Proceedings Joint WHO/FAO/OIE Technical Consultation on ... · Evidence linking bovine spongiform encephalopathy (BSE) and variant Creutzfeldt- Jakob disease (vCJD) in 1996 and the

Proceedings

Joint WHO/FAO/OIE Technical

Consultation on BSE:

public health, animal health and trade

OIE Headquarters, Paris, 11-14 June 2001

© Office International des Epizooties (World Organisation for Animal Health), World

Health Organization and Food and Agriculture Organization, 2002 World Organisation for Animal Health 12, rue de Prony, 75017 Paris, France Telephone: (33-1) 44 15 18 88 Fax: (33-1) 42 67 09 87 Electronic mail: [email protected] www.oie.int ISBN 92-9044-572-6 All rights are reserved by the World Organisation for Animal Health (OIE), World Health Organization (WHO) and Food and Agriculture Organization (FAO). This document is not a formal publication of the WHO. The document may, however, be freely reviewed, abstracted, reproduced and translated, in part or in whole, provided reference is made to the source and a cutting of reprinted material is sent to the OIE, but cannot be sold or used for commercial purposes. The designations employed and the presentation of the material in this work, including tables, maps and figures, do not imply the expression of any opinion whatsoever on the part of the OIE, WHO and FAO concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers and boundaries. The views expressed in documents by named authors are solely the responsibility of those authors. The mention of specific companies or specific products of manufacturers does not imply that they are endorsed or recommended by the OIE, WHO or FAO in preference to others of a similar nature that are not mentioned.

Proceedings – Joint WHO/FAO/OIE Technical Consultation on BSE: III public health, animal health and trade

Contents

Foreword..................................................................................................................... VII

Opening speeches

Romano Marabelli.................................................................................................... IX Bernard Vallat .............................................................................................................X Samuel Jutzi.............................................................................................................. XII David Heymann .....................................................................................................XIV

Background information

Objectives.................................................................................................................... 1 Consultation logistics and organisation of this document .................................. 2

Conclusions and key recommendations

Bovine spongiform encephalopathy: public health, animal health and trade ........................................................................................................ 3

Global risk and global need for action ................................................................... 4 Co-ordination and assistance at the international level........................................ 5

Risk assessment for vCJD and BSE ................................................................ 6

Hazard identification ................................................................................................. 6 Exposure assessment of BSE risk to humans – vCJD ........................................ 7 BSE in cattle ............................................................................................................... 8 Hazard characterisation............................................................................................. 9 Risk characterisation.................................................................................................. 9

Risk management....................................................................................................9

Meat-and-bone meal .................................................................................................. 9 Specified risk materials ............................................................................................ 10 Animals with confirmed or suspected BSE......................................................... 11 Surveillance ............................................................................................................... 11 Compliance ............................................................................................................... 12 Awareness.................................................................................................................. 12

Risk of BSE in sheep and other animal species ...................................... 12

Risk assessment in sheep ........................................................................................ 12

Contents

IV Proceedings – Joint WHO/FAO/OIE Technical Consultation on BSE: public health, animal health and trade

Risk management in sheep ..................................................................................... 13 Other ruminants....................................................................................................... 13 Other farmed animals.............................................................................................. 14 Fur-bearing mammals.............................................................................................. 14 Fish............................................................................................................................. 14 Companion animals ................................................................................................. 14 Passage of infectivity ............................................................................................... 15

Risk communication ............................................................................................ 15

Preamble.................................................................................................................... 15 General principles .................................................................................................... 16 Principles identified ................................................................................................. 16 Dealing with controversial science........................................................................ 17 Guidelines to regulators on good media communications................................ 17 The communication needs of Member Countries.............................................. 17

Specific recommendations to the International Organisations: WHO, FAO and OIE................................................................................................ 18

Abstracts

Opening presentations

M. Ricketts Bovine spongiform encephalopathy: public health, animal health and trade .................................................................................................... 21

C. Brunk Issues of risk communication in public debates about health and safety: the bovine spongiform encephalopathy crisis ............................. 22

Session 1: Risk analysis – hazard characterisation

D. Matthews Epidemiology of bovine spongiform encephalopathy ................................... 23

R. Will Epidemiology of variant Creutzfeldt-Jakob disease ....................................... 25

G. Wells Pathogenesis of bovine spongiform encephalopathy in bovines ................. 26

M. Jeffrey and M. Groschup Bovine spongiform encephalopathy agent infection of sheep...................... 30

A. Alperovitch and J. Huillard d’Aignaux Modelling epidemic(s) of variant Creutzfeldt-Jakob disease......................... 31

A. Fisher, C. Helps, H. Anil and D. Harbour Slaughterhouse techniques and the fate of various tissues in bovine spongiform encephalopathy.................................................................. 33

Contents

Proceedings – Joint WHO/FAO/OIE Technical Consultation on BSE: V public health, animal health and trade

S. Woodgate Animal by-products (rendering and melting): processes and products ................................................................................................................. 35

U. Kihm and P. Comer Use, storage and disposal of meat-and-bone meal and the associated risks...................................................................................................... 37

C. Narrod and J. Otte Global trade in livestock, livestock products and by-products..................... 39

Session 2: Risk assessment and consequence analysis

B. Schreuder, J. Wilesmith, J. Ryan and O. Straub Risk of bovine spongiform encephalopathy from trade in cattle with emphasis on the intracommunity trade......................................... 40

P. Comer Bovine spongiform encephalopathy – human exposure risk assessment ............................................................................................................. 42

G. Pascal The geographical bovine spongiform encephalopathy risk assessment – a first step towards understanding the risk for man................................................................................................................... 43

W. James Assessing the United States controls to prevent bovine spongiform encephalopathy ..................................................................................................... 44

L. Mascitelli Transmissible spongiform encephalopathies – risk assessment in livestock in Argentina .......................................................................................... 45

R. Young The impact of bovine spongiform encephalopathy on the economy of the United Kingdom ..................................................................... 46

N. Morgan Repercussions of bovine spongiform encephalopathy on international trade – global market analysis ..................................................... 48

Session 3: Risk analysis – risk management

D. Heim Control of bovine spongiform encephalopathy in livestock and reduction of human exposure..................................................................... 50

M. Savey and B. Durand Role of current diagnostic and screening tests in bovine spongiform encephalopathy: control and reduction of human exposure ................................................................................................... 52

Contents

VI Proceedings – Joint WHO/FAO/OIE Technical Consultation on BSE: public health, animal health and trade

C. Gaynor Bovine spongiform encephalopathy – risk management and cumulative risk reduction.................................................................................... 54

D. Taylor Technological parameters required to control bovine spongiform encephalopathy during production.................................................................... 56

D. Ward Capacity building for bovine spongiform encephalopathy management .......................................................................................................... 57

I. Chmitelin Cost and cost-effectiveness of bovine spongiform encephalopathy control measures in France................................................................................. 58

A. Thiermann Control of the international spread of bovine spongiform encephalopathy and variant Creutzfeldt-Jakob disease.................................. 60

Session 4: Risk analysis – risk communication

P. Walker Risk communication: findings of the Inquiry into bovine spongiform encephalopathy and variant Creutzfeldt-Jakob disease chaired by Lord Phillips.......................................................................................................... 62

D. McCrea Bovine spongiform encephalopathy: the consumer’s dilemma .................... 63

D. Byrne The decision maker’s dilemma........................................................................... 65

P. Brown The scientist’s dilemma ....................................................................................... 74

Appendix I Composition of Working Groups ......................................... 76

Appendix II Time-table ..................................................................................... 81

Appendix III List of Participants...................................................................... 84

Proceedings – Joint WHO/FAO/OIE Technical Consultation on BSE: VII public health, animal health and trade

Foreword

Evidence linking bovine spongiform encephalopathy (BSE) and variant Creutzfeldt-Jakob disease (vCJD) in 1996 and the discovery in 2000 of BSE in native-born cattle in several countries of the European Union has raised serious concerns on risks to public and animal health. These concerns have now spread beyond Europe in view of the widespread international trade of cattle and other animal by-products.

Many scientific uncertainties still exist and there is an increasing demand for science-based recommendations to ensure sound and reliable policy measures to safeguard human and animal health. It is assumed that human exposure is most likely to occur through consumption of certain infected bovine by-products and that one of the fundamental principles for the protection of public health should include measures to control BSE in animals.

The primary aim of this joint technical consultation involving the Office International des Epizooties (OIE), World Health Organization (WHO) and the Food and Agriculture Organization (FAO) was to provide science-based information to Member Countries, especially to those where the diseases have not yet been recorded. The consultation was also to provide a forum to review problems associated with international BSE control measures ensuring at the same time that unjustified measures are not applied to restrict trade.

Scientific presentations have been made by speakers of international renown on subjects ranging from pathogenesis of BSE to the impact of the disease on the economy of affected countries. The need to implement surveillance systems and the importance of carrying out risk assessment, risk management and risk communication were clearly identified. Aspects of food safety and consumer confidence received much attention and the scientific basis for the continuation of international trade wherever possible, was reviewed. Given the high quality of the presentations and the discussions that followed, we are confident that the objectives of the consultation have been met and that the key recommendations adopted and suggested by the three Organisations will be recognised world-wide.

We wish to express our sincere gratitude and appreciation to all those who devoted their time and expertise to the organisation of this consultation, in particular to the organising committee and the chairmen of the working groups. We are particularly indebted to Professor Robert Will, Director of the United Kingdom National CJD Surveillance Unit, who kindly agreed to chair the conference. Our thanks are also conveyed to the authors and to the staff of the OIE Central Bureau, the WHO and the FAO who checked the manuscripts and prepared the final texts for publication.

Bernard Vallat Director General, OIE

Gro Harlem Brundtland Director General, WHO

Jacques Diouf Director General, FAO

Proceedings – Joint WHO/FAO/OIE Technical Consultation on BSE: IX public health, animal health and trade

Opening speeches

Opening address of the President of the OIE Romano Marabelli

Colleagues Esteemed guests Ladies and Gentlemen

On behalf of the International Committee of the OIE Member Countries, I wish to extend my sincere thanks to the Director General of the WHO and the Director General of the FAO for having bestowed the honour of hosting this Conference on the OIE.

The Representatives of the Member Countries also reaffirmed their determination to combat BSE or prevent its occurrence by applying the methods proposed by scientists and experts. The Veterinary Services are, in fact, on the front line world-wide in the control of BSE and consequently are also committed to the anticipation of problems related to public health. I shall commit myself on behalf of the OIE to providing the necessary information to ensure their full responsibility. This conference will contribute to assisting us in making more rapid progress in the eradication of BSE throughout the world.

I now give the floor to the Director General of the OIE to say a few words.

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Opening speeches

X Proceedings – Joint WHO/FAO/OIE Technical Consultation on BSE: public health, animal health and trade

Opening address of the Director General of the OIE Bernard Vallat

Colleagues Esteemed guests

I wish to express the OIE’s satisfaction in seeing so many world-renowned specialists on BSE and vCJD gathered here today, working in the fields of scientific research, risk analysis for both animals and humans, as well as management of the risks linked to this unique disease.

My warm gratitude also goes to the WHO and the FAO, our co-organisers, for having bestowed on the OIE the honour of hosting this conference. I welcome the spirit of co-operation that prevails between our three organisations, which enables us to demonstrate and strengthen our complementarity in combating this disease and which will allow us in the future to improve our efforts and better utilise our resources to attain the objectives expected by our Member Countries, particularly in the field of communication of the risks related to this disease for both animals and humans.

It can be affirmed that never before in history has a health event of animal origin given rise to so many debates, controversies and economic and social upheavals within and outside the agricultural world. However, the impact of BSE on herds is insignificant in relation to other epizootics (less than 200,000 cattle affected over 15 years out of a global livestock population of nearly one-and-a-half billion). Furthermore, at the current stage of observations from the epidemiological surveillance of human populations, the impact is far from the level of ravages on humans caused by major zoonoses, such as rabies, echinococcosis, tuberculosis or bucellosis.

Nevertheless, the fight against BSE is and must be considered as a priority by our three organisations, especially because this phenomenon bears the seeds for possible spread from its country of origin. Not only does it constitute a threat for public health, but also it contributes to the undermining of confidence of citizens towards the scientific community.

Our organisations must make every effort to restore this confidence by providing assurance that all animal health standards, which we put forward to the international community, are based on a scientific consensus that constitutes the foundation of the texts voted by our Member Countries.

The delay created by the long incubation of the disease and the delay in acquisition of scientific knowledge creates a void. Faced with this void, international organisations and national decision-makers find it difficult to propose timely and appropriate decisions relating to risk management. This gap in time is largely responsible for the loss of confidence on the part of citizens, disoriented by the planetary cacophony of communication on known or suspected risks.

Opening speeches

Proceedings – Joint WHO/FAO/OIE Technical Consultation on BSE: XI public health, animal health and trade

During this week, assisted by the world’s most qualified specialists, we have a unique opportunity to clarify the risks linked to BSE and the most effective means of managing both the origins and consequences of this disease, taking into account the internal or external resources available to our Member Countries because world policies relating to public health and animal health are instituted in accordance with the resulting socio-economic costs and benefits expected.

Even if no new revolutionary discovery is disclosed this week, I hope that the publication of the results of this conference will contribute to the harmonisation of international communication on the risks linked to BSE. May I take advantage of this occasion to welcome amongst us those representatives of consumer groups and of the private sector.

I am convinced that this Conference will also contribute in assisting our organisations to place the finishing touches on the proposals given to our Member Countries to combat this disease more effectively and to prevent its occurrence in places where it does not exist.

Since the OIE was first informed of the existence of this disease, our Organisation has patiently been collating a chapter of the OIE International Animal Health Code, based on the appropriate scientific knowledge provided by the best world experts in the field of animal health and public health. The purpose of this Code chapter is to prevent the spread of BSE through exports of animals and animal products and, especially, to define surveillance methods necessary for all the national Veterinary Services to detect the disease where it occurs.

The Code today constitutes a framework for health legislation in the majority of Member Countries for the prevention or control of BSE at the production and transformation levels. As is the case for existing chapters on other animal diseases and zoonoses, this chapter is the only official international reference for the application of prudent measures relating to trade in cattle and cattle products.

I hope that the results of this conference will enable us to further refine these international animal health guidelines and calmly and clearly communicate them to the international community.

I wish you a successful conference.

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Opening speeches

XII Proceedings – Joint WHO/FAO/OIE Technical Consultation on BSE: public health, animal health and trade

Opening Statement for the Food and Agriculture Organization Samuel Jutzi

This international tripartite consultation is expected to establish the current state of the knowledge of bovine spongiform encephalopathy (BSE) in its risks for human health, animal health and trade. Such knowledge is to support effective and efficient measures at all necessary levels for appropriate risk assessment, risk management, risk mitigation, and for comprehensive risk communication. This is a consultation rather than a conference and thereby puts the emphasis on the expert advice which is expected for actions in the areas of risk mentioned, and will relate to science, research and technology, and to policy and information. The FAO, the United Nations’ specialized organisation for food and agriculture, in participating in this tripartite consultation, is determined to help generate such advice in support of the configuration of a safe, clean and equitable global animal agriculture which satisfies highest ethical standards. This task is truly enormous; animal agriculture in Europe has never before been faced by a similar vote of distrust from the consumers and the society at large. In fact, to state it bluntly, the industry, throughout its various stages and levels, has been largely discredited in the eyes of the consumers. The task ahead to thoroughly reconfigure the supply of animal products so as to respect necessary standards of safety, cleanliness, equitability and ethics is therefore daunting. It requires courageous and unprecedented action by those in charge of setting and enforcing policies and by the industry itself. Many questions are being asked in this context and will need convincing answers. I single out just one or two. The question will, e.g., need to be addressed as to whether there is not a serious mismatch between free market economics and biology, or applied biology what animal agriculture constitutes. Free market forces and deregulation, among others, work in favour of free movement of goods, in favour of economies of scale, in favour of continuous change in trading partners in the search for optimum returns, and, normally, in favour of the externalisation of environmental, health and societal costs. Policy makers and livestock sector are now faced with the hard evidence that these market forces do not adequately factor-in the logics of biology and ecology and thus are not fit by themselves to mitigate the range of substantial risks involved in the supply of animal products.

I hope that this consultation will come up with firm advice as to such apparent needs for the recourse to more stringent market regulation in the interest of a reliable, safe, clean, and equitable animal agriculture. There are encouraging indications that the livestock industry itself is actively looking for effective mechanisms to foster self-regulation. This is true, e.g. for the feed industry. I may also mention an initiative of the European Association for Animal Production to design and negotiate a post-BSE vision for the industry.

As is well known, global animal agriculture is growing faster than any other sub-sector of food and agriculture with the exception of aquaculture. This dynamic growth takes place almost

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Proceedings – Joint WHO/FAO/OIE Technical Consultation on BSE: XIII public health, animal health and trade

exclusively in developing countries and is driven by urbanisation, population increase and by raising incomes which shift dietary habits towards, among others, more animal protein based food. Meat production is expected to double in the next 20 years, with this market production increasingly taking place in larger commercial, intensive, partly industrial units. Such developments largely follow free market forces prevailing in more and more developing countries. With food and feed safety and other sanitary policies often in place, but rarely fully enforced, there is likelihood of substantial risks to environment, human health, animal health, animal welfare and social equity in this development. Market liberalisation and globalisation may indeed, in the absence of strict enforcement of biologically and ecologically justified regulation, contribute to world-wide spread and amplification of such risks.

The consultation addresses such global, extra-European dimensions of the multiple risk aspects and it is hoped that they will receive sufficient attention in this debate.

On behalf of FAO’s senior management, I extend sincere thanks to all those present here who have agreed to invest some of their busy time and to exchange their knowledge and experience in the pursuit of sustainable ways for animal agriculture out of very dangerous ground.

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XIV Proceedings – Joint WHO/FAO/OIE Technical Consultation on BSE: public health, animal health and trade

Bovine spongiform encephalopathy: public health, human health and trade David Heymann

1. The meeting this week at the headquarters of the OIE arises from a consultation held in WHO offices in December 2000 and is a joint effort of the WHO, the FAO and the OIE. The conference wants to respond to mounting concerns over BSE and seek the best answers to questions originating from consumers as well as governments: what is safe to eat? Is there enough being done to protect human populations from vCJD? How can we prevent the further spread of BSE and vCJD and best contain risks where they may already be present? Can BSE be eliminated in the long run? How can we best communicate risks to consumers?

The reason why this consultation is co-sponsored by WHO, the FAO and the OIE, large international organisations dealing with human health, animal health, production and trade is because BSE is a food animal disease and a food safety issue with a human face – vCJD.

2. For more than 10 years after the recognition of BSE in the United Kingdom (UK) (1986), national authorities, principally veterinary services, undertook actions to control its spread in bovine populations and prevent human exposure. For more than 10 years the UK and other European countries initiated groundbreaking scientific studies to determine the nature and elucidate the pathways of transmission of this new, emerging disease of cattle including its possible implications for human health. However, it was only in March 1996 that first evidence became available in the UK that humans could be affected by the BSE agent. The first known zoonotic transmissible spongiform encephalopathy – vCJD had been identified.

For more than 10 years WHO together with its sister organizations (FAO, OIE) also involved with zoonotic and foodborne diseases promoted the implementation of the fundamental measures for limiting disease spread within cattle populations as well as the then hypothesized transmission to humans; and at the same time the continuous review of the science and the regular assessment of the risks for humans.

3. Over time, it became clear that the potential for the disease crossing the species barrier and infecting humans had been underestimated. The agent has not been definitively identified, we don’t have a means of detecting whether people are infected, or whether foodstuff are contaminated, we don’t know the incubation period (except to say that it is long) and so we don’t know how many people will die from their existing exposure. We don’t know the dose to infect and kill a human, so we don’t know how much exposure humans can tolerate – this may mean that we cannot permit any exposure of humans to BSE. We realized how difficult it is to implement regulations and the importance of inspection and implementation oversight.

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Proceedings – Joint WHO/FAO/OIE Technical Consultation on BSE: XV public health, animal health and trade

We discovered over time that the dose needed to infect cattle is very small. This could explain why cross-contamination may have played such an important role in ongoing transmission of disease within cattle and possibly other ruminant populations. This has led to the establishment in European countries of a feed ban involving all major food animal species. This is an example of how continuous improvement in our understanding of the disease lead to the adoption of always stricter control measures. We have also seen that it takes commitment, requires well organized veterinary services, as well as involved health services and a large financial investment to have any chance of controlling BSE.

4. Today we are here because we are all aware of the importance of trade and international markets in the potential distribution of diseases among and between human and animal populations especially when food or feed-stuffs are considered the most likely source of the agent. There can be no denial that potentially infected live animals and potentially contaminated human and animal food and other products have been distributed beyond the boundaries of those countries in which the disease BSE has been officially reported. We are also here today to address the public health implications of BSE at a wider level.

5. There is something else – it would seem that BSE and its human form, vCJD, are ‘man-made’ diseases. It is distressing to think we, though unwillingly, created the conditions in which such a terrible disease could arise, but so it is. However if the conditions for its emergence were unintentionally created, we have also demonstrated the ability to identify the major causes and change those conditions. The success of BSE control programmes in some European countries demonstrates very well that BSE is a disease that may be eliminated in the long run. But I suggest to you that in spite of the 14 years of existence of BSE and 5 of vCJD the situation today is an emergency ? Why urgent? Because trade of potentially contaminated feed and food has already taken place. Many of the countries receiving these trade products have not yet had the benefit of risk analysis and most have no surveillance capacity for either the human or animal disease. It is clear that many countries of the world do not have the financial or organizational capacity to eliminate BSE from their boundaries once it is established and that there may be forces which would discourage reporting of the first case and in turn possibly favour further spread. We have, therefore, a profound responsibility to ensure that measures are taken to stop any further human and animal exposure to the agent and to assist particularly developing countries in determining their BSE status and assessing their risk level. Even within Western Europe, the situation is not stable – the use of new tests and surveillance methods over the past few months uncovered previously unsuspected cases of BSE in countries that considered themselves BSE-free.

6. I will finish with this thought. I am unfortunately reminded that it is almost 20 years to the day of the publication of the report of the first cluster of cases, of one of the most important infectious disease of the late 20th century – acquired immunodeficiency syndrome (AIDS). The first cases of AIDS were geographically isolated; information about it was uncertain and contradictory. Even when solid epidemiological evidence on how to control the disease was developed, it proved very difficult to implement the measures that could prevent the dissemination of this disease. This is not to say that we

Opening speeches

XVI Proceedings – Joint WHO/FAO/OIE Technical Consultation on BSE: public health, animal health and trade

expect vCJD to become a world wide problem of the magnitude of AIDS that is today the most important infectious disease killing humans on our planet but to stress that relatively small cluster of cases of an emerging human disease should never be disregarded.

As the first physicians studying (AIDS), we do not know what lies ahead in vCJD. We do not know if BSE has already established a foothold in other countries. Some may say it has not, but the public health implications are profound if they are wrong. For the next week, the challenge is enormous, as the consultation is charged of a number of issues with global implications whose outcome will influence the development of public and animal health policy planet-wide.

Thank you very much for your attention.

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Proceedings – Joint WHO/FAO/OIE Technical Consultation on BSE: 1 public health, animal health and trade


The identification in 2000 of bovine spongiform encephalopathy (BSE) in native-born cattle in European countries previously thought to be free of the disease has led to increased concern about the extent of the BSE epidemic and raised questions about the possible risks for public health. The concern extends beyond Europe, partly as a result of uncertainty about risks that may result from past international trade of cattle and cattle products from BSE-affected countries.

On 21 December 2000, the World Health Organization (WHO) organised a joint informal meeting between representatives from the WHO, the Food and Agriculture Organization (FAO), the Office International des Epizooties (OIE) and twelve consultants. Representatives from the World Trade Organization (WTO) and the European Commission (EC) also participated. The participants at this meeting concluded that while there were no breakthroughs in the scientific understanding of BSE and variant Creutzfeldt-Jakob disease (vCJD), there is a much greater awareness of the issues involved. These widespread concerns have resulted in demands from countries for science-based and independent advice to create reliable policy for public health. It was recognised, as a principle, that the fundamental measures for the protection of public health would have to include measures to protect animal health, as well as measures applicable to international trade. Hence, it was determined that the three Organisations would hold a ‘Joint Technical Consultation on BSE: public health, animal health and trade’ at the OIE Headquarters in Paris (France) from 11 to 14 June 2001.

Objectives

The principal goal of the Consultation was to provide more quality information to Member Countries, especially for those that do not have experience of BSE and vCJD. This would enable national authorities to determine the actions necessary within their own borders to avoid or reduce risk to human and animal populations, and to export trade. Furthermore, it is important from the international perspective that countries should not export materials that could be contaminated with the BSE agent.

A secondary goal of the Consultation was to provide a forum for the review of some of the most compelling problems in international BSE control, namely: detection, prevention and elimination of the disease, coupled with appropriate risk management.

Certain key policy and communications issues were identified in advance. These included the following: a) identification of the most effective policies to minimise human exposure to

the BSE agent


2 Proceedings – Joint WHO/FAO/OIE Technical Consultation on BSE: public health, animal health and trade

b) identification of the global risk of BSE resulting from trade in live animals and certain products and by-products containing bovine tissues

c) the resulting recommendations for international trade d) the global need for trade-related action e) the need for countries to conduct risk assessments f) the need for countries to implement surveillance systems for BSE and vCJD g) the need for countries to act before witnessing their first case of vCJD or

BSE

h) the difficulties in communicating risks and the true impact of safety measures in the face of incomplete scientific knowledge.

The Consultation did not intend to review issues relating to biologicals, medicines or pharmaceuticals produced from human or animal tissues, or to review issues regarding possible transmission of vCJD between individual human beings.

Consultation logistics and organisation of this document

Professor Robert Will, Director of the United Kingdom (UK) National CJD Surveillance Unit, kindly chaired the Conference. The first two and a half days of the Consultation were spent in plenary presentations, designed to establish the baseline knowledge from which the participants would work. After this, five Working Groups met to discuss specific issues, as follows: a) risk assessment b) risk management – international c) risk management – national d) BSE in sheep and other animal species e) risk communication.

The Consultation closed with a joint session during which the principal recommendations were presented to the full assembly. On 15 June 2001, following the formal Consultation, the Chairs, Rapporteurs and Secretariat met to review the recommendations and to incorporate feedback gathered during the final joint session.

This document contains the key recommendations of the Consultation.

Editing to remove duplication and to improve the readability of the document was performed by the Secretariat and reviewed and agreed to by the Chairs of the Working Groups.

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Bovine spongiform encephalopathy: public health, animal health and trade

This Consultation confirmed that BSE is a risk to animal and public health, as follows:

a) the disease is transmissible to humans; scientific consensus confirms that food is the main avenue of exposure

b) bovines, bovine products and by-products potentially carrying the BSE agent have been traded world-wide, giving this risk a global dimension

c) the exchanges mentioned above have or can have repercussions on public health, animal health and trade.

Protection of public health is the overarching goal of BSE risk management and, at this time, protecting public health is primarily accomplished through preventing and eliminating BSE in livestock populations. The Consultation reiterated existing WHO recommendations, namely: ‘countries should not permit tissues that are likely to contain the BSE agent to enter any food chain (human or animal)’1.

Food can be regarded as safe from BSE only if all appropriate measures to minimise human exposures to the BSE agent are fully implemented and monitored. Although much is known and considerable efforts have been made to control BSE, scientific uncertainty remains and it is important for governments to recognise that consumers will make individual decisions regarding the level of risk they consider acceptable.

In order to introduce appropriate measures to protect public and animal health, national authorities require information on two aspects, as follows:

a) the risk of BSE infection in cattle populations

b) the risk of human exposure to the BSE agent.

1 Report of a WHO Consultation on Public Health Issues related to Human and Animal Transmissible

Spongiform Encephalopathies. WHO/EMC/DIS/96.147 Geneva, Switzerland, 2-3 April 1996



With regard to human exposure, it is recognised that although the infectious dose for humans is not known and not every exposure necessarily results in infection, it is nevertheless essential to minimise exposure.

The Consultation reviewed the commodities that are currently listed in the OIE International Animal Health Code (OIE Code) as ‘unrestricted in terms of international trade’ and concluded that there was no new scientific information to justify modifications to the list. The OIE Code also establishes a list of tissues and products that, depending upon the BSE-status of a country, should not be traded internationally. The Consultation concluded that, for the time being, there is no need to modify this list. However, there is a global risk and thus a global need for action, which is reviewed in the following sections.

Global risk and global need for action

Materials potentially infected with BSE have been distributed throughout the world through trade in cattle and certain cattle products and by-products. These products include rendered animal proteins and compound animal feed containing meat-and-bone meal (MBM)2.

All countries are encouraged to evaluate their potential exposure through systematic assessment of trade data and possible risk factors. These assessments are essential to identify risks that need to be addressed to protect public health and prevent further national and international dissemination of infectivity among susceptible species.

In most cases, the likelihood of a case of vCJD occurring in a country that does not currently have BSE is dependent upon the extent to which people were exposed outside their own country, or were exposed to contaminated imported commodities such as BSE-infected bovine meat products and by-products. It is clear that even countries that do not have BSE cases can potentially experience cases of vCJD in their human population. It must not be automatically assumed that finding a case of vCJD in a country is evidence that BSE is present, even though the likelihood of this must be assessed. Countries must be prepared to investigate vCJD cases with careful regard to possible internal and external exposure. If, and only if, this investigation indicates external exposure as the sole explanation, will there be no need to implement emergency domestic procedures relating to BSE in animals.

The original source and movement of animals and animal products, including MBM, can be masked by international trading patterns which often include the

2 According the OIE Code, ‘meat-and-bone meal means the solid protein products obtained when animal

tissues are rendered, and includes any intermediate protein product other than peptides of a molecular weight less than 10,000 daltons and amino-acids’



processing and re-exportation of products. Consequently, importing countries should be aware of the risks generated by these trading patterns. The risks from illegal trade must also be considered.

Countries should not become complacent about their risk from BSE. The extremely low initial incidence and the low within-herd incidence of BSE cases, long incubation period and non-specific nature of the early clinical signs of BSE can delay the detection of the first cases of disease and so, may mask the severity of the problem.

International risk management strategies should be commensurate with the level of BSE risk for regions, countries and zones. Risk management strategies must be science-based, transparent and not more trade restrictive than necessary for health protection. The choice of the specific risk management strategies must consider the practicality of implementation and means of auditing compliance in each country.

The WHO, FAO and OIE should work to increase world-wide awareness of the clinical signs, epidemiology and relevant risk factors for BSE and vCJD.

Co-ordination and assistance at the international level

Additional resources should be made available to assist nations, particularly developing nations, to assess their potential exposure to BSE-infected materials and to identify measures which may be necessary to manage the risks associated with this exposure. International organisations, such as the WHO, FAO and OIE, have mandates to protect and improve global public and animal health. Co-ordination of efforts among the WHO, FAO and OIE within their specific mandates should optimise the utilisation of any existing and new resources.

All countries should be encouraged to conduct national risk analyses according to appropriate international guidelines (for example, those provided in the OIE Code, Chapter 1.3.2. and Article 2.3.13.1.). The aim should be to enable reliable categorisation of countries on the basis of risk3. It is noted that the current OIE Code provides categories based on the incidence of disease but that the OIE is considering an approach that would categorise countries on the basis of risk. This approach is strongly supported.

It is recognised that conducting risk assessments may be difficult for some countries4. The process of risk analysis is technically complex and potentially expensive. If a country finds that it faces too large a barrier to accomplish this

3 As specified in Articles 2.3.13.2. to 2.3.13.6. inclusive of the OIE Code 4 Countries are invited to examine relevant Codex Alimentarius guidelines and draft guidelines for risk

analysis and risk assessment



task, solutions should be sought from international organisations and from countries with greater expertise and resources (especially risk assessment and active surveillance expertise). Countries should be aware that their trading status may be dependent upon conducting a risk assessment for BSE and upon their undertaking of appropriate measures to manage the level of risk identified.

Risk assessment for vCJD and BSE

Risk assessments should be based on the present state of knowledge about the agent, its transmission, the relevant risk factors and currently available diagnostic methodologies.

It is essential to remember that scientific evidence advances and that there is a need to further our understanding of the spread and biology of both BSE and vCJD.

The Consultation concluded that human exposure to BSE depends upon the following internal and external factors:

a) internal – the geographical risk of BSE infectivity in cattle and the domestic consumption patterns of bovine-derived products

b) external – human exposure to the BSE agent through the importation of infected animals or animal products or through exposure while travelling within geographic areas where BSE is present in the cattle population and where appropriate controls have not been implemented.

Hazard identification5

Although the BSE agent has not been isolated, substantial experimental evidence has accumulated regarding the distribution of infectivity throughout cattle tissues. The Consultation discussed the list of bovine tissues that are known or suspected to carry BSE infectivity. The Consultation noted that the OIE has published a list of specified risk materials (SRMs)6, as has the EC Scientific Steering Committee (SSC). The SSC list includes the rationale for their selection7. According to current scientific knowledge, BSE infectivity has been demonstrated in the following list of tissues to varying degrees: brain, eyes (retina), trigeminal ganglia, the spinal cord, the dorsal root ganglia and the distal ileum.

5 The Codex Alimentarius defines ‘hazard identification’ as the ‘identification of biological, chemical and

physical agents capable of causing adverse health effects and which may be present in a particular food or group of foods’

6 The relevant section of the OIE Code is Article 2.3.13.22. 7 Listing of Specified Risk Materials: a scheme for assessing relative risks to man: Opinion of the Scientific

Steering Committee adopted on 9 December 1997, re-edited version adopted by the Scientific Steering Committee during its third Plenary Session of 22-23 January 1998



Table I provides an estimate of the cattle infectivity dose (ID)50 associated with each tissue at the height of infectivity for that tissue type.

Table I Scientific Steering Committee estimate of cattle infectivity dose (ID)50

Tissue Cattle infectivity dose (ID)50 per BSE case

Percentage of total infective load per bovine

Brain 5,000 64.1%

Spinal cord 2,000 25.6%

Trigeminal ganglia 200 2.6%

Dorsal root ganglia 300 3.8%

Ileum 260 3.3%

Spleen8 26 0.3%

Eyes 3 0.04%

Source: Opinion of the European Union SSC: Human Exposure Risk (HER) via food with respect to BSE, 10 December 1999, page 11

Other tissues that might be infected (such as tonsils and the entire intestine from duodenum to rectum) or that could be contaminated by SRMs (such as might occur during the slaughter process under certain circumstances) should also be considered for removal and destruction. The Consultation recommended a regular review of the list of tissues in the light of emerging scientific evidence and of information on the practical aspects of their exclusion.

Risk assessment may also determine that particular categories of animals no longer represent a risk in relation to all tissues or a particular category of tissue (e.g. the dorsal root ganglia from cattle born after the fully effective implementation of an MBM ban, provided they are not the last born progeny of confirmed cases).

Exposure assessment of BSE risk to humans – vCJD

To better assess the risk of human exposure to BSE, the Consultation recommended an analysis of the pathways along which the BSE agent could be transferred from animals to humans, in particular via food. The evaluation of

8 The SSC hypothesised that the spleen could contain some infectivity based on other TSEs. However, no

such infectivity has since been found after intracerebral inoculation of cattle (personal communication, G.A.H. Wells), Joint WHO/FAO/OIE Technical Consultation on BSE: animal health, public health and trade, Paris, 11-14 June 2001



the pathways should include a comprehensive approach that would include both public health policy and livestock management. Such a pathway analysis will provide the basis for assessing the human exposure risk and to manage that risk, even if an exact quantification remains unlikely. The EC SSC has provided an opinion on the human exposure risk9. That opinion suggested that from a single infected animal entering the food chain, existing pathways could lead to exposure of either a relatively small number of consumers to high doses of BSE-infectivity, or of a large number of consumers to small doses.

Risk factors of relevance to a human exposure risk analysis include the following:

a) biological (tissue infectivity, pathogenesis, i.e. influence of age on infective load and tissues affected)

b) epidemiological (incidence of BSE in a country, as well as BSE-related risks)

c) importation of BSE contaminated commodities and recycling (see the SSC Geographic BSE Risk assessment [GBR]10 and OIE Code11)

d) human factors (slaughter methods, industry practice, cross-contamination, dietary patterns, compliance with sanitary measures, training and education, awareness, surveillance and monitoring, animal husbandry practices)

e) technical (rendering processes, feed production, transport).

The relevant human exposure pathways are likely to differ significantly between countries and it is therefore recommended that whenever a country identifies a risk of BSE, it should take immediate steps to identify the fate of the SRM. International trade in food products may disseminate tissues containing BSE. Therefore, a standardised approach, including a continuous international review process for food in international trade is recommended. The three Organisations should play an instrumental role in this standardisation12.

BSE in cattle

To assess the risk of bovine infection, the Consultation welcomed the fact that the OIE International Committee has invited all Member Countries to establish the necessary documentation and to carry out an assessment of the risk of BSE being present in its domestic cattle herd. To this end, the Foot and Mouth

9 Opinion of the Scientific Steering Committee on the Human Exposure Risk (HER) via food with respect to

BSE, adopted on 10 December 1999, Brussels, Belgium. Opinion on oral exposure of humans to the BSE agent: infective dose and species barrier, adopted by the Scientific Steering Committee on 13 and 14 April 2000, Brussels, Belgium

10 Final Opinion of the Scientific Steering Committee on the Geographical Risk of Bovine Spongiform Encephalopathy (GBR), adopted on 6 July 2000, Brussels, Belgium

11 The relevant sections of the OIE Code are Articles 2.3.13.1. to 2.3.13.6. 12 The OIE Code offers a standardised approach to zoonotic diseases



Disease and other Epizootics Commission of the OIE has the mandate to provide specific guidelines in line with the OIE Code chapter on BSE and to determine if countries meet the OIE criteria to be recognised as BSE-free. It is recommended that these new guidelines take due account of the experience from the application of the GBR assessment exercise carried out by the SSC advising the EC. Countries are encouraged to utilise these guidelines for their own internal assessments, bilateral negotiations and third-party independent assessments.

Hazard characterisation

In the risk assessment process, hazard characterisation has the role of establishing dose response. At this time, information is not sufficient to estimate the shape of the dose response curve, and no information is available to determine the level of infectivity required to cause disease in human beings, or in any animals, except bovines. In bovines, one gram of brain from a clinically ill cow is sufficient to cause infection13.

Risk characterisation

Risk characterisation is the area of risk assessment that, according to the Codex Alimentarius, establishes the probability of infection. At this time, there is a substantial lack of information, which is seriously impeding the production of accurate risk characterisation for both humans and animals.

Risk management

The prevention of BSE is a responsibility shared among all those involved in the food and feed chains from farm to fork. Risks are dynamic. Therefore, to detect changes in risk, risk assessment must be ongoing and risk management must be based on the results of these risk assessments.

Meat-and-bone meal

Meat-and-bone meal of ruminant origin must not be fed to ruminants.

In countries where ruminant MBM is fed to other food animal species, all possible measures must be implemented to ensure avoidance of cross-contamination of ruminant rations with feed for non-ruminant species (e.g. by using species-dedicated MBM production premises and/or feed production premises dedicated to ruminants and non-ruminants). Where such avoidance cannot be guaranteed, MBM from any species should not be fed to ruminants.

13 Experiments are under way to examine the infectivity of smaller amounts of cattle brain



To ensure compliance, it may also be necessary to ban all mammalian protein-based animal feed from ruminant feeds or even from all farm-animal feeds. If cross-contamination cannot be avoided, countries should not trade in these materials.

If a country has identified BSE or, on the basis of a risk assessment, a BSE risk, then MBM for use in non-ruminants should be prepared from non-SRM material by the method prescribed in the OIE Code (Article 3.6.3.1.), or by a method that achieves equivalent or enhanced inactivation.

Guarantees on the quality, condition of production, the source of the ingredients and the composition of MBM, must be a part of international risk management to prevent the introduction or spread of BSE infectivity. International monitoring of compliance with the feed bans needs further development, including reliable certification programmes and screening tests to guarantee the absence of BSE infectivity in ruminant feedstuffs traded internationally. Emphasis must be placed on the development of rapid and reliable tests for the detection of ruminant protein in animal feeds.

Specified risk materials

This Consultation had no reason, at the time of the meeting, to modify the basic list of SRMs as identified earlier in the section entitled ‘Risk assessment for vCJD and BSE: hazard identification’.

Issues such as slaughter methods, cross-contamination during and after slaughter, and difficulties in the identification of specific tissues or organs under slaughterhouse conditions should be taken into account when determining whether products are free of known sources of infectivity. For this reason, risk management options may include the identification and removal of entire bovine heads, as opposed to only removing the brain and eyes, or may include the prohibition of the harvesting of all mechanically-recovered meat (MRM), rather than just the elimination of MRM from the vertebral column.

Whenever the possibility that slaughtered animals may be infected with BSE cannot be excluded, all tissues that have been proved capable of carrying BSE infectivity should be removed and destroyed, i.e. an SRM ban should be imposed. Where this risk is higher, those tissues that under certain conditions are suspected to carry infectivity should also be considered for removal and destruction. If the risk is high, all possible additional precautions should be taken, such as prohibiting cattle over a certain age from entering food or feed chains. The Consultation recommended that the WHO, FAO and OIE review this approach specifically in relation to public health issues. Finally,



consideration may be given to applying separate SRM bans for human food and animal feed.

Animals with confirmed or suspected BSE

Clinically confirmed cases in bovines and any progeny born in the two preceding years to female cases should be destroyed.

Given the limitations of the current knowledge concerning the human infective dose and concerning the pathways for human exposure to infected tissues, the Consultation underlined that, as a precaution, all animals suspected of being infected with BSE should be destroyed.

Where a case has been confirmed, cohort animals, i.e. animals exposed to the same risk, should be destroyed14. For this purpose, adequate, individual animal identification and records of movement of cattle must be in place. In some circumstances, consideration may be given to more extensive slaughter by some authorities, even though no evidence for horizontal transmission exists. This action may be considered for social, political, economic or trading reasons and should be judged on a case-by-case basis.

Surveillance

Surveillance data is fundamental for the safe trade of animals and animal products. Ongoing surveillance data provides an indicator of the effectiveness of risk management measures and monitors the effect of any changes in the overall BSE risk of a region, country or zone. Surveillance strategies should be commensurate with the BSE risk, but surveillance should include both active and passive components, as outlined in Appendix 3.8.3. of the OIE Code, using methods described in the OIE Manual of Standards for Diagnostic Tests and Vaccines.

Countries should strongly consider, on the basis of the risk assessment, the use of appropriate tests on target populations, conducted regularly and on a sufficiently significant number of animals, to provide the necessary confidence that any risks are identified. Contingency planning for action following the identification of the first case of BSE in a country previously without reported cases should be established.

14 The OIE Code Article 2.3.13.4., paragraph 2b, subparagraph iii, provides the following definition, ‘all cattle

either born in the same herd as, and within 12 months of the birth of, the affected cattle or reared together with the affected cattle during the first year of their life, and, in both situations, which may have consumed the same potentially contaminated feed as that which the affected cattle consumed during the first year of their life’



Compliance

Experience in countries with BSE has demonstrated that failure of implementation of adequate measures can lead directly to the failure of BSE control programmes. Implementation of the chosen risk management options must be enforced strictly to protect global health and trade. Efforts by authorities must be directed at ensuring full compliance. Governments must pay particular attention to ensuring all risk reduction measures are actively established, implemented, enforced and audited. In particular, attention should be paid to the prevention of fraud.

Awareness

An ongoing education and extension programme for all those involved in the food and feed chains should be introduced to encourage, in particular, the following:

a) prevention of exposure

b) methodologies that can be audited

c) traceability of raw materials and compound feed

d) traceability of animals

e) identification of cohorts of cattle fed batches of potentially contaminated feed

f) identification and reporting of suspect BSE cases.

Animal and human health authorities should work together closely for these purposes.

To facilitate animal and public health protection from BSE, incentives should be considered (including financial aid and compensation) and disincentives should be eliminated.

Risk of BSE in sheep and other animal species

Risk assessment in sheep

The Consultation noted that it is possible that BSE could be present in some small ruminants because there is evidence that BSE-contaminated MBM has been fed to some sheep and goats15. In recent years, millions of sheep were exported from countries in the European Union (EU). In addition, even where grazing is the normal practice, in some cases MBM from EU countries has been

15 Based on the EC SSC document, Opinion on the pre-emptive risk assessment should BSE in small

ruminants be found under domestic conditions, dated 8-9 February 2001, Brussels, Belgium



imported as a feed supplement for animals, particularly during periods of drought. Consequently, the Consultation concluded that the issue of possible BSE infectivity in sheep is, potentially, global in scope.

The distribution of infectivity in sheep experimentally infected with BSE has been shown to be similar to that of scrapie. Although this idea is speculative, should BSE be present in sheep, the disease may spread laterally between sheep as is the case for scrapie. Should this occur, feed bans would not be sufficient to prevent transmission in sheep populations.

To date, there is no confirmation that BSE is present in small ruminants. However the extent of investigations to detect BSE in sheep has been limited.

Risk management in sheep

It is recommended that individual countries assess the risk that BSE infection could be present in their native sheep and goat populations. Each country should determine the level of risk from both internal and external sources. The Consultation encouraged all countries to require notification and surveillance for transmissible spongiform encephalopathies (TSEs) of sheep and goats and to take steps to mitigate the risks identified. The OIE, FAO and WHO should help to provide and standardise guidance, advice and training for the above if requested. The OIE should complete its draft OIE Code chapter on scrapie of sheep and goats, and should address the specific issue of BSE in sheep and goats. The Consultation further recommended that efforts to investigate and detect the presence of natural BSE in sheep and goats be pursued.

In countries where sheep and goat populations have been potentially exposed to BSE infectivity, measures should be taken to minimise the exposure of humans to infectivity from small ruminants.

Other ruminants

Meat-and-bone meal contaminated with BSE may have been fed to water buffalo, cervids, camelids and other ruminants. There is no evidence of neurological disease caused by the BSE agent in these animals, but there is limited knowledge on the full range of susceptibility. Countries should assess the risk and conduct surveillance on water buffalo, cervids, camelids and other domestic ruminants that may have been exposed to potentially contaminated feed. Research should be conducted to fill existing gaps in knowledge regarding susceptibility in these species.

In the meantime, water buffalo, cervids, camelids and other domestic ruminants should be included in any ruminant feed bans.



Other farmed animals

The research available to date indicates that experimental oral BSE challenge of pigs and poultry with brain material from cattle with BSE does not result in disease and that there is no evidence for residual infectivity present in tissues; there have been no reports of a naturally occurring TSE in these species either16.

In the case of ostriches, there have been reports of a naturally occurring spongiform encephalopathy in red-necked ostriches. However, the disease has not been transmitted experimentally. Consequently, there is some doubt regarding the true nature of this disease. After appropriate precautions, including all those that may result from cross-contamination, have been taken to mitigate risks, rendered animal protein derived from BSE-free materials may be fed to pigs and poultry (see the section above entitled ‘Risk management: meat-and-bone meal’). The EU ban on feeding rendered animal protein to farmed animals was presented as an emergency measure to protect ruminants by avoiding risk of cross-contamination of the ruminant feed system at any level. No experimental study has been performed on horses but, to date, no neurological disease similar to BSE has yet been detected in horses in the UK, where, presumably, any exposure would have been greatest.

Fur-bearing mammals

Under research conditions, BSE has been shown to infect farmed mink by both the oral and intracerebral routes. It is essential that fur-bearing animals must not be re-cycled to food animal species.

Fish

There is ongoing research regarding the susceptibility of fish to the BSE agent. One species of fish has been inoculated with BSE. Results are pending.

Companion animals

It is well recognised that cats are susceptible to BSE (over 85 cats are known to have died from BSE-caused feline spongiform encephalopathy). Dogs in the UK and EU must have been exposed to the BSE agent, yet BSE has not been detected in dogs. Experimental challenges have not been performed on canines.

16 Transmission experiments have shown that pigs are susceptible to intracerebral challenge with the BSE

agent (seven of ten pigs died of disease after intracerebral inoculation). There is no evidence to date that pigs are susceptible to BSE following oral challenge, and there is no epidemiological evidence in the UK that BSE has been naturally transmitted to swine



Passage of infectivity

Laboratory experiments show that mice orally challenged with scrapie have detectable infectivity that passes through the gut. Gut contents and faecal material may therefore contain infectivity, and it is noted that in experimental oral challenges in cattle conducted in the UK, faeces must be treated as medical waste for one month following the challenge. It is concluded that digestive contents and faecal material from livestock or poultry currently being fed with MBM potentially contaminated with BSE should not be used as a feed ingredient for animal feed.

Risk communication

Preamble

In this setting, risk communication is the exchange of information between regulators and those who have a ‘stake’ in the process, with the objective of building a consensus on the appropriate management of risk17.

Stakeholder consultation is a two-way process that includes consumers, industry and all interested parties in the food and feed chain. Risk communication is a critically important aspect of risk analysis because ‘safety’ is a negotiation about the acceptability of risks by those who are the bearers of the risks. Risk communication is the process by which this acceptance is established and maintained. Effective risk communication takes concerns about the need for regulation of risk and so builds public confidence in the risk management process. Maintenance of public confidence is essential for the effective management of risks. Even the most comprehensive risk assessment and the most reliable risk management practices can be undermined and fail if public confidence in risk regulators is eroded. Stakeholders should be involved early, especially when there is debate. Consumer risk perceptions often differ dramatically from those of the experts. For this reason, an important task of risk communication is to develop a clear understanding, through consultation, of the aspects of the risk that are of greatest concern to stakeholders. These may not be aspects of the risk that experts would be most likely to identify or respond to. Experts, for example, tend to focus on the quantifiable aspects of risks, while non-experts tend to be more concerned about qualitative aspects of risks (the degree to which risks are voluntary, who takes the risk versus who gets the benefits, the degree of

17 The Codex Alimentarius defines ‘Risk communication’ as ‘An interactive exchange of information and

opinions throughout the risk analysis process concerning hazards and risks, risk related factors and risk perception, among risk assessors, risk managers, consumers, industry, the academic community and other interested parties, including the explanation of risk assessment findings and the basis of risk management decisions’



1.

2.

3.

4.

certainty in the knowledge about risk, as well as its familiarity and controllability). Experts prefer to withhold judgement on potential hazards when there is a lack of scientific evidence, but to the lay person this gives the appearance of favouring industry and looks like a preference for risk-taking rather than safety. However, exercising precaution requires action to be taken when significant levels of uncertainty remain in science. Consequently, regulatory decisions may be required before sufficient scientific data are available. This is especially true in the most contentious and perturbing risk issues, such as BSE/vCJD. Uncertainty is one of the most critical issues in risk communication. How the proper messages can be communicated when risks are unclear should be addressed. General principles

Four contexts for typical risk communication messages were identified, as follows:

Issues where we think we know the answers (high certainty contexts), recognising that new data can change the conclusions in which you have the highest confidence. For example: is food exposure the cause of vCJD? Issues where we don’t know (high uncertainty contexts). For example: how many people might get vCJD in the future?

Issues where there is debate or controversy (moderate uncertainty). For example: has BSE spread to the rest of the world?

New emerging issues of potential risk. For example: sheep and goats may have been infected with BSE.

Principles identified

The seven principles listed below were identified:

1. Consult all stakeholders at the outset to address their concerns in an open and transparent dialogue.

2. Frame the question and address the full range of concerns about the risk.

3. Frame the response in the context of the full story. The audience may be poorly or well informed. It is important to translate and summarise the story for different audiences.

4. Explain:

– what measures are being taken to reduce the risks, and why

– what is known, what is unknown and explain why this is the case; be open and honest



– what is being done to fill the knowledge gap

– what precautionary measures are being taken in the interim.

5. Give regular updates, even when there is no new information.

6. Be proactive, take the initiative to communicate new information about risks, even though it may be unsettling to the public. Explain what is being done to address these risks.

Dealing with controversial science

Ordinarily, the quality of science is ensured through the peer-review process, but new and important scientific information can, in some cases, merit early communication because it may be relevant to the formulation of new precautionary measures. It is important to present such information within the context of the scientific status of the information, i.e. non peer-reviewed, peer-reviewed, or peer-reviewed and confirmed or supported through repeated investigation. Care needs to be exercised in the treatment of minority scientific opinions; they sometimes prove to be right – an important early claim that BSE was likely to cross the species barrier was dismissed by mainstream science.

Guidelines to regulators on good media communications

– Simplify the scientific message but maintain accuracy

– Use the media as partners to achieve your goal of communication develop; seek a dialogue and an ongoing relationship

– Respond quickly, be candid and understand how the media work; if you decide not to discuss an issue during an interview, explain why

– The media want ‘news’, so know how to frame the message without allowing the process to distort the message

– Be consistent, but be prepared to revise your message in the light of new data

– Prepare a written statement to ensure the media get the message and be able to respond to questions

– Try to get journalists to repeat back the message to see that they have understood and that you have communicated your points clearly.

The communication needs of Member Countries

The Consultation recommended that the WHO, FAO and OIE should collaborate on better communication strategies with their constituencies. They should make every effort to keep all Member Countries informed of developments of BSE and measures for the management of the related risks appropriate to their context. It is especially important to take into account the



different perceptions and capacities to respond to risks in different cultural contexts, especially in the developing world.

Specific recommendations to the International Organisations: WHO, FAO and OIE

1. The WHO, FAO and OIE should work to increase world-wide awareness of the epidemiology and relevant risk factors for BSE and vCJD.

2. Additional resources should be made available to assist nations, particularly developing nations, in assessing their potential exposure to BSE-infected materials and in identifying measures which may be necessary to manage the risks associated with this exposure. International organisations such as the WHO, FAO and OIE have mandates to protect and improve global public and animal health. Co-ordination of efforts among the WHO, FAO and OIE within their specific mandates should optimise the utilisation of any existing and new resources.

3. Whenever the possibility that slaughtered animals may be infected with BSE cannot be excluded, all tissues that have been proved capable of carrying BSE infectivity should be removed and destroyed, i.e. an SRM ban should be imposed. Where this risk is higher, those tissues that under certain conditions are suspected to carry infectivity should also be considered for removal and destruction. If the risk is high, all additional possible precautions should be taken, such as prohibiting cattle over a certain age from entering food or feed chains. The Consultation recommended that the WHO, FAO and OIE review this approach specifically in relation to public health issues.

4. To assess the risk of bovine infection, the Consultation welcomed the fact that the OIE International Committee has invited all OIE Member Countries to establish the necessary documentation and to carry out an assessment of the risk of BSE being present in its domestic cattle herd. To this end, the Foot and Mouth Disease and other Epizootics Commission of the OIE has the mandate to provide specific guidelines in line with the OIE Code chapter on BSE and to determine if countries meet the OIE criteria to be recognised as BSE-free. It is recommended that these new guidelines take due account of the experience from the application of the GBR assessment exercise carried out by the SSC advising the EC.

5. The relevant human exposure pathways are likely to differ significantly between countries and it therefore is recommended that whenever a country identifies a risk of BSE, it should take immediate steps to identify the fate of the SRM. International trade in food products may disseminate tissues containing BSE. Therefore, a standardised approach, including a continuous international review process for food in international trade is recommended.



The three Organisations should play an instrumental role in this standardisation.

6. The Consultation encouraged all countries to require notification and surveillance for TSEs of sheep and goats and to take steps to mitigate the risks identified. The OIE, FAO and WHO should help to provide and standardise guidance, advice and training for the above if requested. The OIE should complete its draft OIE Code chapter on scrapie of sheep and goats, and should address the specific issue of BSE in sheep and goats. The Consultation further recommended that efforts to investigate and detect the presence of natural BSE in sheep and goats be pursued.

7. The WHO, FAO and OIE should collaborate on better communications strategies with their constituencies. They should make every effort to keep all Member Countries informed of developments of BSE and measures for the management of the related risks appropriate to their context. It is especially important to take into account the different perceptions and capacities to respond to risks in different cultural contexts, especially in the developing world.

________


Abstracts

Opening presentations

Bovine spongiform encephalopathy: public health, animal health and trade M. Ricketts

The World Health Organization (WHO) upholds the principle that ‘Eradication of bovine spongiform encephalopathy (BSE) must remain the principle public health objective of national and international animal health control authorities’. This statement is based on the main assumptions that BSE and variant Creutzfeldt-Jakob disease (vCJD) are caused by the same agent and that the most likely route of human exposure is through bovine-based foods.

It is now clearly established that BSE has been present in cattle populations since at least the 1970s and that contaminated bovines and bovine products have been exported to various countries before full control measures were implemented. European countries imported infectivity and through their own rendering industries, recycled contaminated materials fostering internally generated epidemics. Surveillance systems in many countries are still inadequate and BSE may neither be prevented nor recognised early. The geographic BSE risk assessment carried out by the European Commission (EC) has illustrated the widespread distribution of contaminated material and the possibility that BSE could be present in developing countries as well. However, export of potentially contaminated material ceased when the first cases of vCJD were reported in 1996.

Few non-EC countries can identify BSE or vCJD and the lack of reports does not mean that there are no cases outside the EC. Risks exist and WHO is providing support to countries interested in performing risk assessments. Questions that need to be addressed concern the importation of potentially infected material, the processing of such material and the way it has been utilised. In countries with demonstrable risk, surveillance systems should be established for BSE and possibly for CJD. WHO has conducted workshops on transmissible spongiform encephalopathies (TSEs) in various parts of the world and is currently working jointly with the European Union (EU) to develop surveillance systems on CJD in countries of Central and Eastern Europe.

________

Abstracts


Issues of risk communication in public debates about health and safety: the bovine spongiform encephalopathy crisis C. Brunk

‘Safety’ is fundamentally a question of acceptability of risks. Risk communication can either be viewed by the means by which ‘experts’ convince the public to adopt their views or as a 2-way flow of information between industry/regulators and all those who have a stake in the process.

Since conflicts often exist between the expert and the consumer risk perceptions, one of the first tasks of risk communication is to understand the public perceptions of the risk. Experts tend to prefer quantitative algorithms for risk acceptability and assume that risk probability is more important than risk magnitude. Non-experts pay greater attention to the magnitude of the potential harm than to the probability of its occurrence and to the qualitative rather than the quantitative aspects of risk.

Risk acceptability depends on many factors namely the prospect of significant benefit, familiarity, voluntarism, trustworthiness of the manager and whether the options pose even higher risks. Bovine spongiform encephalopathy (BSE) and variant Creutzfeldt-Jakob disease (vCJD) are perceived as risks difficult to accept because vCJD is a dreaded disease, its aetiology and controllability are highly uncertain, farming practices causing it are considered unethical and the risk managers are not viewed as trustworthy.

Risk communication must inspire confidence and trust. A zero-risk claim is risky in cases such as BSE and vCJD where there are high scientific uncertainties, because it takes only one instance (or even a serious allegation) of the hazard to undermine the credibility of the risk producer or manager.

In order to build public confidence, risk communication should avoid unwarranted assurances of ‘zero risk’, and respect public concerns about distribution, and voluntariness of risk and benefits. Additionally, it is important for experts not to minimize the importance of public fears but to take such fears seriously by admitting the real uncertainties in the science, and by communicating the steps that are being taken to minimize risks.

________

Abstracts


Session 1: Risk analysis – hazard characterisation

Epidemiology of bovine spongiform encephalopathy D. Matthews

It was in 1988 that the origin of bovine spongiform encephalopathy (BSE) was elucidated in the United Kingdom (UK), namely the use of ruminant protein in cattle feedstuffs. At that time, only scrapie had been recognised in domestic animals and the recycling of bovine offals was seen as the driving force behind the spread of the epidemic. The regulatory measures then taken were aimed at avoiding this recycling, though it was not known whether the causal agent could be transmitted horizontally or vertically. In September 1990 a ban was introduced on using specified risk material in animal feed. They had been banned from use in products for human consumption in November 1989. In November 1994, the European Union decided to ban the use of mammalian protein in cattle feed. Nevertheless, in April 1995, as new cases continued to occur in the UK, it was suggested that this could be due to failure to apply the measures in force; all possible sources of error therefore had to be taken into account in risk management (mixing of feed destined for different species, returned feed, etc.). A new method of marking banned materials (which from August 1995 also included the entire head of cattle) was introduced at the abattoir. In March 1996, a total ban on meat-and-bone meal (MBM) was introduced for all farmed animals, as it was proving impossible to eliminate all forms of cross-contamination. It was also decided that all cattle over 30 months old should be withdrawn from the food chain by completely destroying their carcasses after slaughter. The infectious dose had been established as 1 gram, or possibly less, of infectious bovine brain (possibly 10 grams of MBM) via the oral route. [In January 1999, measures were also introduced to reduce the number of potentially infected animals arising from maternal transmission. Offspring of confirmed BSE cases were destroyed if the offspring were born after August 1996.] Risk of transmission to offspring is less than 10%. In September 1996, goat and sheep heads were also withdrawn from the food chain, in view of the possibility that the BSE agent might be present in small ruminants. The conclusions that can be drawn are:

1. No country should wait until the first case occurs before taking preventive measures.

2. Decision on preventive measures should be based on a detailed local risk assessment which is conducted before the first case is observed.

3. Countries should carefully monitor the effective application of the regulatory measures that have been decided upon.

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4. An affected country will have to wait 5 years before seeing the effect of these measures on the incidence of the disease.

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Epidemiology of variant Creutzfeldt-Jakob disease R. Will

Through the surveillance network for Creutzfeldt-Jakob disease (CJD) in the United Kingdom (UK), a new variant of the disease, the variant Creutzfeldt-Jakob disease (vCJD), was identified in 1996. The clinical and pathological phenotype was significantly different from that previously observed in CJD and specifically the patients were relatively young with a mean death age of 29 years and the neuropathological appearances were thought to be novel. Subsequent research has provided powerful evidence that there is a link between this new form of human prion disease and bovine spongiform encephalopathy (BSE). To date a total of 102 cases have been identified in the UK. All tested cases are methionine homozygous at codon 129 of the prion protein gene and although this may be a susceptibility factor, variations at this genetic locus can also influence incubation period. The numbers of cases of vCJD are increasing year on year and analyses taking account of changes in time to diagnosis and confirmation have suggested a doubling of cases approximately every 3 years. Long term projections of the future numbers of cases of vCJD have given variable results because of the many uncertainties including the incubation of BSE in humans, the susceptibility of humans to BSE infection and the infective dose. A geographical cluster of cases of vCJD has been identified in Queniborough which may possibly be linked to specific butchering practices, and the incidence of vCJD is approximately double in the north of the UK as compared to the south. There is no definitive explanation for this regional difference in incidence, but it may be related to specific dietary habits and in particular a relative excess of consumption of products containing mechanically recovered meat in the north as compared to the south of the UK. The major risk factors for vCJD are a young age, residence in the UK and methionine homozygosity. There is as yet no positive evidence of increased risk of vCJD through occupation, previous surgical operations, blood transfusion or contact with vCJD cases. A harmonised system for surveillance of CJD in the European Union has been funded since 1993. Three cases of vCJD have been identified in France (none had visited the UK) and one in Ireland (this individual had lived in the UK for 4½ years during the relevant risk period). Although there are a limited number of cases of vCJD in the UK and elsewhere, the long incubation period in these diseases indicates that further cases of vCJD may continue to appear for many years to come.

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Pathogenesis of bovine spongiform encephalopathy in bovines G. Wells

Before the emergence of bovine spongiform encephalopathy (BSE) and the associated publicity regarding its zoonotic potential, the best known example of the transmissible spongiform encephalopathies (TSEs) of animals was scrapie in sheep. The pathogenesis of scrapie has been studied most in experimental laboratory rodent species. In most experimental models of scrapie, after peripheral non-neural routes of infection, replication of the agent can first be detected in lymphoreticular system (LRS) tissue. When the route of introduction of agent into the body is localised, initial involvement will be in LRS tissue draining the infection site. Thereafter, there is a striking amplification of the agent in the LRS and spread by lymphatic/haematogenous routes, giving widespread dissemination throughout the LRS. This precedes replication in the central nervous system (CNS), but is not the means by which infection reaches the CNS. There is now substantial evidence from experimental models of scrapie that involvement of the CNS is by peripheral nervous system (PNS) pathways. In some models employing oral exposure the earliest localised LRS replication is in the gut associated lymphoid tissue (GALT) and autonomic PNS routing to the CNS has been implicated. However, the relative importance of different routes of spread of TSEs within the body is determined by a number of host and agent dependent factors and, therefore, generalisations from an experimental model to a natural disease across a species barrier may not be appropriate. With the occurrence of BSE as a feed-borne epidemic has come greater recognition of the probable importance of the oral route of infection in ruminant species affected by TSEs and, in consequence, studies have increasingly focused on the natural host species to examine pathogenetic events. However, from studies of scrapie infected single breed flocks it appears that valid comparisons can be made between certain experimental models and at least some forms of natural scrapie.

The experimental transmissibility of BSE to cattle by multiple parenteral inoculations has been established with a remarkable uniformity in incubation periods between the two different breeds of cattle inoculated. From this observation together with epidemiological information, sequencing of the bovine PrP gene and evidence of the constant pattern of neuropathological changes in cattle with BSE, it is likely that the major factors which control expression of the lesions in the TSE i.e. PrP genotype of host, agent strain and route of exposure, are, in cattle with BSE, constant. The implication that the epidemic has been due to a single, stable, cattle adapted strain of a scrapie-like agent is supported by the uniformity of the phenotype of disease on primary transmission of BSE to mice. This is in marked contrast to the situation in

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natural sheep scrapie in which it is accepted that variations in the disease phenotype occurs according to differences in breed, agent strain and host PrP genotype. This phenotypic predictability of BSE has allowed the reproducibility required to study the pathogenesis of the disease after oral exposure in cattle. It was also essential to obtain information on the spread of BSE infectivity through the body tissues during the incubation period in support of control measures, which, necessarily, had to be based on previous studies of infectivity in tissues of sheep with natural scrapie.

A pathogenesis study of BSE examined the spatial and temporal development of infectivity and pathological changes in cattle after oral exposure to a single 100g dose of BSE affected brain homogenate at 4 months of age. Groups of challenged and control calves were killed sequentially, at intervals of mainly 4 months, and a large range of tissues collected for standard infectivity assays in conventional mice. The earliest onset of clinical signs in the cattle was 35 months after dosing. Infectivity in non-neural tissues was confined to the distal ileum (6-18 months and 36-40 months post-exposure). In the CNS, the earliest presence of abnormal PrP (32 months post-exposure), was coincident with the earliest detected infectivity and occurred prior to evidence of typical diagnostic histopathological changes in the brain in association with clinical disease, at 36, 38 and 40 months post-exposure. Infectivity was also demonstrated in sensory ganglia of the peripheral nervous system (32-40 months post-exposure). Interestingly, traces of infectivity were also shown in sternal bone marrow from cattle killed 38 months post-exposure.

Previous studies of tissue infectivity (by conventional mouse bioassay) in naturally occurring clinical cases of BSE have found infectivity only in the CNS. Evidence from the pathogenesis study and from further experimental studies suggests that in BSE there is minimal involvement of the LRS. The study also indicated a close temporal association between the detection of infection, abnormal PrP and pathological changes in the CNS, all first apparent only at a late stage (about 90%) of the incubation period.

This apparently restricted distribution of agent in tissues of BSE affected cattle does not seem to be an exclusive property of the BSE agent. Evidence from the experimental transmission of BSE agent to sheep indicates that after parenteral inoculation or oral exposure the pattern of tissue distribution of infectivity in sheep resembles that of scrapie (see M. Jeffrey, this Consultation). During the course of the BSE epidemic in cattle transmission of the agent via contaminated feedstuffs has been implicated in the spongiform encephalopathies presented by a number of ungulate species in zoological collections in Britain. One of the species involved, the greater kudu (Tragelaphus strepsiceros), is, like the domestic cow, a member of the sub-family bovinae. Bioassay, in C57Bl mice, of infectivity in tissues from four affected greater

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kudu have shown the distribution of agent to be closer to the pattern observed in experimental BSE of sheep with involvement of visceral lymph nodes and distal ileum, but with only traces of infectivity in spleen (A.A. Cunningham, J.K. Kirkwood, M. Dawson and G.A.H. Wells, unpublished data). Surprisingly also, traces of infectivity were detected in lung, submandibular salivary gland, conjunctiva and skin of the one animal in which these tissues were examined. The significance of these latter results requires further evaluation, but they might indicate a potential for horizontal transmission in this bovine species.

Epidemiological studies have revealed no evidence of a natural means of transmission among cattle that would sustain the BSE epidemic in Britain. Probable maternally associated transmission risk factors, evident from one cohort study, cannot contribute significantly to prolongation of the epidemic and no evidence of horizontal transmission has emerged. The only experimental study directed toward possible transmission between cattle was one in which 2-3 month-old calves were dosed oro-nasally on three occasions, at 2-3 day intervals with 100ml of a 50% saline suspension of foetal membranes pooled from two pregnant cows killed with BSE in the last month of gestation. The recipient cattle were kept for 7 years after dosing, with no evidence of the occurrence of BSE.

The transmission of TSE from one species to another is dependent on effective exposure, which is defined by a triad of factors: the dose of infectivity, the route of exposure and the extent of the species barrier. Because of the well established reduced efficiency of infection with TSE agents on primary transmission across a species barrier, it has been important for the purposes of risk assessment to examine the relative efficiencies of the bioassay of BSE infectivity by end point titration in cattle and in mice. The resultant value of the underestimation of the infectivity titre of BSE tissue when titrated across a species barrier in mice is a factor of 500 fold. That this relative degree of insensitivity of the mouse bioassay could explain the absence of widespread LRS infectivity in BSE is not supported by the results of assays by intracerebral inoculation of cattle with pooled lymph nodes or pooled spleens from clinical cases of BSE. In this study survival data suggest that, if present, the concentration of infectivity in these tissues is, at least, less than one cattle (ic) LD50/g. Additional studies were initiated to assay selected tissues from the original pathogenesis study by intracerebral inoculation of cattle. As yet these have confirmed infectivity only in tissues which were found to be positive by the mouse bioassay.

A further transmission study has examined the effect of oral inoculum dose on the attack rate and incubation period of BSE in cattle. This experiment is directed toward obtaining an estimate of the limiting dilution of infectivity of BSE for cattle, an essential, but hitherto missing, component of epidemiological

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modelling studies. Interim results suggest a cattle oral ID50 of 0.38g of brain tissue containing 103.5 mouse ID50/g, with a wide 95% confidence interval. The study continues with examination of the attack rate of doses less than one gram.

It can be concluded from the evidence to date that while the pathogenesis of BSE in cattle appears in many respects similar to that of scrapie and some other animal TSEs after oral exposure, the minimal involvement of the LRS in BSE provides a feature which may have considerable comparative importance. Perhaps not essential to neuro-invasion, the widespread involvement of LRS may have critical relevance to shedding of agent and therefore horizontal transmission, carrier status and, in terms of public health, the potential for exposure to bovine products. The lack of LRS infectivity in BSE of cattle will also have been advantageous to disease control. Furthermore, with agreement (so far) between the bioassay of pathogenesis tissue infectivity in conventional mice and cattle, increasing confidence may be attributed to previous negative bioassay results. Finally, more accurate estimates of the dose response of cattle orally exposed to the BSE agent may contribute to geographical risk assessments of effective exposure.

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Bovine spongiform encephalopathy agent infection of sheep M. Jeffrey and M. Groschup

Romney sheep of three different PrP genotypes were orally dosed with brain tissue obtained from bovine spongiform encephalopathy (BSE) infected cattle brains. Twenty-one PrP ARQ/ARQ sheep were dosed at 6 months of age, divided into groups and sequentially necropsied. One sheep from each of two groups of four sheep necropsied at 4 and 10 months post inoculation (mpi) had disease specific PrP accumulation within single lymph nodes. At 16 mpi disease specific PrP accumulations were detected in some viscera, in spinal cord and in brain of 2/4 sheep. Of the sheep killed at 22 mpi three had widespread disease specific PrP in all tissues examined but in two sheep PrP accumulation was confined to the central nervous system (CNS). Clinical disease onset was observed between 20-26 mpi. Three sheep killed with advanced clinical disease had widespread PrP in brain, spinal cord and peripheral tissues. Unchallenged PrP ARQ/ARQ controls and PrP ARR/ARR and PrP ARQ/ARR were negative for PrP accumulation. These results confirm that PrP ARQ/ARQ Romney sheep are susceptible to BSE challenge. The sites at which disease specific PrP accumulation was first detected in these sheep suggest that, within the alimentary system, there is a variable point of infection into the host and rapid spread through the lymphoreticular system once infection has been established. In contrast to BSE in cattle however, most sheep do appear to show disease specific PrP accumulation within the lymphoreticular system. In this context the BSE agent in sheep is not different from natural scrapie.

Immunohistochemistry labelling of PrP peptide sequences in specific cell types of the brain and lymphoreticular system were compared in natural scrapie infected and BSE agent infected Suffolk and Romney sheep. Clinically affected and some pre-clinical BSE agent infected sheep could be differentiated from scrapie by the lesser amount of labelling of some PrP peptide sequences in phagocytic cells of the lymphoreticular system (LRS) and brain. Additionally, BSE agent infected sheep could be differentiated from natural sheep scrapie by the higher levels of intra-neuronal PrP accumulation in brain detected by labelling for a range of PrP peptide sequences. These results suggest that there is strain dependent processing of PrP in specific cell types within the nervous system and the LRS which can be used to differentiate between BSE agent and other scrapie strain infections of sheep.

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Modelling epidemic(s) of variant Creutzfeldt-Jakob disease A. Alperovitch and J. Huillard d’Aignaux

Modelling is a general method used to estimate a variable that cannot be measured or to predict trends (which is the aim in the case of variant Creutzfeldt-Jakob disease [vCJD]). Various mathematical methods are used for this purpose and in certain cases, simulation and modelling are used together. Sensitivity analyses are then used to estimate the variations resulting from changes in the different parameters. Studies on vCJD involve a highly complex variant in this field. Known data consist of the incidence of the disease since 1996, the age distribution of the persons affected, the genotype of all the patients, data on the human population and the genetic differences that it presents, and the annual incidence of bovine spongiform encephalopathy (BSE) since its first occurrence. Experimental data relate to the infectivity of different bovine tissues, and take into account the dates on which the various measures were introduced to avoid the risk of human exposure. Among the data on which little or nothing is known are the incubation period of vCJD in humans, the factors influencing the relationship between the number of cattle entering the food chain and BSE, and the effectiveness of measures aimed at reducing risk. Hypotheses and scenarios are developed on the basis of these data. To date, all the studies of this kind relate to the United Kingdom (UK) and seen the few number of cases recorded in other countries, the only solution is to extrapolate on the basis of the situation in the UK. However, the results obtained are much too imprecise to be of use in decision-making.

Three simulations have been carried out in the UK all aimed at deducing the number of cases observed from the number of subjects infected, the date of infection, and the period of incubation. Of these three components, only the first can be approximated with any degree of confidence. Modelling depends on three groups of hypotheses:

1. The persons affected are all homozygotes for methionine at codon 29 (of the PrP gene?), and this homozygosis is found in 40% of the population.

2. The time of infection is related to the incidence of BSE.

3. The incubation period is modelled using the same techniques as those classically applied to infectious diseases, and this is modulated according to the age at infection.

The first modelling study (1997) concluded that it was impossible to arrive at an estimate. But figures formulated for various means and various standard deviations for the incubation period implied that one could expect 80,000 cases (25-year incubation period). The second study (1998 – 23 cases of vCJD confirmed up to that point) tried to predict mortality due to vCJD. Once again

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the conclusion was that it was impossible to produce an estimate. A simulation was attempted by varying the different parameters within the context of scenarios compatible with the known number of cases. A maximum figure of 14 million cases was put forward, but was revised downwards in 2000 to a maximum of 136,000 cases (with an incubation period of more than 60 years). The third study considered that the risk was proportional to the exposure doses in the population, which were estimated in accordance with the incidence of BSE, and simulations were conducted for the coming 2 years. The most pessimistic result was 1,500 cases.

A further study yet to be published, aimed at determining the uncertainty surrounding the estimation of the number of cases, and considering a highly variable distribution of the incubation periods, has revealed more optimistic results (several hundred cases).

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Slaughterhouse techniques and the fate of various tissues in bovine spongiform encephalopathy A. Fisher, C. Helps, H. Anil and D. Harbour

The slaughter hall of an abattoir is the primary site where the destiny of bovine spongiform encephalopathy (BSE) risk tissues is policed and controlled. Along the slaughter line, from the stunning pen right through to the point of post mortem inspection, there are several critical control points and the fate of raw materials, not only those used for human consumption but also those for industries such as pet food manufacture and cosmetics, is regulated. However, the control measures regarding central nervous system (CNS) tissues may be inadequate and current approved practices could, if used on an animal with BSE, present significant risk. There are two ways in which potential contamination could occur:

1. dissemination of brain tissue during the stunning procedure;

2. dispersal of spinal cord material during the splitting of carcasses.

The authors have shown at least two types of captive bolt gun used to stun cattle prior to slaughter cause haematogenous dissemination of CNS tissue. Similarly, blood from sheep, slaughtered after stunning with a conventional, cartridge operated, penetrating captive bolt, has been analysed for the presence of the brain proteins S-100β (by immunocytochemistry) and syntaxin 1-B (by capture ELISA). Brain tissue was detected in the buffy layer of the jugular venous blood in 2 out of 15 sheep. There were also two animals with neural emboli in the jugular vein following the use of a pneumatically operated United Kingdom (UK) gun. Electrical stunning did not result in any detectable neural tissue.

The final mechanical process in dressing cattle carcasses (and carcasses of sheep not falling in the Young Lamb category) is splitting down the median plane to form two carcass sides. In the majority of abattoirs, carcasses are split using a band saw whilst fewer abattoirs use saws with a reciprocating or circular blade. The sawing process cuts through anything between 10% and 100% of the total length of the spinal cord. We have used enzyme-linked immunosorbent assays (ELISA) to detect glial fibrillary acidic protein (GFAP) and S-100β on the surface of carcasses after splitting and in the abattoir environment, including aerosol sampling in the vicinity of the saw operator. GFAP is the principal intermediate filament protein in mature astrocytes, the most common cell type in the CNS. Defined areas were swabbed on the lateral and medial surfaces of beef carcasses which had been split using either a band saw or a reciprocating saw. The results show that the area adjacent to the spinal canal on the medial surface was contaminated with spinal cord material in all of the carcasses

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examined. This has implications for the butchery and preparation for retail sale of cuts from this region of the carcass. The mean level of contamination produced by the reciprocating saw was significantly lower (P<0.01) than that produced by the band saw. Significant contamination was still present after the carcass had been washed using a drop hose or after treatment with a combined steam-vacuum treatment used to reduce microbial contamination. There was no evidence of aerosolised protein but there were projected particles in the working area. Significantly less CNS contamination was observed on carcasses when the spinal column had been removed, encased in a column of vertebral bone, by an experimental saw with a ring-shaped blade of small radius. This equipment is the subject of further engineering development funded by a European Commission (EC) demonstration project grant.

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Animal by-products (rendering and melting): processes and products S. Woodgate

The global animal by-products industry processes some 70 million metric tonnes (MT) of raw material which are safely converted into protein meals and animal fats by processes such as rendering or melting. Such raw material, if unprocessed, would lead to an environmental crisis. Products of the rendering industry include meat-and-bone meal (MBM), animal fat, poultry meal, blood meal and hydrolysed feather meal and are used in feedstuffs (protein meals and fats) and in the oleochemical industry for soap and fatty acid derivatives production. Products from melting include edible fats such as dripping (beef) and lard (pork), and high protein greaves or meals. The fats are used by the food industry and the proteins by the pet food manufacturers.

Inactivation studies on rendering processes commissioned by the European Union (EU) and the United Kingdom (UK) led to the establishment of new processing standards in the EU in 1994, based on pressure processing providing the maximum risk reduction. Nonetheless, research in the area of transmissible spongiform encephalopathies (TSEs) inactivation and the animal by-product processing industry is still ongoing in the EU and North America. A key subject in risk assessment has been the potential export of animal proteins from the EU. However, the export of animal proteins such as MBM, poultry meals, feather meals are aggregated under one international tariff code and this makes interpretation of these data (to trace ruminant MBM, for example) almost impossible.

The global impact of TSEs (particularly bovine spongiform encephalopathy [BSE] and variant Creutzfeldt-Jakob disease [vCJD]) on the animal by-product industry has been enormous in the past and continues to be so. The potential role of animal by-product processing in both the aetiology and amplification of BSE has been well documented. However, while most accept the role of recycling in the amplification of BSE, not all members of the industry accept the aetiology hypotheses. Possible alternative hypotheses to the ‘scrapie’ theory include (some of many): a unique cattle BSE, organophosphates/mineral imbalance, a one off antelope, and a role for acitinobacter. The unique circumstances surrounding the BSE epidemic in the UK are still uncertain and until this puzzle is solved, many nations will doubt some of the internationally proposed risk measures.

The new standards for animal by-products processing being proposed by the EU are far reaching and emphasise the role of risk reduction. However, their impact on animal agriculture both in the EU and further afield could be significant and far reaching, particularly if attempts are made to ‘impose’ these

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standards on third countries. Here the evolution of geographical based risk (GBR) assessment will be considered and regionalisation by the OIE, based upon risk, will become vital. In particular, removal and destruction of specified risk materials (SRM) for some regions but not others will be a major discussion point in the future. In addition, the role of Codex Alimentarius in developing international standards for feedstuffs for food animals intended for human consumption and the role for animal by-products in the feeds of the future will be crucial.

A model for animal by-product processing and utilization has been developed by the EU based upon human safety, animal health and environmental protection. As a result, some material presenting disease or TSE risk (approximately 15%) will not be allowed to be re-cycled and will be destroyed. Other constraints on feeding practices will be rigorously enforced such as the ruminant recycling ban, but the feeding of naturally omnivorous animals with safely processed animal by-products will be allowed under strict controls.

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Use, storage and disposal of meat-and-bone meal and the associated risks U. Kihm and P. Comer

Epidemiological investigations in the United Kingdom (UK) indicated that bovine spongiform encephalopathy (BSE) was caused by the consumption of infected feed, probably due to the inclusion of animal protein derived feed in the rations for cattle. Therefore, the most important measure to prevent the transmission of the BSE agent is the ban on the feeding of meat-and-bone meal (MBM) to all ruminants.

Another important measure is the adequate treatment of animal waste and cadavers. It is scientifically proven that the processing of the raw material to MBM in a batch process at 133°C and 3 bars of pressure for 20 minutes markedly reduces the risk, but does not completely inactivate the BSE agent if the initial infective dose is high.

Another central point is the exclusion of specified risk materials (SRM) including cadavers from the feed chain. Some material, such as brain and spinal cord, may contain particularly high concentrations of the BSE agent. If these SRM are removed at slaughter and then incinerated, the risk of recycling the pathogen is markedly reduced. However, if these materials are used for further processing to animal feed, there is a high risk of amplification of the BSE agent.

Although all these measures contribute in decreasing the risk, new infections still appear. This is most probably due to the problem of cross-contamination and cross-feeding. Animal feed that is designated for pigs or poultry may contaminate ruminant feed or be inadvertently fed to cattle. Cross-contamination can only be avoided with separated feed lines or a total feed ban of MBM to all farm animals. In most European countries a total feed ban has been implemented since January 2001. Whether this feed ban is effective can only be judged in an approximately 5-year time.

Implementation of the total feed ban may lead to a major problem of storage and disposal of this massive amount of animal wastes. The MBM can only be stored temporarily and the storage depends on the capacity of the rendering and disposal plants in a given country. For safe storage, MBM should be well contained and all operations carried out under high hygienic standards. Labour protection and safe transport should also be important considerations.

Currently, only a few possibilities exist for the disposal of MBM. Various options for the disposal of MBM produced from rendering SRM and cattle under the ‘over thirty months scheme’ (OTMS) have been considered in the

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UK. These have included a dedicated power station, originally designed to burn chicken litter, and two alternative combustion systems at a rendering plant. Potential risks of exposure to BSE infectivity from each of these processes are reported to be low. All these options have the benefit of utilising the energy content of the MBM. In a few countries, MBM is used as a fuel in the cement industry. In other countries where no appropriate use is found, burying of MBM is allowed.

Whether the total feed ban is a sustainable solution is questionable. More than 50% of the total weight of each cow is not used for human consumption, although only a small part of these tissues may potentially contain infectivity. A huge amount of valuable proteins and tallow is incinerated due to the total feed ban. More innovative ideas are thus urgently needed for better use of such resources.

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Global trade in livestock, livestock products and by-products C. Narrod and J. Otte

The bovine spongiform encephalopathy (BSE) crisis has wide global implications, one of the important concerns being the potential spread of BSE through international trade. In order to obtain a crude assessment of the potential international spread of the BSE agent, a study of world trade in products capable of containing the disease agent was undertaken, based on statistical data held by the United Nations, EUROSTAT and the Food and Agriculture Organization relating to international trade between 1988 and 1999 (meat-and-bone meal [MBM], organs, offals, compound feed, live cattle, tallow). The available data shows that substantial quantities of livestock by-products are traded each year among countries of the European Union (EU) (e.g. more than 300,000 tons of MBM) masking the specific origin of any livestock product exported from the EU to the rest of the world. Between 1996 and 1999, most (>60%) of the exports of MBM from the EU went to neighbouring countries in Eastern Europe followed by countries in the Middle East and North Africa (approximately 20%). However, even some countries in East and South-East Asia imported substantial quantities of MBM from the EU over the same period.

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Session 2: Risk assessment and consequence analysis

Risk of bovine spongiform encephalopathy from trade in cattle with emphasis on the intracommunity trade B. Schreuder, J. Wilesmith, J. Ryan and O. Straub

Among the risk factors for bovine spongiform encephalopathy (BSE) to occur in countries outside the United Kingdom (UK), the importation of meat-and-bone meal (MBM) and live cattle from the UK are the most obvious and important ones. The importance of the importation of live cattle has been demonstrated by the cases of BSE in Oman, the Falkland Islands, Denmark, Canada, Germany, Portugal, Italy and the Republic of Ireland, where one or more cattle originating from the UK have succumbed to the disease. The present study from the mid-nineties assesses quantitatively the risk that other countries, in particular those within the European Union (EU), have incurred by importing cattle from the UK during the period before or shortly after the ban on the import of live breeding stock was introduced in 1989.

It does this by assessing the probability that animals imported from the UK in a certain year would have become a detected BSE case, had they not been exported. Using the annual incidence rates available for separate birth cohorts and a given culling rate, a cumulative incidence for each birth cohort was calculated. These figures were then combined with the numbers of live breeding cattle imported from the UK into the other countries of the EU, to give an import-related risk index for each country, assuming that their culling rates were similar to that in Great Britain.

The numbers of cattle imported annually from the UK into the individual Member States of the European Union (EU) were extracted from reports by EUROSTAT, the Statistical Department of the EU, for the years 1985 through 1992 and checked against data provided by the UK Ministry of Agriculture, Fisheries and Food (MAFF) statistical department (Animal Health, International Trade). The mean of both data sets was used to calculate the number of animals imported into each country. The data relate to animals that were not exported with the apparent intention of being slaughtered.

The countries could thus be categorised in terms of the number of cases of BSE they might have expected. It was evident that, with the exception of Greece, not many countries within the EU could substantiate their claims of never having imported this disease at a time that their surveillance system had not (yet) detected any cases. The objective of these analyses, however, was not to expose the potential under-reporting of BSE or to criticise the degree of

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surveillance in Member States of the EU. Rather, it was to highlight the evidence that BSE cases are likely to have occurred in the importing Member States and to highlight the future risk of secondary cases occurring.

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Bovine spongiform encephalopathy – human exposure risk assessment P. Comer

An approach to assessing the potential for human exposure to bovine spongiform encephalopathy (BSE) risks is described. It is based on a number of studies of BSE risks carried out by DNV Consulting, in the United Kingdom (UK) over several years from1996 to the present. The approach taken in these studies was to try and provide a numerical quantification of the risks, but using a relatively simple approach and simple models. This is important to ensure that the assumptions made are clear and auditable. The first task is the identification of pathways. If significant hazards are missed at this stage then they will not be assessed, no matter how sophisticated is the subsequent analysis. In this case the hazard is known – exposure to BSE infectivity. All the ways by which people may be exposed to infectivity need to be identified. It is important to cast the net as wide as possible and include all possibilities. Unrealistic options can be discounted later.

The next stage is to model each of these pathways, in terms of their affect on infectivity. There may be barriers to infectivity transfer or processes that can remove infectivity or result in dilution. At each stage all assumptions should be clearly stated. The different assumptions can often be represented as an event tree.

The overall exposure, in terms of consumption of infective units, can then be assessed by evaluating the event trees. This can be done using probabilistic risk assessment tools in order to take account of the uncertainty in the input parameters. This requires that each variable is defined as a distribution of values rather than as a single point value and the result calculated many times using a simulation programme. This gives a distribution and range of values for the risk results.

The approach is illustrated by two recent examples: assessing the potential impact from BSE infectivity arising from the disposal of carcasses in the recent foot and mouth disease (FMD) emergency in the UK, and risks from dorsal root ganglia in Ireland.

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The geographical bovine spongiform encephalopathy risk assessment – a first step towards understanding the risk for man G. Pascal

It is generally accepted that bovine spongiform encephalopathy (BSE) is transmissible to humans, most probably by exposure to the agent (still not totally characterised) via food but other transmission routes are not excluded. The geographical bovine spongiform encephalopathy risk (GBR) assessment is an attempt to estimate the risk that in a given country or region, bovines could be incubating BSE. There is no evidence that the BSE agent can be transmitted horizontally and vertical transmission has not been demonstrated under practical conditions. Transmission via semen seems to be highly unlikely, as is transmission via embryos. Until other routes are established, the GBR method therefore only takes into account transmission via feed or ingestion of infective tissues.

There are many hypotheses for the origin of BSE (e.g. that it may occur spontaneously and sporadically everywhere). However, none of these hypotheses is yet scientifically proven and the GBR method therefore simply assumes that BSE appeared sometime in the late 70s in cattle in the United Kingdom (UK) due to an unknown event/mechanism, and it was then discovered in 1986. The GBR method assumes that BSE contaminated imports as the only initial source for BSE. It also assumes a positive feed back loop that recycles and amplifies BSE infectivity if it is not controlled.

Good surveillance and culling can reduce the fraction of all infected cattle approaching the end of the incubation period or already showing clinical signs. Controlling slaughtering age of animals, excluding specific risk materials (SRM) from the food chain and improving the rendering process, reduce the infectivity. Prohibiting feeding of ruminant protein to cattle is often inadequate in reducing cattle exposure to BSE. Cross-contamination of cattle feed should also be avoided.

The GBR method is based on imports of cattle and of meat-and-bone meal (MBM). It is a qualitative indication on the likelihood that one or more cattle in a country or region are infected with the BSE agent. The risk to man may be lower in countries with a known and accepted risk than in countries where an unconfirmed risk is ignored. The GBR exercise of the Steering Scientific Committee (SSC) shows that the risk of BSE being present in the domestic cattle herds varies between countries and that many countries outside the European Union (EU) are endangered. These countries are, however, likely to be in the early stages of a BSE epidemic and therefore have a good potential to avoid major outbreaks if appropriate measures are rapidly taken.

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Assessing the United States controls to prevent bovine spongiform encephalopathy W. James

The current United States (US) control measures against the spread of bovine spongiform encephalopathy (BSE) are the importation ban (since 1989) of ruminants and most ruminant products, a surveillance programme, inspection before slaughter, a BSE emergency response plan and animal feed ban regulations.

The Harvard BSE Study is presented. Its goals are to assess the potential ways BSE can arise in the US, to characterise the potential pathways of exposure to infectivity for both animals and humans and to evaluate the US regulations and policies for potential additional prevention and/or control measures. The approach of the study is the development of a simulation model built to characterise the potential pathways of exposures and dynamics over time in the US. The cattle and livestock systems have been modelled and the model used to evaluate the importance of different steps in the cycle for preventing BSE in US herds.

The key factors for the potential BSE animal transmission are the amount of rendering inactivation, the cross-contamination of feeds, the inadequate compliance with feed bans or other controls and finally, the misfeeding on the farm.

The essential factors for the potential human exposure are the amount of specified risk materials potentially available for human consumption and the potential for contamination of muscle or other meat.

The steps of the risk assessment are the hazard identification and characterisation, the exposure assessment and the risk characterisation.

The US policy is based on the results of this risk assessment. The US will indeed evaluate further mitigating measures to maintain and enhance policies that are at the same time proactive and preventive.

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Transmissible spongiform encephalopathies – risk assessment in livestock in Argentina L. Mascitelli

To protect its sanitary status Argentina set up a specific prevention plan for animal transmissible spongiform encephalopathies (TSE) based on a risk assessment carried out in accordance with the regulatory and operational recommendations issued by international organisations.

In 1989 Argentina began an assessment of its animal health status for this new disease which was unknown in the country. The results of the first stage of the assessment, which included a sanitary and production profile of the livestock industry, indicated that the main factors identified in the occurrence of bovine spongiform encephalopathy (BSE) in the United Kingdom (UK) were not present in Argentina (endemic scrapie, use of rendering process material as an input to manufacture meat-and-bone meal [MBM], use of a rendering process that did not inactivate the TSE agent, and feeding ruminants with MBM from ruminants).

In spite of this, and given the importance of meat production both for the domestic market and for export, farmers were informed, preventive actions taken and a detailed study undertaken to identify the sources of risk. Restrictions on imports of MBM were imposed in 1990 and a specific surveillance plan for BSE was introduced in 1993. Additional preventive measures which included a ban on feeding ruminants with MBM from ruminants, and a follow-up of all imported breeding animals, were adopted in 1995.

In March 1996, a Scientific Advisory Committee comprising international and local experts in animal and human TSEs was appointed to assess the global situation with special emphasis on Argentina. Over 4,800 brains from cattle, sheep, goats, camelidae and deer were tested using the state-of-the-art technology as part of the prevention and surveillance plan with negative results. In addition, a comprehensive informative programme has been deployed both within the country and abroad. A surveillance programme for compound feed manufacturing plants was set up in 1997 to identify potential internal risks.

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The impact of bovine spongiform encephalopathy on the economy of the United Kingdom R. Young

Bovine spongiform encephalopathy (BSE) was first identified as a new disease of cattle in the United Kingdom (UK) in 1986, and by 1992, 36,700 cases were already confirmed, a figure equivalent to 1% of the cattle breeding herd in Great Britain (GB) .The economic cost of the disease was then largely limited to the loss in value of infected carcasses and the costs of disposal of specified risk materials (SRM).

The situation was, however, transformed by the possible link between BSE and variant Creutzfeldt-Jakob disease (vCJD) in March 1996. Domestic sales of beef products declined immediately by 40%, and in April 1996 household consumption was 26% below the level seen in the previous year. Export markets were completely lost. The price of beef cattle fell by over 25%, and many abattoirs had to close thus severely affecting an industry that was estimated to be worth £3.2bn a year (0.5% of UK gross domestic product [GDP] and employed 130,000 workers [0.5% of total employment]).

Measures taken to cushion the industry and to help restore public confidence in beef products comprised a ban on all cattle over 30 months of age from entering the food chain, a calf processing aid scheme to provide an outlet for dairy bull calves, which were usually exported, and a compensation and support scheme for primary producers and for the rendering industry. The EU imposed a ban on UK beef exports and reopened beef intervention buying. The total cost in additional public expenditure was approximately £1.5 billion in 1996/97.

The total economic loss to the nation resulting from BSE in the year following the crisis is estimated to be between £740 million and £980 million, equivalent to between 0.1% and 0.2% of UK national income (GDP). Between one half and two-thirds of this cost is accounted for by the fall in the value added of meat production, and the remainder of the national loss resulted from the cost of operating the various public schemes, compliance costs associated with new legislative requirements and costs associated with the adjustments of production to service new markets. The impact on particular sectors and within sectors varied considerably, depending mainly on the distribution of compensation payments, and the degree of specialisation in cattle rearing activities.

The UK domestic beef market appears to have recovered as far as it is going to. Consumption is slightly above though this is due to lower real beef prices. Real

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producer cattle prices fell by 41% between mid-March 1996 and the end of October 1998. Since then prices have recovered a little but are still 28% below the February 1996 level. However, BSE accounts for only part of this fall, the rise in the value of the pound sterling against the ECU/Euro has also had an impact. The aid schemes for producers introduced by the Government to cushion them from the effects of BSE have now all, with the exception of the ‘Over Thirty Month Scheme’, run their course.

The introduction of the ‘date based export scheme’ (DBES) has permitted the regulated export of boneless beef and beef products from animals between 6 and 30 months to other EU Member States since 1 August 1999. But this has not had a significant impact on market prospects as export markets are proving difficult to recover. In 2000, UK beef exports amounted to around 8,500 tonnes of carcass meat. In 1995, approximately 300,000 tonnes was exported, as well as around 30,000 tonnes of live exports (carcass weight equivalent).

The cumulative budgetary cost of BSE since March 1996 is likely to be in the region of £4.0 billion by the end of the financial year 2000-2001.

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Repercussions of bovine spongiform encephalopathy on international trade – global market analysis N. Morgan

International meat markets in late 2000 were thrown into turmoil as bovine spongiform encephalopathy (BSE) outbreaks in previously disease-free European countries led to global restrictions on European Union (EU) livestock and bovine meat product exports. Market uncertainties were compounded by consumer responses to BSE concerns; beef consumption in Europe initially dropped by 40%, forcing prices downward and heightening awareness among EU policy makers regarding market, budget and policy implications. This presentation, using the World Food Model (WFM) of the Food and Agriculture Organization (FAO), attempts to evaluate the impact of the recent escalation in BSE cases on world trade in meat products and prices.

Scenarios, incorporating different assumptions about consumer responses and EU trade shocks, are incorporated into the model and compared to baseline projections which do not include the impact of recent animal disease outbreaks. In one scenario, a 15% reduction in European beef consumption, combined with a 2% reduction in the rest of world, implies a nearly 2 million tonnes, or a 2.8%, reduction in global beef demand. This BSE induced drop in world consumption, combined with only sluggish production responses, due to the biological cycle for beef, leads to an estimated 5% drop in world beef trade, increasing to a 12% decline in 2002. Meanwhile, excess supplies of beef in international markets puts downward pressure on prices. Beef prices, in this scenario, are projected down 3.3% initially with the shock to world beef consumption appearing more ‘permanent’ than that in 1996 as prices continue to be lower than baseline levels through 2006.

The assumption that producers cannot meet the increased demand for other meats (pork and poultry) in the immediate period implies that excess demand will prevail in these markets, placing upward pressure on prices – pork and poultry prices are projected to increase sharply in 2001 and 2002. By 2006, however, these prices are projected to be only marginally higher than baseline levels as consumption returns to baseline levels. Producers of pork and poultry, both of which have a much shorter biological cycle compared to beef, are better able to respond to changing prices by increasing output.

The repercussions of the BSE crisis, while being felt in international meat markets, also has implications for other sectors, such as the feed sector as the ban on the use of meat-and-bone meal leads to a corresponding shift in demand for alternative feeds, both grains and protein meals. Meanwhile, the broader implications of the outbreak cannot be measured by an econometric

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model. Policy makers in Brussels are grappling with the policy implications of having a massive build-up in EU intervention stocks while, in other countries, costs are being incurred as countries impose surveillance measures and targeted testing.

To compound the uncertainty generated by escalating cases of BSE, the recent surfacing and spreading of foot and mouth disease (FMD) in Europe and meat exporting countries in South America, have led to importing countries scrambling to procure FMD free product, pushing meat prices higher. While model results and history imply that the market impact of the present disease outbreaks will certainly dissipate over the next few years, the policy repercussions and questions on what needs to be done to avoid damaging animal disease outbreaks will remain.

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Control of bovine spongiform encephalopathy in livestock and reduction of human exposure D. Heim

The current measures for bovine spongiform encephalopathy (BSE) control and reduction of human exposure are aimed at eradicating BSE in livestock and reducing the risk of human exposure through contaminated food and other products. Measures related to animal health include ban on feeding meat-and-bone meal (MBM) to ruminants, specified risk materials (SRM) ban in feed, elimination of BSE cases, processing of animal wastes and restrictions on imports.

The ban on feeding MBM is considered to be the most important measure. In order to be effective, it should include measures to avoid cross-contamination like separated feed lines. Known infectious tissues in BSE affected cattle comprise brain, spinal cord, eye, trigeminal ganglia, dorsal root ganglia and ileum. Removal and incineration of SRM, such as brain and spinal cord, reduce the risk of recycling of the BSE agent. Further processing of such material amplifies the risk. Furthermore, an efficient passive and active surveillance system is necessary for the identification and subsequent elimination of BSE cases. Different culling approaches are possible but with varying effectiveness. Cohort culling (feed-cohort and birth-cohort) is more motivating than herd culling for farmers to declare suspect cases. Processing raw material in a batch process at 133oC with 3 bars of pressure for 20 minutes has proved effective although this does not completely inactivate the agent if the initial infective load is high.

Import regulations should be based on a risk assessment, which has to take into consideration the material imported, and the BSE status of the exporting country. Although it is known that MBM and cattle have been exported all over the world, unfortunately, it is not yet possible to detect infection in these imported cattle or MBM. It will be some years before a country can determine whether or not the problem has been imported. Imported MBM is eaten by domestic animals and the SRM will be recycled and will find its way into animal feed. This feed will in turn be eaten by domestic cattle which will not fall sick until an average of 5 years later thus leading to a steady amplification of the BSE agent. If prophylactic measures are not taken in good time, and the surveillance is not efficient, it may take decades before an epidemic is seen.

Although the ban on feed for ruminants has proved to be rather effective, it is not considered sufficient for a complete eradication of BSE. The effect of the

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additionally implemented SRM ban seems up to now rather good, although this measure does not also reduce the infectivity to zero, mainly due to the problem of cross-contamination and cross-feeding. The effect of the total feed ban can be judged only in 5 years time.

Measures for minimising risks for human health require identification and elimination of infected animals before entering the slaughterhouse. An extensive information on BSE symptoms and intensive ante-mortem inspection of cows is necessary. Sanctions for non-reporting of clear clinical suspects should be considered. The systematic ban of SRM and mechanically recovered meat (MRM) from the food chain is and will remain crucial for the protection of the consumer. The list of tissues included in the SRM varies in the different countries. Nevertheless, the most important point is that tissue, known to harbour potential infectivity, should be removed. Until today, infectivity has not been demonstrated in muscle or milk.

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Role of current diagnostic and screening tests in bovine spongiform encephalopathy: control and reduction of human exposure M. Savey and B. Durand

Unlike conventional disease causing agents (bacteria, viruses, parasites), the transmissible spongiform encephalopathy (TSE) agent cannot be routinely isolated or cultured. There is no specific detectable cellular or serological reaction in the live animal. Disease diagnosis relies only on changes observed in the central nervous system of dead animals.

The conventional basis of disease confirmation has been the demonstration of the morphological features of spongiform encephalopathy by histopathological examination. The most prominent features include a bilateral symmetrical vacuolisation of the neuronal perikarya and the neutropil. This method, however, requires skilled pathologists and cannot be applied to group investigations. Rapid tests based on PrPres identification are now being utilised. These comprise specific western blot (WB) and ELISA tests. They can be carried out in less than 24 hours and can be used to screen large populations. These tests also require trained personnel and standardisation. Positive cases have to be cross-checked with other acceptable tests such as immunohistochemistry (IHC) or ‘research’ W.B. or enzyme-linked immunosorbent assay (ELISA). Like IHC or histopathology they are not able to detect bovine spongiform encephalopathy (BSE) in the infected animal during the early and middle incubation periods.

Tests have been prescribed both for passive and active surveillance. Passive surveillance involves the detection of BSE in clinically suspect animals and diagnostic tests such as histopathology or immunohistochemistry are applicable. Active surveillance requires Rapid Tests capable of detecting BSE in large animal populations where specific clinical signs cannot be observed. The target is to be able to detect cases in populations where the incidence is about one case per million adult animals (i.e. over 2 years old). Sampling size and strategy are therefore very important. Passive surveillance must be implemented on a targeted bovine population including every clinically suspect case in cattle over 2 years old. Active surveillance could be implemented in sub-populations where the risk is significantly higher than in the whole population (i.e. fallen stock) or in a specific population for a specific purpose (i.e. every animal slaughtered over 2 years old). Random sampling or whole population sampling can be used depending on the level of confidence needed as well as the use of the results for risk assessment and/or risk management. Test results provide important information on disease incidence as well as geographical and age related distributions. These data are essential for the risk management policy maker.

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Prevention of human exposure will have to rely on the destruction of clinically affected animals and destruction of animals belonging to the same herds or cohorts. The essential public health measure remains the systematic elimination of specified risk materials (SRM) from the food chain.

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Bovine spongiform encephalopathy – risk management and cumulative risk reduction C. Gaynor

Risk management has been defined as a process of weighing policy alternatives and selecting the most appropriate regulatory action, integrating the results of risk assessment with social, economic and political concerns in an effort to reach a desired objective. In terms of bovine spongiform encephalopathy (BSE), the principal objectives for policy makers are the protection of consumer health and the protection of animal health.

In the 1980s when BSE was first diagnosed, it seemed reasonable at the time to adopt the simple approach of:

1. preventing access by ruminants to the hazard by placing a ban on the feeding of meat-and-bone meal (MBM) to ruminants, and

2. the removal of suspect animals from the human and animal feed chain.

However, events which occurred in the mid 1990s forced a re-appraisal of this approach. Firstly, in countries with BSE there emerged numbers of BSE cases in animals born after a ban on MBM. Secondly, the link between variant Creutzfeldt-Jakob disease (vCJD) in humans and BSE in cattle was established.

In particular, it was an appreciation of the risk associated with cross-contamination at feedmills, the ability of the agent to survive certain rendering processes, and the demonstrated small size of a potential infective dose which caused risk managers to reconsider what constituted an appropriate regulatory response. In terms of BSE, the interests of both consumers and cattle are best served by the implementation of a series of risk reduction measures designed to act in an additive or cumulative manner such that the sum of the individual effects ensures that the risk of exposure is reduced if not entirely then to a very negligible level.

Each country chooses the regulatory response which best suits their individual situation. The risk management strategy applied in Ireland relies on four main risk reduction measures. Additional consumer protection is provided by the testing of all animals greater than 30 months of age entering the human food chain. The four main risk reduction measures include:

1. the removal of infected and high risk animals from the food/feed chain;

2. the removal of the specified risk materials (tissues in which the highest levels of infectivity are to be found);

3. the treatment of MBM at 133°C and 3 bars for 20 minutes, and finally

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4. the elimination of MBM in ruminant feed and the prevention of cross-contamination by stringent control of the production, transport, storage and utilisation of MBM, as well as requiring mills using MBM to be dedicated to the production of non-ruminant feeds.

In conclusion, risk management is an iterative process, which needs to take account of new scientific developments and field observations. Risk managers must constantly re-appraise their decisions in the light of results achieved. The history of BSE can be divided up into two distinct periods, before and after the 1996 House of Commons announcement. The two different time periods are characterised by two different approaches to risk management and risk mitigation.

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Technological parameters required to control bovine spongiform encephalopathy during production D. Taylor

Because of widespread exportation of material potentially infected with bovine spongiform encephalopathy (BSE) from the United Kingdom (UK), the future BSE free status of certain countries is not necessarily assured. Thus, companies that manufacture products derived from bovine tissues may have to rely more heavily on being able to demonstrate that their manufacturing procedures can remove or inactivate the BSE agent.

It was discovered that the BSE agent could survive exposure to some rendering procedures. Therefore it was decided that meat-and-bone meal (MBM) (from ruminant tissues) should only be produced by batch-pressure system, although it was considered that even this method might not be completely effective under worst-case conditions. Tallow has been considered generally to be relatively free from any BSE-related risk, although this has been kept under constant review. It is recently reported that autoclaving processes become less effective as the concentration of lipid within which the prion rods were suspended were increased. There is, however, also evidence that BSE infectivity does not preferentially migrate into the tallow fraction during actual rendering conditions but tends to remain in the MBM fraction.

Exposure to sodium hydroxide is not efficient to achieve complex inactivation, but a number of studies have indicated that complete inactivation can be achieved by combining the procedure consecutively or simultaneously with autoclaving.

Currently, it is being investigated whether hot alkaline hydrolysis might be incorporated into rendering systems to produce entirely safe MBM and tallow. This process also can deal with relatively large volumes of material.

Current studies on gelatine indicate that this product is safe with the processes used (acid and alkali) even if the starting materials were sometimes contaminated with the BSE agent. If there were to be any doubts about its safety, these could be annulled by introducing the sodium hydroxide step described above after the process.

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Capacity building for bovine spongiform encephalopathy management D. Ward

It is clear that countries need legislation to make bovine spongiform encephalopathy (BSE) and other transmissible spongiform encephalopathy (TSE) diseases notifiable. Legal authority to examine or seize suspect animals is required as is the obligation for sufficient funds to be made available to pay equitable compensation.

Disincentives to report suspicious TSE cases must be replaced with clear incentives for livestock owners to report. Authorities need to carefully evaluate the potential reporting disincentive of whole herd culling when one TSE positive animal is detected versus a limited culling on only positive animals and their birth cohorts. The classification code of the ‘Office International des Epizooties (OIE)’ for free or infected countries or zones also need to encourage active surveillance and reporting.

Useful incentives for reporting in various developed countries include: coverage of cohorts to remove and destroy animals dying on farms, zoological parks and homes and prompt diagnosis followed by compensation payments at fair market value prices to owners of culled suspect cases.

A minimal essential infrastructure and capability for targeted, active surveillance is required in order to find and diagnose TSE diseases in both animals and humans. The core structures are relatively light in terms of infrastructure. Trained human resources and abundant contact with the public are essential. Public awareness messages and surveillance systems will have to be tailored to various livestock rearing systems and will vary among countries. There is an urgent need for developing countries to report the behavioural abnormalities and neurological signs observed in positive BSE cases, if and when they occur.

Care needs to be taken that the costs of a TSE surveillance system are commensurate with the risk of the disease being either imported or propagated within a country where indigenous animals are present. The capacity for risk analysis is essential to obtain information, not only on TSE disease status, but also on matching the surveillance costs with the risk.

An effective risk analysis unit is essential in order to manage the risks from imports, for reporting on TSE status and for communicating health risks to the public. Likewise, such a unit would liaise with decision makers in all aspects of TSE risk management and communication.

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Cost and cost-effectiveness of bovine spongiform encephalopathy control measures in France I. Chmitelin

The yearly number of bovine spongiform encephalopathy (BSE) cases has been extrapolated on a 12-month period based on the epidemiological data presently available. Control costs have been restricted to direct costs, including those resulting from the forthcoming removal of spinal columns.

BSE control measures consist in prevention, surveillance and eradication. The yearly direct costs are estimated at approximately 835 million euros, or 75 euros per bovine animal older than 24 months or 2 million euros per positive case detected.

Preventive measures include the systematic removal of specified risk materials (SRM) in slaughterhouses, the incineration of fallen and culled stock, the incineration of condemned tissues in slaughterhouses and the feed ban for farmed animals. These measures are fundamental but costly, representing 2/3 of the total costs of control measures. However, the effectiveness is difficult to assess because of the long incubation period.

Regarding the surveillance of BSE, France has three complementary measures in place. These are the epidemiological surveillance of clinical cases in the national herd, the epidemiological surveillance of cattle at risk (fallen stock and emergency slaughtered cattle aged over 24 months) and the systematic testing of healthy slaughtered cattle over 30 months of age. These three programmes make it possible to estimate the actual incidence. The projected incidence is around 3.8 cases per 12 months on 100,000 for cattle aged over 24 months. The surveillance represents a cost of 15 euros per bovine aged over 24 months, or 68 euros per animal checked and 410,000 euros per positive case. The epidemiological surveillance of clinical cases is less costly (7,200 euros per detected case), but the programme is not that effective as it only represents a quarter of the detected cases. The surveillance of cattle at risk represents the majority of the detected cases for an average cost of 112,300 euros per case.

Testing of healthy slaughtered animals required to declare meat fit for human consumption, is extremely costly (1.8 million euros per detected case) and the charge is mainly passed to consumers.

The eradication measures consist in the culling of the entire herd of origin and the culling of all cattle originating from that herd. The total annual direct costs represent 13% of total costs of control measures. Although full compensation is paid, farmers still object to these measures. An alternative solution would be

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the culling of birth cohorts. Another problem concerning the implementation of control measures is the shortage of storage areas and incineration capacities for meat-and-bone meal.

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Control of the international spread of bovine spongiform encephalopathy and variant Creutzfeldt-Jakob disease A. Thiermann

As the international standard-setting organization for animal health and zoonoses, the Office International des Epizooties (OIE) has relied on the advice of the world’s best experts on bovine spongiform encephalopathy (BSE) and other transmissible spongiform encephalopathies (TSEs) to develop its standards. The OIE has made recommendations since 1990 but the first international standards on the safe trade of bovines and bovine products to prevent the spread of BSE and thereby the risks of variant Creutzfeldt-Jakob disease (vCJD) were adopted in May 1992. These standards which have been updated yearly taking into account new scientific findings and experiences are contained in Chapter 2.3.13. of the OIE International Animal Health Code (the Code) on BSE.

The BSE status of a country can only be determined after a detailed risk assessment has been conducted, addressing all elements identified in Article 2.3.13.1. of the Code. These factors are: the feeding of ruminant meat-and-bone meal (MBM), the importation of potentially BSE-infected MBM, the importation of cattle or embryos, and an on-going education programme for veterinarians, farmers and workers. Particular emphasis is placed on the quality and specificity of the surveillance and monitoring system which must utilize the proper methodology commensurate with the risk factors identified.

A country can be considered free of BSE if a risk analysis demonstrates that appropriate measures have been taken for the relevant period of time to manage any risk identified and that there has not been any indigenous case of BSE for at least 7 years. Countries with no indigenous case but whose measures to address all risks identified have not been applied for the relevant period of time, are given a provisionally free status. A country or zone having an incidence greater or equal to one indigenous case per million cattle over 24 months of age, or not complying with the criteria for provisional freedom, is considered in the low incidence category. A country is considered in the high incidence category when it has not met the criteria for low incidence, or when the incidence is higher than one indigenous case per million cattle population over 24 months of age. At present only the United Kingdom and Portugal are in this high incidence category.

The Code recommends that milk and milk products, semen, protein-free tallow, dicalcium phosphate, hides and skins, as well as gelatin and collagen prepared from hides and skins should be traded without restrictions. Specific requirements are provided for trading in cattle, fresh meat, bovine embryos and

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ova from each of the risk categories. Other articles address recommendations for dealing with meat-and-bone meal as well as other specified risk materials for various uses. Recommendations are also provided for trading in gelatin and collagen prepared from bones, as well as tallow (other than protein-free) and intended for food or feed, and depending on the origin of the bones.

It is concluded that measures regarding trade must be based on transparent and scientific assumptions commensurate with identified risks and not aimed simply at regaining consumer confidence as this can unjustifiably restrict trade and eventually increase consumer distrust.

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Session 4: Risk analysis – risk communication

Risk communication: findings of the Inquiry into bovine spongiform encephalopathy and variant Creutzfeldt-Jakob disease chaired by Lord Phillips P. Walker

The Report of the United Kingdom (UK) Committee of Inquiry into bovine spongiform encephalopathy (BSE) and variant Creutzfeldt-Jakob disease (CJD) identifies important lessons for risk communication. Examples are found in the Southwood Report, the introduction of the specific bovine offals (SBO) ban and in statements made after a BSE-like disease were found in a cat. Among other lessons is the importance of explaining the reasoning underlying scientific advice, and that government should clearly tell both the public and those responsible for enforcement the reasons for, and the importance of, any precautionary measures that they introduce. The Committee of Inquiry came to the firm conclusion that a policy of openness is the correct approach. When responding to public or media demand for advice, the Government must resist the temptation of attempting to appear to have all the answers in a situation of uncertainty. Food scares and vaccine scares thrive on a belief that the Government is withholding information. If doubts are openly expressed and publicly explored, the public are capable of responding rationally and are more likely to accept reassurance and advice if and when it comes.

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Bovine spongiform encephalopathy: the consumer’s dilemma D. McCrea

The link between bovine spongiform encephalopathy (BSE) and variant Creutzfeldt-Jakob disease (vCJD) has led consumers throughout the world to ask fundamental questions about the safety of foods, especially beef. Consumers want to know what is safe to eat, and on whom they can rely for advice and protection. Unanswered questions due to the numerous uncertainties concerning transmissible spongiform encephalopathies (TSEs) have generated much doubt for consumers. In the United Kingdom (UK) and other European countries consumers have lost trust in the official agencies who are supposed to inform and protect them about food safety.

While it is known that BSE is one of several types of TSEs that can jump the species barrier, there are still many uncertainties: little is known about the exact cause, the incubation period, the infective dose or whether infectivity is present in milk, and whether it has been transmitted to offspring or other species, such as sheep. It is assumed that human exposure can be minimised by controlling the disease in animals and removing all risk materials from the food chain. Therefore, every possible precautionary measure must be taken to protect public health. Risk reduction strategies should override all trade considerations. Control measures should be fully enforced, and defaulters severely sanctioned.

There is a strong perception that communication between consumers on the one hand and scientists, regulators and policy makers on the other, has been deficient during the early stages of the BSE crisis in Europe. This was re-enforced by the Phillips Inquiry into BSE in the UK. Consumers wish to be informed about the current status of knowledge on BSE, the uncertainties and risks involved, the origin of food, as well as the public health measures being taken so that they can make informed choices on what they eat. A policy of openness should be the preferred approach and Government must resist the temptation to appear to have all the answers in a situation of uncertainty. Consumers must be involved at all stages of the risk analysis process and not merely expected to accept policies of the end process.

More research is required to resolve the uncertainties and scientists should endeavour to develop better methods of detection of the disease, especially in the live animal. Extensive surveillance must be applied and the results publicised. Barriers between scientists, regulators, enforcers and consumers must be broken down to ensure food safety and to protect public health. Communication must be an on-going open, dialogue involving consumers, allowing them to hear the evidence and make up their own minds about the current state of evidence and the risks about what is safe to eat.

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Consumers International (CI) is an international collation of independent consumer organisations with over 220 members in over 100 countries worldwide. Food safety and BSE particularly are major issues within CI.

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The decision maker’s dilemma D. Byrne

Ladies and Gentlemen

I am very pleased to join you today in Paris for this important conference.

I especially welcome the tripartite nature of the conference. There is a very distinguished panel of speakers, all well known to the scientific and public health community. It is entirely appropriate that the three major international organisations in the respective fields of human health, food and agriculture and animal health should meet to discuss bovine spongiform encephalopathy (BSE) and its risks.

The lessons to be learned from BSE must inform policy in all these important areas. While the links between your respective areas of competence are not always immediately clear, they exist. It is a cliché, but a valid cliché, that our systems of agricultural and food production and veterinary health have a major influence on public health.

Directly, through threats to food safety arising from food-borne diseases and zoonoses. And, less immediately evident, but of even greater consequence, through nutrition. But, this conference is on BSE and I will focus my address on this disease.

We are all aware of the huge damage done by BSE. It is perhaps useful to reflect on the full extent of that damage:

– More than 180,000 cases of BSE discovered

– More than 5 million cattle destroyed in the United Kingdom (UK) under the ‘over thirty month scheme’ to stop potentially infected animals entering the food chain

– The costs of the various protective measures introduced throughout the European Union (EU), including the wide scale testing of cattle for BSE and the ban on meat-and-bone meal in animal feedstuffs

– The huge economic consequences of the successive crisis which have led to sharp falls in beef consumption in the EU and expenditure running to billions of EUROS on market support measures

– The damage to the image of the European agricultural industry and the confidence in the safety of its products

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– The damage to the credibility of public authorities and the scientific community due to the perceived mistakes in the handling of the crisis which has had a profound impact on a range of other issues.

But, most of all, we must reflect on the human cost. A recent landmark was passed with the confirmation of the 100th case of variant Creutzfeldt-Jakob disease (vCJD) in the EU. We do not yet know the full extent of the disease. Estimates, from credible sources, range up to 170.000 potential human victims. Hopefully, these upper estimates will prove to be excessive but only time will tell.

The European Commission has been a key player in the unfolding crisis and is uniquely positioned to draw conclusions on the lessons to be learned. And it has been a very painful process for the Commission. I have not and will not hide the fact that mistakes were made in the handling of the crisis. That is a matter of record set out in the report of the European Parliament in the matter.

However, I am convinced that the Commission has taken very radical measures to address these mistakes. I can point to the following examples:

– The major changes to the European Treaties to strengthen EU powers in the area of public health

– The radical re-organisation of the Commission to bring a range of key services together under a single roof and under the direction of a single Commissioner

– The extensive legislative agenda on key public health and food safety issues, including the proposal to create an independent European Food Safety Authority.

All of these developments have their origin in the BSE crisis. It gave the political impetus for a radical overhaul of how the Commission approaches key public health issues. To put it very bluntly, the Commission realised that any mishandling of public health led to very important risks. The public, the electorate, are less forgiving of mistakes or negligence in relation to their health than virtually any other issue.

This is especially the case in relation to BSE. Let me remind you of the comprehensive nature of the measures in place in the EU to protect consumers from any risks of transmission of the disease:

– The removal of the full range of specified risk materials from cattle, sheep and goats

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– The strict controls on the processing of animal by-products and the ban on the feeding of processed animal proteins – meat-and-bone meal – to all farm animals

– The testing of all bovines, at slaughter, aged over 30 months destined for the food chain – over 1.75 million such tests were carried out in the first 3 months of this year alone

– The comprehensive measures on research, surveillance and eradication of BSE

– The large number of inspections carried out by the Commission’s Food and Veterinary Office on Member State compliance with the protective legislation in force.

I am convinced that the full application of these measures ensures the protection of consumers from the risks of BSE.

These measures are now all brought together in a single legal text which will enter into force on 1 July 2001. This text also includes the Community’s new risk classification measures which incorporates the code of the Office International des Epizooties (OIE) on BSE. It will provide a comprehensive framework to address the key issues in relation to BSE – monitoring and surveillance, eradication, risk classification, risk materials, laboratory analysis etc.

Let me also remind those in attendance here today from outside the EU, that these measures apply also to exports. Thus, for example, when the decision was taken to ban meat-and-bone meal, this ban was extended to exports. And I took the precaution of writing to the ambassadors of your countries to the EU to advise them of the ban and of the need to take the necessary measures in relation to any such products imported from the EU.

It has been difficult to convey to consumers how the various measures that have been put in place contribute to reducing the risk from BSE. Too often, national or commercial interests in Member States have intervened and so consumers were presented with conflicting messages on the safety of beef.

One lesson I draw from all of this is the need for clear communication that consumers will understand and trust. It is my hope that the European Food Authority will quickly fill this role and gain the trust and confidence of consumers on all issues regarding food safety.

I would now like to turn to the decision making process involved in the Commission’s handling of BSE. In so doing, I begin with an open

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acknowledgement that is one of the most politically sensitive dossiers on the Commission and EU agendas for the past several years. It has provoked some very sharp and difficult political confrontations. And it has led to the resignation of several key political figures in the Member States.

I live with the knowledge that this is a dossier where any mistake carries a very high cost. This is perhaps the ‘decision maker’s dilemma’ referred to in the title to my address. A situation, to quote my Oxford mini-dictionary, ‘in which a choice must be made between unwelcome alternatives’.

Clearly, all the key decisions in relation to BSE have confronted the Commission with difficult choices, especially given the continued scientific uncertainties. In this context, my approach has been guided by four key criteria:

– An evaluation of the existence of a risk, real or potential, to public health and consumer protection

– The scientific evidence or the evidence of failings in control measures giving rise to such a risk

– The options available to tackle that threat in the quickest and most effective manner possible in a proportionate and non-discriminatory manner and, lastly

– The measures necessary to communicate the decision taken to the Member States and the public in an open, transparent manner.

I am satisfied that the first of these criteria has always taken precedence: the interests of public health and consumer protection. Any other policy would be both irresponsible and dangerous. The changes agreed in the Community’s decision making process in recent years, resulting from the BSE crisis, provide a number of important safeguards to ensure that the public interest is well protected in the decision making process.

– All key pieces of legislation are now decided by co-decision between the Member States and the European Parliament. This ensures very open and transparent debate on all the relevant issues – the consumer’s greatest ally.

– There is a system for independent scientific risk assessment, again carried out in an open and transparent manner. This system has been especially diligent in respect of BSE which has taken up a huge share of the time and resources of our scientific committees.

– And finally, there are the institutional changes which I mentioned earlier, namely the creation of a focus within the Commission – the Directorate General for Health and Consumer Protection – which is not distracted by other considerations, economic or political.

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There are, of course, alternative approaches. I could opt always for the most radical approach and propose the most hard-line and draconian measure possible.

If this approach succeeded, I would be vindicated. If it failed, I could always point the finger of blame at the opponents of the proposals concerned. Effectively, I could leave it to them to take the hard and dangerous decisions on where the public interest lies between the competing policy options.

I have rejected this approach. It would be irresponsible. It would be demagogic. And ultimately it would be a real threat to public health protection as the credibility and real motives behind Commission decisions would be undermined. It would only be a matter of time before such measures were exposed as an attempt to secure short-term public approval or as a shield against potential criticism.

This is my position also on the repeated demands on the Commission to invoke the ‘precautionary principle’ on public health issues. I am a strong defender of the precautionary principle and have worked hard in its defence in a range of international organisations.

But if it is to become a code or shorthand for blocking or banning everything which is objectionable, its credibility will very quickly be lost. It is a principle which must be applied within an open and transparent framework which ensures that it is not used to promote any trade or political agenda.

In this respect, the Commission has taken the time and effort to spell out exactly, in a major policy document, how it understands and interprets this principle. I would encourage our trade partners to engage the Commission in the follow-up to this initiative so that we all have a clear understanding of the issues involved.

A suspicion that consistently lingers in relation to food safety decisions taken by the Commission is protectionism. This is perhaps accounted for by the fact that some of the more bitter trade disputes revolve around food or food related issues – hormones, bananas, for example. The perceived vulnerability of the EU Member States to competition in agricultural goods is also often cited as a motivating factor.

This is, to put it very mildly, absolute nonsense. I have not and will not allow trade considerations to dictate my approach towards public health and food safety issues. Nor have I encountered anything other than full support from my Commission colleagues in this respect, including my colleagues in the Agriculture and Trade portfolios.

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Let me return to BSE as an example. The Commission has imposed a range of controls on imported meat and meat products. Indeed, if the proposals I presented to the Commission yesterday are approved by the Member States, these controls will be strengthened to include, for example, imported gelatine and tallow.

However, these decisions are soundly based on the independent advice of the Commission’s Scientific Steering Committee. Effectively, this Committee has adopted opinions on the risk status, with respect to BSE, of third countries that export such products to the EU.

This process was carried out in an entirely open and transparent manner and on the basis of data supplied by the third countries concerned. It has allowed the Commission to identify the potential risk attached to imports. And to propose the appropriate safeguards to ensure that our consumers enjoy a comparable level of protection in relation to such imports as applies to EU products. But, to repeat, it has not been used for protectionist purposes.

For example, key competitors of the EU in the agricultural area, like Australia, New Zealand, Brazil and Argentina have been placed in category I (‘highly unlikely to present a BSE risk’) of the risk assessment exercise. This is the highest and safest category, unfortunately not enjoyed by any Member State of the EU. And very significantly, these countries are exempted from the most rigorous controls such as the removal of specified risk materials (SRM).

In fact, an estimated 85% of the EU’s imports of meat and meat products come from third countries which fall within category I of our geographical risk assessment. This, surely, is the answer to claims that this evaluation process is motivated by protectionism. Indeed, I understand that the Commission’s risk categorisation increasingly serves as the international standard in this area, even in trade not involving the Member States of the EU.

In this respect, I would actively encourage the OIE to accelerate its work on risk classification of BSE and commit the Commission to providing you with full co-operation in this respect.

And, more importantly, I would call on third countries to implement control and surveillance measures to provide a full and transparent picture of their epidemiological status with regard to BSE. The experience and knowledge available from the EU’s experience of BSE and the rapid detection tests now available ensure that this can be effectively implemented. It will be a sound and cost effective investment if it ensures that the past mistakes and errors of Europe are not to be repeated in your countries.

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The work agenda on BSE is not, however, complete. Let me give you some idea of its continuing impact on my work agenda.

Yesterday, in the weekly meeting of the Commission, I secured my colleagues agreement to a range of new initiatives in relation to BSE, for example:

– the testing of ‘at risk’ cattle for BSE from 24 rather than 30 months

– the introduction for the first time of the testing of sheep and goats for TSEs

– tighter controls on specified risk materials

– the continuation of the existing ban on meat-and-bone meal which was scheduled to expire at the end of this month.

Later that day, I discussed with the European Parliament the Commission’s proposals for a new regulation on the treatment and processing of animal by-products. There are 16 million tonnes of such products produced in the EU each year. Poor processing standards were a key factor in the BSE crisis. This proposal is fundamental to preventing any repeat or similar failing. Good progress was made and there is now an excellent prospect that this legislation will be in place before the end of this year.

Later that same day, I had a similar discussion with the Parliament with the Commission’s proposal for a European Food Authority. This initiative also has its origins in the BSE crisis. And to an audience with a heavy representation from the scientific community, the Commission’s objectives are clear. We want an independent, transparent, assessment on potential risks.

There is now a good prospect, following the Parliament’s opinion on the proposal, of a political agreement between the Member States by the end of this month. The deadline set by the Heads of Government for the Authority to be up-and-running by 1 January 2002 remains on target.

Thus, to repeat a little, within the last 24 hours the Commission has made real progress on several key initiatives related directly and indirectly to BSE.

I am close to concluding. It will not have escaped your notice that the focus of my address has been on the BSE and the decision making process in the EU. This should not hide or obscure the very important work going on elsewhere in the Commission on BSE related issues.

On research, my Commission colleague Philippe Busquin yesterday published a comprehensive paper outlining the Commission’s activities in this field. There is a clear recognition, which I am sure you all share, of a need for much more

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research into TSEs and in particular the human form, variant CJD. I see as particular priorities research into:

– more sensitive tests for the early detection of transmissible spongiform encephalopathies (TSEs)

– minimum infective dose, the extent of the species barrier and the period of incubation, and

– inactivation methods.

I believe the Commission has done its work to promote and support projects in these areas. Member States and third countries should, however, play their part in fulfilling their responsibilities in the research field.

On epidemiological surveillance, CJD and its variant are already included in the Community network for surveillance, prevention and control of communicable diseases. We are supporting, within my Directorate General, a number of key projects in the surveillance field. These aim, in particular, to bring neurologists and neuropathologists into closer co-operation, throughout the EU, in order to detect at an early stage any emerging trends in relation to CJD. This work must be carried out in close collaboration with the World Health Organization (WHO) if it is to achieve its full potential.

On the issue of risk assessment, I have already spoken at length about the European Food Authority. Professor Pascal, the Chairman of the Commission’s Scientific Steering Committee, also addressed you yesterday on the issue of risk assessment. I would like only to encourage the scientific community to seize the opportunity offered by the Commission to have a more forceful role in relation to food safety.

The valid allegation has been made in the past that policy makers blurred the lines between risk assessment and risk management. But, is it not equally valid that scientists were too complacent in their role? There is a need for scientists to be more assertive in presenting the case for science in furthering society’s aims and aspirations.

Finally, arising from crisis such as BSE and foot and mouth disease, there is a real and genuine debate underway in Europe on the extent to which our systems of agricultural production are a factor in these crises. There is also an acceptance that quantity has been given priority over quality. Reforms are already underway which will lead to systems of production which take greater account of environmental, rural development and animal welfare considerations.

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I hope that the participants here today, in particular those from outside Europe, will leave Paris with a greater appreciation of BSE and its risks. More particularly, I hope you will leave with the conviction that the European Commission is playing its part in protecting the public from these risks.

Thank you for your attention.

________

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The scientist’s dilemma P. Brown

One of the major dilemmas is time. Because of the comparatively long incubation times in animals infected with transmissible spongiform encephalopathies (TSE), any experiments that require bioassays often require months to years to complete, yet public health management needs immediate answers. Therefore, very shrewd choices must be made not only with respect to the question to be investigated, but also how much investigation is needed. Two examples illustrate the problem. Leukodepletion of human blood was implemented because of the observation in rodents that infectivity was concentrated in white cells. Subsequently, it was found that the normal precursor protein in rodents was concentrated in white cells, but in humans was concentrated in platelets, raising a strong possibility that any infectivity in human blood might also be concentrated in platelets, making leukodepletion irrelevant. A second example is the oft-repeated statement that muscle has no detectable infectivity. However, this statement is based on extremely small sampling experiments and a little arithmetic shows that many thousands of animals would have to be inoculated to prove the absence of infectivity in even a 6 oz hamburger, and then it could be objected that only one hamburger had been tested!

Other experiments require so much time to be performed that by the time we have the answer the question is historical, for example, studies undertaken now to determine the minimum infectious dose of bovine spongiform encephalopathy (BSE) in primates. Some important questions that have practical future implications concern whether BSE will become endemic or infect sheep and whether variant Creutzfeldt-Jakob disease (vCJD) will cause secondary transmission.

Another dilemma is generated by competition. In the scientific world, hasty publication may result in the publication of unverified data. A better approach would be to encourage that preliminary data be presented at scientific meetings, as in the past. Pressure to publish is also generated by fear that the media will learn of the preliminary results and release them, causing unwanted consequences.

An additional issue is conflict of interest. Most scientists today are connected with industry or government. Industry is driven by profit and so is distrusted; government denials and misinformation have also led people to believe that their government is generally untruthful. These sad facts lead into the final problem, which concerns communication. Who is going to speak? In a democracy, nobody can be prevented from talking, and ‘loose cannons’ abound

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in science as in every other walk of life, with occasional serious consequences for the public perception of an issue. Given the inevitability of such misinformation, it would be wise to assemble a central and authoritative TSE advisory committee that can peer review and issue official reports. The Ministry of Health in each country can then set priorities for that country, since BSE/vCJD can be important in some but insignificant in others. This can be a difficult task since it implies a prediction regarding the possible extent of the problem, and a prediction can always be wrong.

_______


Appendix I Composition of Working Groups

Working Group 1: ‘Risk assessment’ Meeting room – 2 rue Logelbach

1. Stuart MacDiarmid(a) 2. Mo Salman 3. Philip Comer 4. Jean-Philippe Deslys 5. Herbert Budka 6. Allan Fisher 7. William James 8. Joachim Kreysa(b) 9. Leonardo Mascitelli 10. Danny Matthews(b) 11. Clare Narrod 12. Maurizio Pocchiari 13. Gerald Wells 14. Maura Ricketts(c) 15. Robert Will 16. Albino Bellotto(c) 17. Amanda Hill 18. Gina Zanella(d) (a) Chair (b) Rapporteur (c) Secretariat WHO (d) Secretariat OIE

Composition of Working Groups


Working Group 2: ‘Risk management, international’ Meeting room – Salon Ramon, OIE Headquarters

1. Will Hueston(a) 2. Isabelle Chmitelin 3. Dagmar Heim 4. Allan Hogue(c) 5. Marco Jermini 6. Samuel Jutzi 7. John Kellar(b) 8. François Meslin 9. Nancy Morgan 10. Armando Giovannini 11. Joachim Otte 12. Gretchen Stanton 13. David Taylor 14. Alex Thiermann(d) 15. Ladawalya Ratanakam 16. Andrew McKenzie (a) Chair (b) Rapporteur (c) Secretariat WHO (d) Secretariat OIE



Working Group 3: ‘Risk management, national’ Meeting room – Salon Leclainche, OIE Headquarters

1. Colm Gaynor(a) 2. Robert Young 3. Daniela Battaglia 4. Tina Vares 5. Ray Bradley 6. Gardner Murray(b) 7. James Pearson(d) 8. Palrin Radomvivat 9. Marc Savey 10. Francisco Trigo 11. David Ward 12. Stephen Woodgate 13. Paola Pergami(c) 14. Nikola Belev (a) Chair (b) Rapporteur (c) Secretariat WHO (d) Secretariat OIE



Working Group 4: ‘Risk of BSE in sheep and other animal species’ Meeting room – Salon Ovale, OIE Headquarters

1. Linda Detwiler(a) 2. Peter Braam(c) 3. Thierry Chillaud(d) 4. Nora Hunter 5. Martin Jeffrey(b) 6. Ron Rogers 7. Alexander N. Panin 8. Talib Ali 9. Bram Schreuder 10. Emmanuel Vanopdenbosch 11. Moises Vargas

(a) Chair (b) Rapporteur (c) Secretariat WHO (d) Secretariat OIE



Working Group 5: ‘Risk communication’ Meeting room – Vittoz Conference Room, OIE Headquarters

1. Conrad Brunk(a) 2. Anik Alperovitch 3. William Banga 4. Rachid Benaissa 5. Ezzadine Boutrif 6. Paul Brown 7. Fernando Crespo León(d) 8. Colin Feek 9. Carlos Dora 10. Diane McCrea(b) 11. Elisabeth Gaston 12. Marie-José Nicoli 13. Haluk Anil 14. Andrew Speedy(e) 15. Jorgen Schlundt(c) 16. Bernard Vallat 17. Antonio di Giulio (a) Chair (b) Rapporteur (c) Secretariat WHO (d) Secretariat OIE (e) Secretariat FAO

Joint WHO/FAO/OIE Technical Consultation on BSE: 81 public health, animal health and trade

Appendix II Time-table

Monday 11 June

Registration: 12.00-1.30

Opening of the Consultation Chair: Robert Will

1.30-2.00 Introduction B. Vallat (OIE) S. Jutzi (FAO) D. Heymann (WHO)

2.00-2.15 Opening Presentations Maura Ricketts

2.30-3.00 Risk Communication Conrad Brunk

Session 1: Risk analysis – hazard characterisation Chair: Bernard Vallat 3.00-3.30 Epidemiology of BSE Danny Matthews 3.30-4.00 Epidemiology and pathogenesis of

vCJD Robert Will

4.00-4.30 Coffee break 4.30-5.00 Pathogenesis of BSE in bovines Gerald Wells 5.00-5.30 BSE in sheep and other domestic

animals Martin Jeffrey and Martin Groschup

5.30-6.00 Modelling vCJD epidemic(s) Annick Alperovitch and J. Huillard d’Aignaux

6.00-6.30 Slaughterhouse techniques and fate of various tissues

Alan Fisher and Haluk Anil

Tuesday 12 June

Session 1 (cont.) 8.30-9.00 Rendering processes and products Stephen Woodgate 9.00-9.30 Use, storage and disposal of MBM

and the associated risks Ulrich Kihm and Philip Comer

9.30-10.00 Trade in livestock, animal feeds and livestock products

Clare Narrod and Joachim Otte

10.00-10.30 Coffee break

Time-table


Tuesday 12 June (contd)

Session 2: Risk analysis – risk assessment and consequence analysis Chair: Samuel Jutzi

10.30-11.00 Risk of BSE from trade in cattle Bram Schreuder

11.00-11.30 Human exposure risk assessment Philip Comer

11.30-12.00 EU-GBR (livestock) Gérard Pascal

12.00-12.30 US (Harvard) risk assessment William James

12.30-2.00

12.30 Lunch Press briefing: public health and food safety

2.00-2.30 Argentina risk assessment (livestock)

Leonardo Mascitelli

2.30-3.00 Effect of BSE on UK livestock industry

Robert Young

3.00-3.30 Repercussions of BSE on international trade

Nancy Morgan and Gretchen Stanton


Chair: Maura Ricketts

3.30-4.00 Control of BSE in livestock and reduction of human exposure

Dagmar Heim

4.00-4.30 Coffee break

4.30-5.00 Role of current diagnostic and screening tests in BSE control and reduction of human exposure

Marc Savey

5.00-5.30 BSE risk management and cumulative risk reduction

Colm Gaynor

5.30-6.30 Briefing for WG

Wednesday 13 June

Session 3 (cont.) 8.30-9.00 Technological parameters required

to control BSE during production David Taylor

Time-table


Wednesday 13 June (contd)

Session 3 (cont.) 9.00-9.30 Capacity building for BSE

management David Ward

9.30-10.00 Problems in implementation, cost and cost-effectiveness of control measures

Isabelle Chmitelin

10.00-10.30 Control of international spread of BSE and vCJD

Alex Thiermann

10.30-11.00 Coffee break Session 4: Risk analysis – risk communication Chair: Robert Will 11.00-11.30 Philips Inquiry Paul Walker 11.30-12.00 The Consumer’s dilemma Diane McCrea 12.00-12.30 The Decision maker’s dilemma David Byrne 12.30-01.00 12.30

The Scientists’ dilemma Press briefing: animal health, trade and agriculture

Paul Brown

01.00-01.30 Closing remarks Robert Will 01.30-02.30 Break for lunch; end of sessions for

observers

02.30-05.30 Working Group meetings 05.30-06.30 Progress Report for Working

Groups

Thursday 14 June 08.30 Working Group meetings (cont.) 02.00-05.30 Plenary to review results of

Working Groups

05.30-06.00 Final revisions 06.00-06.30 End of consultation, close of all

sessions

06.30 Press conference

________


Appendix III List of participants

Annick Alperovitch Head Inserm Unit 360 Hopital de la Salpétrière 75651 Paris cedex 13, France tel: (33-1) 42 16 25 44 or 40 fax (33-1) 42 16 25 41 [email protected] Haluk Anil University of Bristol Division of Food Animal Science Department of Clinical Veterinary Science Langford BS40 5DU United Kingdom [email protected] Angel Sartori Arellano Head of Delegation Permanent Representative of Chile to FAO 00198 Rome, Italy [email protected] William Banga Hôpitaux de Lyon Attaché Scientifique PHRC - Porte 16 1, place de l’Hôpital 69288 Lyon cedex 2, France tel: (33-6) 83 89 20 46 fax: (33-4) 72 40 59 09 [email protected] Rachid Benaïssa Member of the OIE Code Commission Secrétaire général Ministère de l’agriculture 12, bd Colonel Amirouche 16000 Alger, Algeria tel: (213-21) 71 17 12 poste 2840 fax: (213-21) 71 88 70 [email protected]

Carlo Berlingieri Head of Unit European Commission DG Health and Consumer Protection C/1 Office: B 232 6/81 Rue de la Loi, 200 1049 Brussels, Belgium tel: (32-2) 295 57 31 fax: (32-2) 295 95 79 [email protected] Jean Boyazoglu Secretary General World Association for Animal Production Via Nomentana 134 00162 Rome, Italy tel: (39-06) 86329141 fax: 39-06) 86329263 [email protected] Robert Brackett Senior Microbiologist Office of Plant and Dairy Foods and Beverages Center for Food Safety and Applied Nutrition FDA. 200 C Street SW HFS-300 Washington DC 20204, USA tel: (1-202) 205 8139 fax: (1-202) 205 4422 [email protected] Ray Bradley Private BSE Consultant 41 Marlyns Drive Burpham Guildford GU4, United Kingdom tel: (44-1) 483 57 55 75 fax: (44-1) 483 57 55 75 [email protected]

List of participants


Paul Brown Laboratory of Central Nervous System Studies National Institute of Neurological Disorders and Stroke National Institutes of Health Building 36, Room 4 A05 36 Convent Drive Bethesda MD 20892-4066, USA [email protected] Jeanne Brugère-Picoux Ecole nationale vétérinaire d’Alfort Unité pédagogique de pathologie médicale du bétail et des animaux de basse-cour 7, avenue du Général-de-Gaulle 94704 Maisons-Alfort cedex, France tel: (33-1) 43 96 71 27 fax: (33-1) 43 96 09 67 [email protected] Jean-Baptiste Brunet Ministère de l’Emploi et de la Solidarité Délégation des Affaires européennes et internationales (DAEI) Bureau des Affaires multilatérales 8 avenue de Ségur 75350 Paris 07 SP, France tel: (33-1) 40.56.60.00 Conrad Brunk Academic Dean Conrad Grebel College University of Waterloo Waterloo, Ontario N2L 3G6 Canada tel: (1-519) 885 0220 x 233 [email protected]

Herbert Budka Director Institute of Neurology University of Vienna AKH 4J P.O. Box 48 1097 Vienna, Austria tel: (43-1) 40400 5500; fax: (43-1) 40400 5511 [email protected] David Byrne Commissioner for Health and Consumer Protection European Commission Rue Belliard 232 1040 Brussels Belgium tel: (32-2) 2967126 Vincenzo Caporale Vice-President of the OIE FMD Commission Direttore, Instituto Zooprofilattico Sperimentale dell’Abruzzo e del Molise ‘G. Caporale’ Via Campo Boario 64100 Teramo, Italy tel: (39-861) 33 22 79 fax: (39-861) 33 22 51 [email protected] Peerasak Chantanaprateep Director Institute of Health Research Chulalongkorn University Chulalongkorn Soi 62 Phyathai Road Bangkok 10330, Thailand tel: 2188149 fax: 2532395 [email protected]


86 Joint WHO/FAO/OIE Technical Consultation on BSE: public health, animal health and trade

Isabelle Chmitelin Chef des vétérinaires officiels (CVO) Directrice générale adjointe Direction générale de l’alimentation Ministère de l’agriculture et de la pêche 251, rue de Vaugirard 75732 Paris cedex 15, France tel: (33-1) 49 55 81 77 fax: (33-1) 49 55 55 91 [email protected] Patrick Coelembier European Fat Processors and Renderers Association bd Baudouin 18 (bt4) B-1049 Brussels Belgium tel: (32-2) 2035141 fax: (32-2) 2033244 [email protected] Philip Comer Director of Client Services DNV, United Kingdom tel: 44 (171) 716 6535 [email protected] Patrick Cunningham European Association for Animal Production Via Nomentana, 134 00162 Rome, Italy tel: (39-06) 86329141 fax: (39-06) 86329263 [email protected]

Jean-Philippe Deslys Head of the Prion Group Commissariat à l’énergie atomique Life Sciences Division Medical Research Department Neurovirology Unit CEA/DSV/DRM/SNV B.P. 6 92265 Fontenay-aux-Roses cedex France tel: (33-1) 46 54 82 79 fax: (33-1) 46 54 77 26 [email protected] Linda Detwiler Senior Staff Veterinarian USDA/APHIS Veterinary Service 320 Corporate Blvd Robbinsville, NJ 08691-1598, USA tel: (1-609) 259 5825 fax: (1-609) 259 2477 [email protected] Antonio Di Giulio Research Officer Health, Food and Environment European Commission Directorate General Research Rue de la Loi 200 B- 1049 Brussels, Belgium tel: (32-2) 299 58 86 fax: (32-2) 296 43 22 [email protected] Baptiste Dungu Agricultural Research Council Onderstepoort Veterinary Institute Programme Manager Vaccine Production and Development Exotic Diseases Private Bag X5 Onderstepoort 0110, South Africa tel: (27-12) 529 95 11 fax: (27-12) 529 94 32 [email protected]



Colin Feek Chief Medical Adviser Ministry of Health 130 Old Porirua Rd Ngaio, Wellington, New Zealand tel: (64-4) 496 2390 [email protected] Alan Fisher School of Clinical Veterinary Science University of Bristol United Kingdom tel: 44 0 117 928 9271 fax: 44 0 117 928 9324 [email protected] Elizabeth Gaston USDA/FSIS, USA tel: (1-202) 3207066 [email protected] Michael C. Gaynor Chief Veterinary Officer Department of Agriculture, Food and Rural Development Kildare Street Dublin 2, Ireland tel: (353-1) 607 24 84 fax: (353-1) 676 29 89 [email protected] Armando Giovannini Istituto Zooprofilattico Sperimentale dell’Abruzzo e del Molise ‘G. Caporale’ Via Campo Boario 64100 Teramo, Italy tel: (39.0861) 33.22.79 fax: (39.0861) 33.22.51 [email protected]

Penny Greenwood Acting TSE Policy Coordinator Animal Health Production Division Canadian Food Inspection Agency 59 Camelot Drive Camelot Court Nepean, Ontario K1A 0Y9 Canada tel: (1-613) 952 80 00 ext. 4647 fax: (1-613) 952 88 84 Martin Groschup Federal Research Centre for Virus Diseases of Animals Institute of Immunology Paul-Ehrlich Str. 28 72076 Tübingen, Germany tel: (49-7071) 9670 fax: (49-7071) 96 7303 [email protected] Michael Hansen Research Associate Consumers Policy Institute/ Consumers Union Publisher of Consumer Reports 101 Truman Avenue Yonkers New York 10703-1057 USA tel: (1-914) 378 24 52 fax: (1-914) 378 29 28 [email protected] Dagmar Heim Office vétérinaire fédéral Etat-Major, Affaires internationales Case Postale 3003 Bern Switzerland tel: 41 (31) 324 9993 fax: 41 (31) 323 8594 [email protected]



Amanda Hill Food Safety, Legal and Evaluation Australia New Zealand Food Authority (ANZFA) P.O. Box 7186 Canberra ACT 2610 Australia tel: (61-) 62 71 22 85 fax: (61-2) 62 71 26 85 [email protected] Ulrich Hoffmann Economic Affairs Officer United Nations Conference on Trade and Development (UNCTAD) Trade, Environment and Development Section International Trade and Commodities Division Office E-8017 Palais des Nations 1211 Geneva 10, Switzerland tel: (41-22) 907 57 80 fax: (41-22) 917 02 47 [email protected] William D. Hueston Associate Dean Virginia-Maryland Regional College of Veterinary Medicine Avrum Gudelsky Veterinary Center 8075 Greenmead Drive College Park MD 20742-3711, USA tel: (1-301) 314 68 10 fax: (1-301) 314 68 55 [email protected]

Nora Hunter Institute for Animal Health Neuropatholgenesis Unit Ogston Building, West Mains Road Edinburgh EH9 3JF United Kingdom tel: 44 131 667 5204 fax: 44 131 668 3872 [email protected] Jaana Husu-Kallio Vice-President of the OIE Regional Commission for Europe Director General Department of Food and Health Ministry of Agriculture and Forestry Kluuvikatu 4 A PO Box 30 00023 Helsinki, Finland tel: (358-9) 160 3385 fax: (358-9) 160 4777 [email protected] Freddy J. Ib Chairman, Feed Safety Committee and Meat Committee, World Renderers Organization Dakavej 10 8723 Losning, Denmark William James Director, Food Animal Sciences Division Office of Public Health and Science USDA, FSIS Room 343 Aerospace Center 1400 Independence Avenue SW, Washington, DC 20250 USA tel: (1-202) 690 6566 fax: (1-202) 690 6565 [email protected]



Martin Jeffrey VLA Lasswade Pentlands Science Park Bush Loan Penicuik Midlothian E26 0PZ Edinburgh, United Kingdom tel: (44-131) 445 6169 fax: (44-131) 445 6166 [email protected] Faouzi Kechrid Vice-President World Veterinary Association BP 267, Cité Mahrajène 1082 Tunis, Tunisia tel: (216-1) 566 881 fax: (216-1) 565 009 [email protected] John A. Kellar OIE BSE Ad hoc Group Disease Surveillance Science Advisory and Management Division Canadian Food Inspection Agency 3851 Fallowfield Road, Room C305 Nepean, Ontario K2H 8P9 Canada tel: (1-613) 228 66 98 fax: (1-613) 228 66 75 [email protected] Ulrich Kihm Directeur Office vétérinaire fédéral Schwarzenburgstrasse 161 3003 Liebefeld-Berne Switzerland tel: (41-31) 323 8501 fax: (41-31) 324 8256 [email protected]

Jeong-Weon Kim Senior Researcher Food Technologist Korea Health Industry Development Institute Dept of Industry and Technology 57-1 Noryangjin-Dong Dongjak-Gu, Seoul 156-800 Republic of Korea tel: (82-2) 21 94 74 02 fax: (82-2) 21 824 17 62 [email protected] Tae-Yung Kim Deputy Director Animal Health Division Livestock Department Ministry of Agriculture and Forestry 1 Chungang-Dong Kwachun City, Kyungii-Do Republic of Korea tel: (82-2) 500 19 40 [email protected]

Joachim Kreysa European Commission DG Health and Consumer Protection C/1 Office: B 232 6/71 Rue de la Loi, 200 1049 Brussels, Belgium tel: (32-2) 295 36 92 fax: (32-2) 295 95 79 [email protected]

Koon-Jae Lee Clearance Planning Division Korea Customs Service 920 Dunsan-Dong Seo-Gu, Taejon, 302-701 Republic of Korea tel: (042) 481 78 17 fax: (042) 481 78 19 [email protected]



Régine Lefait-Robin Inspecteur général de santé publique Ministère de l’Emploi et de la Solidarité Délégation des Affaires européennes et internationales (DAEI) Bureau des Affaires multilatérales 8 avenue de Ségur 75350 Paris 07 SP, France tel: (33-1) 40.56.60.00 Marc Le Maguer Director General, Food Directorate, Health Products and Food Branch Health Canada HPB Building, Room 1216 (0701A5) Tunney’s Pasture Ottawa, Ontario K1A 0L2 Canada tel: (1-613) 957 7821 fax: (1-613) 957 1784 [email protected] Diane McCrea Consumers International Global Policy and Campaigns Unit 24 Highbury Crescent London N5 1RX, United Kingdom tel: (44-171) 226 6663 ext. 223 fax: (44-171) 354 0607 Stuart MacDiarmid OIE BSE Ad hoc Group National Manager, Risk Analysis Biosecurity Authority Ministry of Agriculture and Forestry P.O. Box 2526 Wellington, New Zealand tel: (64-4) 474 4100 fax: (64-4) 474 4133 [email protected]

Romano Marabelli President of the OIE International Committee Direttore Generale Dipartimento degli Alimenti, Nutrizione e Sanità pubblica veterinaria Ministero della Sanità Piazza Marconi, 25 00144 Rome – EUR, Italy tel: (39-06) 5994 3945 / 3946 fax: (39-06) 5994 3217 [email protected] Leonardo Mascitelli Director de Tráfico Internacional Servicio Nacional de Sanidad Agropecuaria (SENASA) Paseo Colon 367, Piso 5 1063 Buenos Aires, Argentina tel: 54 11 4345 4110/4112 ext: 1532, 1533 fax: 54 11 4343 5668 [email protected] Danny Matthews TSE Programme Manager Veterinary Laboratories Agency, New Haw, Addlestone Surrey KT15 3NB United Kingdom tel: 44-1932-359512 fax: 44-1932-354929 [email protected] Andrew McKenzie President of the Codex Committee on Meat Hygiene Group Director Ministry of Agriculture and Forestry Food Assurance Authority PO Box 2526 Wellington New Zealand [email protected]



Paul Merlin ‘Cellule ESB’ Direction générale de l’alimentation Ministère de l’agriculture et de la pêche 251, rue de Vaugirard 75732 Paris cedex 15, France tel: (33-1) 49 55 88 16 fax: (33-1) 49 55 51 06 [email protected] Rubén Moreira Zúñiga Servicio Agrícola y Ganadero Ministerio de Agricultura Avda Bulnes N° 140, Piso 7 Casilla 4088 Santiago, Chile tel: (56.2) 698 2244-429/696 7311 fax: (56.2) 671 6184 [email protected] Roger Morris Gilruth Professor of Animal Health Director Massey University EpiCentre Institute of Veterinary Animal & Biomedical Sciences Wool Building, Private Bag 11 222 Palmerston North, New Zealand tel: (64-6) 350 5031 fax: (64-6) 350 5716 [email protected] Yasmini Motorjemu Nestlé Avenue Nestlé 55 Vevey 1800, Switzerland fax: (41-21) 924 2810

J. Gardner Murray President of the OIE Regional Commission for Asia, the Far East and Oceania Chief Veterinary Officer/Executive Manager Product Integrity, Animal and Plant Health Agriculture, Fisheries and Forestry Australia (AFFA) GPO BOX 858 Canberra, ACT 2601, Australia tel: (61-26) 272 5848 fax: (61-26) 272 5697 [email protected] Marie-José Nicoli President French Federal Consumer’s Union ‘Que-Choisir’ Publications Director 11, rue Guenot 75011 Paris, France [email protected] Patrick O’Mahony Chief Specialist Food Safety Authority of Ireland Veterinary Public Health Abbey Court, Lower Abbey Street Dublin 1, Ireland tel: (353 1) 817 13 00 fax: (353 1) 817 13 01 [email protected] Terezinha Padilha Research Scientist Animal Health Management Embrapa-ARS Program Building 1040 Room 105 BARC East Beltsville MD 20705, USA [email protected]



Alexander N. Panin Member of the OIE Code Commission Director, All-Russia State Research Institute for Control, Standardisation and Certification of Veterinary Drugs Ministry of Agriculture & Food 5 Zvenigorodskoye shosse 123022 Moscow, Russia tel: (7-095) 253 1491 fax: (7-095) 253 1491 [email protected] Gérard Pascal INRA Direction scientifique nutrition humaine et sécurité alimentaire 147, rue de l’Université 75338 Paris cedex 07, France Fabrice Peladan c/o International Life Science Institute 1126, 16th Street N.W. Washington, DC 20036, USA tel: (1-202) 659 0074 fax: (1-202) 659 8654 [email protected] Yuantar Pruksaraj Inspector General Ministry of Agriculture and Cooperatives Rajdamnernnok Ave Bangkok 10200, Thailand tel: (662) 281 08 45, 08 57, 59 55 Ext. 347 fax: (662) 281 39 53 or 281 15 53

Olivier Prunaux ‘Cellule ESB’ Direction générale de l’alimentation Ministère de l’agriculture et de la pêche 251, rue de Vaugirard 75732 Paris cedex 15, France tel: (33-1) 49 55 83 24 fax: (33-1) 49 55 51 06 [email protected] Pairin Radomvivat Food and Drug Administration Ministry of Public Heath Nonthaburi 11000, Thailand tel: (662) 590 71 79 fax: (662) 591 84 60 [email protected] Laddawalaya Ratanankorn Department of Livestock Development Disease Control Division Phya-Thai Road Bangkok 10400, Thailand tel: 66 2 252 5967 Scott Ratzan USAID, Global Bureau Population, Health and Nutrition 1300 Pennsylvania Avenue, NW RRB 6.06-72 Washington, DC 20523, USA tel: (1-201) 712 5022 fax: (1-202) 966 9623 [email protected]



Greg Roche General Manager Food Safety, Legal and Evaluation Australia New Zealand Food Authority (ANZFA) P.O. Box 7186 Canberra, ACT 2610, Australia tel: (61-2) 62 71 22 85 fax: (61-2) 62 71 26 85 [email protected] Ron Rogers Senior Scientific Advisor Bureau of Microbial Hazards Room C-309 Ross Avenue, Sir Frederick G. Banting Building Tunney’s Pasture - 2203G3 Ottawa, Ontario K1A 0L2 Canada tel: 613-952-9706 fax: 613- 954-1198 [email protected] Louis Russel c/o International Food Information Service Lane End House, Shinfield Road Shinfield, Reading RG2 9BB United Kingdom tel: 44 118 9883895 fax: 44 118 9885065 [email protected] M.D. Salman Colorado State University Center of Veterinary Epidemiology and Animal Disease Surveillance Systems College of Veterinary Medicine and Biomedical Sciences Fort Collins, Colorado 80523-1676 USA tel: (1-970) 491 79 50 or 03 53 fax: (1-970) 491 18 89 [email protected]

Victor Hugo Sancho Vargas Vice-President of the OIE Regional Commission for the Americas Director Dirección de Salud Animal Ministerio de Agricultura y Ganadería Apdo. 70-3006, Barreal-Heredia San José, Costa Rica tel: (506) 262 0221 fax: (506) 262 0221 [email protected] Marc Savey Directeur de la santé et bien-être des animaux Agence française de sécurité sanitaire des aliments (AFSSA) 23 av. du Général-de-Gaulle, BP 19 94701 Maisons-Alfort cedex France tel: (33-1) 49 77 13 58/90 05 fax: (33-1) 43 68 97 62 [email protected] Niteen Sawant Project Manager Food Safety Industry Council for Development of the Food and Allied Industries PO Box 160 Ramsgate, Kent CT12 4GB United Kingdom tel: (44-1234) 222 620 fax: (44-1234) 222 277 [email protected] Bram Schreuder Edelhertweg 15 8219 ID- Lelystad POB 65, 8200 AB Lelystad The Netherlands tel: 31 320 273 911 fax: 31 320 238 050 [email protected]



Sabine Schueller c/o International Federation for Animal Health rue Defacqz, 1 1000 Brussels, Belgium tel: (32-2) 541 01 11 fax: (32-2) 541 01 19 [email protected] Hazel Sheridan Veterinary Inspector Department of Agriculture and Food 3 Centre, Agriculture House Kildare Street Dublin 2, Ireland tel: 353 1 607 29 75 fax: 353 1 661 90 31 [email protected] Gretchen Stanton Senior Counsellor Agriculture and Commodities Division World Trade Organization 154 rue de Lausanne Geneva 21, Switzerland tel: (41-22) 739 5086 fax: (41-22) 739 5760 [email protected] Jiri Svoboda Conseiller Délégation permanente de la République tchèque auprès de l’OCDE 40, rue de Boulainvilliers 75016 Paris, France tel: (33-1) 45 20 35 47 fax: (33-1) 45 20 35 54 [email protected]

Grégoire Tallard Directorate for Food, Agriculture & Fisheries Agricultural Markets & Trade Division OCDE-OECD 2, rue André-Pascal 75016 Paris, France tel: (33-1) 45 24 94 93 fax: (33-1) 45 24 95 16 [email protected] David M. Taylor Principal Research Scientist Institute for Animal Health BBSRC/MRC Neuropathogenesis Unit Ogston Building, West Mains Road Edinburgh EH9 3JF United Kingdom tel: (44-131) 667 5204 fax: (44-131) 668 3872 [email protected] Lajos Tekes Director Central Veterinary Institute Tábornok u. 2 Budapest, XIV H-1149 Hungary tel: 36 1 2527278 fax: 36 1 2226070 [email protected] Francisco Trigo-Tavera Presidente de la Asociación Panamericana de Ciencias Veterinarias (PANVET) México [email protected]



Adriaan van der Schans Senior Officer International Veterinary Affairs Department of Veterinary and Food Policy and General Environmental Affairs Ministry of Agriculture, Nature Management and Fisheries 73, Bezuidenhoutseweg P.O. Box 20401 2500 EK The Hague The Netherlands tel: (31-70) 378 42 99 fax: (31-70) 378 61 41 [email protected] Emmanuel Vanopdenbosch Head of Dpt of Pathology and Epidemiology Veterinary and Agrochemical Research Institute Groeselenberg 99 B-1180-Brussels, Belgium tel: (32-2) 375 4455 fax: (32-2) 375 0979 [email protected] Jean Vignal c/o International Dairy Federation Square Vergote 41 B-1030 Brussels Belgium tel: (32-2) 7433913 fax: (32-2) 7330413 [email protected] Elisabeth E. Vindel c/o International Dairy Federation Square Vergote 41 B-1030 Brussels, Belgium tel: 0032 2 7433913 fax: 0032 2 7330413 [email protected]

Paul Vossen European Commission DG Health and Consumer Protection C/1 Office: B 232 6/74 Rue de la Loi, 200 1049 Brussels, Belgium tel: (32-2) 295 85 54 fax: (32-2) 295 95 79 [email protected] Paul Walker QC Brick Court Chambers 7-8 Essex Street London WC2R 3LD DX: LDE 302 United Kingdom tel: (44-207) 379-3550 fax: (44-207) 379-3558 [email protected] Gerald Wells Consultant Department of Pathology Veterinary Laboratories Agency New Haw, Addlestone Surrey KT15 3NB United Kingdom tel: (44-1932) 357 498 fax: (44-1932) 357 805 [email protected] Robert Will National Creutzfeldt-Jakob Disease Surveillance Unit Western General Hospital Crewe Road Edinburgh, EH4 2XU Scotland tel: 44 0131 537 21 28 fax: 44 0131 343 14 04 [email protected]



Man-Soo Woo Quarantine Officer Quarantine & Inspection Division National Veterinary Research and Quarantine Service Ministry of Agriculture and Forestry 480, Anyang 6-Dong, Manan-Ku Anyang-City, Kyunggi-Do, 430-016 Korea tel: (82.31) 467 19 37 fax: (82.31) 467 17 17 [email protected] Stephen Woodgate Prosper de Mulder Greenleigh Kelmarsh Rd Clipston; Mkt. Harborough Leics LE16 9RX United Kingdom [email protected]

Laurence Wrixon Secretary General of the International Meat Secretariat 17, place des Vins-de-France 75012 Paris, France tel: (33-1) 44688454 fax: (33-1) 44688453 [email protected]

mailto:[email protected]


Participants from the World Health Organization

Avenue Appia 20, 1211 Geneva 27, Switzerland

Albino Belotto Regional Advisor Veterinary Public Health Program Division of Disease Control and Prevention Pan American Health Organization 525 23th Street N.W. Washington, DC 20037, USA tel: (1-202) 974-3191 fax: (1-202) 974-3643 Peter Braam Scientist, Animal and Food-Related Public Health Risks, Department of Communicable Disease, Surveillance and Response WHO, Geneva tel: (41-22) 791 3882 fax: (41-22) 791 4893 Peggy Braun Animal and Food-Related Public Health Risks, Department of Communicable Disease Surveillance and Response WHO, Geneva tel: (41-22) 791 3835 fax: (41-22) 791 4893 [email protected] Fadela Chaib WHO, Geneva tel: (41-22) 791 3228 [email protected]

Carlos Dora WHO Regional Advisor Health Impact Assessment WHO European Centre for Environment & Health Via Francesco Crispi 10 00187 Rome, Italy Tel: (39-06) 48 77 541 or (39-06) 48 77 539 [email protected] David Heymann Executive Director Transmissible Diseases WHO, Geneva Allan Hogue Food Safety, Sustainable Development and Healthy Environments Protection of the Human Environment WHO, Geneva tel: (41-22) 791 4204 fax: (41-22) 791 4807 [email protected] François-Xavier Meslin Coordinator Animal and Food-Related Public Health Risks Department of Communicable Disease Surveillance and Response WHO; Geneva tel: (41-22) 791 2575 fax: (41-22) 791 4893 [email protected]



Ana Padilla Marroquin Blood Safety and Clinical Technology Quality and Safety of Plasma Derivatives and Related Substances, Health Technology and Pharmaceuticals WHO, Geneva tel: (41-22) 791 3892 fax: (41-22) 791 4836 [email protected] Paola Pergami Medical Officer Animal and Food-Related Public Health Risks, Department of Communicable Disease Surveillance and Response WHO, Geneva tel: (41-22) 7912381 [email protected] Maura Ricketts Animal and Food-Related Public Health Risks Department of Communicable Disease Surveillance and Response WHO, Geneva tel: (41-22) 791 3835 fax: (41-22) 791 4893 [email protected]

Jorgen Schlundt Coordinator Food Safety, Sustainable Development and Healthy Environments Protection of the Human Environment WHO, Geneva tel: (41-22) 791 3445 fax: (41-22) 791 4807 [email protected] Tijs Tobias Animal and Food-Related Public Health Risks, Department of Communicable Disease Surveillance and Response WHO, Geneva [email protected]


Participants from the Food and Agriculture Organization

Viale delle Terme di Caracalla, 00100 Rome, Italy

Daniela Battaglia FAO HQ (AGAP), Rome tel: (39-06) 57 05 67 73 [email protected] Ezzedine Boutrif Food Quality and Standards Service FAO Food and Nutrition Division Rome tel: (39-06) 57 05 24 25 [email protected] Samuel Jutzi Director FAO Animal Production and Health Division Agriculture Department, Rome tel: (39-06) 57 05 33 71 fax: (39-06) 57 05 57 49 [email protected] Nancy Morgan FAO, Rome Clare Narrod FAO HQ (AGAL), Rome tel: (39-06) 57 05 50 49 [email protected] Erwin Northoff FAO, Rome tel: (39-06) 570 5 3105 [email protected]

Joachim Otte Senior Officer Livestock Information and Policy, AGA, FAO tel: (39-06) 57 05 36 34 [email protected] Andrew Speedy Senior Officer Animal Nutrition and Feed Information, AGA FAO, Rome [email protected] Ali Talib FAO Regional Office Near East tel: 20 2 331 6137 [email protected] Tiina Vares Livestock Development Officer FAO Sub-Regional Office for Central and Eastern Europe Benczúr utca 34 1068 Budapest Hungary tel: (36-1) 461 20 25 fax: (36-1) 351 70 29 [email protected] Moises Vargas Teran FAO Regional Office Latin America tel: 56-2 337-2111 [email protected] David Ward FAO HQ (AGAH), Rome tel: 39 365 705 6464 [email protected]



Participants from the Office International des Epizooties

12 rue de Prony, 75017 Paris, France

Bernard Vallat Director General, OIE, Paris tel: (33-1) 44.15.18.88 fax: (33-1) 42.67.09.87 [email protected] James E. Pearson Head, Scientific and Technical Department, OIE, Paris [email protected] Thierry Chillaud Head, Information and International Trade Department, OIE, Paris [email protected] Gina Zanella Deputy Head, Information and International Trade Dept, OIE, Paris [email protected] Yoshiyuki Oketani Chargé de mission, OIE, Paris [email protected] Hiroyuki Kamakawa Chargé de mission, OIE, Paris Fernando Crespo León Chargé de mission, OIE, Paris Maria Zampaglione Communications Officer, OIE, Paris [email protected] Nikola T. Belev President of the Regional Commission for Europe OIE Regional Coordinator for Eastern Europe Bld Wasil Lewski 110 1527 Sofia, Bulgaria tel: (359-2) 944 1514 fax: (359-2) 462 910 [email protected]

Emilio J. Gimeno Honorary President of the OIE OIE Regional Coordinator for the Americas, Cerviño 3101 1425 Buenos Aires, Argentina tel: (54-1) 803 4877 fax: (54-1) 803 3688 [email protected] Yoshihiro Ozawa OIE Regional Representation for Asia and the Pacific East 311, Shin Aoyama Building 1-1-1 Minami Aoyama, Minato-ku Tokyo 107-0062, Japan tel: (81-3) 5411 0520 fax: (81-3) 5411 0526 [email protected] or [email protected] Amadou Samba Sidibe Honorary President of the OIE OIE Regional Coordinator for Africa B.P. 2954, Bamako, Mali tel: (223) 24 60 53 / 22 07 24 fax: (223) 24 15 83 / 23 94 47 [email protected] Ghazi Yehia OIE Regional Coordinator for the Middle East Bureau de la soie, Kefarchima P.O. Box 268, Hazmieh, Lebanon tel: (961-5) 430 741 / 2 fax: (961-5) 430 743 [email protected], or [email protected] Alejandro Thiermann President of the OIE Code Commission [email protected]



Documents

Proceedings Joint WHO/FAO/OIE Technical Consultation on ... · Evidence linking bovine spongiform encephalopathy (BSE) and variant Creutzfeldt- Jakob disease (vCJD) in 1996 and the