrom the Apure plains to the Arauca low-lands, spreading rapidly through the entirecountry. Subsequently, in 1951, a Valléevirus was discovered in the Valle del CaucaDepartment, Cali district, and again,quickly spread through the country.

At the request' of the Government ofColombia, and after testing, it was foundthat the modified live virus vaccine of theA24 Cruzeiro strain was sufficiently attenu-ated for the cattle of this country; more-over, it gave them excellent protectionagainst the type A Vallée viruses that werepresent in the countryside. Consequently,it was decided to carry out a limited andcontrolled vaccination program in theBogotá savanna with approximately 5,000to 6,000 cattle forming part of a bovinepopulation of 120,000 Holsteins basicallyused for milk production.

1956-19651963-19651961-19621962-19641963-1964

196419651965

26,6854,917

66911,4222,699

2,3097,2556,489

103/1,43485/ 50819/ 10335/ 59250/ 419

14/ 11333/ 73031/ 446

7/1,15927/1,083

3/ 9190/1,1335/5,440

66


The results of the five-year application(1963-1967) indicated that when an indi-vidual review was made of the animals,postvaccinal reactions, all very benign, werefound in 24 out of 296 cattle in 1963 and50 out of 295 in 1964. Animals with mani-fest signs formed an extremely low per-centage which varied from 0.1 to 0.05 percent (4/4,499 in 1963 and 2/4,727 in 1964).

In the Bogotá savanna experiments havebeen made with a vaccine prepared with astrain of 0, virus (Campos) modified byserial passages in embryonated eggs to the71st and 100th passage level (7, 8). A sum-mary of the results of these tests indicatesthat the postvaccinal reactions were 31/550at the 71st passage and 0/396 at the 100th.

During 1966 and 1967, bivalent vaccineswere applied to 5,000 and 6,000 cattle, re-spectively. The results of this applicationare not yet all available for analysis.

Ecuador

Foot-and-mouth disease, type A, wasdiagnosed in Ecuador for the first time in1956 in the so-called Litoral. In this regionthere are approximately 600,000 head ofcattle, mostly of a mixed Cebu-criollo type.

The Andean part of Ecuador, where mostof the country's high-grade cattle breedingregions are located, was kept free from thedisease until 1967 by means of strict quar-antine and sanitary control measures, ex-cept for three outbreaks of virus type OVallée, in 1962, 1965, and 1967, and an-other of type A Vallée in 1965. The firstoccurred in the Province of Carchi, and wasintroduced by cattle that came from Co-lombia. The second outbreak of type Ooccurred in the southern Provinces of Loja,Azuay, and El Oro. The third outbreak oc-curred in the Provinces of Pichincha(Sierra) and Guayas, Los Rios, and Manabí(Litoral).

The outbreak of type A Vallée was de-tected in Carchi Province in the north of thecountry. These outbreaks were, however,quickly brought under control by means ofmass vaccination in the northern districtswith inactivated vaccines and with modifiedlive-virus vaccine type O Vallée (Campos)in the south, coupled with rigorous measuresof control on cattle movements.

The Government of Ecuador decided touse a modified live virus vaccine for thecontrol of the outbreaks in view of theencouraging results obtained in Guyana, inVenezuela, and in experiments performedby the Pan American Foot-and-MouthDisease Center in Brazil.

In cooperation with the Center, steps weretaken to obtain the necessary knowledgefor both production of the vaccine and itsuse in the field. The first step was a potencytest of the A24 Cruzeiro vaccine (90th pas-sage) in a small number of cattle, at theFoot-and-Mouth Disease Institute in Gua-yaquil. Twelve fully susceptible youngsteers were vaccinated. Four others wereleft without vaccination in close contactwith the vaccinated animals. None of thevaccinated animals showed lingual or hooflesions. Three weeks after vaccination allanimals were inoculated intradermolin-gually with 4 x 10,000 LD50,,/ of a patho-genic virus strain isolated in Ecuador. Noneof the vaccinated animals showed signs ofgeneralization, but the four contact animalspresented generalized lesions.

After this preliminary and successful test,controlled and limited field trials were made.

These field trials were performed first ona small scale at the farm called "La Paz"and later in the areas of Barranca Chicaand Hacienda El Recreo, where vaccinationagainst foot-and-mouth disease had neverbeen applied.

The total of animals found with reac-tions was 44. However, only three of those


animals were reported by the farmers. Allother reactors were found only after carefulinspection of the mouth and hoofs; they hadbeen undetected by the farmers because ofthe absence of significant salivation orlameness.

The percentage of animals with lesions inthe Barranca Chica area (43/312) wasgreater than that observed in El Recreo(1/126). The explanation for this must bethe fact that the farms in Barranca Chicawere stocked mainly with cattle from thedisease-free Andean region, whereas at theHacienda El Recreo outbreaks of the dis-ease had been reported a year previous tothe vaccination. There were also two farmsin Barranca Chica in which type A viruswas diagnosed a year previous to the vac-cination. No reactors were found on thesefarms.

Although theoretically the group of ani-mals between 6 months and 1 year old mustbe without maternal or any other antibody,the animals vaccinated within this agegroup were the ones that showed the low-est rate of reactors (0/38). Unfortunately,the small number of calves that were ac-tually inspected on the farms in the Bar-ranca Chica area was too small to warranta definite conclusion regarding the relativeunsusceptibility of this group to the vaccine,compared with older cattle. There was nodrop in milk production, and no abortionsor deaths occurred. Of all reacting cattle,only three animals were indicated by thefarmers as having lesions.

In February 1967 an outbreak of virustype O Vallée appeared in Pichincha Prov-ince (near Quito) and spread to other farmsin the Province of Cotopaxi and in Ca-yambe (Sierra).

New outbreaks appeared later in theLitoral in the Provinces of Guayas, LosRíos, and south of Manabí. Faced with thisemergency, the Ecuadorian animal health

authorities applied the plan of action pre-viously used successfully in the 1965 out-break in Loja, Azuay, and El Oro Provinces.This plan covered three zones:

1. The infected zone, where cattle werevaccinated with modified live virus vaccine(avianized strain O Campos, passages 101-106).

2. The suspected zone, surrounding thefirst zone, where cattle were vaccinated par-tially with modified live virus and partiallywith inactivated vaccine (Waldmann type)followed by modified live virus vaccine.

3. The protection zone, surrounding thesecond zone, where cattle were vaccinatedwith inactivated vaccine, followed by modi-fied live virus vaccine.

The first outbreak was diagnosed on8 February 1967 on a farm in PichinchaProvince (infected zone); the second ap-peared at a distance of 45 km from the first.The disease spread rapidly to other farmsand about 50 new outbreaks were reportedin the first 28 days (nearly two farms in-fected every day). This infected zone hasexcellent conditions for rapid propagationof the disease: cattle with no previous his-tory of infection; an extensive network ofroads with heavy circulation of vehicles fortransport of animals and animal products;and the existence of small country roadsbetween farms, allowing a heavy circulationof people and animals.

During the vaccination of cattle withinthe infected zone, it was impossible to de-termine exactly the number of farms inwhich the cattle were in the incubation pe-riod of the disease, or were infected duringthe period when the vaccine was not yetprotecting them adequately. For this reasonit was impossible to determine which of theanimals were infected by the field virus anr'which really had postvaccinal reaction..

In the suspected zone (in which there

68

Studies on Live Virus Vaccines

were fewer outbreaks than in the first zone),the use of the modified live virus vaccineproduced a small number of postvaccinalreactions, ranging from 3 to 7 per cent. Thisacceptable percentage is completely differ-ent from the one found in the infected zone,where the average varied between 5 and45 per cent in some cases. The unusual pro-portion of affected cattle following vaccina-tion in the latter zone, as compared withthat in the suspected zone, was due to theconditions previously described for bothzones. In the remaining parts of the sus-pected zone and in the protection zone wheresimilar treatments were applied, postvac-cinal reactions were not significant.

The situation in the provinces of theSierra indicated that the use of the vaccines,together with the sanitary measures, re-sulted in the rapid control of the diseaseand prevented its spread.

Sixty-seven outbreaks were reported be-tween 7 March and 29 April in the Litoralprovinces, and about 30,000 head of cattleare estimated to have been infected beforethe administration of modified live virusvaccine. Vaccination of these cattle wasdelayed by the floods produced by heavyrains (Lombardo et al., cited by Palacios,8).

During 1967, 1,099,902 doses of vaccine,particularly modified live virus vaccine,were applied and the immediate spread ofthe disease to the Provinces of El Oro,Esmeralda, and the remainder of Manabíwas prevented.

In the course of 1968 outbreaks of typeO Vallée subtype O and type A Valléesubtype A27 appeared in Manabí, Pichincha,Cotopaxi, Los Ríos, and Imbabura. A Valléevirus was diagnosed in Carchi, Esmeralda,and Guayas.

It is noteworthy that owing to variouscircumstances, Ecuadorian authorities couldcarry out only 32 per cent of the vaccination

program in 1968, and only 845,211 doses ofvaccine were administered.

Because of these events, there was anationwide epizootic for the first time in1969, and a great deal of anxiety was gen-erated at all levels. The Pan AmericanFoot-and-Mouth Disease Center (11) con-ducted a study which was presented to thecorresponding officials in July 1969, in whichthe following observations were made:

1. In the cases examined in well-cared-for herds that had undergone systematicvaccination with some type of vaccine(modified or inactivated) a low incidenceand only slight losses were observed.

2. Higher morbidity, more lesions, andgreater losses were observed in herds sub-ject to deficient handling and irregular and/or incomplete vaccinations.

3. Total serious attacks (frequently 100per cent morbidity), with high mortalityand large economic losses, were observed onfarms that, according to cattle raisers andveterinarians, were not vaccinated.

4. Cases were recorded in which vaccines(inactivated or modified) were administeredwhen the cattle were already sick or in themiddle of the incubation period. This wasshown by the appearance of vesicular le-sions in the days immediately followingapplication of the vaccine.

5. No indications were found that themodified virus had produced outbreaks ofthe disease or any other adverse effects.

Chile

In light of the interest that the modifiedlive virus vaccines could have for Chile, theencouraging results of other countries, andthe experimental trials previously carriedout, in which domestic cattle showed ex-cellent immunity to local viruses and onlyslight pathogenicity, a field application pro-

69


gram was planned for the Province ofLlanquihue.

Modified live virus vaccine prepared withA2 , Cruzeiro strain, passage 92, was ad-ministered in 5,587 red and white Holsteincattle; it was complemented three weekslater with inactivated bivalent vaccineagainst O Vallée virus and C Waldmannvirus. Out of 670 individually controlledanimals, 14.1 per cent were found to havepostvaccinal lesions; 4.1 per cent of thesehad vesicular characteristics, while the other10 per cent were of the desquamative type.

Seven cases of benign anaphylactic re-actions and two abortions occurring be-tween the 4th and 6th days after vaccina-tion were also observed. These animals,however, showed no lesions that could beattributed to the vaccine applied.

TABLE 2-Annual distribution of foot-and-mouthdisease outbreaks in Venezuela, 1950-1969.

Year

19501951195219531954195519561957195819591960196119621963196419651966196719681969

Total

Type of virus

O A Total

38 - 3858 5 6321 - 21

6 1 75 6 11

53 10 6331 48 7928 12 4030 - 3072 4 7632 7 3994 88 18241 31 7243 12 5533 4 3777 8 8546 21 6763 5 6833 48 81

804 310 1,114

Venezuela

Foot-and-mouth disease (type O Vallée)made its first appearance in Venezuela in1950, spreading rapidly through most of themidwestern portion of the country. It hasmaintained its enzootic character in thisregion up to the present.

Type A Vallée virus was discovered intwo zones, in the north (Puerto Cabello,1951) and along the border with Colombia(Táchira, 1954). It spread from the borderto the midwest following an epizootic out-break in late 1956 and during 1957. Fromthat time forward, the presence of bothtypes of virus has become normal. Untilrecently there was a zone subject to spo-radic outbreaks, comprising the easternstates, and another area free of the disease,made up of Bolívar State and the Amazonand Delta Amacuro Territories. Table 2shows the number of outbreaks reportedfrom 1950 to 1969, which total 1,114 foruoun uypes: 8u4 of O virus and 310 ofA virus. The years in which the greatest

number of outbreaks of O type occurredwere 1950, 1951, 1956, 1960, 1962, 1966,1967, and 1968. Until 1967 only subtype 0Owas known, and in that year subtype 01made its appearance.

The greatest incidence of A Vallée virusoccurred in 1957, when it spread through theenzootic zone; in 1962, when the new sub-type A 8,, Zulia appeared; and in 1969, whennew areas were infected, almost certainlydue to the appearance of a new subtype(Venezuela 1970).

Venezuela undertook a campaign againstthe disease in 1950. Production of vaccinebegan in 1951 with the use of inactivatedWaldmann type. In that year, vaccinationstotaled 2,411,600 doses.

In June 1962 an epizootic outbreak ofA Vallée virus affected the southern part ofZulia State. The information obtained seemsto indicate that it was the continuation ofa focus found some months earlier/in thePerijá district of thob '-~o?-r.± le char-acteristics of this outbreak showed that theWaldmann vaccine, produced until that

70


time from the A Vallée Táchira strain, didnot provide adequate protection against thenew virus. A survey cited by Palacios (7,8) covering approximately 6,000 animals(vaccinated several times during 1961 and1962) revealed that 79 per cent of themcontracted the disease, with a range of from44 to 94 per cent on the different farms. Thisobservation was confirmed by immunitytests done at the Veterinary Research Cen-ter of Venezuela. Serologic studies carriedout at the Pan American Foot-and-MouthDisease Center and the Venezuelan Centerdemonstrated a great difference between thestrain of virus used in the production of thevaccine and the one found in the field. Theseresults were confirmed by the World Refer-ence Laboratory at Pirbright, England, andthe new subtype was classified as A18(Zulia).

Because of the danger of spread of thedisease through the techniques used for thepreparation of the Waldmann-type vaccine(inoculation of cattle in slaughterhouseslocated in the center of the country), thepossibility of using a modified live virusvaccine was considered. Studies performedat the Pan American Center and at theVenezuelan Center had shown promisingresults with strains modified through serialpassages in chick embryos and day-oldchicks. Strain A Cruzeiro (subtype A24)modified by Zahran and Bernal (cited byPalacios, 7, 8) was selected for the firsttrials. Good protection was obtained withthe use of this virus against strain A18

(Zulia), as well as an acceptable degree ofpostvaccinal reactions.

In December 1962 a total of 500,000 doseswere administered to the major dairy cattleherds, in the central and western areas ofthe country (Villegas, cited by Palacios,7, 8). Later on, when more experience hadbeen gained in the laboratory, it was foundthat, in order to obtain good immunity with

virus from the 92nd passage, it was neces-sary to inoculate more than 107.0 LD50o/r, a

requirement that made it very expensiveto produce the vaccine using embryonatedeggs. Further studies with fewer passagesshowed that it was possible to obtain goodimmunity with virus from the 67th and 80thpassage levels, titers ranging from 105'6 to1067 LD,,/rl per vaccinating dose.

Postvaccinal reactions with passages 92and 80 were studied by Villegas and foundto be, respectively, 0.81 per cent (297/36,663) and 2.33 per cent (99/4,243). Ingeneral, these reactions were mild.

The administration of this vaccine con-trolled the new epizootic, confining it toZulia State, which has a cattle populationof about 1,000,000 animals. Through massvaccination in the enzootic area, it waspossible to prevent the disease from spread-ing to the rest of the country, where thecattle population amounted to 5.5 millionhead.

There have been very few outbreaks oftype A Vallée since 1963 and subtype A,,has not been found since 1962.

In 1967 the virus subtype A2 7 was diag-nosed in Colombia. Fearing the possibilityof infection in Venezuela, a joint study wasundertaken by the Pan American Foot-and-Mouth Disease Center and the VeterinaryResearch Center to determine the degree ofprotection afforded cattle by the modifiedA24 Cruzeiro virus against the new subtype.

Bernal, Balestrini, et al., in studies notyet published, found that the 80th passageis capable of conferring acceptable protec-tion in cattle 30 days after vaccination withtiters of 1066 and 1074 LDso/ri, respectively,while at the 92nd passage the specific im-munity induced against the new subtypewas inadequate (Table 3). Both passagesproduced highly effective specific immunityagainst their homologous subtype. Studieson the duration of immunity were also con-


TABLE 3-Pathogenicity and immunity results in cattle using two passage levels of modified A2,Cruzeiro live virus.

No. of LDo/írlcattle inoculated 4

88888888

6.67.46.57.26.67.66.57.5

Immunity to:

Virus A24 Virus A27

Pathogenicity Vaccinated Controls Vaccinated Controls

1/8 - - 6/8 -

5/8 - - 6/8 -0/8 - - 1/8 -

1/8 - - 3/8 0/4 ̀

1/8 7/7 - - 0/44/80/80/8

8/88/88/8 0/4

4 Loq. 10 of the LDso/ri inoculated per vaccine dose.b Cattle in contact during the 30 days of vaccination. Exposure with 10,000 LDo/rli intradermolingually.

ducted by the same researchers, and it wasshown that eight months after revaccination50 per cent of the animals used in the testwere immune to the heterologous subtype(8/16) and 75 per cent were immune to thehomologous virus (12/16).

These tests apparently explain why theA,, virus has not posed a serious threat tozones such as Aragua State which are wellvaccinated twice a year.

In the early months of 1970, A Valléevirus was diagnosed in samples taken invarious states (Bolívar, Apure, Monagas,Zulia, and Amazon Federal Territory).When the samples were sent to the Pan

American Foot-and-Mouth Disease Centerfor subtyping, a new subtype for SouthAmerica, which we shall call Venezuela 1970until the World Reference Laboratory as-signs it a number, was discovered. Researchwas immediately begun to determine whatprotection the modified vaccines would givecattle against the new subtype. As some ofthe zones affected by the new virus werefreed or are free of foot-and-mouth disease,it was thought advisable to import a smallbatch of 10,000 doses of inactivated bivalentvaccine.

Immunity was tested by direct intra-dermolingual challenge in cattle, 21 days

TABLE 4-Studies on immunity in cattle induced by bivalent modified live virusvaccine (A. Cruzeiro, passage 80, and 01 Campos, passage 73).

LDso/ror

Immunity against:

Virus A Venezuela 70 Vir

Protection b

Vaccines ml a Vaccinated Controls Vaccinm

Bivalent A24.' 8 2/9 0/4 7/8

modifiedlive virls

A24 - Oi 0O.4

Inactivated 10 mlbivalent subcut. 4/10

A-G (imn- 50 mlported) subcut. 3/3 0/4

a In suckling mice, applied in doses of 4 ml of vaccine (2 ml each virus).b Number protected. Number vaccinated.

us A24 Cruzeiro

Protection

ated Controls

0/4

Passage

80

92

80

92

72


TABLE 5-Results of pathogenicity, immunity, and contagiousness tests in cattle and swine inoculatedwith foot-and-mouth disease vaccine (modified through serial passages in chick embryo and in day-old-chicks, virus type O Vallée, subtype Oa, strain O Lara).

Testing

Preparation of Cattle Swinevaccines

Coneta- Conta-Passage Material LDso Patho- gious- LDso Patho- gious-

No. used p/dose genicity Immunity a ness p/dose genicity Immunity ness

101-103 Embryo, day-oldchick heart, gizzard b 5.2-7.3 43/174 124/143 0/14 5.9 6/6 9/10 4/6

162-163 Day-old chick-heart

182 Day-old chick-heart

202 Day-old chick-heart

301 Day-old chick heart

5.4-8.3 0/ 54

6.0-7.5 0/ 12

42/ 51

12/ 12

62-8.3 2/ 24 16/ 24

5.8-7.6 0/ 6 5/ 6

a Tested by inoculation of 2 X 10,000 LDso (pathogenic virus, suckling mouse).b By seroneutralization tests.

after vaccination, using the modifiedHenderson-Galloway technique.

The results, given in Table 4, show thatwhile the modified live virus vaccine con-tinued to confer adequate protection againstits homologous virus, as shown by the pro-tection from generalized lesions (7/8), theprotection in this experiment against theVenezuela 1970 virus (2/9) was deficient.This seems to confirm the serologic resultsobtained by the Pan American Foot-and-Mouth Disease Center.

The inactivated vaccine was not testedagainst its homologous virus since the latterwas not available, but it is believed that itmay contain the subtype A, 7.

The results obtained using this vaccine atthe normal dosage of 10 ml, administeredsubcutaneously in cattle, were very similarto those produced by the modified live virusvaccine. Protection from generalized le-sions was 4/10. In testing the innocuity ofthe inactivated vaccine, four cattle wereused to obtain 80 negative results to theintradermolingual inoculation as a mini-mum requirement for vaccine innocuity.

Moreover, they were inoculated subcutane-ously with 50 ml, i.e., five times the normaldosage. Three of these cattle, which were ingood health, were also inoculated with theVenezuela 70 virus. They were all protectedfrom generalized lesions and had no locallingual lesions whatsoever.

Research will go on in order to find thedegree of protection of modified live virusvaccines with a greater antigenie content(107-5 and 108' 5 LD50/rl), as well as the ef-fects of revaccination and the duration ofimmunity.

Table 5 refers to the results obtained byPalacios et al. (cited by Palacios 7, 8) usingthe O Lara strain (type O Vallée, subtype03) modified by serial passages in embryo-nated eggs and day-old chicks. At passages162 and 163, a marked decrease in patho-genicity for cattle was recorded. Good im-munity in cattle inoculated with virus fromall the passages studied, with the exceptionof passage 202, was obtained. Susceptiblecattle in contact with vaccinated animalsdid not contract the disease. The patho-

6/6

6/6


TABLE 6-Experimental field application of foot-and-mouth disease in cattle in the enzootic zone ofCalabozo, Venezuela (passages 101-103 in embryonated eggs and day-old chicks, virus type O Vallée,subtype 03 strain O Lara).

Contagious-LD5o Pathogenicity ness

6.76.06.7

6.0-6.7

3/ 3,7297/ 6,4170/10,928

10/21,074

O

OO

Remarks

No contagiousness notedNo contagiousness notedOne bovine showed symptomsof anaphylactic shock

O

genicity of this virus for swine is very high,even at passage 301.

Table 6 summarizes data obtained byPalacios et al. (7, 8) in the experimentalapplication of the viruses of passages 101-103 in natural conditions in an enzootic zonein Venezuela. Only 10 cattle, or 0.05 per centof the 21,074 animals vaccinated showedfoot-and-mouth disease lesions. This re-markably reduced pathogenicity, in com-parison with the percentage mentioned inthe previous table, appears to be relatedto the fact that these animals had beenpreviously inoculated with inactivated vac-cine, from one to three years prior to theapplication of the modified live virusvaccine.

The production of modified live virusvaccine using the Lara strain of the O Valléevirus (modified by serial passages in day-old chicks and embryonated eggs) was be-gun at the end of 1964, using virus of pas-sages 101-103. The use of this vaccine ona large scale was followed by some post-vaccinal reactions. While the percentagesrecorded (0.3 to 1.5) were quite low incomparison with the total number of ani-mals vaccinated, they were higher than ex-pected in some farms, particularly amongpurebreed animals. Consequently, afterstudies made by the Veterinary ResearchCenter of Venezuela (mentioned previously,Table 5), a vaccine was administered in1965 which was prepared with virus frompassages 162 and 163 in day-old chicks.

Since that time, no adverse reactions havebeen reported in vaccinated cattle.

To maintain immunity, vaccination is ef-fected in Venezuela every six months. Fieldobservations, conducted since 1962, with theapplication of 39,706,042 doses of A24 Cru-zeiro vaccine and 33,470,602 of type O, sub-type O3 (Lara) and O, (Campos) (Table 7)seem to confirm that this interval is ade-quate. It has been observed that outbreaksoccurring during the 1962-1969 period inareas or farms where animals had beenvaccinated every five to seven months gen-erally have given evidence of good resist-ance to the disease. The same has held truein laboratory experiments in which animalsrevaccinated with the O0-Campos strainhave shown immunity for up to 10 months.

The most serious problem related to theapplication of modified live virus vaccine incattle was the appearance of anaphylacticshock. Preliminary data from a survey

TABLE 7-Vaccine doses against type A and OVallée of foot-and-mouth disease used in cattle inVenezuela, 1962-1969.

Vaccine dosesType of virus

Year A 0 Total

1962 801,640 - 801,6401963 3,663,445 - 3,663,4451964 4,135,510 2,067,755 6,203,2651965 4,716,355 4,716,355 9,432,7101966 4,222,550 4,519,900 8,742,4001967 8,444,677 8,444,677 16,889,3541968 6,369,200 6,369,200 12,738,4001969 7,352,715 7,352,715 14,705,430

Total 39,706,042 33,470,602 73,176,644

Year

196119621963

Total

No. of cattlevaccinated

3,7296,417

10,928

21,074

74


covering 18,275 animals revealed that thepercentage of anaphylactic shock was 1.5.In various areas, a considerable increasewas observed between the first and seconddoses of vaccine. According to a study of13 farms in the central region, the incidencerose from 0.03 per cent (2/5,739) to 2.1 percent (114/5,394) during the second vaccina-tion, an increase of about 70 times (Goic,cited by Palacios, 7, 8).

The studies carried out jointly at thePan American Foot-and-Mouth DiseaseCenter and the Venezuelan Veterinary Re-search Center resolved this problem by dis-covering that the anaphylactic reactionswere due to the antibiotics used in thevaccine (penicillin and streptomycin) (Qui-roz et al., 7, 8).

Once the vaccines were used without theseantibiotics, no anaphylactic reactions wereobserved during the administration of some35,000,000 doses of modified live virus vac-cine A,4 Cruzeiro and 33,400,000 doses oftype O in the years 1964-1969.

In 1965-1966, outbreaks of type O Valléevirus which principally affected swine werereported. When a higher incidence than wasexpected was produced in cattle in 1966,

more thorough serologic studies of the natu-ral strain were conducted. These studiesrevealed that the field virus was a differentsubtype from that commonly found in Ven-ezuela since 1950, and it was classified assubtype 03. This new virus had the serologiccharacteristics of the subtype 01.

The information obtained at the Veteri-nary Research Center (Bello, cited byPalacios, 8) indicated that the vaccine pre-pared with O Lara strain (subtype 03modified by passages 162 and 163 in day-oldchicks) provided from 80 to 100 per centprotection against the homologous virus invarious experiments with 25 head of cattle.These results confirmed once more thoseobtained previously by Palacios et al. Thesame vaccine, challenged with the heterolo-gous virus (new 01 strain), provided only28 per cent protection in experiments carriedout with 32 head of cattle.

The Pan American Foot-and-Mouth Dis-ease Center sent the O Campos strain (sub-type O1) modified in embryonated eggs toVenezuela for study. Research covered pas-sages 101, 74, and 72. From Table 8 it canbe seen that only passages 72 and 74 con-

TABLE 8-Results of immunological studies in Venezuela in cattledifferent vaccines of type O modified live virus.

Vaccine

0 CaR14 B2 E101

O CaR14 B2 E72

O CaR14 B2 E74

O CaR14 B2 E101O Lara P163

O CaR14 B2 E101

O Lara P163

Control animals

LDso/,rper dose

10'7/5ml106'9/5ml10."'/5ml

107.7/5ml103''/5ml10'-4/5ml

10'7/5ml

10'7./5m1l}10m

107'4 /5mlX 2

1077/5mlX 2

Pathogenicity

1/60/61/6

2/62/62/6

4/10

1/10

2/8

0/8

inoculated with

Immunity

1/63/63/6

4/54/65/6

7/9

2/10

3/8

0/8

0/8

Note: Test inoculation LD: 4 X 103, 4 LDso pathogenic virus modified in successive passagesin suckling mice.

75


ferred adequate protection against the newnatural strain. Likewise, it was apparentthat neither the vaccine prepared with amixture of the O Lara (03, passage 163)and the O Campos (01, passage 101), norrevaccination at two-week intervals withone or the other strain, offered sufficientprotection against the natural strain (4, 5).

According to information obtained fromthe Ministry of Agriculture and Livestockof Venezuela, no significant postvaccinalreactions were produced by the administra-tion of 22,000,000 doses of bivalent modifiedvaccine prepared with O Campos virus(passage 74) and Cruzeiro virus (passage80) from 1967 to 1969. Solid immunity,however, was obtained when the vaccinewas correctly applied and contained thenecessary minimum amount of antigen(about 10 .55 LD5o/rl per dose).

Observations made in 1967 in AraguaState, a dairy-farming area well controlledby means of periodic vaccination againstfoot-and-mouth disease (Romeda Rada,cited by Palacios, 8), indicated that the newvaccine applied to 19,744 head of cattle pro-duced very slight postvaccinal reactions in32 animals belonging to four farms whosebovine population was 1,578 head (2 percent). At the same time, it was noticed thatduring outbreaks of foot-and-mouth disease(type O) on two farms that raised bothcattle and swine (the former vaccinated),the disease affected only the swine.

In a study currently in preparation on theduration of immunity, Bernal, Balestrini,and collaborators report that in cattle re-vaccinated with bivalent modified live virus,Campos strain, passage 74, highly satis-factory immunity could be conferred forup to 10 montlis. This is based on thehigh percentage of protection (24/32) con-ferred against intradermolingually chal-lenged pathogenous virus.

Summary and Conclusions

Research on the various modified livevirus vaccines and their large-scale appli-cation in various parts of the world hasshown them to be one more weapon for usein the fight against foot-and-mouth diseasein cattle, independently or in conjunctionwith inactivated vaccines.

Applications in the Middle East, Africa,and South America have shown that in spiteof some postvaccinal reactions in cattle,their application in active foci has suc-ceeded in halting the disease or interferingwith its spread.

Some modified live virus vaccines haveeven shown an ability to immunize cattleagainst heterologous subtype viruses. Atruly interesting case is that of the A24

Cruzeiro strain which, at least in this study,has conferred protection against three dif-ferent subtypes (A18, A19 and A27). Re-vaccination produces a better and longerlasting immunity, which may endure al-most one year against homologous viruses.The application of polyvalent vaccines doesnot seem to increase pathogenicity nor tointerfere with the production of antibodies.

So far, there is no proof for attributingany outbreak of foot-and-mouth disease incattle to the modified vaccines; neverthe-less, it is important to point out that sub-type A24 has been applied in Venezuelasince 1962 without that virus ever havingbeen diagnosed in the field. It is interestingto note that when 01 virus appeared in thecountry in 1966, a vaccine produced with0, virus was being used. As for swine,Venezuela has had three cases of trans-mission of the 03 modified virus to thatspecies, which lives in close contact withthe cattle, one of which was corroboratedby laboratory tests. Three cases, however,do not represent a very significant figure ina vaccination campaign that administered

__76


39.7 million doses against type A Valléevirus and 33.4 million doses against type OVallée.

Immunity in young cattle continues to bea problem even with this vaccine, but stud-ies mentioned here seem to indicate thatmonthly vaccinations (three times) couldextend immunity up to five or six months.

Although the live virus vaccine consti-tutes a useful weapon, this does not meanthat there are not many other aspects thatrequire serious study. Perhaps the most im-portant is the development of a method thatpermits a rapid, short-term modificationof field strains which, because they are sodifferent from the subtypes in the vaccinesadministered, break the immunity impartedby the modified vaccines. Outstandingexamples are of those of Israel, where ani-mals were vaccinated with the modified Aostrain and the A22 strain appeared, and

Venezuela, where subtype O1 emerged whenanimals were vaccinated with 03. Anothersolution might be the establishment of aninternational center or organization thatwould have a bank of modified strains witha wide range of protection such as is thecase with the A2, Cruzeiro virus.

More thorough studies should be under-taken in connection with the problems ofcarriers and the survival of modified virusesin tissues. The modified strains should alsobe looked at more closely, since it appearsthat their behavior differs.

A certain number of markers for eachstrain are necessary in order to discover itsbehavior with regard to carriers and otherepidemiological problems. It is also neces-sary to increase research in order to betterunderstand the behavior of these modifiedstrains when they are utilized on other spe-cies of animals such as swine and sheep.

REFERENCES

(1) Augé de Mello et al. "Supervivencia enbovinos del virus modificado de la fiebre aftosa."Presented at the 5th Pan American Congress ofVeterinary Medicine and Zootechnics, Caracas,Venezuela, 1966.

(2) Bachrach, Howard L. "Foot and Mouth Dis-ease." Ann Rev Microbiol 22, 1968.

(3) Bernal, C. et al. "Estudio sobre la modifica-ción de una cepa de virus de fiebre aftosa (tipoA Vallée) y su utilización como vacuna." Presentedat the 5th Pan American Congress of VeterinaryMedicine and Zootechnics, Caracas, Venezuela,1966.

(4) Bernal, C., J. Balestrini, and I. Delgado.Unpublished data.

(5) Bernal, C. and J. Balestrini. Unpublisheddata.

(6) Galloway, I. A. "Results of the Use of TwoLive Attenuated Strain Vaccines RHO-1 (SAT2

Type) and RV-11 (SAT1 Type) in ControllingOutbreaks of Foot and Mouth Disease." BullOffice Int Epizoot 57(5/6): 748-788, 1962.

(7) Palacios, Carlos, Mário V. Fernandes, andC. Bernal. "Modified Live Virus Vaccine againstFoot-and-Mouth Disease." Document RES 5/16,presented to the PAUO Advisory Committee onMedical Research, June 1966.

(8) Palacios, Carlos. "Estudios sobre vacunasde virus vivo contra la fiebre aftosa." Bol OficSanit Panamer LXIV(5), May 1958.

(9) Viljoen, J. H. B. "The Successful Use ofAttenuated and Inactivated Foot and Mouth Dis-ease Vaccine in Major Epizootic." Bull Offce IntEpizoot 61:9-10, 1964.

(10) Veterinary Research Center, Venezuela.Several authors. Unpublished research data.

(11) Report of the Pan American Foot-and-Mouth Disease Center, July 1969.

77

ACCIDENTS AND REACTIONS OBSERVED INFOOT-AND-MOUTH DISEASE VACCINATIONS

PROFESSOR MANFRED W. MUSSGAY *

A discussion of the accidents and re-actions that may be observed after vac-cination of cattle against foot-and-mouthdisease demands a short description of thekinds of vaccines most frequently used inthe field. Table 1 offers a schematic survey.In principle, we must distinguish between"inactivated vaccines" and "live vaccines."The latter were discussed in detail by Dr.Palacios. I shall restrict my contribution tothe "inactivated vaccines." These are basedon the classical Waldmann-Kobe-Pyl vac-cine which consists of virus harvested fromtongue lesions of infected cattle; the virus isadsorbed onto colloidal aluminum hydrox-ide and is then inactivated by formalin andheat. Later, Frenkel replaced the costlysource by growing the virus in surviving

* President, Federal Research Institute for Ani-mal Virus Diseases, Tibingen, West Germay.

TABLE 1-Types of foot-and-mouth disease vaccine

Type Virus source

Waldmann-Ktbe-Pyl Aphthae of catt

Frenkel Cultured tonguiepithelium of ca

Inactivated Tissue culture:vaccines Permanent cell lines

Baby hamster kidney(BHK)

fragments of bovine tongue epithelium.With the development of cell monolayercultures in which virus can propagate, itbecame possible to use them also for theproduction of foot-and-mouth disease virus.At present, permanent cell lines, mostlyBHK-21 cells cultivated on glass surfacesor in suspension, and primary cultures de-rived from calf kidney are used. Further-more, some industrial houses and laborato-ries changed the inactivation procedure;inactivation in these places is performed byusing acetylethylenimine, ]3-propiolactone,or hydroxylamine. Finally, an attempt wasmade to replace aluminum hydroxide bysaponin or-as is done frequently-to en-hance the adjuvant effect of aluminum hy-droxide by the addition of saponin. Consid-ering the accidents and reactions, it shouldbe mentioned that foot-and-mouth disease

frequently used for vaccination of cattle.

Adjuvants,Inactivation

Formalin and heat

Formalin and heat

AcetylethylenimineFormalinfl-propiolactoneHydroxylamine

adsorbents

Aluminum hydroxide


Aluminum hydroxideSaponinOil adjuvants

Primary cultures Calf

Attenuated by passages in:Live Suckling or adult mice;vaccines rabbits;

eggs; eggs and chicken;calf kidney cell cultures.

fkidney

78

Foot-and-Mouth Disease Vaccines-Accidents and Reactions

vaccines, besides their three main ingredi-ents (virus, substance used for inactivation,and adjuvant), contain organic matter de-rived from the tissue or cells used for viruspropagation, and they may also containadmixtures such as antibiotics, tissue cul-ture fluid, glycerol, vitamins, polyglycols,methyl cellulose, Tween-like compounds,and silicons.

Postvaccinal complications can generallybe classified into three main groups, as listedin Table 2 (3). Complications in groups 1and 2 occur very rarely, provided that in-nocuity and immunizing potency of the vac-cines are controlled by forceful regulationsbefore their use in the field. Most accidentsand reactions are due to so-called vaccinaldamages; they include allergic reactions,disturbances of pregnancy, local reactionsat the site of inoculation, stress caused bythe mere act of vaccination, and changes inmilk quality. Considering first the influenceof a foot-and-mouth disease vaccination onthe quantity and quality of milk, it can bestated (6) that vaccination usually does notlead to a reduction of the quantity, but thatthere may be an increase in the fat concen-tration, a prolongation of the lab-coagula-tion time, and a decrease of protein andsodium contents in the first two milkingsafter vaccination. Local reactions at thesite of inoculation occur regularly and aremainly caused by the aluminum hydroxide(4). These tissue reactions may on rareoccasions become infected and result in theformation of local abscesses, or phlegmons,but they usually disappear within weekswith no complications. Stress caused by theact of vaccination is a small risk associated

TABLE 2-Postvaccinal complications.

1) Disease due to unsafe vaccine, i.e., vaccinewhich still contains residual infectious virus.

2) Foot-and-mouth disease infections due to in-complete immunity.

3) Vaccinal damages.

with any injection. whatsoever and thuswarrants no comment. The most severevaccinal damages are due to allergic re-actions and to abortions.

Considering the allergic reactions, wemust distinguish between reactions of theimmediate type and of the delayed type.

Allergic reactions of the immediate typeappear within seconds to minutes or witha delay of six to eight hours after vaccina-tion (3). They are clinically characterizedby restlessness, sweating attacks, trembling,asthmatic coughs, angino-neurotic edemasdeveloping at eyelids, lips, the vagina, lungs,the brain, and joints; furthermore, saliva-tion, acute circulatory insufficiency, shock,and local or generalized swelling of the skinwith a nettle-rush-like urticaria are ob-served. The urticaria is often overlookedbecause it frequently disappears after oneto two hours. Usually, all low- to high-grade skin reactions fade away five to sixhours after their appearance, without anymedical treatment. Animals showing theshock syndrome may suddenly die. Iftherapy is necessary, antihistaminics, cor-tisone, circulation drugs, and sodium bi-carbonate may prove beneficial.

The clinical picture of the delayed-typereactions is characterized by weeping ec-zema, which may be local or generalized(3). These eczemas appear from severaldays up to three weeks after vaccinationand may persist for a number of weeks.They are seen at the neck, dorsum, vulvaregion, udder, hind extremities, and mouthregion. In the latter case, the first symp-toms may be confused with foot-and-mouthdisease, mucosal disease, and malignantcatarrhal fever.

A significant increase in the frequency ofallergic reactions after foot-and-mouth dis-ease vaccination was observed in 1967 and1968 in the Federal Republic of Germany.In 1967 a program was begun in which all

79


cattle more than six weeks old were vac- type reaction increased. The data from thecinated once a year with trivalent vaccines other states of the Federal Republic (5) arecomposed of inactivated foot-and-mouth based on an upper estimate and demon-disease virus types O, A, and C. In the strate, as in Bavaria, that the percentagescourse of this program, 14 to 15 million of vaccinated animals showing symptomscattle are to be vaccinated each year. First of allergic reactions were higher in the tworeports (3) on the increase of allergic re- groups of animals immunized with BHK-action came from Bavaria in 1967 and were type vaccines than in the two groups ofsoon confirmed from other states of the animals immunized with one of the twoFederal Republic (5). It was noticed that Frenkel-type vaccines. By 1969 most of theallergic reactions occurred more frequently animals had been vaccinated with Frenkel-in cattle vaccinated with BHK-type vac- type vaccines; as a result, the incidence ofcines than in those immunized with Frenkel- allergic reactions dropped by a factor oftype vaccines. This is illustrated in Table 3. about 10 as compared with the groups ofIt can be seen that in Bavaria in 1967 animals vaccinated with BHK-type vac-3,021,758 cattle were immunized with a cines in 1967 and 1968 (5). SummarizingBHK-type vaccine; 33 out of 100,000 vac- the data presented, it is evident from Tablecinated animals responded with an allergic 3 that immunization with BHK-type vac-reaction of the immediate type, i.e., 996 ani- cines was followed by a significantly highermals. Nine out of 100,000 showed symptoms incidence of allergic reactions than was im-of a delayed-type reaction; in this group, munization with Frenkel-type vaccines. Al-1,238 cases of abortion were reported, i.e., lergic reactions after BHK-typevaccination41 cases in 100,000 vaccinated animals (3). occurred in the range between 0.07 andBy comparison, vaccinal damages were less 0.09 per cent; reactions of the delayed-typefrequently encountered in the group of ani- were predominant, reaching values betweenmals immunized with a Frenkel-type vac- 0.05 and 0.08 per cent.cine. In the following year, 1968, the num- The observations mentioned raise threeber of animals responding with a delayed- main questions:

TABLE 3-Allergic reactions and disturbances of pregnancy after foot-and-mouth disease vaccination.

State

Bavaria

Fed.Rep.Germany

Year

1967

1968

1 Sept.1967to

May1968

kexcluang 1 Dec.Bavaria) 1968

toAug. 1969

Typesof

vaccines

BHK IFrenkel I

BHK IFrenkel I

BHK IBHK IIFrenkel IFrenkel II

Frenkel IFrenkel II

Number ofvaccinated

animalsused for

statisticalevaluation

3,021,7581,192,502

3,093,6501,169,084

Allergic reactions(number of affectedanimals in 100,000

vaccinated animals)

Immediatetype

332

136

1,203,9681,615,803

730,022221,807

24413

3,660,7811,840,705

Delayedtype

9o

79o

481722

4 35 4

Disturbancesof pregnancy(number of af-fected animals

in 100,000vaccinated

animals

4125

1714

80(?)2

125

45

80

Foot-and-Mouth Disease Vaccines-Accidents and Reactions

1. Is there a relationship between allergicreactions and disturbances of pregnancy?

In my opinion, this question cannot be an-swered at present, nor can a definite decisionbe made whether disturbances of pregnancy andabortions occur more frequently after vaccina-tion with Frenkel-type vaccines than afterimmunization with BHK-type vaccines. Fur-thermore, it cannot be determined whetherdisturbances of pregnancy are due to the foot-and-mouth disease vaccines themselves or to themanipulations in the course of vaccination.

2. Why did a significant increase of allergicreactions in animals vaccinated with BHK vac-cines occur in Germany, whereas in other coun-tries which also used this type of vaccine on aregular schedule such an increase was not re-ported?

I must confess that I have no explanation forthis situation. Several speculations have beenput forth, but none is based on the results ofclear-cut experiments.

3. What is the cause of the allergic reactions?Experiments were performed (3) in which

substances used for the production of foot-and-mouth disease vaccines were tested for theirpotency to induce allergic reactions of the im-mediate type. The compounds tested includedantibiotics, emulgators, suspension stabilizingsubstances, antioxidants, and heterologous as wellas formalin-treated homologous bovine proteins.Guinea pigs, goats, and calves were sensitizedwith these substances and were then used foractive systemic anaphylaxis and active cutaneousanaphylaxis tests. Moreover, passive cutaneous

TABLE 4-Inducers for allergic reactions

Preparations used Immediate typin the experiments reaction

Calf serumCalf serum

Formalin-treatedAntibioticsEmulgators (cremophor,

methylcellulose, sodiumcarboxymethyl cellulose,carbowax)

Purified foot-and-mouthdisease virus

Extracts of:Primary calf kidneyPrimary calf kidneyformalin-treated

BHK cellsBHK cells

chloroform-treated

+++

anaphylaxis and a precipitation test in a liquidmedium were applied. Sensitized cattle of thefield were also subjected to active cutaneousanaphylaxis tests with the substances mentionedand to purified foot-and-mouth disease virus,extracts of primary calf kidney cells, and BHKcells, respectively (3, 2).

Table 4 summarizes the results. The experi-ments clearly demonstrated (3, 2) that animalsrepeatedly sensitized by BHK vaccines re-sponded frequently with an immediate-type reac-tion after administration of formalin-treatedcalf serum. In some cases an immediate-typereaction was observed after injection of extractsof BHK cells and of formalin-treated extracts ofprimary calf kidney cell cultures. Antibiotics,saponin, and suspension stabilizing substancesare able to act as inducers of an allergic state ofthe immediate type (3), but in the incidencesobserved in Germany they played only a minorrole. An interesting observation is that bothBHK- and Frenkel-sensitized animals showedmanifestations of reaction after the applicationof infectious as well as inactivated purified typeO foot-and-mouth disease virus (3, 2). Cutane-ous reactions using animals sensitized by BHKvaccinations and performed with extracts de-rived from primary calf kidney cell cultures andfrom BHK cells demonstrated that BHK-typevaccines induce hypersensitivity of the delayedtype to components of BHK cells but not tomaterial of primary calf kidney cell cultures. Inanimals sensitized with Frenkel-type vaccine anallergic response could be elicited neither with

i of the immediate and delayed types.

Delayed typereaction

+/-

+

+

+/-

+

+

Comments

Strong inducersInfrequentInfrequent

Frequent

Occasional

Strong inducers

Occasional

81

Vaccines lor Foot-and-Mosuth Disease Control

extracts of BHK cells nor with native materialof primary calf kidney cell cultures.

Concerning the components of BHK cells ableto induce hypersensitivity, we obtained evidencethat the extracts of BHK cells contain at leasttwo active substances, one of which can beeliminated by a combined treatment with chloro-form and arcton and which is therefore consid-ered to be a lipoprotein in nature (2). BHKvaccines with a weak capacity for sensitizationcan be obtained if the virus is precipitated withpolyethylene glycol, leaving about 90 to 95 percent of the protein impurities-including thenonviral inducers for allergic reaction-in thesupernatant (1).

In conclusion one can say that allergicreactions of the immediate and delayedtypes can occur after vaccination with bothBHK-type and Frenkel-type vaccines. Theover-all frequency of the complications isusually not high; such complications occurmore frequently in animals vaccinated withBHK-type vaccines than in those immu-nized with Frenkel-type vaccines. In 1967and 1968, in the Federal Republic of Ger-many an unusual increase of allergic re-actions was observed in cattle immunizedwith BHK vaccines, necessitating effortsto diminish their application. As a conse-quence of the investigations immediatelyperformed, the following proposals can bemade:

1. Vaccines used for a vaccination pro-gram on a regular schedule should be puri-fied with regard to nonviral proteins. Thisconsideration applies mainly to vaccinesprepared with virus grown in permanentcell line cultures.

2. Inactivation by formalin shguld bereplaced by other means.

3. Vaccine admixtures should be tested

before use in order to eliminate substancesinducing an allergic state or anaphylactoidreactions.

4. Under special circumstances it maybecome necessary in the course of system-atic vaccinations to change the kind of cellsused for vaccine production. There is someevidence that even differences between vari-ous BHK cell lines exist with regard toinduction of an allergic state.

Finally, I would like to comment brieflyon reactions in pigs after foot-and-mouthdisease vaccination.

Inactivated foot-and-mouth disease vac-cines used for immunization of cattle do notcommonly induce a sufficient immunity inpigs. However, recent investigations withvaccines containing an oil adjuvant haveshown that a high degree of protection canbe induced in pigs. Unfortunately, suchvaccines often produce a lesion at the siteof injection, and this makes their routineapplication for animals used for meat pro-duction unacceptable at present. Work is inprogress to overcome this drawback. In ourInstitute, we found (7) that the oil adjuvantcan be replaced by DEAE-dextran, whichdoes not produce such severe tissue re-actions as those observed after the applica-tion of an oil adjuvant.

Although several kinds of accidents andreactions may occur after foot-and-mouthdisease vaccination, there is no reason torefrain from the use of this preventive mea-sure in combating the disease. Continuousefforts to improve the vaccine quality maylead to a situation in which such accidentsand reactions will be virtually negligible.

BIBLIOGRAPHY

(1) Bahnemann, H. Personal communication.(2) Bauer, K., O. R. Kaaden, and M. Mussgay.

Untersuchungen iber Allergien vonm Spáttyp nach

der Schutzimpfung von Rindern mit Maul- undKlauenseuche (MKS)-Vakzinen (in preparation).

(3) Mayr, A., J. Ringseisen, G. Baljer, B. Bib-

82

Foot-and-Mouth Disease Vaccines-Accidents and Reactions 83

rack, J. Wallner, and H. Zimmer. Untersuchungeniber Art, Umfang und Ursachen der Impfschadennach der Maul- und Klauenseuche-Schutzimpfungin Bayern in den Jahren 1967/68. Zbl Veterinaer-med (B) 16:487, Berlin, 1969.

(4) Rohrer, H. Maul- und Klauenseuche. In:Handbuch der Virusinfektionen bei Tieren. Bd. II,VEB Gustav Fischer Verlag, Jena, S. 23, 1967.

(5) Statistical Survey of the Federal ResearchInstitute for Animal Virus Diseases, Tibingen,1968 and 1969.

(6) Terplan, K., G. H. Emde, H. Otto, O. Raeth,

R. Trost, and J. Zaadhof. Zum Einfluss der MKS-Schutzimpfung auf Zusammensetzung und Ver-arbeitungsfahigkeit der Milch unter Bericksich-tigung der Vertraglichkeit verschiedener Vakzinen.Tierárztl. Umschau 24:6, 1969.

(7) Wittmann, G., K. Bauer, and M. Mussgay."Versuche zur Schutzimpfung von Schweinen mitVakzinen aus inaktiviertem Maul- und Klauen-seuche-(MKS)-Virus. II. Versuche mit Aethyl-aethylenimin (EEI)-inaktiviertem Virus undDiaethylaminoaethyl-Dextran (DEAE-D) als Ad-juvans." Arch Ges Virusforsch 29:139-159, 1970.

NEW VACCINES AND FUTURE PROSPECTSIN FOOT-AND-MOUTH DISEASE IMMUNIZATION

DR. JERRY J. CALLIS *

It gives me particular pleasure to speakto you at this III Inter-American Meetingon Foot-and-Mouth Disease and ZoonosesControl. I am grateful to the Pan AmericanSanitary Bureau for the opportunity to pre-sent to the delegates of the countries repre-sented at this meeting information on foot-and-mouth disease vaccines and futureprospects on immunization and vaccinetesting. Many of you are no doubt con-sidering changes in some aspects of yourprogram, and all of us present here arehopeful that our comments and the discus-sion to follow will be useful.

Foot-and-mouth disease must be consid-ered a world problem if progress is to bemade in controlling its spread. No countryor region may maintain an isolationistpolicy, for the virus does not respect na-tional boundaries. A campaign against it ishandicapped if it is waged piecemeal and ifeach country or part thereof acts as thoughit were a self-contained unit. Internationalcollaboration is essential for the effectivecontrol of this disease (1).

In the Americas, the necessity for co-ordinated action for the prevention andcontrol of the disease on an extensive ter-ritorial basis was recognized and imple-mented by the initiative of certain membercountries of the Organization of AmericanStates. This resulted in 1951 in the creation

* Director, Plum Island Animal Disease Labora-tory, U.S. Agricultural Research Service, Green-port, Long Island, New York.

of the Pan American Foot-and-Mouth Dis-ease Center as a project of the Pan Ameri-can Sanitary Bureau. Thus at that time theBureau, through its Center located nearRio de Janeiro, joined other internationalorganizations such as the International Of-fice of Epizootics, the Food and AgricultureOrganization of the United Nations, and theEuropean Commission for the Control ofFoot-and-Mouth Disease-all of whichwere formed to take international actionin regard to this problem.

The virus has the ability to spread rap-idly and, as a consequence, causes economicproblems in the country in which it existsbecause of its effect on meat, milk, andbutter. It therefore interferes with tradewherever it occurs, and it is safe to say thatthe price of almost every animal product onthe world market is in some way affected bythe disease. Perhaps the greatest loss re-sults from interference with the normalimport and export trade of animals andproducts of animal origin and other farmproducts. Such interference takes the formof rigid restrictive measures that must beapplied for control or eradication or ofactions adopted by disease-free countriesagainst products from infected countries(2).

In countries where the disease exists spo-radically, control is brought about by eradi-cation of the infected animals. Generallyspeaking, countries with land boundarieshave to contend with a different set of cir-

84

New Vaccines and Future Prospects in Immunization

cumstances and, in these instances, evenif it were possible to control the diseasethrough slaughter, there is a question ofwhether the countries' neighbors would al-low them to remain free. Thus, the diseaseincidence in these countries is usually con-trolled by procedures that include vaccina-tion. For this reason, it is apparent thatthe problem of developing an improved,cheaper, and more rapidly produced vac-cine must receive continuing attention. Allthe Governments and international organi-zations involved in the control of the dis-ease are generally agreed on the urgentnecessity of more effective control leadingto lower incidence of the disease, with thehope of ultimate eradication.

There are generally two types of foot-and-mouth disease vaccines in use today:inactivated and modified live virus. Thelatter is used routinely in only a few coun-tries that do not export meat. Those coun-tries that have a surplus of meat use in-activated virus vaccines because manymeat-importing countries will not acceptmeat from countries where modified livevirus foot-and-mouth disease vaccines havebeen used, for fear that such products maybe harboring the modified virus.

During the last calendar year, accordingto estimates, more than 500 million doses ofinactivated foot-and-mouth disease vaccinewere produced and used throughout theworld. It is further estimated that 300 mil-lion doses were used in South America. Inaddition to the inactivated vaccine, another5 to 10 million doses of living virus vac-cine were applied in a limited number ofcountries.

Several types of modified live virus vac-cines have been developed. Two have beenused more widely than the others. One,developed by modifying the infectivity ofthe virus by passage in suckling mice, wasused in some of the African nations. The

other, which is being routinely used, is pro-duced in day-old chickens or embryonatedchicken eggs. A description of this productis given elsewhere in this program (3).

Although modified or live virus foot-and-mouth disease vaccines have never beenused widely, research is continuing on suchproducts in a limited number of places. Forvirus infections in general, live virus vac-cines stimulate a longer-lasting immunityand protection against a wider antigenicspectrum than do inactivated vaccines. Thisfactor is important when a virus as variableas that of foot-and-mouth disease is con-sidered. Live virus vaccines may also offerconsiderable cost advantages over inacti-vated virus vaccines. Unfortunately, how-ever, the foot-and-mouth disease live virusvaccines thus far developed have not fullymeasured up to the goals that were set andtherefore have never been widely used.

In spite of these disappointments, re-search is continuing in an effort to developmodified strains of the virus which, wheninoculated into animals naturally suscepti-ble to foot-and-mouth disease virus, willreplicate sufficiently to stimulate a highlevel of immunity, yet not produce clinicalsigns of the disease. Work is continuingalong the classical lines of serially passag-ing viruses in various mediums in the hopethat a nonvirulent but immunogenic straincan be developed. Newer techniques arebeing tried, including the isolation of viruspopulations that grow in the cold, the se-lection of viruses that produce characteris-tic plaques in tissue culture systems, andthe induction of mutagenesis by chemicaland physical means. Even though the pros-pects for success are not bright, efforts arecontinuing and should be encouraged be-cause of the benefits which would accruefrom the use of such products in some areasof the world where the costs of inactivatedvaccines might be prohibitive.

85


Inactivated foot-and-mouth disease vac-cines have been in use for more than 30years. The methods of production havebeen changed at frequent intervals to en-compass new techniques. Most of the in-activated vaccine in use today containsvirus which is propagated by the Frenkeltechnique, in explants of surviving bovinetongue epithelium. Generally, the virus isinactivated with formalin and adjuvantedwith aluminum hydroxide. In some in-stances, saponin is added for its reportedimmune-enhancing properties. When prop-erly prepared, tested, and applied, vaccinesof this type are capable of reducing thedisease incidence to the point of eradication.

Several changes are being suggested andconsidered in the formulation of the in-activated foot-and-mouth disease vaccine.Of the several methods available for virusproduction, it appears that propagation ina tissue culture system may be used in-creasingly, especially in those countrieswhere the demand for vaccine may exceedthe available tongue tissue supply andwhere the technology for virus productionexists. Virus produced by this method maybe readily incorporated into a vaccine withlittle additional processing other than cen-trifugation and inactivation. This methodcontrasts with the mincing, extraction, andfiltration steps which are necessary withvirus produced by the Frenkel method.

Traditionally, formaldehyde has beenused to inactivate foot-and-mouth diseasevirus, either before the virus is adjuvantedor more often after adjuvanting with alumi-num hydroxide. The kinetics of inactiva-tions of formaldehyde have been studiedthoroughly and, because of variability ofthe rate, it is difficult to predict when in-activation is complete. The time of inacti-vation is generally thought to be longer thanthat taken into account by most vaccineproducers. In these instances, the virus that

is not inactivated by the formaldehyde isprobably masked by the aluminum hydrox-ide. Because of the variability of the rateof inactivation by formalin and the possibleinteraction of formalin and aluminum hy-droxide on the virus, a search for a betterinactivant goes on constantly. Among thosebeing studied, acetylethylenimine seems tobe the current new inactivant of choice be-cause of its first-order inactivation curveswithout a secondary or tailing effect (4).Ethyl-ethylene imine is also being widelyresearched and appears promising (5).These inactivants seem to be free of reac-tions which affect the immunizing proper-ties of the virus. Recently, formaldehydehas become suspect as one of the causes ofpostvaccinal complications which have beenobserved with some products. Two types ofreactions occur-the immediate anaphylac-tic type and the delayed cutaneous type (6).These reactions are being studied, and ifformaldehyde continues to be implicated asthe cause, a change to other inactivants willbe made, perhaps sooner than otherwisewould have happened.

Aluminum hydroxide has been the ad-juvant of choice for foot-and-mouth dis-ease vaccine for more than 30 years. Theenhancing effects of this colloidal adjuvanthave been well demonstrated. Recently, in-complete Freund's adjuvant, consisting ofpharmaceutical-grade mineral oil and Ar-lacel, has been used with good results inswine (7). There are, however, some prob-lems with this adjuvant which must be re-solved before it can be placed in wide-scaleuse. Methods must be developed for pro-duction of the emulsion on a commercialscale; the reactions which develop in somevaccinated animals must be diminished; orthe animals must be vaccinated where thereaction is not objectionable. Aside fromthese problems, this adjuvant seems to en-hance the immunizing properties of some

86


antigens better than aluminum hydroxidedoes and over a longer period of time. Ithas been especially useful in swine. Quiterecently DEAE-dextran has been used as anadjuvant with good results, from the stand-points of both enhancement of immunityand freedom from local reaction in thevaccinated animal (8).

Concentrated and purified foot-and-mouth disease virus (9) is now being pro-duced by various methods, and virus devel-oped by these means seems to offer severaladvantages over that contained in tissueculture fluid (10). Perhaps most impor-tantly, it permits accurate quantitation ofviral mass, and as soon as more informationis obtained it should be possible to relatethis to the antigenic mass necessary to im-munize against a given type of virus. It isalso possible to include a large antigenicmass in a small volume, thus reducing theproblems associated with handling largevolumes of a vaccine. This procedure shoulddiminish the problems which might becaused by the adjuvant, as well as theallergic problems being encountered as aresult of the interaction of formaldehydeand proteins in the tissue culture fluid. Useof purified antigens in vaccines must, how-ever, await development of economicalmeans of production by one of the severalmethods being researched. Such methodsinclude precipitation with ammonium sul-fate, differential centrifugation, treatmentwith sodium deoxycholate, sucrose gradientcentrifugation, precipitation with polyeth-ylene glycol, and foaming.

Methods for producing milligram quanti-ties of concentrated and purified foot-and-mouth disease virus were necessary beforethe chemical, physical, and immunologicalproperties of the virus could be assessed.The virus has been determined to be about23 millimicrons in diameter and is made upof 32 capsomeres, which appear to form a

symmetrical capsid for the ribonucleic acidcore of the virus (11). Studies are nowbeing made on the peptide and amino-acidcomposition of foot-and-mouth disease vi-rus, and although these studies have barelygotten under way, significant differenceshave been demonstrated in the amino-acidcompositions of virus types A, O, and C(12). Work is being carried forward to findmethods for the preparation of artificialantigens, which give rise to antibody pro-duction against natural protein antigenssuch as those of simple viruses. Synthesisof an artificial antigen against foot-and-mouth disease virus is a hope for the future.

The primary structure of the protein coatof the virus is being studied, and it remainsto be seen whether any of the peptides haveimmunological activity. It is hoped that oneof them will have the same antigenicity asthe intact virus. In this event, knowledgeabout the amino acids and their arrange-ments would be a prerequisite to attemptsat synthesis.

This discussion would not be completewithout considering the role or potential ofinterferon in control of foot-and-mouthdisease (13). Its use as a possible means ofprotecting animals against a number of vi-rus infections is now attracting the atten-tion of many scientists throughout theworld. Interferon, a substance normallyproduced by cells in response to virus infec-tion or stimulation by nonviral agents, iscapable of protecting other cells againstinfection by a variety of viruses. It differsfrom specific antibody in that its effect isnot restricted to one virus type, it does notaffect the virus directly, and it is producedearlier during infection than antibody.However, the effectiveness of interferon ismeasured in days, or at most a few weeks,whereas antibody is effective for monthsand even years.

Several interferon inducers are being used

87

Vaccines jor Foot-and-Mouth Disease Control

against viruses. These are synthetic poly-anions, double-stranded RNA, other vi-ruses, bacteria, endotoxins, rickettsiae, fun-gal extracts, and mutagenic agents. Theproblems that remain to be resolved beforethese agents can be useful against foot-and-mouth disease virus include demonstrationof products that (1) are nontoxic and non-infective, (2) are not permanently incor-porated into animal cells, (3) will stimulateenough interferon for sufficient duration,(4) have no carcinogenic potential, (5)have acceptable costs, and (6) possess over-all safety. All products under investigationfall short on one or more of these criteria.However, there is sufficient hope of resolvingthese problems to warrant more research.

In addition to stimulating interferon,some of these compounds, especially thepolynucleotides, have had the capacity ofrepairing or stimulating the immune re-sponse. The stimulatory effects of theseproducts on foot-and-mouth disease anti-gens are being tested, and the preliminaryresults are encouraging. In one instance, anoninfective component of foot-and-mouthdisease virus has been complexed withbovine serum albumin and shown to invokeantibody response against foot-and-mouthdisease virus in rabbits. Similar work isunder way on using Poly I:C and Poly AUfor enhancing inactivated vaccines. Theseproducts are being investigated to learnwhether preliminary findings from labor-atory animals will prevail when the princi-ples are applied in animals naturally sus-ceptible to foot-and-mouth disease.

The importance which this group attaches

to the testing of foot-and-mouth diseasevaccines is amply demonstrated by the factthat a subcommission on foot-and-mouthdisease of the regional technical commissionon animal health was convened in BuenosAires during March 1969 to make recom-mendations on this general subject. It willbe neither possible nor necessary to repeattheir recommendations here; nevertheless,some important points should be amplified.The provision of means to determine anti-gen content, vaccine innocuity, and potencyis the first step that those responsible fororganizing or improving campaigns shouldconsider. Innocuity and potency testsshould be conducted on each and everybatch of vaccine produced. It is highlydesirable that such tests be conducted inthe species of animal which the product isintended to protect. The potency testsshould be carried out in such a way as toensure that the vaccine provides protectionagainst the type and subtypes of virus oc-curring in the field and is of adequate po-tency to produce a high degree of produc-tion. The tendency among vaccine producers(14) is to evaluate the potency in terms ofprotective doses. When these steps arefollowed systematically, the duration of im-munity will become more prolonged witheach subsequent vaccination. An inherentpart of vaccine control is a separation ofresponsibility through the establishment oflaboratories whose responsibility is to cer-tify vaccines, not to become involved in theproduction or application of the productsbeing tested.

REFERENCES

(1) Mohlman, HI. "Der derzeitige Stand der (2) Callis, J. J., P. D. McKercher, and J. H.Forschung uber das Virus der Maul- und Klauen- Graves. "Foot-and-Mouth Disease-A Review."seuche. Arch Exp Veterinaermed 8:316-393, 1954. J Amer Vet Med Ass 153:1798-1802, 1968.

88


(S) Palacios, Carlos A. See this volume, pp. 58-77.

(4) Bachrach, H. L. '"Foot-and-Mouth Disease,"Ann Rev Microbiol 22:201-244, 1968.

(5) Wittmann, G., K. Bauer, and M. Mussgay."Versuche zur Schutzimpfung von Schweinen mitVakzinen aus inaktiviertem Maul- und Klauen-seuche-(MKS)-Virus. II. Versuche mit Aethyl-aethylenimin (EEI)-inaktiviertem Virus und Di-aethylaminoaethyl-Dextran (DEAE-D) als Adju-vans." Arch Ges Virusforsch 29:139-159, 1970.

(6) Mayr, Anton and Manfred W. Mussgay."Investigations on Complications Observed afterVaccination of Cattle against Foot-and-MouthDisease." European Commission for the Controlof Foot-and-Mouth Disease. Report of the Meet-ing of the Research Group of the Standing Tech-nical Committee at the Zooprophylactic Experi-mental Institute, Brescia, Italy, 24-28 September1969. Rome: Food and Agriculture Organization,1970, pp. 200-212.

(7) McKercher, P. D. and P. Gailiunas. "Re-sponse of Swine to Inactivated Foot-and-MouthDisease Vaccine." Arch Ges Virusforsch 28:165-176, 1969.

(8) Mussgay, Manfred W. "A Potent Inacti-vated Foot-and-Mouth Disease Vaccine for Pigs."European Commission for the Control of Foot-and-Mouth Disease. Report of the Meeting ofthe Research Group of the Standing TechnicalCommittee at the Zooprophylactic ExperimentalInstitute, Brescia, Italy, 24-28 September 1969.Rome: Food and Agriculture Organization, 1970,pp. 191-199.

(9) Polatnick, J. and H. L. Bachrach. "Produc-tion and Purification of Milligram Amounts ofFoot-and-Mouth Disease Virus from Baby Ham-ster Kidney Cell Cultures." Appl Microbiol 12:368-373, 1964.

(10) Morgan, D. O., P. D. McKercher, andH. L. Bachrach. "Immunogenicity of Nanogram toMilligram Quantities of Inactivated Foot-and-Mouth Disease Virus. II: Comparative Responseof Guinea Pigs and Steers." In: Proceedings,U.S. Livestock Sanitary Association, 72nd AnnualMeeting, pp. 407-415, 1969.

(11) Bachrach, H. L., and S. S. Breese, Jr. Puri-fication and Electron Microscopy of Foot-and-Mouth Disease Virus." Proc Soc Exptl Biol Med97:659-665, 1958.

(12) Bachrach, 1I. L. and J. Polatnick. "Amino-Acid Composition of Three Immunological Typesof Foot-and-Mouth Disease Virus." Proc SocExptl Biol Med 124:465469, 1967.

(13) Richmond, J. Y. and L. D. Hamilton."Foot-and-Mouth Disease Virus Inhibition In-duced in Mice by Synthetic Double-Stranded RNA(Polyriboinosinic and Polyribocytidylic Acids)."Proc Nat Acad Sci 64:81-86, 1969.

(14) Brooksby, J. B. "Some Notes on the DoseResponse Relationship." European Commissionfor the Control of Foot-and-Mouth Disease. Re-port of the Meeting of the Research Group of theStanding Technical Committee at the Zooprophy-lactic Experimental Institute, Brescia, Italy, 24-28September 1969. Rome: Food and AgricultureOrganization, 1970, pp. 32-37.

89

PART III

HEALTH ASPECTS OF THE IMPORTAND EXPORT OF ANIMALS AND ANIMAL

PRODUCTS INTENDED FOR CONSUMPTION

PRESENT STATUS OF THE PRODUCTION AND CONSUMPTIONOF ANIMAL PRODUCTS IN THE HEMISPHEREAND PROSPECTS IN THE NEXT TEN YEARS

JOSÉ J. CAÑÓN *

Despite the vast natural resources exist-ing in Latin America for a greater develop-ment of the livestock industry, productionin this basic sector of the economy is visiblystagnated in most of the countries. This isparticularly true in the case of beef andmilk, whose production per inhabitant hasbeen deteriorating year after year, as a re-sult of which consumption levels havedropped and the participation of LatinAmerican meat on the international markethas decreased. Considering Latin Americaas a whole, this stagnation of the livestocksector constitutes a serious obstacle to agri-cultural development and to economic de-velopment in general. Studies carried outby the Food and Agriculture Organizationof the United Nations (FAO), the EconomicCommission for Latin America (ECLA),and other international agencies havepointed out the factors responsible for theslow growth of livestock production, andat the same time the great possibilitiesexisting in Latin America for stepping upthat production to meet both domesticrequirements and the continuously expand-ing overseas demand.

The purpose of this article is to presenta summarized general analysis of the situa-tion as well as of past trends of supply anddemand for beef and milk products and the

* Deputy Director, Joint ECLA/FAO Agricul-tural Division, Santiago, Chile. This study wasprepared in collaboration with the Division.

93

prospects over the next 10 years. The limi-tations of this study make it necessary torestrict it to a predominantly regionalanalysis.

Situation and Trends

Livestock Area

It is estimated that Latin America's pas-ture land includes 535 million hectares, butthat only 12 per cent of this area is underartificial or cultivated pastures while mostof it (470 million hectares) is covered bynatural pastures whose productivity ismuch lower. Considering grazing capacityin the proportion of 1 to 3, the total pasturearea would be approximately 200 millionhectares, in terms of artificial pastures;thus, the density of the cattle populationwould be about one head per hectare ofartificial pasture, plus the grazing corres-ponding to the equine, sheep, and goatspecies. Needless to say, the capacity ofpastures varies greatly from country tocountry and from one livestock zone toanother; it is of two or more head perhectare on the extensive improved pasturesin the Argentine Pampa, in certain livestockzones in Uruguay and Brazil, and in tropi-cal pastures of higher quality. A very lowgrazing capacity is registered in the Andeanregions of Bolivia, Ecuador, and Peru andan even lower one in the eastern plains of

94 Import and Export of Animals

Colombia, the Venezuelan plains, and thearid zones of Mexico, where as many asfive and even 10 hectares are required peranimal. It is true that the low productivityof the tropical pastures of Bolivia, Brazil,Colombia, Peru, and Venezuela is due notonly to the predominance of natural pas-tures, but also in great measure to extremeconditions of draught or rains that fre-quently cause seasonal pasture crises; thesealso occur with certain frequency in Argen-tina, Chile, and Uruguay.

It is often said, and with good reason,that Latin America possesses an immensepotential for livestock development. Infact, in addition to other advantages, theregion has a great proportion of new landsuitable for meat and milk production, suchas the large land reserves existing in mostof the tropical countries, especially Bolivia,Brazil, Colombia, Mexico, Peru, Venezuela,and those of Central America. On the otherhand, the use of natural instead of artificialpastures provides an ample margin for ex-pending grazing capacity, and at the sametime a much greater productivity can beachieved in existing pastures through im-proved management practices and betterutilization. In general terms, the region'sforage potential does not present any in-surmountable obstacles to attaining a muchgreater development of livestock produc-tion.

Livestock Population

Despite the deficiencies of available sta-tistical information, it can be estimated,on the basis of livestock censuses and othersources, that Latin America's present cattlepopulation is approximately 230 millionhead, the proportion being 90 head per100 inhabitants. The ratio is 94 head per100 inhabitants in the countries of theLatin American Free Trade Association

(LAFTA), 55 in the Central AmericanIsthmus, and 51 in the rest of LatinAmerica. The proportion has been decliningin the last 30 years, as the mass of bovinelivestock has increased at a slower ratethan the population. The highest propor-tion of bovines per inhabitant is found inArgentina, Paraguay, and Uruguay, whichis in line with their high consumption levelsand their tradition as meat-exporting coun-tries. However, it should be pointed outthat in the case of Argentina and Uruguaythe cattle-population relationship has ex-perienced an appreciable decrease, in spiteof low demographic growth in those twocountries. The lowest proportion is regis-tered in Chile and Peru, which are stronglivestock and meat importers.

The 11 LAFTA countries have a total of213 million head of cattle, representing93 per cent of the bovine population inLatin America; Brazil has the largest herd,followed by Argentina, Mexico, Colombia,Uruguay, Venezuela, Cuba, Paraguay, Peru,and the remaining countries. It is im-portant to note that Argentina, despitehaving a much smaller herd than Brazil,produces 71 per cent more meat, which isdue to a higher slaughter rate and a greateryield of carcass meat. But at the regionallevel, it is important to remember that al-though Latin America's herd is double thatof North America, the latter producesnearly three times as much meat and fivetimes as much milk as the Latin Americancountries.

Beef and Milk Production

Beef. Latin America's beef production in1968 was estimated at approximately 6.2million tons (carcass weight), representing18 per cent of world production, whichamounted to approximately 34.9 milliontons according to preliminary FAO esti-

Status of Production and Consumption of Animal Products

mates. Out of the region's total (excludingexports of live cattle) 41 per cent corre-sponds to Argentina, 24 per cent to Brazil,14 per cent to Mexico and Colombia whoseproduction yields are very similar, 4 percent to Uruguay and 17 per cent to the re-maining 15 countries. The LAFTA coun-tries produce 94 per cent. Out of the totalof 8.1 million tons of red meats (beef, pork,and mutton) produced in 1968, 77 per centcorresponds to beef and nearly 20 per centto pork.

Beef production in kilograms per inhabi-tant for the same year was estimated asfollows:

Argentina 109.3 Costa Rica 16.2 Cuba 24.3Bolivia 10.4 El Salvador 6.2 DominicanBrazil 17.1 Guatemala 10.0 Republic 5.2Chile 18.4 Honduras 9.1 Haiti 2.4Colombia 20.4 Nicaragua 24.7Ecuador 7.3 Panama 23.5Mexico 9.0Paraguay 51.4 CentralPeru 6.0 AmericanUruguay 85.8 Isthmus 12.7Venezuela 19.1

LAPTA 25.6

From the above list it may be seen thatthe highest production levels correspond toArgentina, Uruguay, and Paraguay whilethe lowest are those of Haiti, El Salvador,Peru, Ecuador, Mexico, and Bolivia. Brazil,Chile, Colombia, and Venezuela hold anintermediate position.

Milk. Latin America production of cow'smilk in 1968 was 22.5 million tons, which isequivalent to only 6 per cent of world pro-duction. Within the region, the greatestvolume corresponded to Brazil, with 31 percent of the production, followed by Argen-tina with 22 per cent, Mexico 13 per cent,Colombia 10 per cent, Chile 5 per cent,Ecuador and Peru jointly 4 per cent, andthe remaining South American countries-except Bolivia and Paraguay, which showthe lowest production figures-and Cubacontributed with 3 per cent each; a sub-regional total of 4 per cent corresponds tothe Central American Isthmus.

The highest production per inhabitant

corresponds to Uruguay, with 217 kilo-grams, closely followed by Argentina; pro-duction fluctuates between 90 to 108 kg inCuba, Ecuador, Costa Rica, Nicaragua,Colombia, and Chile, in an ascending order,and is below 80 kg in the remaining coun-tries.

Production Trends

In contrast to the greater development ofagricultural production as such, the totalphysical volume of animal production hasover the long term increased at a lowerrate than the population growth. In fact,during the last 20 years the populationincreased by 76 per cent, i.e., a cumulativeannual rate of 2.9, while livestock produc-tion only increased at a rate of 2.2, whichis clearly inferior to demographic growth(Table 1 and Figure 1). The developmentrate, of course, shows notable differencesbetween countries and between one itemand another. Production of poultry (meat

,

115

lli

105

9y

95

75

tl148-t195E1

AGRICULTURAL CROPS

*., ' --.>. ---- , ---'

*A ""'''' p--4A S -

4_ -- _,---;

'* "...... L

-". ....-. - ?:'~..

I I . .0 .961 A2 el U4 65 sI el 9i

YIARS

FIGURE l-Index of agricultural and livestockproduction in Latin America, 1948-1952 to 1968.

95-


TABLE 1-Bovine yields in Latin America, average 1962 to 1966.

Beef

Country

ArgentinaBoliviaBrazilChileColombiaEcuadorMexicoParaguayPeruUruguayVenezuela

LAFTA TotalTotal Central

American IsthmusTotal, rest of

Latin AmericaTotal, Latin

America

Source: Studies by the

Slaughteringrate

24.6

8.818.812.912.4

9.711.213.616.613.2

153.6

11.5

15.0

Kg perslaughtered

animal

209

192234200153186178134218177

199

170

170

Kg perhead

51

174526221820223623

27

23

22

Kg per cowin production

425

4261,700

995500

2,000536680410685

840

1,205

625

Kg percow

298

763303

179

124

13.8 197 27 850

Joint ECLA/FAO Agricultural Division and FAO Production Yearbook (1968).

and eggs), pork, and milk has been in-creasing at a greater rate, which hasbrought about an improvement of the pro-duction level per inhabitant. On the otherhand, deterioration of production has beenevident in the case of beef and mutton pro-duction. During the period under study,total poultry and egg production wasdoubled and milk and pork production in-creased approximately 70 per cent. Beefproduction only increased by 41 per centduring this long period, at a yearly rate ofonly 1.7 per cent. Wool and mutton pro-duction per inhabitant decreased consider-ably.

Even though briefly, it is advisable toconsider trends by countries, especiallythose in Argentina, since it is the most im-portant beef producer and exporter andfluctuations in its livestock production arereflected in considerable changes in the re-gional totals. Even if trends in this countryreveal an increment in beef production inabsolute terms, at a cumulative yearly rateof 1.4 per cent between the pre-war years(1935-1939) and the 1948-1950 period, and

of 1.5 per cent between this period and1966, these increases were inferior to thepopulation growth and the result was adecrease of availabilities for national con-sumption and export. It is important tonote that a new period of prosperity in live-stock production started in Argentina in1964; livestock population, which was esti-mated at 42.3 million head that year,reached nearly 51.5 million head in 1968,which is equivalent to a cumulative incre-ment of 5 per cent a year; meat produc-tion increased considerably during the sameperiod, at a yearly rate of 5.8 per cent.During the 1958-1968 decade productionincreased more than population only inBolivia, Nicaragua, Panama, and Vene-zuela; it was almost equal to demographicgrowth in Colombia, Costa Rica, El Salva-dor, and Mexico; in Chile, Ecuador, andGuatemala it increased at a rate of 2 percent; and Brazil, Cuba, Haiti, Honduras,Paraguay, Peru, and Uruguay showed in-creases of less than 1 per cent. The mostimportant increases in pork productionwere registered in Brazil and Mexico. Im-

Milk

-__


portant and sustained increases of milk pro-duction per inhabitant were obtained onlyby Venezuela, while a notable decline wasregistered in most of the Latin Americancountries. In the region as a whole, pro-duction per inhabitant decreased from 91 kgin 1958 to 87 kg in 1968.

Productivity Levels

Meat and milk yield per animal andphysical productivity of livestock in generalnot only vary from country to country, andeven within one zone, but are also subjectto important changes of a seasonal andcyclic character. It is for this reason thataverage figures over a sufficiently represen-tative period (1962-1966) are used in thisstudy.

It is an undeniable fact that the evolu-tion of livestock production in LatinAmerica and its productivity levels com-pare very unfavorably with those in coun-tries with a greater economic development.Basically, this disadvantageous situationmust be attributed principally to the slow-ness with which the livestock industry isabsorbing the progress of science and tech-nology. Outdated livestock managementsystems still prevail in many areas andthere is a marked backwardness with re-spect to breeding efficiency, health control,genetic improvement of animal breeds, pas-ture improvement and feeding practices and,in general, management and administrationmethods. This is confirmed by some exam-ples.

Under predominant conditions of mixedbovine production, the proportion of cowssuitable for breeding within the herds barelyreaches an average of 45 per cent, exceptin Argentina and Uruguay and in isolatedalthough numerous cases of herds with ahigh reproduction efficiency in other LatinAmerican countries. It is evident that thelimited availability of suitable breeding

cows is caused, in relative terms, by thedefective composition of the herds whichfrequently have a high proportion of adultsteers for fattening. On the other hand, thecalving rate in relation to the number ofbreeding cows reaches a regional averageof only 50 per cent and maybe less; to thisshould be added the death rate of calves onvery large farms, which make up themajority.

Regarding the slaughtering rate and theyield of meat per carcass, figures are not-ably low in most of the countries; the high-est levels are those of the Argentine beefindustry, with a slaughtering rate doublethat of many other countries, followed byUruguay and Chile. The highest meatyields per hectare and per live head ofcattle correspond precisely to these threecountries with a temperate climate.

Productivity levels in dairy farms alsoleave much to be desired. Frequently onlybetween 50 and 70 per cent of the cows aremilked, while in other countries with ad-vanced dairy industries this figure is oftenas high as 85 and 90 per cent and the milk-ing period is longer, as may be observed inHolland, Denmark, the United States, andCanada, for example. Although in LatinAmerica higher milk yields are obtained inthe three temperate countries, the fact isthat the average for the region (850 kg percow in production) and all of the nationalaverages are between five and six timesbelow the yields obtained in North Americaand Western Europe. The numerous diffi-culties existing in tropical zones for the pro-duction of milk at high efficiency levels arewell known. In this connection it shouldbe repeated that the improvement in yieldsthat can be achieved in those zones willdepend particularly on the measure in whichfeeding deficiencies and obstacles hinder-ing the adaptation of foreign breeds to thetropical environment can be overcome.

97


Factors Limiting Livestoclc Production

The many factors limiting animal pro-duction in Latin American countries havebeen discussed in some detail in variousstudies. It is therefore only relevant toconsider their nature and incidence in ageneral manner:

a) Feeding deficiencies: Seasonal foragecrises; predominance of natural pastureswith a low nutritional value; shortage ofartificial or cultivated pastures; inadequateutilization and management of pastures;insufficient water supplies and mineral ele-ments; and carelessness in the control oftoxic plants and weeds.

b) Diseases and pests: Infectious andcontagious diseases and parasites, whichcause numerous losses, slow down growth,and represent an economic drain becauseof the decrease in meat and milk yields. Asit is the basic subject of this conference,special mention should be made of foot-and-mouth disease, which is present to agreater or lesser degree in all of the SouthAmerican countries, in many of which itconstitutes a serious obstacle to the de-velopment of animal production and to agreater foreign trade of fresh, packed, andfrozen meats and live cattle.

c) Low level of genetic improvement:Predominance of native types and lowyielding crossbreeds in large tropical areas;a critical shortage of proven breeding males;limited progress in artificial insemination;and frequent confusion regarding selectionand crossbreeding practices.

d) Administrative and managerial de-ficiencies in many aspects of animal pro-duction.

e) Economic factors: Slowness of privateand public investment in infrastructureworks, improvement of existing exploita-tions, and expansion of pastures. Livestock

producers frequently complain of the lowprofitability of invested capital.

f) Institutional factors: Limitation ofcredit for livestock production in virtuallyall of the countries; serious marketing de-ficiencies; the slow progress of research andtechnical assistance; shortage of techni-cians and intermediate-level personnel;some inadequate land tenure structures;and important gaps with respect to inte-grated livestock development policies in thecountries.

Foreign Trade in Beef

Latin American beef and live cattle ex-ports continue to be an important sourceof foreign exchange; they amounted to atotal of 586 million dollars in 1967.* Thevolume of the Latin American exports is inthird place after Western Europe andOceania. However, the region's participa-tion in world exports decreased from 31per cent during the 1948-1952 period to 19per cent in 1965-1967. While WesternEurope quintupled its meat exports duringthis period and Oceania increased them by72 per cent, Latin America only managedan increase of 47 per cent. Moreover, tomaintain a relatively high export level,Argentina and Uruguay, and to a lesserdegree other countries, have had to draw toa greater or lesser degree on meat suppliesfor domestic consumption. Argentina's beefexports represent a little over two-thirds ofLatin America's exports. In 1969 shipmentsfrom that country reached a peak volumeof 561,295 tons (including trimmings andmeat extract), for a value of nearlyUS$367 million. Uruguayan exports, whichare second in importance, recovered signif-icantly in 1968 and 1969, showing an in-

* Examen de las características, tendencias yproblemas principales de la economia mundial dela carne. FAO Document CCP:Mah 69/3, May1969.


crease of 63 per cent over the low levels of1965-1967. During this same triennium,Mexican exports of live cattle averaged557,160 head, followed by Argentine ex-ports-with a yearly average of 141,333head of cattle-and then Colombian, Hon-duran, and Brazilian exports in that order.Paraguay continues to be an importantexporter of dressed meat. The countries ofthe Central American Isthmus have incre-mented their meat and livestock exportssubstantially in recent years; the first weredoubled, increasing from 25,500 tons in1965 to 49,960 tons in 1967. The UnitedKingdom and the European EconomicCommunity absorb around 70 per cent ofLatin America's meat exports. However,because of various restrictions establishedby these two important meat importers andthe sustained campaign for promoting do-mestic beef production, Latin Americanexporters have intensified their efforts toovercome these difficulties, expand theirtrade with other countries, and find newmarkets. The importance of the UnitedStates as a buyer of dressed and tinnedmeat continues to increase.

It is worth mentioning that, despite acertain increase observed in recent years,intraregional meat and livestock tradeaccounts for only a small proportion ofLatin American exports; Chile and Peru arethe main importers from Argentina andColombia.

It is an obvious fact that despite markedfluctuations in the volume of world beeftrade and a tendency for prices to increase,prospects indicate that demand will in-crease at a greater rate than production inthe importing countries.

Consumption Levels

With the exception of Argentina, Uru-guay, and Paraguay, beef consumption is

noticeably low in the Latin Americancountries, particularly in Bolivia, Ecuador,Mexico, Peru, and in the Central AmericanIsthmus, where it barely reaches 8-10 kgper inhabitant/year. Consumption de-creases in Argentina and Uruguay duringthe last few years have been caused by asustained high export level, and in the caseof Chile this is due partially to difficultiesin domestic supplies and the substitutionof beef consumption. Production in theCentral American Isthmus has remainedstationary in the last 10 years, and for thisreason export increases have been made atthe expense of domestic consumption. Ex-cepting the River Plate countries, it may bestated that consumption of meat of differ-ent types per inhabitant averages 20 kg ayear, which is obviously far below nutri-tional requirements of animal protein.

The participation of beef in total meatconsumption is extraordinarily high inArgentina, Paraguay, and Uruguay. InBrazil, Colombia, Central America, Mex-ico, and Venezuela, between 75 and 80 percent of meat consumption corresponds tobeef, followed by pork and in a muchsmaller proportion by sheep and goat'smeat. Beef consumption in Bolivia, Ecua-dor, and Peru barely represents half of thetotal meat consumption, because of theimportant contribution of sheep and otheranimal species.

Regarding the consumption of milk andmilk products, important deficiencies occurin all the Latin American countries inrelation to the requirements of a normaldiet. Average milk consumption per in-habitant in the region is only about 100liters a year, in terms of whole milk; thisis barely one-third of the consumption inthe United States, Canada, and New Zea-land. Brazil, Colombia, and Venezuelamust increase their fresh milk supplies sixtimes to reach the recommended consump-

99


tion level of 400 grams a day. Chile wouldhave to triple it, and Argentina to doubleit. The rest of the countries would requirean extraordinary effort to remedy theirextremely low consumption levels of milkand milk products.

It is a well known fact that protectivefoods, such as meat and milk, have rela-tively high prices, as a result of whichthe purchasing power of low-income con-sumers for these basic products is very low.However, if we take into account futurepopulation' and income growth, as theprincipal factors determining demand, itmay be expected that supply problems willbe aggravated, unless production or im-ports grow at a greater rate. Because ofthe high elasticity of demand for meat andmilk in relation to income in most countrieswith precarious consumption levels, thecontinued increase of prices will be inevita-ble unless production for domestic con-sumption increases at the same rate as therise in demand and the improvement ofavailable incomes.

To complete this brief analysis of thepresent situation of meat and milk produc-tion and consumption in Latin America, itshould be pointed out that while the NorthAmerican citizen consumes a little over 90kg of proteins a year, of which 62-65 kgare of animal origin, total protein suppliesof most of the Latin American countriesbarely reach two-thirds of the amounts in-dicated for the United States of Americaand Canada; what is more serious, onlyone-third is animal protein while the re-maining two-thirds are proteins fromstarchy vegetables that are normally con-sumed. In brief, consumption of animalprotein in 90 per cent of the Latin Ameri-can population has remained at a standstillfor many years, at a level equivalent to 20per cent of protein supplies in developedcountries. This situation aggravates social

problems of hunger, malnutrition, and dis-eases caused by protein deficiencies amongthe poorer sectors. In accordance with itsnew plans of action, FAO is concentratingits activities on five aspects of primary im-portance, one of which is the elimination ofthe protein imbalance; and as a part of thisnew approach, it is promoting a livestockdevelopment strategy in Latin America.

Production and Consumption Prospects

The following section presents a pros-pective study of the development of beefand milk demand and supply in LatinAmerica during the decade of the 70's.Taking into account also the balance offoreign trade, this analysis shows possiblegrowth of production and consumption. Inview of the great variety of factors affect-ing supply and demand, the projections(for 1975 and 1980) are of a hypotheticalnature. Consumption projections have ahigher degree of feasibility, as they havebeen based principally on the well-knowntrends in the population and to a lesserdegree on available income per inhabitant,which is much less dynamic because of itsinadequate distribution and the continuingprice increases. On the other hand, projec-tions of supply refer only to meat andmilk production that it will be necessary toreach by 1975 and 1980 in order to satisfyconsumption requirements. The capacityof the countries to meet potential demanddepends entirely on the measure in whichthey are able to promote livestock develop-ment.

Hypothesis A (Tables 2 and 3) is asimple extrapolation of trends registered inthe past decade and as such it is onlypresented as a basis for comparison, toindicate the large production and consump-tion gaps that will occur in Latin Americain the next few years if the aforementioned


TABLE 2-Projection of beef production, foreign trade, and apparent consumption, inLatin America, 1975.

(Thousands of tons of carcass meat)

Production Exports

Apparent Per-capitatotal con- consumption

Imports sumption (kg)

Hypothesis ALAFTA countries 6,649 1Rest of Latin America 477Total, Latin America 7,126 1

Hypothesis BLAFTA.countries 7,559 1Rest of Latin America 545Total, Latin America 8,104 1

Source: Joint ECLA/FAO Agricultural Division cc

stagnation continues. For this reason, theprojection of the historic trend cannot beconsidered as a satisfactory alternative forthe growth of meat and milk supplies anddemand, because of the adverse effect thatwould have on agricultural and economicdevelopment in general, and because itwould lead to an aggravation of the lowconsumption levels per inhabitant prevail-ing in large sectors of the population.

Hypothesis B not only considers theeffect of population and income on con-sumption, as far as demand is concerned,but also takes into account the habits andpreferences of the consumers, certain poli-cies for self-sufficiency in some countries,programs for the substitution of a part ofbeef consumption for other meats, plans forsubstituting imports, and policies for in-creasing and diversifying exports, even atthe expense of domestic consumption-be-

TABLE 3-Projections of beef production,Latin America, 1980.

14262

204

14262

204

5,565471

6,056

6,367527

6,894

20.011.919.0

22.913.321.7

cause this complex interaction of factors iswhat ultimately determines the variouslevels of consumption. This approach issimilar to the one adopted by FAO in theIndicative World Plan for AgriculturalDevelopment.

In accordance with this second hypothe-sis, effective demand for beef would be of8.1 million tons in 1980, or 2.8 million tonsmore than in 1966-1968, which is equi-valent to a highly feasible increment rateof 3.3 per cent. As it is estimated that theexport demand may have doubled by theend of the decade, the combined growth ofdomestic and foreign demand would havereached a yearly rate of 3.8 per cent. Thismeans that for this demand to be trans-formed into domestic consumption and realexports, production would have to be in-cremented at the same rate, as no importsfrom outside the region are taken into

foreign trade, and apparent consumption, in

(T'housands of tons of carcass meat)

Production Exports

Apparent Per-capitatotal con- consumption

Imports sumption (kg)

Hypothesis ALAFTA countries 7,226 2,005 158 5,419 168Rest of Latin America 512 94 72 490 13.5Total, Latin America 7,778 2,099 230 5,909 16.0

Hypothesis BLAFTA countries 9,363 2,005 158 7,516 23.4Rest of Latin America 667 94 72 645 17.8Total, Latin America 10,030 2,099 230 8,161 22.2

Source: Joint ECLA/FAO Agricultural Division computation.

101


account. As approximate supplies requiredfor 1975 and 1980 are 8 and 10 million tons,respectively, these figures should be con-sidered as production targets toward whichlivestock development must be aimed. Itis true that it is not feasible to achievesuch a great development in livestockproduction in a 10-year period, as longer-term plans are required to overcome obsta-cles of a technical, biological, financial, andinstitutional nature hindering animal pro-duction. However, much can be done in thisdirection. Consequently, prospects are thatgrowing demand for beef will not be fullymet in the present decade, and this willcontinue to encourage price increases, un-less sound regulatory policies are adopted.

Considering that the internationalmarket for beef is extremely favorable, be-cause of great foreign demand and highprices on the world market, it is to be ex-pected that traditional Latin Americanmeat exporting countries and others thatare developing their exports will continueto increment their sales abroad, even at theexpense of domestic consumption, as hashappened in the past. This trend has cer-tainly been taken into account whenformulating these projections.

As regards beef consumption per in-habitant, prospects are not at all encourag-ing because of the reasons stated above. Infact, if supplies continue to increase at theslow rate observed in the last 10 or 15 years(hypothesis A), availabilities per person,which in 1958-1960 and 1966-1968 wereonly 23 and 21 kg, respectively, will con-tinue to deteriorate, decreasing to 19 kg in1975 and 16 kg in 1980. Under hypothesisB, in which an accelerated productiongrowth is assumed together with a con-tinued expansion of exports, an increase ofbarely 1 kg would be obtained after 10years. The need therefore arises to makeup for foreseeable consumption gaps of this

type of meat with pork and poultry, forwhich there is also great demand in coun-tries where there is a deficit of meat pro-duction. Production of these two meatitems can be incremented quickly andeasily within short and intermediate terms,as is being done in several countries of theregion.

Regarding milk, total consumption, inapproximate figures, increased from 19million tons in the 1958-1960 triennium toa little over 22 million tons in 1965-1967,representing an increment of 18 per cent inseven years, at a cumulative annual rate ofonly 2.4 per cent, which is lower than thedemographic growth rate. For this reason,despite increasing imports of milk products,total milk consumption per inhabitant de-creased from 94 to 92 kg during that period.If this slow expansion of real demand formilk should continue during the next 10years, per-capita consumption would con-tinue to be practically stagnated, unlessimports are greatly increased, which is un-likely because of self-sufficiency and for-eign exchange savings policies. Recentconsumption trends should not be pro-longed, of course, if the greater economicdevelopment which is to be expected andnew strategies for social improvementwhich are beginning to arise are acceptedas a fact. It is for this reason that underhypothesis B it has been assumed thatthere will be an additional demand of ap-proximately 10 million tons in 1975 andof approximately 16 million in 1980, inrelation to total consumption estimatedfor 1965-1967. This would mean that theyearly growth rate of demand would be ofapproximately 4 per cent and, if it shouldbecome effective, it would increase per-capita consumption to 100 kg (in terms offluid milk) in 1975 and to 105 kg in 1980.A higher relative increment of demand hasbeen assumed than in the case of meat be-


cause of the effect of imports and becausemilk production is considered to be moreelastic in Latin America. Undoubtedly,large surpluses of exportable milk productsfrom developed countries will continue torelax international prices, a circumstancewhich under assumed conditions of orderlymarketing and distribution (withoutdamaging national production) may rep-resent a relatively important growth ofimports (Table 4).

In conclusion, there is a great potentialdemand for beef and milk which will con-tinue expanding uninterruptedly. As wasnoted above, it has been estimated thatdemand for beef-including foreign de-mand-will grow at a cumulative yearlyrate of 3.8 per cent and demand for milkand milk products will grow at approxi-mately 4 per cent; in other words, com-bined demand for these food productsmight grow at an annual rate of 3.9 percent.

Prospects regarding supplies, which inthe case of meat are equal to production,are uncertain because future suppliesdepend largely on livestock developmentand marketing policies, on one hand, andon the other, on the resources, means, andincentives available to producers. It isvery difficult to evaluate the future situa-tion and the changes that might take place

with respect to these factors. What maybe stated with full certainty is that theprolongation of historic production trends,which show a visible stagnation, wouldaggravate the imbalance existing in mostof the countries between meat supplies anddemand; at such a slow rate, productionwould reach 7.8 million tons in 1980, whichin comparison with estimates on totaldemand shows a deficit of 2.4 million tons.Under these clearly undesirable conditions,supplies would be 22 per cent lower thandomestic and foreign demand by 1980.

Milk production in previous years in-creased a little more than beef production,at a compound yearly rate of 2.4 per cent.If it should continue to increase at thesame rate, it would rise from a yearlyaverage of 21.2 million tons estimated in1965-1967 to 26.3 million in 1975 and 29.4million in 1980. When compared withdemand projections under hypothesis B,these figures show a production deficit of9 million tons in 1980, with very limitedpossibilities for covering it entirely withimports. In order to meet future demandin that year and at the same time achievea complete substitution of imports, produc-tion would have to be increased to 39 mil-lion tons, representing an increment of 83per cent, equivalent to a yearly rate of 4.4per cent. For various reasons, such an

TABLE 4-Projections of milk production and demand in Latin America, 1975 and 1980.(Thousands of tons)

1975 1980

Per-capita Per-capitaTotal pro- Total con- consump- Total pro- Total con- consump-

duction sumption tion (kg) duction sumption tion (kg)

Hypothesis ALAFTA countries 24,059 26,899 97 26,970 31,178 97Rest of Latin America 2,208 2,730 69 2,476 3,165 68Total, Latin America 26,267 29,629 96 29,446 34,843 95

Hypothesis BLAFTA countries 28,937 28,937 104 35,253 35,253 109Rest of Latin America 2,945 2,945 74 3,577 3,577 77Total, Latin America 31,882 * 31,882 100 38,830 a 88,830 105aRequired production, not projected.Source: Joint ECLA/FAO Agricultural Division computation.

103


accelerated increment of production wouldonly be feasible over a very long term.Consequently, it must be kept in mind thatin the case of meat as well as milk, projec-tions are only intended to draw attentionto the magnitude of the imbalance betweensupply and demand that may occur in thefuture and to the need for introducing pro-grams and changes required to modifytrends and decrease the differences.

Considering Latin America's vast re-sources for livestock exploitation and thegreat increase in demand that is envisaged,the region is facing the urgent need to con-centrate efforts on the development ofmeat and milk production, in order to im-prove the low nutritional levels affectingmore than 80 per cent of the populationand to continue maintaining its importanceas an exporting region. Without intendingto make a quantitative assessment of thepossibilities and limitations for increment-ing beef and milk production during theSecond Development Decade sponsored bythe United Nations, it should be mentionedthat there are no insurmountable obstaclesof a technical type to achieving an ac-celerated development of cattle production.The following facts confirm this.

Cattle herds in the region have beenincreasing in number at a rate slightlybelow population increases. Nevertheless,the livestock history of several LatinAmerican countries shows much greater in-crements, as was the case recently inArgentina, Mexico, and Paraguay, andduring different periods in Brazil, Colom-bia, and some Central American countries.Economic incentives have encouraged theapplication of improved reproduction tech-niques and greater care of breeding herds,as a result of which cattle numbers havebeen increased. If it is true, on the onehand, that the proportion of breeding cowsand their calving rates show a rather low

average for the region, it is also true thatthere is an ample margin for improvingreproductive efficiency of herds throughmeasures leading to greater care of breed-ing cows, an adequate supply of bulls, ex-pansion of artificial insemination services,control of diseases affecting calving rates,and improvement of cattle feeding. In thisconnection is it worth mentioning that atthe experimental and commercial produc-tion levels in all the countries, there aremany-although still not sufficient-ex-amples of the significant manner in whichlivestock numbers can be increased.

The death rate, which has an importanteffect on livestock inventories, is particu-larly high in the case of young calvesbecause of the insidious attack of colibacil-losis, salmonellosis, or paratyphoid, pneu-monia, pyobacillosis, and a great manyother diseases caused by parasites. In suchcases the death rate may be as high as 30 to40 per cent in herds under careless manage-ment. It has also been sufficiently demon-strated that by intensifying health controlmeasures the death rate can be consider-ably reduced. If it is accepted that mor-tality in the bovine species is of the orderof 7 per cent at present, it is no technicalfeat to reduce it to 6 per cent in the courseof 10 years. Such a decrease would have agreat multiplier effect on the size of herds.

Regarding yields and productivity, scopefor improvement is equally broad, but itmust not be forgotten that comprehensivelong-term livestock development plans arerequired to achieve such an improvement.In any event, it is highly feasible to in-crease the slaughtering rate of cattle pro-gressively by- shortening the- fatteningperiod and increasing the proportion ofyoung animnals available for slaughter, atan age from 2 to 2%12 years, instead of 4 to5 years as is: the case in many meat-pro-ducing areas. In fact, many producers are


managing to do this. On the other hand,independently of age, the meat yields perslaughtered animal and per pasture areaunit can be increased through better feed-ing practices. Neither is it technicallyimpossible to increase the slaughtering ratefrom the present average of 14 per cent,to 16 per cent within 10 years. In the caseof dairy production, which it is easier tointensify in temperate climates, yields percow and per cow in production could begreatly augmented. They could be morethan doubled in the Argentine Pampa.Milk production in Uruguay increased ata yearly rate of 6 per cent between 1949and 1960, thanks to an increase in the pro-ductivity of pastures and milk herds. Tech-nical progress in central Brazil, certain

areas of the Colombian and Ecuadorianhighlands, and dairy zones in Chile, Cen-tral America, Cuba, and Venezuela is veryencouraging. Milk production in the lattercountry increased by 73 per cent between1950 and 1958, that is, at a yearly rate of7 per cent.

Finally, it should be remembered thatmuch can be achieved in reducing theincidence and morbidity of diseases affect-ing meat and milk production and yieldsby intensifying campaigns for both pre-venting and curing diseases. There is nodoubt that beef and milk production couldbe increased considerably through large-scale control of foot-and-mouth disease,brucellosis, mastitis, and diseases causedby hematozoons and external parasites.

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HEALTH PROBLEMS INVOLVED IN THE IMPORT AND EXPORTOF FOODSTUFFS OF ANIMAL ORIGIN

DR. FERNANDO QUEVEDO :

International trade in foodstuffs, par-ticularly animal protein foods, has in-creased considerably during recent years,and because of the growing worldwidedemand for proteins it is certain that thevolume of such trade will increase still fur-ther.

As this trade increases, there must alsobe an intensification of current healthmeasures to prevent an increase in thedissemination of pathogenic organismstransmitted in foods of animal origin.

These organisms can be grouped in twocategories: (a) those associated withendogenous animal infections transmissibleto man (zoonoses), including bacterial,fungal, virus, helminth, and protozoanspecies and (b) exogenous contaminants offood, which may cause infections or poison-ing in man.

The measures necessary to preventhealth problems associated with organismsof the first category correspond specificallyto the services of veterinary medicine. ThePan American Zoonoses Center is dedi-cated to the investigation and solution ofproblems of this category.

This paper will refer in more detail to thepublic health problems caused by theexogenous contaminants of the secondgroup.

*Pan American Zoonoses Center, Ramos Mejía,Buenos Aires, Argentina.

Salmonellosis

Of the pathogenic organisms for whichfood of animal origin serves as a vehicletransmitting infection to man, the most im-portant group is undoubtedly the Salmo-nella, which belong to both of the twocategories mentioned above.

The International Committee onMicrobiological Specifications for Food(ICMSF) of the International Associationof Microbiological Societies (IAMS), in itsmost recent publication (36), defineshuman salmonellosis as a gastrointestinalinfection usually of greatest severity in thevery young or very old, though severeillness, with some mortality, may occur inany age group. The disease is characterizedby an elevated temperature, diarrhea(sometimes sufficient to lead to severe

dehydration), intestinal pain, and perhapsvomiting. Consumption of contaminatedfood is the most common cause. An in-cubation period of about six to 18 hours isusual. The duration of the disease mayvary from a few days to a few weeks,depending in part on the efficacy of thetherapy applied. A subsequent carrierstate may persist in an asymptomaticpatient for a few weeks to several months,and Salmonella typhi may be excretedintermittently throughout the carrier'slifetime.

Among all diseases transmitted by food,

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Health Problems in the Import and Export of Animals

the salmonelloses are also the ones morefrequently reported. The number of per-sons affected per annum by this disease isextremely high. In the United States ofAmerica today it constitutes one of themost important problems among communi-cable diseases, amounting to 2 millionhuman cases yearly. In the United King-'dom morbidity figures are similar. Inother countries, notwithstanding defi-ciences in surveillance as well as in report-ing of cases, it is certain that the salmo-nelloses have the same graveness.

As a logical consequence of the magni-tude of the problem, there are very signifi-cant economic losses. Considering only theexpenses of medical treatment and associ-ated losses, such as absence from work bythe affected individuals, the impact onthe American economy is of the order ofUS$200 million annually (25). To these fig-ures must be added the costs of preventivemeasures and the losses deriving from thedestruction or reprocessing of contaminatedproducts. For example, the cost due torejection of a preparation of powderedmilk found contaminated with Salmo-nella has been estimated at approximatelyUS$5 million. Expenses incurred for pro-fessional and auxiliary personnel by vari-ous government agencies concerned withthe problem have been equally high. Thelarge sums allocated to investigation of thedisease must also be added to the total.

Livestock. owners and food processorsalso suffer large losses because of salmo-nellosis. In this regard the U.S. Depart-ment of Agriculture, in a report presentedin 1969 before a specialized committee ofthe National Research Council (25), pointsout that the economic influence of Salmo-nella infection for livestock and avian in-dustrialists can be summarized in the fol-lowing points:

* Losses due to mortality and morbidityof the infected animals.

* Costs of drugs and veterinary services.* Decrease in dairy cattle production.* Decrease in the average weight incre-

ment of cattle, swine, sheep, chickens, andturkeys.

* Decrease in egg production.* Loss of consumer confidence in dairy

and poultry products, especially in eggsand their derivatives, which is reflected inthe lower prices paid to the producer.

* Production losses due to rejection, re-processing, and/or destruction of livestock,meat and derivatives, dairy and poultryproducts which are found contaminatedwith Salmonella after the processing and/or distribution.

Besides the expenses listed above, in-dustrialists invest large amounts of moneyin their own programs of research andin bettering equipment and facilities withthe object of reducing contamination andrecontamination of their products to theminimum.

A discussion of all of the epidemiologicalaspects of salmonellosis is outside the scopeof the present report. However, we willpoint out that animals are importantreservoirs of Salmonella, obtained throughtheir feed, particularly animals which areused as a source of food by man. This isreflected in the fact that food of animalorigin, such as red meat, poultry, eggs, andtheir derivatives, are the principal sourcesand disseminators of salmonellosis, whetherit be by direct consumption or by cross-contamination in factories, restaurants,and family kitchens. Some animal-origindrugs and pharmaceuticals have also beendesigned as sources of Salmonella out-breaks (29).

Human carriers play an important rolein the dissemination of Salmonella. Al-though it has been pointed out that their

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proportion does not exceed 0.3 per centin the developed regions, in other areasthat percentage notably increases (14).Workers at food industries can becomecarriers of Salmonella. It has been sug-gested, therefore, that for this group ofworkers salmonellosis be considered as anoccupational disease (12).

Poor sanitary practices, rodents, domes-tic carnivores, birds, and insects, especiallyflies (28), are important factors in the prop-agation of salmonellosis.

Finally, we can say that although morethan 1,000 different serotypes are known,only 100 of them are frequently isolated.It has been observed that only 10 serotypesare the ones that occupy the first placesin the isolation from human and non-hu-man sources.

Information on the most common sero--types is of great importance for publichealth specialists. Epidemiological surveil-lance of salmonellosis, which should beimplemented worldwide, would help to con-trol this disease. The U.S. Center forDisease Control in Atlanta, Georgia, thePublic Health Laboratory Services in En-gland, and, since 1966, the EuropeanRegional Office of the World Health Orga-nization have established epidemiologícalsurveillance in their respective geographicareas.

In some regions, particularly in LatinAmerica, we can point out the presence ofthe Arizona group of bacteria, which maycause problems similar to salmonellosis.

Health Problems Caused by PrefornedBacterial Toxins in Foods

In this group we find only staphylococcalintoxication and botulism. There is noclear information on t;he nature of the dis-ease profduced by Clostridium perfringens.

Staphylococcal Food Poisoning

This disease is characterized by nausea,vomiting, diarrhea, general malaise, andweakness. In severe cases there may be col-lapse and other signs of shock. The symp-toms start 30 minutes to three hours afterconsumption of food. Total recovery maytake three days to one week (3). Mortalityis low except in the case of children and thevery old, who often die of dehydration.

The symptoms are caused by specificpolypeptides, which act as emetic toxins.Four classes of these enterotoxins havebeen characterized: A, B, C, and D. Theyare relatively thermostable, especiallywhen found in foods (3).

The responsible microorganism is the en-terotoxic Staphylococcus aureus.

For the enterotoxin to be produced, thestaphylococcus that contaminates the foodhas to proliferate abundantly, requiringnutrients, adequate temperature, and time.Food such as meat, dairy and egg products,and seafoods may stimulate the enterotoxinproduction.

The contamination of food is effected invarious ways. Mastitis-affected cows arean important source of contamination, butthe most common way is through foodhandlers. A person with infected woundsor respiratory infections, by handling foodproducts, coughing, sneezing, or expectorat-ing, disseminates appreciable quantities ofstaphylococci on them. Simple refrigera-tion is not always sufficient to impede theproduction of toxin; and once the toxin isproduced, the heating of food is not enoughto eliminate it. All food containing entero-toxins must be destroyed.

To give an idea of the importance of thispoisoning, we can mention that in theUnited States of America in 1967 it wasresponsible for 25 per cent of the outbreakbof foodborne diseases; in 1968 and duringthe first six months of 1969, it was the most


frequent cause of those diseases, account-ing for 25 per cent of all reported cases and25 per cent of all outbreaks (7, 8, 10).

Botulism

This disease is not frequently present,but it is nevertheless very important owingto its high mortality (50 per cent). Food ofanimal origin, like meat and fish deriva-tives, have been incriminated in seriousbotulism outbreaks.

The responsible agent, Clostridium bot-ulinum, an anaerobic spore-forming orga-nism, produces a thermolabile toxin whichis the most powerful known. One ten thou-sandth of a microgram is enough to kill amouse (3). The toxins capable of affectingman are the types A, B, E, and F.

The incubation period is rarely shorterthan six hours. It is generally between 12and 26 hours, but it can sometimes belonger.

The principal symptoms are related tothe central nervous system, while digestivedisturbances and vomiting may or may notbe present. The characteristic symptomsare muscular weakness, double vision,speech and swallowing difficulties, and res-piratory and cardiac paralysis. In severecases, particularly with type E cases, forwhich seafood serves as the vehicle, deathmay occur 20-24 hours after ingestion, butit generally occurs after three to six days.

The thermoresistant spores of C1. botu-linuin are widely but irregularly distrib-uted in nature. Effective sanitary measuresand adequate technical processes minimizethe risk of botulism.

Clostridium perfringens-Bacillus cereus

The exact nature of this disease has notbeen well defined, and it is not known if itis an actual infection or an intoxication.

However, ingestion of food contaminatedwith a large number of Clostridium per-fringens causes, after 8-18 hours, severeabdominal pain and diarrhea. This food-borne disease has not been given the im-portance it deserves except in the UnitedKingdom. However, in the United Statesin 1968 Cl. perfringens was the cause of thelargest number of cases of diseases of foodorigin, and during the first semester of 1969it accounted for 40 per cent of all -cases,against 25 per cent noted for staphylococciintoxications. Meats and their derivativesare the most frequent vehicle of this illness(17) but milk, cheese, and shellfish havealso been incriminated in some outbreaks.

The anaerobic' spore-forming organism,Cl. perfringens, is found in soil, water, milk,dust, drains, and the intestinal tract of manand animals. If the animals do not receivethe necessary care immediately before be-ing slaughtered (for example, 24-hour restafter transport, and feed and water ad-ministered before slaughter), they may suf-fer an internal contamination by systemicmeans though they may be clinicallyhealthy (40). Adequate sanitary measuresand a correct application of refrigeration,especially after cooking, prevent the mas-sive multiplication of the organism.

A disease with similar symptoms and epi-demiological characteristics is caused byBacillus cereus, a spore-forming aerobicorganism which can be found in large num-bers in sausage, powdered milk and eggs,and also in food of vegetable origin.

Many other microorganisms are capableof producing food-poisoning symptoms,evén if they are not strictly considered aspathogens. However, it is necessary topoint out that these organisms must bepresent in highly concentrated form inorder for symptoms to break out.

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Indicator Organisms

These are mieroorganisms whose presencein food is undesirable, not necessarily be-cause they are considered pathogenic, butbecause they may indicate contaminationwith dangerous organisms or precarious hy-gienic conditions during production, stor-age, and/or transportation of the food prod-uct. For reasons of safety and esthetics,their investigation is an almost generalrule, especially with food involved in in-ternational commerce.

Among these indicator organisms we findEscherichia coli, coliforms, enterobacteriain general (total count), enterococci, staph-ylococci, Streptococcus salivarius, Clostrid-ium sulfite reductors, and of course, in aquantitative estimate aerobic mesophilicbacteria, psychrophilic and thermophilicmicroorganisms, and anaerobics.

Although the subject is outside the scopeof this report, which centers on publichealth problems, it should be mentionedthat many microbial species are capable ofaltering the commercial quality of food, in-fringing heavy losses on producers who areforced to destroy stocks because of majorchanges that occur in the organoleptic char-acteristics of the food (6, 11).

International Trade in Animal-Origin Food

Because of their growing importance ininternational trade and their significanceto public health, special attention shouldbe given to problems arising from the fol-lowing foods: meat and derived products,dairy products, fish and fish products, de-hydrated protein concentrates, egg prod-ucts, and seafood. These also constituteimportant sources of foreign currency formany Latin American countries.

Meat and Meat Products

These are the products most frequentlyinvolved in foodborne diseases.

With reference to salmonellosis, meatsserve as the most frequent vehicle for thisinfection.

Veterinary inspection before slaughterhelps to discover and separate clinicallysick animals. Unfortunately, the same doesnot hold true for animal carriers or thosethat develop a subelinical disease; theseare slaughtered and later processes such asbleeding, skinning, splitting, and especiallyboning-which notably increase exposedsurfaces and handling-result in contami-nation of the environment, the food han-dlers, and the utensils used. If adequatesanitary measures are not applied, espe-cially good disinfection practices, and if theroom temperature during the process is notsufficiently low (10 ° C or less), Salmonellawill finally be found in high proportions inthe finished product samples. Furthermore,misapplication or interruption in the coldchain during storage or transportation willfavor multiplication of dangerous micro-organisms.

Aware of the serious risks involved, largemeat-importing countries routinely searchthese products for Salmonella, and very sig-nificant results are obtained.

For example, England during 1961, 1962,and 1963 found between 5 and 90 per centsamples of imported beef and mutton con-taminated. During the same period, 50 to60 per cent of horse meat samples werefound contaminated; products from someestablishments showed 100 per cent con-tamination (16). Unfortunately, most con-taminated meat samples were from SouthAmerica.

These findings, together with the dis-closure of Salmonella outbreaks in whichthe responsible serotypes corresponded to


the ones isolated in the meat, induced En-glish authorities to adopt a series of restric-tive measures. They decided to importmeat coming only from establishments ap-proved by their technical representatives,on the basis of stipulated sanitary condi-tions.

The United States, Canada, and someEuropean countries intensified their con-trols and requirements after their investi-gators obtained findings similar to those ofthe British. The United States and Canadabase their import programs on the require-ment that meat and derived products behandled and processed under the samestandard inspection procedures as those ob-served by their own systems (32) (38). Toensure that the requirement is met, theUnited States and other countries sendtechnical missions to the exporting coun-tries to select the most appropriate estab-lishments.

This new requirement has led many in-dustrialists to approach the problem withfirmness, investing large amounts of moneyin order to comply with the sanitary andtechnical specifications laid out by the im-porting countries.

Results are beginning to be favorable.Let us take, as an example, the frozen,packed, boneless, raw horse meat analyzedin English laboratories (18). Argentina in1964 had 39.4 per cent of positive samples;in 1967 this was reduced to 13.6 per cent.Paraguay in 1964 had 31.6 per cent posi-tive samples, and only 14.0 per cent in1967. Brazil in 1965 had 19.7 per cent, andin 1967 had 16.3 per cent. For Uruguay,figures are available only for 1966 and1967, and these do not show significantdifferences.

Important measures to cope with theseproblems have been taken by the LatinAmerican Governments. The official Ar-gentine action is refiected in the program-

ming of intensive courses for veterinaryinspectors, the improvement of official con-trol laboratories, and other similar activi-ties. Especially important was the publish-ing and wide distribution in 1969 of theAnimal Health Regulations: Inspection ofAnimal-Origin Products and Derivatives(Decree 4.238/38) (2), a very useful toolof great value in the solution of theseproblems.

Authorities in Uruguay, with great ur-gency, have dictated new regulations toprovide veterinary personnel and auxiliarieswith full-time positions offering more ade-quate remuneration; and they are organiz-ing intensive training seminars for newlyappointed veterinary personnel to give themup-to-date information on the subject.Also, they are proposing official action to bedeveloped with reference to bacteriologicalcontrol, designed to ensure the hygienicquality of meats.

At the international level, the countriesof the southern cone, through COTERSA(Regional Technical Committee on Ani-mal Health), are devoting close attentionto the sanitary aspects of exportable meatsand derived products.

Importing countries should appraisethese efforts in their true perspective. Forexample, to request frozen meat totally freeof Salmonella is irrational, given the par-ticular characteristics of the problem. Theaction taken against imported meat ismade more difficult to understand by thefact that meat products in the importingcountries themselves are also frequentlycontaminated. In Great Britain 15 per centof calves were found to be excreting Salmo-nella when entering slaughterhouses. Thecarrier rate for Salmonella in calves variedfrom year to year, but on one occasion wasas high as 35 per cent. The situation in theUnited States appears to be similar to thatin Europe. A survey showed that 50 per

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cent of finished animal by-products exam-ined in U.S. establishments contained Sal-monella (35).

Australian horse meat (frozen, boned,and packed), was found contaminated inBritish laboratories: in 1965, 17.3 percent; in 1966, 25.9 per cent; and in 1967,40 per cent (18).

All these developments indicate the ne-cessity of intensifying control and sanitarymeasures related to the meat industry, andalso of improving the technical processeseven further.

Precooked frozen packed meat, for ex-ample, after removal of recontaminationrisks, will have an ever-growing demand onthe international market.

We do not wish to dwell further on therisks offered by other meat products suchas sausages and canned meat. Let us, how-ever, remember the sad episode of typhoidfever in Aberdeen caused by corned beef,contamination of which was finally attrib-uted to the cans which were cooled in con-taminated water, after autoclaving.

Milk and Dairy Products

A very good review of diseases trans-mitted by milk and milk products has beenmade by Kaplan et al. (22).

With reference to dairy products in-volved in the international trade, powderedmilk has been responsible for salmonellosisand staphylococcal enterotoxic outbreaks.Also, certain varieties of cheese have beenfound to be implicated.

It should be emphasized, however, thatthe technological progress made in thedairy industry and the systematic practiceof pasteurization and other controls haveextraordinarily reduced the involvement ofdairy products in foodborne diseases.

Poultry

Modern poultry breeding is done in largeestablishments; mixed dehydrated feedsare used, and these are frequently contami-nated with Salmonella.

Slaughter and subsequent processing-bleeding, feathering, evisceration, washing,chilling, and freezing-contribute to thedissemination of Salmonella, with the re-sult that poultry meat serves as a very im-portant vehicle of salmonellosis.

Elliot, at the Meat Industry ResearchConference in 1969, indicated that verifiedanalysis of 597 chicken carcasses (whole,i.e., 1,200 g for each sample) showed a 28.5per cent rate of contamination with Salmo-nella. More complete information on thisinvestigation was published later (34).

The use of water with a high concen-tration of chlorine has given impressiveresults in some countries, leading to anappreciable reduction in contaminated car-casses (40).

Chicken, duck, and turkey meats, besidesbeing contaminated with Salmonella, mayserve as vehicles for enterotoxic staphylo-cocci and Clostridium perfringens.

Fish and Fish Products

Fish and fish products have been in-criminated frequently (31) in staphylococ-cal food poisoning, salmonellosis, and botu-lism, particularly in countries where fish isan important part of the diet. We shall notrefer to the disease caused by Vibrio para-haemolyticus, since we do not have infor-mation on its effect on the internationalfood trade.

With reference to salmonellosis, thisproblem usually arises when the fish arecaught in contaminated waters, or duringprocessing. Fish taken in the open sea willhave their intestinal tracts clear of entero-bacteria (5).


The principal problem caused by thistype of food is related to type E botulism.This risk apparently has been increasedby consumption of vacuum-packed smokedfish. More research on this particular sub-ject is required. Detailed information ontype E botulism outbreaks caused by fishproducts from 1932 to 1957 has been pub-lished by Shewan (31). Cases occurring inthe United States and Canada from 1899 to1964 are shown in publications by Meyerand Eddie (23). Interesting data on thissubject may be found in "Botulism 1966,"by Ingram and Roberts (19).

Dehydrated Protein Concentrates

The practice of feeding cattle and poultrywith dehydrated protein concentrates hasgreatly increased, as has the volume ofinternational trade in these items.

Unfortunately, these feeds constitute oneof the principal sources of Salmonella car-riers among animals. In fact, they repre-sent the first link in the chain "feed-cattle-meat-man," having been incriminated asoriginal sources of contamination in sal-monellosis outbreaks due to ingestion ofmeat and by-products (20).

The presence of Salmonella in these prod-ucts is explained by recontamination suf-fered after their processing, through birds(21), insects (28), and rodents, and by man

himself. This is applicable to meals pro-cessed from meat, blood, fish, and feathersas well as to those of vegetable origin.

Well-controlled processing and the useof adequate sanitary measures to avoid re-contamination offer very good results. Thishas been demonstrated (27) in fish reduc-tion plants in Peru, the major producer offish meal, where serious problems were en-countered when products were found con-taminated with Salmonella. Manufacturersin that country, through their industrialassociations and with the help of specialists

from the universities, were able to notablyimprove the hygienic quality of their prod-ucts. Mass transport of protein concen-trates in large containers brings with it newproblems that increase the recontaminationrisk.

Egg Products

Frozen and powdered eggs have causednumerous salmonellosis outbreaks. Theseproducts, which are used in the productionof ice cream, puddings, and pastry andwhich generally are submitted to heat pro-cesses after their reconstitution, offer greatdanger. Let us recall that total counts orcoliform tests practiced on these productsin most control laboratories are not alwaysrelated to the presence or absence of Sal-monella (35) and may give a false indica-tion of safety.

Pasteurization processes and adequatehygienic measures are diminishing the risksconnected with egg products.

Shellfish

Export and import of frozen or precookedshellfish acquires more importance eachday. These products have been associatedwith staphylococcal food poisoning, sal-monellosis, and epidemic hepatitis. Thepractice of fishing in contaminated areas,and improper hygienic-sanitary conditionsduring processing and packaging are themajor factors favoring contamination.

The health problems related to all of thefoods mentioned above are many and com-plex, and the intensification of measuresdirected toward their solution is an urgentnecessity.

Official Control

Authorities in each country will have toimprove and increase their control over

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foodstuffs, especially those entering inter-national trade. In regard to controls onmanufacturers in their own countries, it isimportant to remember that the modernconcept of control relies on food surveil-lance, in contrast to the classical conceptof inspection.

Inspection methods are retrospective, re-gressive, punitive, and uneconomical if theyare applied without surveillance. On thecontrary, surveillance methods are prospec-tive and preventive and are carried out bystudying the processing chain to determineat which point the contaminating agententers this chain.

Certainly, surveillance should not replaceconventional methods such as inspection,but it will indicate the direction and extentof the food protection measures neces-sary (39).

Surveillance should be conducted at theprimary source of production, during proc-essing, storage, and distribution, and evenat places of consumption.

Help to Industries

Government authorities should help in-dustrialists continuously, offering technicaladvice, encouraging personnel training, andshowing interest in their problems. Topoint out their deficiencies in production isnot sufficient; rather, ways to eliminatethem have to be shown. Controls shouldserve to encourage industry, not to destroyit. After all, industry is fundamental forthe countries' development.

For no reason, though, should this policybe synonymous with complacency in theface of bad-quality export products. Forexample, the granting of official approvalor good-quality certificates without theperformance of strict controls is bad prac-tice and discredits the industrialist as wellas the official agency that grants them.

Furthermore, even when such official cer-tificates are easily obtained, they do nothelp in evading the controls imposed by theimporters. Many cases confirm this ob-servation. One of them, published by ajournal of international circulation (30)relates that during the second half of 1960the Liverpool (England) laboratory re-jected 10,000 cans of Yugoslav canned ham(10 pounds each) because they were foundcontaminated with a great variety of micro-organisms, among them Clostridium per-fringens, although the official certificate oforigin guaranteed its quality and safety(30).

Cases such as these have even given riseto doubts concerning the advantage ofofficial certificates in international foodtrade.

Reprocessing

Other more radical measures imple-mented by large importing countries haveresulted in indiscriminate reprocessing of allfood of animal origin coming from areaswhere general sanitary conditions leavesomething to be desired. For example, totallots of meat would be irradiated at theunloading port, all fish meal consignmentswould be repasteurized, etc.

It is evident that such a procedure wouldbe totally undesirable for different reasons.

1) It would not stimulate exporters toimprove the hygienic quality of their prod-ucts.

2) The development of food technologyand training of competent technicians wouldnot be encouraged.

3) A continuous contamination of load-ing and unloading ports and of transportmedia would be favored.

4) It would be necessary to establish longquarantine periods for the products, alwaysunpleasant and uneconomical.


5) Decrease in the organoleptic and com-mercial value of the products would beencouraged, whether by the action of themicroorganisms, which under certain con-ditions could continue to develop (for in-stance, psycrophilic microorganisms inmeat or fish), or by the nature of the re-processing. It is important to point out thelatter because of the decrease in the nutri-tive value of some food by repeated treat-ments.

6) Finally, the food prices would notablyincrease, causing economic loss to producersand to consuming public.

Destruction of Contaminated Food

The reprocessing described above couldbe feasible when food is found highly con-taminated with Salmonella. On the otherhand, systematic destruction would be muchmore difficult, not only for economic rea-sons but also because such practice wouldrepresent a large reduction in the worldsupply of protein. In some countries thereis a tendency to avoid Salmonella investi-gation in food, so that supplies will not haveto be destroyed if found contaminated (40).Also, the lack of official control of importedfood results in a situation in which sub-standard products, which do not meet therequirements implemented in regions orcountries that have adequate industrial andofficial controls, are marketed without dif-ficulty in areas where controls are noteffective (35).

Good Manufacturing Practices

Throughout this report we have insistedon the importance of hygienic and sanitarymeasures for obtaining noncontaminatedfood. For these principles of hygiene to beeasily understood by industrialists and by

personnel responsible for production, theyhave to be explained in a clear and com-prehensive manner.

A compilation of these principles andrecommendations should be prepared in theform of codes or regulations of good manu-facturing practices for each type of in-dustry. Government technicians, industryrepresentatives, and specialists from uni-versities and research centers should col-laborate in their preparation.

There are various codes of this type al-ready published which have shown mag-nificent results. Application has been vol-untary in some cases and compulsory inothers. Those prepared by Hobbs (15), theSouth African Bureau of Standards (33),AFDOUS (U.S. Association of Food andDrug Officials) (1), U.S. Food and DrugAdministration and Department of Agricul-ture (37), and the Committee of FoodHygiene of the Codex Alimentarius Com-mission of FAO/WHO are good examples.

The Sanitation Handbook (37), for ex-ample, prepared by the U.S. Department ofAgriculture, is of great value for meat-processing establishments. The Spanishversion of this useful manual has been in-corporated in the series of Technical Notesof the Pan American Zoonoses Center andis being widely distributed (26).

Microbiology Control Laboratories

Insofar as official control is concerned,the participation of microbiology labora-tories in the international food trade ismost important. Their intervention pro-tects public health by avoiding the importor export of contaminated products.

With reference to industry, privatelaboratories assist in the proper selectionof raw material and in the approval or re-jection of the finished product before it islaunched on the market (36). A good ex-

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ample is the favorable experience obtainedwith microbiology laboratories in the dairyindustry, which were largely responsible forthe notable decrease in health problemscaused by milk and milk products.

Every industrial establishment shouldinstall its own control laboratory or makeuse of the services of commercial labora-tories. The industrialist should not waitfor the official laboratory to inform him ofhis product's quality.

It is necessary that analytical methodsand techniques be standardized at the inter-national level. Certain attempts are al-ready giving good results (24, 36), but inthis respect many problems are encoun-tered; the complete analysis of these is out-side the scope of this report. However, withcoordinated efforts and official support, therequired results can be obtained.

Microbiological Criteria

Microbiological criteria (standards, spe-cifications, limits) are useful instruments inthe international food trade. By familiariz-ing themselves with them, industrialists willknow the standards that should be met.

Such criteria must be established meth-odically and on the basis of appropriateexperimental studies. Figures cannot be in-vented nor "pulled out from the air" (13).They have to be rational and feasible toattain. Too rigid criteria discourage indus-trialists or cause dishonest producers toemploy fraudulent methods which are dan-gerous to health and which cannot alwaysbe detected.

Training

The scarcity of specialists in food hygieneand microbiology and of professionals welltrained in the modern aspects of food tech-

nology is a factor that may prove an ob-stacle to the effectiveness of measures takento reduce the risks in the international foodtrade.

It is necessary to stimulate and help uni-versities and research centers to organizeproper training in food microbiologythrough intensive courses for postgraduates.

Research

Research in food microbiology, hygiene,and technology, as well as in other scientificdisciplines, is essential. Proof of this is thegreat volume of research done in this fieldby the more industrialized .countries, andthe prodigious sums of money invested byGovernments and industries in those pro-grams.

However, in this field it is necessary thatthe results of tests and research done inother regions be adapted to our own area,taking into account, among other factors,the climatic or ecological differences, dif-ferent methods of breeding and feedinganimals, particular characteristics of ourseas and fishing industry, variations inmicrobial flora, practices of food workersand handlers, and differences in generalhealth conditions.

Because of the complexity of the prob-lems to be dealt with-embracing such dis-ciplines as microbiology, toxicology, tech-nology, and public health-comprehensiveresearch will only be possible if there aresufficient numbers of trained personnel, anadequate number of laboratories, well-equipped pilot plants, and continuing co-operation and support on the part of thecompetent authorities.

Recommendations

In view of the magnitude of the problemsinvolved and the fact that Latin American


countries will have to increase the produc-tion and exportation of food while at thesame time meeting the higher quality re-quirements of importers, a number of mea-sures, coordinated at the continental level,should be taken without delay.

First, the education and training of pro-fessional personnel specialized in the foodsciences should be promoted, and universi-ties and scientific centers should be providedwith the material assistance they need inorder to properly discharge that function.

Codes of hygienic manufacturing prac-tices for each type of industry should bedrawn up or adopted as soon as possible.They should be widely circulated to putthem into the hands of persons engaged in

the processing, storage, transport, and saleof foodstuffs.

Expert representatives of our countriesshould be encouraged to take a more activepart in the various committees of theCodex Alimentarius (FAO/WHO).

Appropriate steps should be taken tostandardize methods of food control, es-pecially of foods involved in internationaltrade.

To coordinate the above-mentioned ac-tivities, regional centers should be estab-lished under the auspices and with thetechnical assistance of the United Nationsspecialized agencies, and should undertakeresearch and training activities and providethe countries with technical assistance inmicrobiology and food hygiene.

BIBLIOGRAPHY

(1) "AFDOUS Frozen Food Code." AFDOUSQuart Bull 26:25-42, 1962.

(2) "Argentina Sanidad Animal (Inspección deProductos, Subproductos y Derivados de OrigenAnimal)." Reglamentación (Buenos Aires) 4:238-268, 1968.

(3) Bergdoll, M. S. "Bacterial Toxins in Food."Food Technol 23:530, 1969.

(4) Bowmer, Ernest J. "The Challenge of SaI-monellosis: Major Public Health Problem." AmerJ Med Sci 274:467-501, 1964.

(5) Buttiaux, R. "Salmonella Problems in theSea." Fish as Food (Vol. 2). Edited by G. Borgs-trom. Academic Press, 1962.

(6) Buttiaux, R. and M. Catsaras. "Les bac-téries psychotrophes des viandes entreposées enchambre froide. Influence de la température et del'humidité relative." Ann Inst Pasteur Lille 17:107-116, 1966.

(7) Center for Disease Control (USA). Food-borne Outbreaks: Animal Summary, 1967. At-lanta, Georgia, 1967.

(8) Center for Disease Control (USA). Food-borne Outbreaks: Animal Summary, 1968. At-lanta, Georgia, 1968.

(9) Center for Disease Control (USA). Salmo-nella Surveillance Report: Annual Summary, 1968.Atlanta, Georgia, 1968.

(10) Center for Disease Control (USA). Food-borne Outbreaks: January-June, 1969. Atlanta,Georgia, 1969.

(11) Clark, D. S. "Growth of Psychrotolerant

Pseudomonads and Achromobacter on ChickenSkin," Poultry Sci XLVII: 1575-1578, 1968.

(12) Edwards, P. R. "Salmonellosis: Observa-tions on Incidence and Control." Ann NY AcadSci 70:598-613, 1958, quoted by Galton et al.(Ref. 14).

(13) Elliot, R. Paul. Microbiological Standardsfor Meat and Poultry Products under Federal In-spection. Presented at a Symposium on Microbio-logical Standards for Foods. Madison, Wisconsin,9 April 1969.

(14) Galton, Mildred M., J. H. Steele, and K. W.Newell. "Epidemiology of Salmonellosis in theUnited States." In: The World Problem of Sal-monellosis, edited by E. van Oye. The Hague,1964.

(15) Hobbs, Betty C. Food Poisoning and FoodHygiene. London, 1953.

(16) Hobbs, Betty C. "Contamination of MeatSupplies. Part I: Salmonella and Staphylococcus."Monthly Bull Minist Health (London) 24:123,1965.

(17) Hobbs, Betty C. "Contamination of MeatSupplies. Part II: Clostridium welchii and Toxo-plasma." Monthly Bull Minist Health (London)24:145, 1965.

(18) Hobbs, Betty C. and R. J. Gilbert. "Micro-biological Standards for Foods: Public HealthAspects." Chem Industr 7:215, 1970.

(19) Ingram, M. and T. A. Roberts. "Botulism1966." In: Proceedings, Fifth International Sym-

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posium on Food Microbiology, Moscow. London,Chapman and Hall, 1967.

(20) Jacobs, J., P. A. M. Guinee, E. A. Kampel-macher, and Van Keulen. "Studies on the Inci-dence of Salmonella in Imported Fishmeal." ZblVeterinaermed(B) 10:542, 1963.

(21) Kampelmacher, E. A. and D. A. A. Mossel.Rapport Zoonoses. National Public Health Insti-tute. Utrecht, The Netherlands, 1963.

(22) Kaplan, M. M., L. V. P. Abdussalam, andG. Bijlenga. "Milk-Borne Diseases." In: MilkHygiene. World Health Organization, MonographSeries H8. Geneva, 1962.

(23) Meyer, K. F., and B. Eddie. Sixty-FiveYears of Human Botulism in the United Statesand Canada. George Williams Hooper Founda-tion, University of California, 1965.

(24) Mossel, D. A. A. and F. Quevedo. Controlmicrobiológico de los alimentos. CLEIBA Mono-graph Series No. 1. National University of SanMarcos, Lima, Peru, 1967.

(25) National Academy of Sciences. An Evalua-tion of the Salmonella Problem. Washington,D. C., 1969.

(26) Pan American Zoonoses Center. Manualpara inspectores sanitarios de mataderos (firstpart). Nota Técnica No. 10, PAHO/WHO, BuenosAires, 1969.

(27) Quevcdo, F. "Les enterobactéries dans lafarine de poisson." Ann Inst Pasteur Lille 16:157-162, 1965.

(28) Quevedo, F. and N. Carranza. "Le role desmouches dans la contamination des aliments auPérou." Ann Inst Pasteur Lille 17:199-202, 1966.

(29) Quevedo, F. Microbiología de productosfarmacéuticos y cosméticos. Presented at FirstNational Symposium on Drug Control. BuenosAires, Argentina, 1969.

(30) Semple, Andrew B. "The Control of Im-ported Food." J Roy Inst Public Health 28:297,1965.

(31) Shewan, J. M. "Food Poisoning Caused byFish and Fishery Products." In: Fish as Food(Vol. 2). Edited by G. Borgstrom, Academic Press,1962.

(32) Somers, R. K. "Protecting the Consumer."In: International Symposium on Health Aspectsof the International Movement of Animals (SanAntonio, Texas, August 1968). Scientific Publica-tion PAHO 182, Washington, D. C., 1969.

(SS) South African Bureau of Standards. Codeof Practice for Food Hygiene. Pretoria, SouthAfrica, 1956.

(34) Surkeiwicz, B. F., W. R. Johnston, A. B.Moran, and G. M. Krumm. "A BacteriologicalSurvey of Chicken Eviscerating Plants." FoodTechnol 23:80, 1969.

(35) Thatcher, F. S. "The Microbiology of Spe-cific Frozen Foods in Relation to Public Health:Report of an International Committee." J ApplBact 26(2) :266-285, 1963.

(36) Thatcher, F. S. and D. S. Clark (eds.).Microorganisms in Foods: Their Significance andMethods of Enumeration. University of TorontoPress, 1968.

(37) U. S. Department of Agriculture, Consumerand Marketing Service. Sanitation Handbook ojConsumer Protection Programs. October, 1968.

(38) Wells, K. F. "The Canadian Viewpoint."In: International Symposium on Health Aspectsof the International Movement of Animals (SanAntonio, Texas, August 1968). Scientific Publica-tion PAHO 182, Washington, D. C., 1969.

(39) World Health Organization. Report on theInter-Regional Seminar on Foodborne Diseasesand Food Hygiene Practice. Copenhagen, August,1969.

(40) World Health Organization. Microbiologi-cal Aspects of Food Hygiene. Report of a WHOExpert Committee with the Participation of FAO.Technical Report Series 399. Geneva, 1968.

DISEASE PROBLEMS ASSOCIATED WITH THE IMPORT ANDEXPORT OF ANIMAL PRODUCTS INTENDED FOR

CONSUMPTION

DR. TEODORICO TERRY *

International movements of livestock areusually carried out in order to achieve oneof the following objectives:

1. To promote the development or im-provement of livestock, through the useof male and/or female breeding animalsfrom another country whose livestock num-bers are usually substantial because itpossesses the necessary natural resourcesand technological facilities.

2. To replace over-mature animals byothers produced at lower cost in the export-ing country. The reduced cost may be dueto the fact that the exporting country pos-sesses resources not available to the import-ing country, as in the case of natural pas-tures. This type of movement is usuallylimited to dairy cattle, either unregisteredor a pure breed developed by crossbreeding.Nevertheless, it may involve transport ofmany thousands of head per year.

3. To transfer young steers from onecountry to another for fattening and con-sumption. This type of movement is fre-quent among bordering countries, particu-larly when one of them has good facilitiesfor breeding while the other has a goodconsumer market, attractive prices, andfacilities for fattening the animals. Manydifferent types of arrangements made arefor these movements, depending on prevail-ing conditions in international trade areasand livestock production practices.

* Assistant Director for Animal Health, Minis-try of Agriculture and Fisheries, Lima, Peru.

4. To import young steers for slaughtershortly after arrival at their destination inthe importing country, in order to com-pensate for local meat production shortages.

Livestock other than cattle are alsotraded, particularly sheep, for which thereis a good market in some countries. Themovement of live animals has been andcontinues to be one of the ways in whichcontagious diseases and animal parasitesare most easily spread from country tocountry and from continent to continent.Foot-and-mouth disease is one of the mostwidespread diseases in the entire world andthe movement of livestock has contributedsignificantly to its dissemination.

To achieve the goals for which livestockimports and exports are intended, it isessential to use the methods which researchand technology have made available toanimal health specialists for the purpose ofreducing animal diseases. Otherwise, theresults may be negative, producing losses ofunpredictable dimensions.

The movement of livestock always in-volves certain risks, some of which arelisted below:

1. The possibility of introducing moreserious exotic diseases-for example, thedanger of introducing a devastating animaldisease from one country to another oreven from one continent to another. Thesediseases include contagious pleuropneu-monia in cattle, bovine plague, and Africanswine fever, which fortunately has notspread to the Americas.

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2. The possibility that major livestockdiseases which exist in both exporting andimporting countries may develop to epizoo-tic proportions through imports of diseasedand/or carrier animals. This has been thesource of some epizootic waves of foot-and-mouth disease which have occurred inseveral South American countries. Suchwaves sometimes become explosive in theexporting country itself because of the con-centration of animals from various areas.

3. The possibility that diseases which areusually undetected on the originating farmsmay occur in explosive outbreaks at thetime of concentration of animals of diverseorigin in the exporting country, withintransit holding facilities, or in the receptionor quarantine centers of the importingcountry. Such diseases include infectiousbovine rhinotracheitis, viral diarrhea, andparainfluenza 3, which, when combined withthe stresses caused by confinement andtransportation, produce clinical symptomsand losses which oftentimes are severe andare practically indistinguishable from thoseof "shipping fever" or hemorrhagic septice-mia. The infectious bovine rhinotracheitisand diarrhea viruses have caused problemsin movements of livestock from North toSouth America.

4. The possibility that diseases whichhave a low prevalence in the exportingcountry may become very highly prevalentwhen introduced into herds of the import-ing country because of different ecologicaland management conditions that are morefavorable for the organisms. Bovine tuber-culosis may be cited as an example. Itusually reaches a high level of prevalenceafter its introduction through diseasedanimals into herds that are managedthrough a close-confinement system, suchas holding and breeding operations carriedout in corrals, in which the animals arenever sent to pasture.

5. The possibility that internal and ex-ternal parasites, as well as blood parasites,which affect animals moved from one coun-try to another, may propagate and estab-lish themselves in the livestock native tothe country of importation. In such casesit may be found that the cattle are infestedwith ticks (Boophilus) that transmitbovine piroplasmosis and anaplasmosis.These blood diseases cause considerablelosses when they attack animals from areasformerly free of them.

Many measures may be adopted in orderto prevent all these dangers. Althoughtransfers of live cattle generally entailgreater risks than the movement of freshmeat and animal products, it is possible toavoid-at least in some cases-the trans-portation of stock from countries or areasof countries in which such movementswould be dangerous. Prevention can beaccomplished by means of improved knowl-edge of the epizootiology of diseases, theirdistribution, control methods employed invarious countries, and periodic reports onthe changes that occur in health conditionsin exporting and importing countries. Suchinformation is provided through interna-tional agencies such as WHO and PAHO,the Pan American Foot-and-Mouth Diseaseand Zoonoses Centers, the InternationalOffice of Epizootics (OIE), and FAO. Suchknowledge is also very useful in establishingtechnical standards that the animal healthauthorities of the exporting country, thecountry or countries of transit, and the im-porting country may agree to implement.

International transport of breedinganimals does not always entail the samehealth risks ás the transport of livestockfor purposes of consumption. In breedinganimals, tuberculosis and bovine brucel-losis constitute a serious threat to nativeanimals which are in proximity with the

Disease Problems Associated with Import and Export of Animals

imported livestock, as well as to their prog-eny.

The movement of livestock to consumermarkets usually involves large numbers ofanimals. Although they are slaughteredshortly after reaching their destination,during round-up operations in the exportingcountry and during transit to the slaughter-house in the importing country they maycause serious epizootics if they are affectedby a highly communicable disease, and es-pecially a disease that can be contractedby indirect as well as direct contact.

External parasites, such as certainDiptera (flies), which may accompany theanimals while they are in transit, may com-plete the cycle and establish themselves inthe importing country if the environmentat the point of destination is conducive toreproduction and the population of maleand female parasites is adequate. Thepossibility of such a development is greaterin the case of large-scale movements ofanimals destined for slaughter because theyare usually subject to less stringent healthrequirements than those pertaining to live-stock imported for breeding purposes.

Transport of fresh meat and other animalproducts is not exempt from risks. In theliver and kidneys of swine affected by foot-and-mouth disease which are preserved bymeans of refrigeration, the virus may re-main viable for long periods and causeepizootics in the importing country ifbrought into contact with susceptible ani-mals. In this case, the native swine may besusceptible if they feed on refuse that hasnot been boiled or sterilized in some otherway. Bone meal obtained by means of aprocess that does not ensure sterilizationmay transmit Bacillus anthracis and pro-duce anthrax in animals which receive suchmeal in their feed as a mineral supplement.However, in the case of imports of freshmeats from countries which have an efficient

animal health organization and maintainstrict sanitary controls for slaughterhousesand for the export of slaughterhouse by-products, the risk is very small when com-pared with that involved in the movementsof live animals.

Thus, from the standpoint of animalhealth, when it is necessary to importproducts to compensate for shortages innational production of meats or otheranimal products, fresh meats should bepreferred.

For various reasons, at present there isconsiderable international trade in liveanimals destined for slaughterhouses. Oneof the reasons is that in order to carry oninternational trade in fresh meats, and topack, distribute, and sell them to the con-sumer, a special infrastructure is required,including refrigerated transportation andstorage facilities, and also such exportproducts are subject to more stringentcontrols than those applied to animals thatare slaughtered locally.

Furthermore, purchasers usually preferthe meat of freshly slaughtered animals;they object to frozen meats because theyare unaccustomed to preparing and con-suming them. And finally, in certain casesimports of live animals permit the opera-tion of slaughterhouses with greater capaci-ties than in circumstances where suppliesare obtained from national sources only. Inmany instances, of course, the reasonslisted may not apply, and trade in liveanimals may be replaced by trade in freshmeats.

Thus, in the interest of the importingcountry, priority may be assigned to theestablishment of an infrastructure designedto permit the aforementioned substitution.Furthermore, in the case of a country whoselivestock capital is increasing and willeventually cover the needs of its internal

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market, the same structure could be usedin national production.

Perhaps the most difficult task will bethat of changing consumer preferences. Thiscan be achieved, at least in some cases, ifthe processing techniques employed permitthe presentation of a product that is indis-tinguishable from those obtained fromanimals slaughtered locally, and also resultin the improved appearance of certain prod-ucts. Likewise, information regarding thecorrect preservation and use of refrigeratedmeats would tend to achieve the same pur-pose.

If complete substitution is achieved andthe requirement for cooking or heat sterili-zation of all refuse fed to animals in theimporting country is established, particu-larly in the case of swine, the danger ofintroducing and disseminating diseaseswould be reduced considerably.

As long as there is international trade inlive animals for slaughter, health standardsshould be adopted and applied in the ex-porting country and in the country orcountries of transit, as well as the importingcountry.

Such standards should establish the gen-eral requirement that the animals shouldoriginate from areas where there have beenno problems with communicable diseases,and that the farms or ranches of originshould participate in the disease-preventionprograms applied in the exporting country.Furthermore, it is highly desirable that,

prior to transit, the animals be vaccinatedagainst those preventable diseases to whichthey may be exposed until their arrival andslaughter in the importing country. Itshould also be established that transportfacilities, as well as resting places of cattle,should be controlled by the official animalhealth authorities. Such authorities shouldalso supervise cleaning and disinfectionoperations after their use by each herdof animals.

In addition, the feed received by the ani-mals while in transit should originate inplaces that are free of outbreaks of con-tagious animal diseases and of infestationby parasites. During transit from theirpoint of origin to their final destination, thelivestock should not have contact with ani-mals which have been subject to less rigidsanitary and health control. Preferably,each shipment should comprise animalsfrom a single area that has uniform animalhealth conditions.

Importing countries must report findingsof any test that is of significance from thestandpoint of animal health in internationaltrade.

One of the most effective measures foralleviating the problems caused by interna-tional movements of livestock for purposesof consumption will be the adoption of mul-tinational programs for control of commun-icable diseases and parasites which affectthe animals that are of greatest importancefor the respective national economies.

NEED FOR UNIFORM ANIMAL HEALTH GUIDELINES ANDREGULATIONS GOVERNING THE IMPORT AND EXPORT OFANIMALS INTENDED FOR CONSUMPTION AND BREEDING

DR. H. O. KONIGSHOFER *

Present International Activities

The need has long been recognized foruniform animal health guidelines and regu-lations governing the import and export ofanimals intended for consumption andbreeding, and work for this purpose is un-der way in many parts of the world. Thefollowing are only a few examples.

In Europe, the six countries of the Euro-pean Economic Community have been ne-gotiating for more than 10 years in thisfield, and several Community directiveshave resulted from that work. Other direc-tives, mainly those concerning importsfrom outside the Community, are still underdiscussion. In the Council of Europe, anagreement has been reached concerning thetransportation of live animals. The UnitedNations Economic Commission for Europehas held meetings of experts to discuss fa-cilitation of inspection procedures in inter-national inland traffic in Europe.

In the Organization for Economic Coop-eration and Development (OECD), a gov-ernmental organization of 22 countries,most of them situated in Western Europeand North America, sanitary regulationsfor international trade in slaughter stockand meat have been discussed for more than10 years and considerable progress has beenmade in the technical field, although a finalagreement has not yet been reached. OECD

* Food and Agriculture Organization of theUnited Nations, Rome, Italy.

has also endeavored to prepare an agree-ment for the description of the quality-de-termining properties of carcasses, with thepurpose of coordinating the various meat-grading systems applied at present on thenational level.

In the Near East, the work of unificationand standardization was initiated by theLeague of Arab States, and a meeting washeld in Khartoum (Sudan) in 1957, whichreached a near concurrence of opinion oncertificates to be used in the region. In 1966a Symposium on International Traffic inAnimals in the Near East Region was heldin Beirut (Lebanon), under the auspices ofFAO, which agreed on some basic princi-ples. Later, an Animal Production andHealth Commission for the Near East Re-gion was formed, which held its first meet-ing in Beirut in May 1969. As an outcomeof one of the recommendations of thatmeeting, negotiations are now under wayfor a regional agreement on certificates forslaughter animals.

In Central America, the work of theInternational Regional Organization forHealth in Agriculture and Livestock(OIRSA) is well known to the participantsof this meeting.

The International Air Transport Asso-ciation (IATA), a nongovernmental inter-national aviation organization, has drawnup guidelines for air transport of live ani-mals, on the basis of the recommendationsof a study group established for that pur-

123


pose. The facilitation division of the gov-ernmental International Civil Aviation Or-ganization (ICAO) is at present studyingthe possibilities of harmonizing the require-ments concerning veterinary disinfectionand disinsectization of planes on interna-tional flights, and of drafting guidelines forthe use of containers for animals and ani-mal products.

A committee for meat and meat productsis working within the framework of thejoint FAO/WHO Codex Alimentarius Com-mission. This committee seeks to formulateinternational agreements on certain stan-dards and, if possible, also an internationalcode of practices for slaughterhouses. It isworking on a worldwide level, in close co-operation with the aforementioned OECDgroups.

The International Office of Epizootics(OIE) has made remarkable contributionsto the international work on veterinaryregulations, since its establishment in 1924.FAO, through interagency agreements, ismaintaining close cooperation with OIEand with WHO/PAHO in this field. In 1964a joint FAO/OIE/WHO meeting was heldin Bern (Switzerland) on basic principlesfor the control of international traffic ofanimais and animal products. The conclu-sions and recommendations of that meeting,which continue to be valid, are presented inAppendix 1 to this paper.

The governing body of FAO has re-peatedly stressed the need for further studyof the international aspects of veterinaryregulations. Paragraph 258 and extractsfrom paragraphs 291 and 318 of the reportof the Fifteenth Session of the FAO Con-ference held in Rome, 8-27 November 1969,are shown in Appendix 2.

In the framework of these activities, ageneral review of laws and regulations gov-erning import and export of livestock andassociated products in Latin America was

prepared by the FAO Legislation Branch,in cooperation with the Animal HealthBranch, and was published in 1968 as aFAO working document (Animal HealthMonograph No. 9). This document wasdistributed to the directors of veterinaryservices of all countries of the Americas,and it is hoped that it will prove usefulin future work.

Purposes and Objectives

It is obvious that such extensive activitieshave not been developed without reason,and in fact there are many purposes andobjectives envisaged, among which the fol-lowing general considerations can be dis-tinguished:

a) Multilateral agreements aimed at theliberalization of trade are obviously boundto remain of rather limited value, as longas flexible sanitary and health requirementscan at any time be misused as a pretextfor nonimplementation. Agreements onveterinary health requirements are there-fore an indispensable precondition for thesatisfactory working of international or re-gional commercial agreements on trade inanimals and animal products.

b) Diverging and sometimes contradic-tory requirements in the various importingcountries are embarassing for exportingcountries. It is felt that many of thesedifficulties could be eliminated through in-ternational standardization, or at leastharmonization.

c) Transporters have to comply with avariety of formalities, different at eachfrontier and in each exporting, importing,or transit country. They feel that theserequirements could be harmonized, andlargely simplified, without detriment to thefinal sanitary and health objectives en-visaged by these requirements.

d) Nearly all Governments are inter-

Health Guidelines and Regulations 125

ested in information on foreign veterinarylegislation, for various purposes: to obtainguidance in their import decisions, to con-form with the requirements of potentialimporters, or to prepare reference materialfor their own legislative bodies. No inter-national organization is at present in aposition to provide adequate informationon this subject, and consequently there isan enormous duplication of effort in thevarious national Governments, causing ageneral feeling that the present chaoticsituation must be amended in some way.

Latin America has special reasons to beinterested in this work. There is an enor-mous potential for livestock production inthe region, which is still largely unutilized,although a nutritional demand for moreanimal protein undoubtedly exists in theworld. It has been stated with good reasonthat the protein gap is not so much a prob-lem of production, as one of distribution.With increased prosperity, the nutritionaldemand will progressively develop into atrue commercial demand. The most im-portant single factor limiting the access ofSouth American meat to world markets isthe presence of foot-and-mouth disease.Great efforts are being made to eradicatethis disease from the Hemisphere and tocontrol or eradicate the various zoonoseswhich constitute a hazard to public health.It is important that these efforts not befrustrated and that the results once ob-tained be reliably maintained. The mosteffective way to achieve this end will be toprotect the Americas as a whole. For thatpurpose, animal health regulations based onuniform guidelines must be enacted andequally enforced by all the countries.

Prospects and Problems

The prospects of achieving agreementson uniform animal health guidelines are

promising in Latin America. The precon-ditions are in fact more favorable thanin many other parts of the world. Thereis, first of all, a recognized common in-terest. The earning of foreign exchangethrough meat exportation is necessary forthe technical development of the Region;all Latin American nations will profit, eco-nomically and socially, from that commondevelopment.

Further, the expansion of trade withinthe Region is in the economic interest ofall the countries. The veterinary super-vision of animal trade within LatinAmerica, especially trade in slaughterstock, may be developed into a powerfulinstrument of common animal disease in-telligence, which is needed for joint veteri-nary action. It is also in the common inter-est that these technical objectives beachieved through proper coordination andharmonization, without unnecessary obsta-cles to intraregional trade.

Importation of breeding animals fromother continents may be desirable in theframework of organized and well-plannedlivestock improvement programs. Hereagain, it is a matter of common interest toensure, through uniform guidelines andregulations enforced by all countries con-cerned, that such imports are effectedwithout hazards to the animal health situa-tion in the Hemisphere.

The regulatory and technical precondi-tions are also favorable for an agreementon uniform guidelines. The aforementionedsummary prepared by the FAO Legisla-tion Branch shows that veterinary legisla-tion in the various Latin American coun-tries is based largely on identical technicalprinciples and very similar legal ap-proaches. To mention only one importantexample, the compulsory veterinary con-trol of exports appears to be a commonfeature of nearly all the legislations. Othercommon principles include a certain pref-

Need jor Uniform Animal


erence for the vertical approach to animaldisease control, through organized cam-paigns; and, for the time being mainly inthe field of veterinary food inspection, thebasic idea of a graduation of obligationsand privileges according to the type of in-spection received. These principles of timephasing and systematically graduated en-forcement may become important elementsin the future uniform animal health guide-lines of an area that is so rapidly develop-ing and is characterized by such a widerange of differences in basic conditions.

In spite of a justified optimism, however,the problems and difficulties should not beunderestimated. One of the first questionsto be resolved is that of the working proce-dure. It is quite obvious that withoutdirect contact on the technical level, agree-ment can never be reached. On the otherhand, Governments may insist that anystatement which may commit the countrymust be channelled through the ministryof foreign affairs; this is, of course, alengthy procedure and hardly suitable forthe purpose. The solution of the dilemmafound in other regions and groups of coun-tries may perhaps serve as a model forLatin America; it consists in forming

groups of experts, where the veterinary ser-vices of all participating countries are rep-resented and authorized to discuss and ex-change correspondence on the technicallevel, in their capacity as technical expertsonly and with the understanding that nostatement made by them, in speech orwriting, shall commit the Government con-cerned. Experience has shown that in thisway it is possible to arrive at draft agree-ments, on the technical level, which arelikely to be acceptable to the Governmentsof participating countries. The Govern-ments, of course, remain always free to ac-cept or to reject the agreements proposedby their groups of technical experts.

The method of procedure is not the onlyproblem. In spite of the far-reaching con-currence of opinion on matters of principleand on scientific approaches, there are stilltechnical and administrative implicationsat the executive level which must bethoroughly discussed before an agreementon uniform guidelines and coordinated im-plementation of veterinary regulations canbe reached. The first step must be toinitiate such discussions. No time shouldbe lost, since the favorable prospects exist-ing at present are not likely to last forever.

Need for Uniform Animal Health Guidelines and Regulations

Appendix 1

RECOMMENDATIONS OF THE FAO/OIE/WHO MEETING ON BASICPRINCIPLES FOR THE CONTROL OF INTERNATIONAL TRAFFIC OF

ANIMALS AND ANIMAL PRODUCTS

Bern, Switzerland, 12-17 October 1964

The meeting prepared, discussed and approved the following recommendations:

Animals and Animal Products

The meeting recommended:that governments organize in their countries a veterinary service adequately provided

with qualified staff and means to ensure an efficient control of animal diseases as well asinspection of meat and products of animal origin;

that the veterinary service be in a position to confirm as soon as possible outbreaksof contagious animal diseases in their country and to transmit this information to thecompetent international organization;

that veterinary sanitary regulations established regarding importations and exporta-tions of animals and animal products concern only sanitary matters with the exclusionof all economic considerations;

that each country adopt lists of animal diseases of significance for importations andexportations, taking into account the risk of their spread and the means of controlavailable, on the basis of the lists already established by OIE;

that account be taken of work already carried out by various international organiza-tions on:

(a) the definition of conditions under which animals can be declared free of the above-mentioned diseases, taking into account the most recent diagnostic methods.These methods should be standardized;

(b) the definition of conditions under which a country may be declared free fromthe above-mentioned diseases;

(c) the modalities under which quarantine should be organized.that under the aegis of the different international organizations studies be undertaken

concerning the consequences of vaccination in international traffic of animals, meat andproducts of animal origin;

that taking into consideration the new storage techniques, the report of the FAO/OIEMeeting on International Regulations for the Import and Export of Cattle Semen,held in Cambridge in 1955, be brought up to date;

that studies be undertaken to establish the methods of treatment (for example heat,irradiation, etc.) which will assure the destruction of virus in meat, meat products andall products of animal origin;

that the inspection of meat and products of animal origin be carried out by a sufficientnumber of specialized veterinarians who may be assisted by qualified lay inspectorsunder their supervision, applying inspection methods and practices harmonized on aninternational basis;

127

128 Import and Export .of Animals

that detailed international standards concerning conditions with respect to construc-tion, management, hygiene and especially potable water supplies, to be fulfilled byslaughterhouses, and establishments handling meat and other products of animal originfor export purposes be promulgated;

that the work on the Codez Alimentarius be taken into consideration and encouraged;that sanitary requirements prescribed by an importing country with respect to its

imports be comparable to those of all countries in which the health status of livestock,the technical equipment and the efficiency of the veterinary services are similar;

that adequate advance notification of conditions governing the importation of animals,meats and products of animal origin be given by importing countries;

that taking into account points already agreed, the drafting of model certificates andidentification systems suitable for use in international traffic of animals and all productsof animal origin should continue.

Fish and Fish Products

Recognizing the necessity for the sanitary control of international traffic in fish andfish products the meeting recommended:

that this task be entrusted to appropriate government services since these productsmay be the cause of the transmission of infectious and parasitic diseases of man andanimals, including fish, and

that OIE and FAO continue their work on this subject and that other internationalorganizations working in this field be invited to collaborate.

Associated Items

Recognizing the risk of animal and human disease transmission inherent in garbageand other refuse from ships, planes, trains or road transport engaged in internationalcommerce, the meeting recommended:

that governments introduce regulations requiring that when such garbage or refuseis removed from carriers, it be immediately incinerated or, if this is not feasible, it beburied or sterilized with strict sanitary precautions;

Recognizing the potential danger of disease transmission through the use of hay,straw and other plant materials for the packing of manufactured products in inter-national commerce and considering the general availability of other acceptable materials,not associated with animal production, the meeting recommended:

that all countries encourage commercial shippers to use other generally availablematerials such as man-made materials;

Recognizing the need for the control of international movements of biologicalproducts for the prevention or treatment of disease, and of living pathogens and ofvectors of disease, the meeting recommended;

that committees of existing organizations further study these matters and recommendmeasures that should be adopted by governments.

International Transport

The meeting recommended:that the transport of animals, meat and products of animal origin should be carried

out in such a way as to avoid any risks of propagating disease for transit countries aswell as the country of destination and that to this effect, adequate disinfection and

Need for Uniform Animal Health Guidelines and Regulations

disinsectization of means of transport particularly by aircraft, be carried out in accord-ance with norms to be agreed upon. In this connection, points of entry, in particularairports, should be equipped with adequate animal health installations;

that transport of animals should take place in suitable vehicles under veterinarycontrol and in such conditions as will avoid unnecessary distress;

that studies be continued to determine the best conditions for the transport ofanimals, meat and products of animal origin;

that close cooperation be established with organizations concerned with transportationat the national and international levels.

The Future Role of International Organizations and Any New Bodies WhoseEstablishment AMay Be Proposed

The meeting recognizing the value of the work done by the various organizationsand appreciating the results already obtained in the control of international traffic inanimals and animal products, realizing the need for promoting international trade, whilemaintaining adequate safeguards against the introduction of animal diseases, consideringfurther that the time has come when there would be advantage in a degree of standardi-zation of the practices, recommended that:

(a) collaboration in this field be continued under the existing agreements betweenOIE, FAO and WHO and with other interested organizations;

(b) FAO and OIE cooperate in the production of a comprehensive dossier of regu-lations governing animal import and export, their products and associated items;this should be iIl such a form as to permit constant revision for the informationof authorities;

(c) present available information and supplementary information obtained fromgovernments should be collated and systems of harmonization devised;

(d) the basic principles as elaborated in the report should be followed as far aspossible by governments;

(e) in view of the importance to the economies of the developing countries of theexport of animals and animal products, special consideration should be given tothe problems involved by international organizations;

(f) in view of the limitations placed upon the traffic of animals and their productsfrom developing countries due to the presence of diseases, FAO should givesympathetic consideration to requests for help in this connection from suchcountries;

(g) since it is realized that harmonization on a global basis is impossible at present,existing regional committees of FAO and OIE, in cooperation with other organi-zations, should be requested to foster regional harmonization, particularlybetween countries in which the animal health situation is comparable.

The meeting having discussed the veterinary aspects of the international traffic inanimals and animal products,

recognizing the need of a more efficient use of information available in the variousbureaus, central and regional, of international organizations,

recommended that FAO, OIE and WHO investigate the possibility of establishinga joint international center for veterinary documentation and information in Paris.

129


Appendix 2

EXTRACTS FROM THE REPORT OF THE FIFTEENTH SESSION OFTHE CONFERENCE OF THE FOOD AND AGRICULTURE

ORGANIZATION OF THE UNITED NATIONS

Rome, Italy, 8-27 November 1969

Paragraph 358, page 69

Particular attention was directed to the potential of livestock production as a sourceof foreign exchange, especially beef production in developing countries. The greatestsingle impediment to the export of livestock products lay in the incidence of diseases,although advances were being made in their control, particularly in Latin Americaand Africa. The Conference requested FAO to intensify its efforts in this field and toassist member countries in the establishment of quarantine measures. The Organiza-tion should study the health regulations which appear to be impeding meat importsand keep potential exporters informed as to these. The creation and recognition ofdisease-free zones was proposed, and it was noted that this would be closely examinedby FAO, in cooperation with other interested bodies, during the coming biennium. Inaddition to its actions in respect of disease control and the elimination of trade barriersagainst meat, FAO should strengthen its work on improving local breeds and shouldcontinue its appraisal of the world's grassland resources.

Extract from paragraph 291, page 57

. . . The great potential which existed for beef and milk production, particularlyin Africa and Latin America, was frequently stressed; and the Conference consideredthat this should be developed through programs of disease control of cattle, the estab-lishment of an international code for the control of animal diseases, and of healthregulations for processing . . .

Extract from paragraph 318, page 62

The need for implementation of quarantine and other measures in the control ofanimal diseases, including foot-and-mouth, rinderpest, contagious bovine pleuropneu-monia, tickborne diseases, and trypanosomiasis was strongly emphasized by the Con-ference although it was recognized that the degree of importance of each would varybetween individual countries ..

PRESENT AND FUTURE PROBLEMS ASSOCIATED WITH THEIMPORT AND EXPORT OF ANIMALS AND ANIMAL PRODUCTS,

AND THEIR EFFECT ON THE ECONOMIC DEVELOPMENT OFCOUNTRIES

DR. ERNEST E. SAULMON *

It is with distinct pleasure that I appearhere today to discuss with you a matter forwhich I have real concern-the introduc-tion and spread of devastating livestockdiseases as a result of the internationalshipments of animals or animal products.My concern is not borne of unreasoningfear or undue apprehension, but rather ofthe full realization that the matter to whichI now address myself becomes more of achallenge every day. Each new trade routeopened, every development in transporta-tion technology, the continued expansion ofcommerce, and expanded travel by theworld's population are all mixed blessings.Although they promote better living condi-tions and contribute to a more affluentsociety, they also create problems withrespect to possible livestock disease spread.To those of us who bear the responsibilityfor protecting our nation's livestock andpoultry from possible devastation fromalien diseases, these rapid movements ofanimals, people, and products pose seriousproblems.

What once was a leisurely trip of severalweeks or even months by sailing vessel cannow be accomplished in a few hours byplane. The built-in quarantine period thatexisted en route for animals transported byocean vessel no longer exists. Similarly,there is danger from exposure of susceptible

* Director; Animal Health Division, AgriculturalResearch Service, U. S. Department of Agriculture,Hyattsville, Maryland, USA.

native animals to imported animals thatmight be silent carriers of diseases which,though perhaps not considered of greateconomic consequence in the country oforigin, could be devastating in the countryof destination. This situation can be likenedto that in which Europeans, in their ex-plorations of the New World, wroughthavoc with native populations of the areaby introducing such diseases as measles-but perhaps there was some measure ofretribution then, for the same venturesomevoyagers returned home from this Hemi-sphere with well-established cases of a newdisease called syphilis.

Fortunately today technology has helpedthe sentinel forces to combat animal dis-ease by developing certain safeguards.These include standards for specific kindsof quarantines, better pesticides for pre-cautionary treatments, a wider choice ofeffective disinfecting compounds, andgreater selectivity for certain health condi-tions through the formulation of new andmore meaningful diagnostic procedures.These are all available as components of aprotective regimen which each country mayestablish when dealing in the internationalmovement of animals and animal products.

In the United States of America, severalacts of Congress authorize the Secretary ofAgriculture to provide protection to the na-tion against the introduction of animaldiseases, but it is interesting to note thatthe same legislation also makes provision

131


for the expansion of export trade in live-stock and animal products by prescribingrequirements for animals intended for ship-ment to foreign countries and for their hu-mane handling in transport. In addition,there are procedures for the inspection andcertification of export animal products tocomply with the import requirements of thereceiving country.

In a discussion of this entire field, it iseasy to oversimplify such an intricate andcomplex system, which is required to serveas a barrier against animal diseases offoreign origin and thus protect a nation'seconomy; however, suffice it to say thatsuch a system must be constantly reviewedto be sure that it keeps pace with the times.

Any nation's demand for imports of ani-mals or animal products is usually basedupon the economic needs of its citizens. Theneed for new breeds, new bloodlines, or newgerm plasm, or the importation of animalproducts in the development of new in-dustries, must be weighed against the risksof disease introduction. Every importingcountry must therefore accept the fact thatthe international movement of animals, ani-mal products, and related materials alwayscreates some degree of risk. However, webelieve that applying the knowledge drawnfrom many sources and acquired over theyears in combating animal diseases willgive us a substantial amount of assurancethat most importations may be completedwithout undue risk to our native animalpopulation.

Every country is, or should be, proud ofthe animals and agricultural commoditiesit exports to foreign countries. Since inter-national commerce is most beneficial to theexporting country when it is repetitive,acceptability in the country of destinationis most important. Trade in animals, ani-mal products, and related materials tendsto draw countries together. Under suchcircumstances, the need for veterinary

authorities and other officials of the coun-tries in question to develop and maintainclose contact in connection with problemsrelating to international trade may becomeone of the more important bonds forgedbetween those countries. To that end, andto help its economy, an exporting countryshould be expected to take all reasonableprecautions so that only sound and healthyanimals, as well as disease-free and uncon-taminated animal products, are exportedto foreign countries. No country, however,can offer a complete guarantee that suchshipments will never be the means of dis-ease introduction or spread.

It may be surprising to many of you tolearn that the United States is primarilyan importing country insofar as livestock isconcerned. It imports from 750,000 to 1.3million cattle annually, while exporting ap-proximately 100,000. For livestock exports,we are often asked to certify that the ani-mals in the shipment or the herd of originor the area of origin are entirely free of acertain named disease. This is possiblewhen such certification refers to such dis-eases as foot-and-mouth disease, rinder-pest, vesicular exanthema, bovine conta-gious pleuropneumonia, and other diseasesthat do not exist in the United States. Itmay be possible also with respect to brucel-losis, tuberculosis, scabies, and hog cholera,diseases for which we have official controlor eradication programs. For certain otherdiseases that may not be included in ourcontrol and eradication programs, certifica-tion becomes a more difficult matter.

We make every effort to use acceptedlaboratory test procedures as valuable toolsto help clarify the status of herds or areasof origin. However, when definitive diag-nostic tests have not been established oraccepted, the tests themselves sometimescreate problems. These facts are well un-derstood by animal health specialists, butto a lesser extent by others connected with

with Import and Export of Animals 133

the livestock industry. Thus, problems mayarise when veterinary health officials mustnegotiate on health matters through non-technical offices in diplomatic channels bymeans of persons not thoroughly knowl-edgeable in this area. Most assuredly,language barriers and different interpreta-tions or concepts can be most successfullydealt with by direct negotiations betweenveterinary health officials in the two coun-tries concerned. This has not been possibleoften enough in the past, but we are hopefulthat such direct dialogue may be a moreaccepted practice in future negotiations.

In our country, imported meat and ani-mal products are divided into two classes:those from countries that are declared in-fected with foot-and-mouth disease orrinderpest, and those from countries con-sidered free of such devastating diseases.All meat and animal products are subjectto port-of-entry inspection, and it is theresponsibility of our Animal Health Divi-sion to determine eligibility of such prod-ucts for entry.

Fresh meat and other meat productsderived from ruminants or swine originat-ing in countries where foot-and-mouth dis-ease or rinderpest exists could carry thevirus, and thus the international movementof such products is an ever-present threatto disease spread. To be safe for importa-tion, such products must first be processedin a manner to destroy the virus, if present,and then they must be handled in such away as to prevent contamination afterprocessing. A very real problem involvedwith meat is that although thorough cook-ing (heating) destroys the virus, no ac-curate practical test exists to determine theexact temperature to which the productwas heated.

Other animal products, such as organs,glands, skins, hides, and bones, are potentialsources of various kinds of animal diseases.All such animal products must be inspected,

and those that present a high risk musteither be refused entry or be permitted re-stricted entry so as to be transported andprocessed in a manner that will renderthem safe. This necessitates the assignmentof appropriate supervisory personnel oversuch transport and processing, as well asthe disposal of affluent material from theprocessing and the cleaning and disinfec-tion, as appropriate.

This leads us to a major part of oursubject: What are the effects of import-export problems on the economic develop-ment of countries? Livestock health of-ficials in each country must assume theresponsibility for preventing the entry andspread of devastating diseases that couldadversely affect the livestock productionor the economy of their country. Sometimessuch officials appear less apprehensive aboutthe introduction of diseases that alreadyexist in their country than about a similardisease that is not known to exist there.This is not necessarily a valid position,because there are other factors which mustbe considered. The Western Hemisphere,for example, remains in the very fortunateposition of being free from many diseasesprevalent in other parts of the world. Afri-can swine fever, African horsesickness, andrinderpest are but three examples of suchdiseases. Thus, if for no other reason, thethreat of each of these devastating diseasesshould be cause for all the animal healthofficials in every country in this Hemisphereto be equally concerned with internationalshipments that might lead to the introduc-tion and spread of any of them. Further,although some types of foot-and-mouthdisease now occur in some areas of theHemisphere, other types are not present.The introduction of foot-and-mouth diseasestrains SAT-1, SAT-2, SAT-3, or Asia-l,for example, could certainly create asdevastating results in a country alreadyinfected with types A, O, and C as would

Present and Future Problems Associated


the introduction of any of the seven typesinto a country then free of all such types.

Much of the landmass area in the West-ern Hemisphere is agriculturally oriented,and thus livestock production is an im-portant, if not a major, part of the economythat must be protected. The point we aretrying to make is that even though acountry in the Hemisphere may be infectedwith one or more types of foot-and-mouthdisease, the officials in that country shouldbe as concerned with precautionary meas-ures to prevent the introduction and spreadof additional types as are the officials in acountry that is free of all seven types offoot-and-mouth disease. In reality, thenecessity for continued international move-ments of animals and animal productsshould bring about closer liaison betweenappropriate health officials in the countries,so that adequate precautionary measuresagainst the introduction and spread of dis-ease can be applied as a combined effort forthe uniform protection of all the countries.

One area of growing concern to us, andone that is most difficult to control, is thatof increased world travel. A livestock ownermay be in contact with animals in onecountry at a given moment and a fewhours later be on a ranch in another countrythousands of miles away. Could he be amechanical carrier of livestock diseases?Unfortunately, yes! Or someone hunting inAfrica may take the cape of a wild boar tohis country as a trophy. If the wild boarwere infected with African swine fever(and many such animals are inapparentcarriers), this could be an effective methodof disease introduction and dissemination.The fact that dangerous disease organismsare not visible to the naked eye makes itvery difficult for the average traveler tounderstand when he is told that his per-fectly harmless-looking animal product

may actually be a carrier or transmitterof devastating livestock diseases. It mayalso be difficult to explain the legal ortechnical reasons for applying arbitrary re-strictions on the importation of any animalor animal product, but those reasons, ifbased on facts and experience, must beadhered to in order to protect a nationagainst disease introduction, even at therisk of momentary ruffiled feelings of aworld traveler.

Export certification of animal productsis an important function of the veterinaryservice of any country. Whereas animalscan be inspected, tested, quarantined, andeven vaccinated against some diseases, ani-mal products in most cases cannot. Import-ing countries must depend, in part, uponcertifications issued by veterinary officialsin the country of origin. Such statementsand certificates must be examined to deter-mine that they are reliable, factual, andnot misleading; otherwise the integrity oflater certification will be questioned.

One other avenue we can follow is to poolour knowledge for disease prevention. Thereporting of disease conditions in our coun-tries through the regular channels shoulddefinitely be continued. New techniquesfor disease diagnosis and prevention shouldbe shared by all countries once their valid-ity is recognized. Finally, one of the bestapproaches is to be sure that we keep alllines of communication with each otheropen. Regular formal meetings, such as thisone and others as necessary, will give us abetter understanding of problems as theydevelop, thus promoting early resolution.In this way, I believe we can minimize oravoid many of the pitfalls connected withour respective import-export programs.

We in the Americas must not only con-tinue to be conscious of the economics ofanimal agriculture in our respective coun-

Present and Future Problems Associated with Import and Export of Animals

tries and take such steps as may be neces-sary to protect and improve the healthstatus of our animal populations, but wemust work together in the exchange of sci-

entific knowledge, technological know-how,and general information to bring about im-provements that will be reflected in the eco-nomic expansion of the Hemisphere.

135

ANNEXES

Annex 1

EPIDEMIOLOGICAL SURVEILLANCE OF FOOT-AND-MOUTHDISEASE

DR. ROBERTO GOIC MARTINIC AND DR. VICTOR H. MOSCOSO *

The II Inter-American Meeting on Foot-and-Mouth Disease and Zoonoses Control(Rio de Janeiro, May 1969), in ResolutionI, supported the proposal of the PanAmerican Foot-and-Mouth Disease Centerto institute an inter-American epidemio-logical surveillance program against thisdisease. It further recommended that theaffected countries in the Americas submit tothe Center at regular intervals epidemio-logical reports on outbreaks, identifying thetypes and subtypes of causative virus, inaccordance with the guidelines issued by theCenter; that the Center analyze and dis-tribute this information to the animalhealth services of the countries of theAmericas; and that it follow the same pro-cedures for vesicular stomatitis.

A number of measures and activitieswere undertaken in order to build a systemwhich will lead gradually toward this ob-jective, according to the Center facilitiesand the various situations and capacitiesof the national agencies in this field.

The first steps were taken toward or-ganizing and developing the regular infor-mation furnished by the countries, as isdescribed in PASB Document RICAZ2/9(mimeographed), "Data on Foot-and-Mouth Disease in South America." Thisled to the publication and distribution ofthe Epidemiological Report on Foot-and-

*Pan American Foot-and-Mouth Disease Cen-ter, Rio de Janeiro, Brazil.

Mouth Disease and Vesicular Stomatitis,which in the first issue summarized all theavailable data on laboratory-confirmed di-agnoses of foot-and-mouth disease andvesicular stomatitis in Central America,Panama, and South America during 1968and the first half of 1969. The followingtwo issues covered similar material for thethird and fourth quarters of 1969. Startingin 1970, the publication was issued monthly.Each issue contains epidemiological newsand comments, according to the data pro-vided by the countries.

Argentina, Colombia, Paraguay, andUruguay subdivide their information infortnightly periods. Chile, Ecuador, andthe Brazilian State of Rio Grande do Sulprovide monthly information, while Vene-zuela maintains bimonthly statistics. Un-fortunately, delivery of data to the Centercontinues to be irregular in many cases, butclose attention is being given to the matterin order to ensure the regular and timelyreceipt of all statistics. The informationreceived from the other states of Braziland from Bolivia and Peru has in generalbeen scarce and sporadic, as is reflectedin the Center's publications.

The Epidemiological Report is mailed toall Member Countries of the Pan AmericanHealth Organization, a total of 105 ad-dresses, including 26 Ministers and Secre-taries of Agriculture, 32 directors of live-stock and chiefs of animal health, and 14

139

140 Annex 1

official diagnostic laboratories for vesiculardiseases. Furthermore, it is mailed to inter-national bodies, such as the Inter-AmericanDevelopment Bank, the International Officeof Epizootics, the Food and AgricultureOrganization of the United Nations, and tothe International Regional Organization forHealth in Agriculture and Livestock, whichincludes Mexico, Central America, andPanama.

Another increasingly important functionforming part of the epidemiological sur-veillance program is the analysis of fieldsamples of foot-and-mouth disease sent bythe countries, in order to detect the presericeof virus strains which have characteristicsdifferent from the usual ones and whichmay affect significantly the defense-attackrelationship of the viruses in the field.

During 1969 and up to March 1970, theCenter verified the existence of six virusstrains with qualities of new subtypes,found in Argentina, Colombia, Paraguay,Peru, Uruguay, and Venezuela, respec-tively. The results were made known tothe interested parties, and in certain casesimmunity studies were completed, for im-mediate application. Temporary identifica-tion was allotted to these viruses, until afinal classification is given by the WorldReference Laboratory. They were named:A Colombia/69, A Peru/69, A Uruguay/68,A Venezuela/70, C Argentina/69, and CParaguay/69. The letter signifies the typeof virus to which the studied strain belongs,while the number is the year when thesample was obtained. In 1969, 610 vesicularsamples from all the Latin countries ofSouth America and from Guyana, as well as41 samples from Central America andPanama, were tested.

With a view to increasing the effective-ness of these services, especially as regardsthe availability of specialized personnel, theCenter is making the necessary studies to

improve the vesicular diseases surveillancesystem, taking as a basis foot-and-mouthdisease, which could even serve as a frameof reference for a system encompassinganimal communicable diseases in general.

The immediate purpose of the project isto contribute to the prevention and controlof foot-and-mouth disease in the Americas,through the collection, analysis, and dis-semination of comparable epidemiologicaldata on animal vesicular diseases. Amongits objectives are the assessment of the ani-mal population's characteristics and of thedistribution and frequency of vesiculardiseases which affect it, as well as the de-termination of factors related to the trans-mission and spread of the diseases and theirsocioeconomic effects.

In order to attain this goal, an attemptwill be made to develop a methodologywhich will include the evaluation of eachcountry's possibilities, definition of theminimum of comparable information re-quired, testing of the reliability of the datasources, and formulation of adequate pro-cedures for the collection, classification,analysis, and distribution of data.

An important aspect of the project isthe definition of parameters which will bestfulfill the objective of measuring the distri-bution and frequency of the disease. Ingeneral, the animal health services maintainsystems which do not offer the necessaryinformation for evaluating the disease. Inline with the advances in modern veterinaryscience, and particularly epidemiology,marked changes must take place in theattitude of professionals and in the activi-ties of the agencies responsible for the col-lection of epidemiological data. This proc-ess of change is usually slow, and to pursuethis objective the Center has undertakencertain exploratory activities. These havegiven good preliminary results in Brazil(State of Rio Grande do Sul), where the

Epidemiological Surveillance of Foot-and-Mouth Disease

foot-and-mouth disease campaign now pub-lishes a monthly epizootiological bulletin,containing adequate data for assessing thestatus of the disease.

During 1970 the Center hopes to take thenecessary steps for implementing a com-plete system of epidemiological surveillance

of vesicular diseases in the Americas.Meanwhile, it will continue to publish theMonthly Epidemiological Report, and en-deavor to gradually improve the basicinformation provided by the countries,utilizing a special printed form recentlydeveloped for this purpose.

141

Annex 2

LIST OF PARTICIPANTS

Governments BOLIVIA

RepresentativeARGENTINA Dr. José Luis Roca García, Minister of Agri-

cultureRepresentative

Dr. Lorenzo A. Raggio, Secretary of Statefor Agriculture and Livestock

A IternateDr. Jorge Borsella, Director General of

Animal Health, Secretariat of State forAgriculture and Livestock

AdvisersDr. Victorio V. Olguín, Director of Inter-

national Health Affairs, Secretariat ofState for Public Health

Dr. Juan Tomás Bowler, Acting TechnicalDirector, Health Campaign Services,Secretariat of State for Agriculture andLivestock

Dr. Alberto S. López Araoz, TechnicalSecretary, Department of Animal Health,Secretariat of State for Agriculture andLivestock

Dr. Estela S. Menchaca, Vice-President, Na-tional Institute for Agricultural and Live-stock Technology, Secretariat of State forAgriculture and Livestock

Dr. Luis Felipe Martínez Fontes, Director,Meat Inspection, Secretariat of State forAgriculture and Livestock

Dr. Carlos Hugo Caggiano, Deputy As-sistant, Foot-and-Mouth Disease Controland Reference Laboratory, Health Cam-paign Services, Secretariat of State forAgriculture and Livestock

BARBADOS

RepresentativeDr. Malcolm B. Proverbs, Senior Veteri-

nary Officer, Ministry of Agriculture, Sci-ence and Technology

AlternateDr. Angel Gutiérrez, Chief, Technical Live-

stock Service, Ministry of Agriculture

BRAZIL

RepresentativeDr. Ezelino Arteche, Secretary General of

Agriculture, Ministry of Agriculture

AlternatesDr. Raimundo Cardoso Nogueira, Director-

General, Animal Production Desk, Min-istry of Agriculture

Dr. Sergio C. Bogado, Director, VeterinaryDepartment, Rural Field Foundation,Ministry of Agriculture

Dr. Silvino C. Horn, Chief, Foot-and-MouthDisease Vaccine Control Unit, Ministryof Agriculture

Dr. Evandro Horta Costa, Coordinator,Foot-and-Mouth Disease Campaign, Min-istry of Agriculture

Dr. Claudio M. W. Figueiró, Director, Di-vision of Animal Health Protection, Min-istry of Agriculture

Dr. Ivo Torturella, Director, Zootechnicsand Veterinary Division, Department ofResearch, Ministry of Agriculture

Dr. Milton G. Guerreiro, Director, Veteri-nary Research Institute "Desiderio Fina-mor," Ministry of Agriculture

CHILE

RepresentativeMr. Lautaro Gómez Ramos, Director of

Animal Health, Agricultural and Live-stock Service, Ministry of Agriculture

142

List of Participants 143

AlternateDr. Eduardo Gutiérrez Jara, In Charge of

Vaccination Program, National Foot-and-Mouth Disease Project, Agricultural andLivestock Service, Ministry of Agriculture

COLOMBIA

RepresentativeDr. Gabriel Baraya, General Manager,

Colombian Veterinary Products Company(Agency of the Ministry of Agriculture)

A IternateDr. Jaime Estupiñán Arias, Director, Animal

Sciences Department, Colombian Agri-cultural and Livestock Institute (Agencyof the Ministry of Agriculture)

AdvisersDr. Germán Bello García, Scientific Di-

rector, Colombian Veterinary ProductsCompany

Dr. Osvaldo Acosta Jarma, Director, AnimalHealth Service, Colombian Agriculturaland Livestock Institute

COSTA RICA

RepresentativeDr. José Luis Solano Astúa, Chief, Sub-

Department of Animal Health, Ministryof Agriculture and Livestock

CUBA

RepresentativeDr. Pedro Roca, Director, National Veterin-

nary Medicine Institute

AlternateDr. José Hidalgo Peraza, Director of Animal

Health, National Veterinary Medicine In-stitute

DOMINICAN REPUBLIC

RepresentativeDr. Luis María Cuevas, Assistant Director

of Livestock, Secretariat of State forAgriculture

ECUADOR

RepresentativeMr. Rubén Espinosa R.,

culture and LivestockMinister of Agri-

A IternatesDr. Miguel Angel Arévalo, Director of Ani-

mal Health, Ministry of Agriculture andLivestock

Dr. Luis Eloy Flor Cedeño, Chief of theDepartment of Laboratories, AnimalHealth Center, Ministry of Agricultureand Livestock

EL SALVADOR

RepresentativeMr. Ricardo R. Granada Pineda, Assistant

Director-General of Livestock, Ministry ofAgriculture and Livestock

FRANCE

RepresentativeDr. Louis R. Perpére, Departmental Director

of Veterinary Services, Ministry of Agri-culture

GUATEMALA

RepresentativeDr. Juan F. Urquizú Gutiérrez, Animal

Health and Quarantine Officer, Ministry ofAgriculture

GUYANA

RepresentativeHon. Robert J. Jordan, Minister of Agricul-

ture and Natural Resources

A IternateDr. Frank E. Mongul, Deputy Chief Agri-

cultural Officer, Ministry of Agricultureand Natural Resources

HONDURAS

RepresentativeMr. Julio C. Pineda, Minister of Natural

Resources

AlternateDr. Carlos H. Aguilar Avila, Chief, Animal

Health, Ministry of Natural Resources

144 Annex 2

JAMAICA

RepresentativeDr. Cedric L. Bent, Deputy Director of

Veterinary Services, Ministry of Agricul-ture and Fisheries

KINGDOM OF THE NETHERLANDS

RepresentativeDr. Robby G. Lieuw-A-Joe, Veterinary

Surgeon, Ministry of Husbandry, Agricul-ture, and Fisheries, Paramaribo

A lternateDr. Amador P. Nita, Minister of Labor,

Health and Social Welfare, Willemstad,Curacao

AdvisersMr. Gosse de Vries, Government Veterinary

Surgeon, Oranjestad, ArubaMr. Jan van Strien, Assistant Chief of

Veterinary Services, Department of PublicHealth

MEXICO

RepresentativeDr. Gustavo Reta Pettersson, Director-Gen-

eral of Animal Health, Ministry of Agri-culture and Livestock

NICARAGUA

RepresentativeHis Excellency Mr. José León Sandino,

Ambassador of Nicaragua to Argentina,Buenos Aires

PANAMA

RepresentativeDr. Pablo T. Quinteno Pinzón, Vice-Minister

of Agriculture and Livestock

AdviserDr. Nicolás Alvarez T., Regional Director,

Agriculture and Livestock Region No. 1,Ministry of Agriculture and Livestock

PARAGUAY

RepresentativeDr. Parisio Pineda Ayala, President, Na-

tional Foot-and-Mouth Disease Service

A IternateDr. Félix Humberto Paiva, Director of Ani-

mal Health, Ministry of Agriculture andLivestock

AdviserDr. Deogracio Villalba, National Foot-and-

Mouth Disease Service

PERU

RepresentativeGeneral Jorge Barandiarán Pagador, Minister

of Agriculture and Fisheries

AlternatesDr. Francisco S. Miranda V., Military At-

taché, Embassy of Peru, Buenos AiresCaptain Carlos H. Román La Hoz, Assistant

to the Minister of Agriculture

TRINIDAD AND TOBAGO

RepresentativeDr. Lionel M. Robinson, Minister of Agri-

culture, Lands and Fisheries

A lternateDr. Leonard V. Butcher, Head, Animal

Health Division, Ministry of Agriculture,Lands and Fisheries

UNITED KINGDOM

RepresentativeDr. John Reid, Chief Veterinary Officer.

Ministry of Agriculture, Fisheries andFood, Surrey

A lternateMr. Robert H. Ewart, Veterinary Attaché,

British Embassy, Buenos Aires

UNITED STATES OF AMERICA

RepresentativeDr. Frank Mulhefn, Deputy Administrator,

Agricultural Research Service, Depart-ment of Agriculture, Washington, D. C.

URUGUAY

RepresentativeDr. Juan María Bordaberry, Minister of

Livestock and Agriculture

List of Participants 145

AlternatesDr. Guillermo P. Lockhart, Zoonoses Co-

ordinator, Ministry of Livestock and Agri-culture

Dr. Nelson Magallanes Pastorino, Labora-tory Coordinator, Foot-and-Mouth Dis-ease Department, Ministry of Livestockand Agriculture

Dr. Walter S. Faliveni, Director of AnimalHealth, Ministry of Livestock and Agri-culture

VENEZUELA

RepresentativeDr. Humberto Olmos, Chief, Foot-and-

Mouth Disease Department, Ministry ofAgriculture and Livestock

CANADA

Official ObserverDr. Albert E. Lewis, Associate Director,

Contagious Division, Health of AnimalsBranch, Department of Agriculture

Pan American Sanitary Bureau

Dr. Abraham Horwitz, DirectorDr. Emilio Budnik, Chief, Zone VIDr. Pedro N. Acha, Chief, Veterinary Medi-

cal ServicesDr. Harold B. Hubbard, Veterinary Medical

ServicesDr. Enrique Mora, Veterinary Adviser,

Zone VDr. Benjamín L. Morán, Veterinary Adviser,

Zone IV

Chief, Secretariat ServicesMr. Luis Larrea Alba, Jr., Chief, Personnel

and Conference Section

Public InformationMr. David Lajmanovich, Washington, D. C.

Pan American Foot-and-Mouth Disease CenterDr. Mário V. Fernandes, DirectorDr. Roberto Goic Martinic, Acting Chief,

Field Advisory ServicesDr. José Freire de Faria, Foot-and-Mouth

Disease Area Adviser, Zone IV, Lima,Peru

Dr. Eugene Papp, Foot-and-Mouth DiseaseArea Adviser, Zone I, Caracas, Venezuela

Dr. Edwin Pérez, Foot-and-Mouth DiseaseArea Adviser, Zone IV, Bogotá, Colombia

Dr. Horacio Mónaco, Chief, Training Section

Dr. Karl Federer, Chief, Diagnostic andReference Center

Pan American Zoonoses CenterDr. Boris Szyfres, DirectorDr. Rubén Lombardo, Chief, Technical

ServicesDr. Fernando Quevedo, Chief, Food Micro-

biology Section

ConsultantsDr. Jacob G. van Bekkum, Director, Central

Veterinary Institute, Amsterdam, TheNetherlands

Dr. John B. Brooksby, Director, AnimalVirus Research Institute, Pirbright, Surrey,England

Dr. Jerry J. Callis, Director, Plum IslandAnimal Disease Laboratory, U.S. Agri-cultural Research Service, Greenport,Long Island, New York

Prof. Manfred W. Mussgay, President, Fed-eral Research Institute for Animal VirusDiseases, Tibingen, West Germany

Dr. Carlos A. Palacios, Director, VenezuelanResearch Center, Ministry of Agricultureand Livestock, Maracay, Venezuela

Dr. Ramón Rodríguez, Department of Inter-national Affairs, University of Chile,Santiago

Dr. Ernest E. Saulmon, Director, AnimalHealth Division, Agricultural ResearchService, U. S. Department of Agriculture,Hyattsville, Maryland

Dr. Teodorico Terry Elejalde, Assistant Di-rector for Animal Health, Ministry ofAgriculture and Fisheries, Lima, Peru

Dr. Enrique García Mata, Adviser, AnimalHealth, Secretariat of State for Agricultureand Livestock, Buenos Aires, Argentina

Observers

INTER-AMERICAN DEVELOPMENT BANK

Mr. Ildegar Pérez Segnini, Executive Director,Washington, D. C.

Mr. Carlos A. Paz, Representative in Argen-tina, Buenos Aires

Mr. Oscar Valdés Ornelas, Livestock Specialist,Division of Agricultural Projects Analysis,Washington, D. C.

Dr. Ramón A. Vega, Project Officer, Santiago,Chile

Dr. Abraham Arce, Project Officer, BuenosAires, Argentina

Dr. Félix Alvarez Gamarra, Project Officer,Asunción, Paraguay

146 Annez 2

INTERNATIONAL BANK FOR RECONSTRUCTION

AND DEVELOPMENT

Mr. Ramsay H. Khouri, Specialist in Livestock,Livestock Division, Agriculture Projects De-partment, Washington, D. C.

UNITED NATIONS DEVELOPMENT PROGRAM

Dr. Miguel Albornoz, Resident Representa-tive, Buenos Aires, Argentina

UNITED NATIONS CHILDREN'S FUND

Dr. Albert J. Reynolds, Deputy Regional Di-rector, Santiago, Chile

INTER-AMERICAN INSTITUTE OF

AGRICULTURAL SCIENCES

Dr. Hernán Caballero, Director, GraduateSchool, Agricultural and Livestock Sciencesof Argentina, Buenos Aires

INTERNATIONAL OFFICE OF EPIZOOTICS

Dr. Carlos Ruíz Martínez, President-Counsel-lor, National Council of Agricultural Re-search, Director, American Region, Caracas,Venezuela

Professor F. Lucam, Vice-President, Foot-and-Mouth Disease Commission

FOOD AND AGRICULTURE ORGANIZATION OF

THE UNITED NATIONS

Mr. Juan F. Yriart, Regional Representativefor Latin America, Santiago, Chile

Dr. Franck J. Peritz, Regional Officer for Ani-mal Health, Santiago, Chile

Dr. Fabián Recalde, Regional Nutrition Officer,Santiago, Chile

Dr. José J. Cañón, Deputy Director, JointECLA/FAO Agricultural Division, Santiago,Chile

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FOOT-AND-MOUTH DISEASE AND ZOONOSES CONTROL

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