Archivo: Grupo de Investigación
1999 Session of the Research Group of the Standing Technical Committee of EuFMD
Maisons-Alfort, France
29 September to 1 October 1999
Introduction
A Session of the Research Group of the Standing Technical Committee of the European Commission for the Control of Foot-and-Mouth Disease (EuFMD) was held at the Agence FranÇaise de Sécurité Sanitaire des Aliments (AFSSA), Maisons-Alfort, France, from 29 September to 1 October 1999.
Dr Y. Leforban, Secretary of the European Commission for the Control of Foot-and-Mouth Disease introduced Dr Martin Hirsch, Director-General of AFSSA, who welcomed the participants and gave a brief address on the activities of AFSSA. Dr B. Vallat, Directeur Général Adjoint, Direction Générale de l'Alimentation, Sous-Direction de la Santé et de la Protection Animales, sent his apologies for being unable to attend due to other pressing commitments.
Dr Hirsch referred to the recent outbreaks in the Caucasian countries and in the Mediterranean region and underlined the importance of strict vigilance to prevent the return of FMD in member countries of the European Union. The choice of the site for the meeting, was particularly appropriate. The laboratory of Maisons-Alfort, founded in 1901, is the oldest FMD laboratory in the world and it was here in 1904 that the three FMD virus types A, O and C were discovered for the first time by Professor Vallée.
He then described the role of the new Agency - AFSSA - that was created on 1 April 1999 and regroups all the national veterinary research laboratories which to date have been under the directorship of the Centre National dëEtudes Vétérinaires et Alimentaires (CNEVA). FMD research and diagnosis is carried out at the Alfort Veterinary Research Laboratory (AFSSA-Alfort) and at the Bovine Research Laboratory, Lyon (AFSSA-Lyon). In the case of suspicion of an outbreak in France these laboratories provide assistance and expertise to the Veterinary Services of the Ministry of Agriculture. AFSSA-Alfort also organises training workshops for staff from the Departmental Directorates while the Lyon Laboratory ensures permanent vigilance for FMD through the French epidemiological network. It is also responsible for one of the three European FMD antigen banks and stocks the equivalent of 11.5 million doses of vaccine in the form of concentrated antigen.
AFSSA's activities fall under three Ministries: Health, Agriculture and Consumer Protection. In addition to 12 laboratories located throughout France, it includes the French State Hydrology Laboratory and several expert committees involved in the assessment of food quality and safety. AFSSA works in close partnership with other similar structures in Europe and in the field of reference laboratories within the European network.
AFSSA with its objective of protecting human health covers a very wide role in the food sector and is responsible for evaluating health and nutritional risks in food products destined for both human and animal consumption.
In conclusion, Dr Hirsch wished the meeting success in their deliberations and a pleasant stay at Maisons-Alfort.
On behalf of FAO and of Dr R Marabelli, Chairman of the EuFMD, Dr Leforban welcomed the Members of the Group to Maisons-Alfort, especially the new participants, Dr C. Griot, Switzerland and Dr J.M. Sanchez Vizcaino, Spain. He extended thanks to the Ministry of Agriculture and to the Director General of AFSSA for having accepted to host the annual Session of the Research Group. He expressed special appreciation to all those who gave so generously of their time for the organisation of the meeting, Dr E. Plateau, Director of AFSSA-Alfort, Dr L. Sanite, International Department, AFSSA and Dr Michelle Remond.
Dr Leforban recalled his long personal association with the French Ministry of Agriculture during his 7-year period of employment with CNEVA (now AFSSA) and he stated that it was a pleasure for him to return to Maisons-Alfort and renew acquaintanceship with his former colleagues and friends. He underlined the leading role France had played in research on FMD and FMD vaccine and said that the choice of this historical place as a venue for the meeting was highly significant.
He thanked the Group for their high-quality input to the activities of the Commission, and Dr K. De Clercq for his efforts to maintain the high scientific level of the work of the Group following the outstanding Chairmanship of Dr A.I. Donaldson.
Appreciation was also expressed for the work of the experts who had participated in the recent missions to the CIS countries and to Russia and and to those who contributed to the Working Group on the European Pharmacopoeia.
The situation of FMD continues to be a cause for concern with the recent occurrence of Asia 1 type in Iran and the probably new A strain in Turkey. The advice of the Group to the Commission is essential and the role of the WRL in the epidemiological surveillance of viral strains is also essential and should continue to be strongly supported.
Dr Leforban wished the Group a fruitful Session and an enjoyable stay at Maisons Alfort.
The Session was chaired by Dr K. De Clercq, Belgium. Members of the Group present were : Dr M. Amadori, Italy, Dr S.J. Barteling, The Netherlands, Dr A.I. Donaldson (Ex Officio), UK. Dr M. Danes, Romania, Dr C. Griot, Switzerland, Dr I. Gurhan, Turkey, Dr B. Haas, Germany, Dr P. Have, Denmark, Dr Y. Ivanov, Bulgaria, Dr J.M. Sanchez Vizcaino, Spain and Dr H. Yadin, Israel.
The EU Scientific Veterinary Committee on Animal Health and Animal Welfare was represented by Professor G.F. Panina.
The following observers attended from France: Dr Arnaud Roulet (MinistÏre de lëAgriculture), Dr Michelle Remond, Dr FranÇois Moutou, Dr Guillaume Gerbier, Dr Jean Marie Gourreau, Dr Claude Kaiser (AFSSA-Alfort), and Dr Jean Yves Madec (AFSSA-Lyon).
Members of the Group acted as rapporteur for the different items and Dr Y. Leforban, Dr J. Ryan and Ms J. Raftery of the European Commission for the Control of FMD provided the Secretariat.
Before presenting the Agenda for adoption, Dr De Clercq on behalf of the Group thanked the Ministry of Agriculture, the Director General of AFSSA, the Director of AFSSA-Alfort and his co-workers for their assistance in organizing the meeting for the Working Group on amendments to the Pharmacopoeia FMD Monograph. He welcomed the members of the Research Group, Prof. Panina who was representing the EU Scientific Veterinary Committee on Animal Health and Animal Welfare, and extended thanks to Dr Susan Horst, Wageningen, who had accepted to present her scientific work despite the very short time at her disposal.
He informed the meeting that Drs Westergaard and Fuessel from the new EC Directorate General of Health and Consumer Protection sent their apologies for not being able to attend and he once again reminded the Members of the deep interest with which the Executive Committee followed their research activities.
- Item 1 Adoption of the Agenda
- Item 2 Epidemiology, risk analysis and surveillance
- Item 3 Serosurveillance
- Item 4 AFSSA
- Item 5 Vaccines
- Item 6 Biosecurity and Quality Assurance in FMD laboratories
Environmental aspects of FMD control - Item 7 SVD Information about the request to remove SVD from the OIE List A
- Item 8 Any other business
The Agenda was adopted as proposed.
Item 2: Epidemiology, risk analysis and surveillance
Dr Horst presented her thesis and the ongoing work of Wageningen University on computer simulation models that would help in setting priorities for policy makers by quantifying the risk and economic consequences of exotic animal disease introductions (Appendix 1). While the research project "Risk and Economic Consequences of Contagious Animal Disease Introduction" was a co-operative venture between Wageningen University, the Dutch Government and private industry and therefore based solely on the risks for the Netherlands, the models developed can have wider application.
The key to effective epidemiological and economic modelling for decision making purposes is the integration of economic data with the extensive historical and experimental data on the biological aspects of the virus and virus spread and with a new method of modelling virus introduction and the key risk factors that affect virus introduction rates.
Models describing the spread of virus within a country already exist (InterSpread model) and can be used to evaluate different control strategies. The economic consequences of outbreaks were also calculated using the EpiLoss model. The crucial missing section of the necessary components was a model of virus introduction.
Dr. Horst described the limitations of real life experiments and deterministic simulation models and indicated that her VIRiS model would overcome these limitations by using stochastic modelling (Monte Carlo Sampling) of the uncertainties. The VIRiS model intends to predict the number and location of primary outbreaks in the Netherlands over a 5 year timeframe. The key inputs for the model are the frequency of outbreaks in European countries, the duration of the High Risk Period (the period in which virus is already present in the country but not yet detected or under control) and the Risk factors (the vehicles used for virus transfer - live animals, animal products, trucks etc.). The data to quantify these inputs comes from historical information (trade/epidemiological information), specific research where possible and finally from experts.
The elicitation of the opinion of experts was considered useful and necessary as their experience combines experience and understanding of current and future circumstances. The elicitation and quantification of expert opinion took place in workshops where the participating experts completed a computerised questionnaire. Some of the elicitation used the Conjoint Analysis technique that is widely used in marketing studies to elicit the subjective views and preferences of consumers.
The outputs of the model indicated that the Netherlands was likely to experience 1 FMD outbreak in the next five years and that the Eastern region of the Netherlands was most likely to experience a primary FMD outbreak due the influence of the risk factor "import of livestock". Another important risk factor was found to be returning trucks and when investigating different scenarios, the complete elimination of this risk resulted in a reduction of expected annual losses of more than 10 million Dutch guilders. In this way, VIRiS can add to the evaluation of animal disease prevention programs and serve as a useful tool for policy makers.
Dr Gerbier presented a paper (Appendix 2) on mathematical analysis of the interactions between the animal density and FMD spread by a computerised model. By analysis of several outbreaks such as Taiwan 1997, France 1981, UK 1967-68, etc. with several parameters (effect of density, herd size, and distance between the herds) he concluded that the highest spread of FMD might arise if transmission of infection between herds was as successful as transmission within a herd. He also added that in reality there was a negative interaction between the herd size and distance between herds.
The next paper (Appendix 3) presented by Dr Moutou covered a qualitative risk analysis of the introduction of FMD from Transcaucasian countries to Europe through Russia based on the 3-week mission of OIE/FAO/CE in those countries in March 1999. By taking into account infectious agent prevalence, importance of trade, survival capacities of the virus, contamination potentials and transmission probabilities he considered that there is a ’lowë risk for transmission of FMD from Transcaucasian countries to Eastern Europe.
Dr Leforban reviewed the FMD situation in Mediterranean Maghreb (Appendix 4) and outlined the history of FMD in Morocco, Algeria and Tunisia starting from the previous outbreaks between 1989 and 1992 which had affected mainly small ruminants with high mortality in lambs. In the second part of his presentation he explained the recent O type outbreaks in that area in 1999 which affected mainly cattle. Taking into account the high small ruminant population and based on the FAO/RADISCON experience in the region, he suggested the selective vaccination strategy for control of the disease in the region.
Dr Donaldson presented a risk analysis (Appendix 5) of FMD in western North Africa (Morocco, Algeria and Tunisia) for Europe. It was based on the outbreaks in that area since 1977, agriculture, animal population, animal movement and trade with Europe. The importance of small ruminants was also discussed. Finally he listed a number of safeguards to minimise the risk of spread of FMDV from that area to Europe (see conclusions and recommendations).
Dr Yadin summarised the FMD situation over the last 12 months in Israel, Jordan, Palestine and Lebanon (Appendix 6). No FMD outbreak occurred during 1998 in Israel whereas in 1999, 43 outbreaks had been recorded in the region (21 in Israel, 2 in Lebanon, 3 in Palestine and 17 in Jordan). Both cattle and small ruminants were affected. O1 type FMDV was responsible in all of these cases. The results of ELISA indicated that the circulating virus is antigenically related to O Dalton (r=0.9-1.0). Genetic analysis showed that all the 1999 FMD outbreaks in those countries originated probably from a common source.
Dr Gurhan described the FMD situation in the last 12 months in Turkey (Appendix 7). There were 44 recorded outbreaks. 3 of them were type A and 41 type O. Type O virus circulating during 1999 was still antigenically close to the vaccine strain (O1 Manisa 69) (r=0.4). However, the responsible agent for type A outbreaks during 1999 was no longer close to A Mahmatli 65 (current vaccine strain of SAP Institute, Ankara) nor to the A Iran 96 (r<0.2). Following A Iran 96 outbreaks in Turkey at the beginning of 1998, an emergency vaccination programme with homologous vaccine was applied with the assistance of EU in Thrace. A serosurvey to detect the efficacy of the vaccination campaign was carried out and the results showed that the seroprevalence was 67% for large ruminants and 42% for small ruminants.
Following the notification of type Asia1 outbreak in Iran by OIE a number of preventive measures have been taken by Turkey in order to face this risk of spread including production of one batch of monovalent vaccine for the emergency cases. A letter has been sent to the Veterinary authorities in Iran asking for further information on the epidemiological situation and a proposal for technical collaboration.
Conclusions and Recommendations
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Risk analysis and computer simulation of disease transmission promise to be useful tools for the evaluation of different disease control strategies. It is recommended that these tools should be further elaborated and evaluated for the control of FMD.
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The Group recommended the organization of a Workshop on risk analysis and expert opinion together with experts from Wageningen University on the occasion of the next open Session in Sofia in September 2000. The programme and objectives of the Workshop should be defined in advance between the Chairman of the Group and Wageningen experts. The outputs of the Workshop should be beneficial to the Group and to EuFMD member countries.
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The FMD situation in the CIS countries, North Africa, Turkey and the Middle East remain of high concern regarding the risk of transmission of FMD to Europe. The disease situation in those regions needs to be monitored constantly. Furthermore, it is important to direct efforts to the technical collaboration and support for control of the disease and to maintain a high level information exchange with these countries.
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The epidemiology of FMD in Turkey and Iran is of particular concern. Turkey should increase vigilance and consider slaughter of animals affected by the serotypes which are not included in the vaccine of the current vaccination campaign, such as the Asia 1 strain which is currently affecting Iran.
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The support for technical assistance for Turkey proposed by the EU in 1998 for the QC of vaccine produced in Turkey and for surveillance should be implemented.
In respect of the situation in North Africa, the following was recommended :
1. The maintenance of effective systems of disease surveillance, reporting and control of FMD in North Africa
2. Increasing awareness of travellers and tourists through posters or leaflets about the risks to animal health of importing animal products.
3. The maintenance of coastguard patrols in the western Mediterranean
4. The vigilance and co-operation of customs officials at ports and airports in Europe
5. The destruction of foodstuffs removed from ships and aircraft at ports of entry into Europe
6. The effective heat treatment of waste food from restaurants and institutions before it is fed to animals.
Dr. Donaldson reviewed some of the surveillance work carried out in North Africa in the recent past (Appendix 8) and drew conclusions on the usefulness of serosurveillance for directing FMD control in North Africa and other, similar areas. The results show the decrease of antibody titres over time in small ruminants. In all surveys there was a very clear clustering of seropositive animals within flocks and of seropositive flocks within provinces which was consistent with the known distribution of clinical disease. In contrast to the positive sera from 1992, the structural proteins (SP) ELISA-positive sera from the 1994-1996 surveys were all negative to non structural proteins (NSP). Possible reasons for that were discussed. Antibodies (Ab) to NSP appear later than Ab to SP and fall below the detectable level earlier. Therefore the required sampling frame, particularly in sheep, has to be determined.
Dr Sanchez-Vizcaino presented results from a FMD serosurveillance in Morocco (Appendix 9a). 335 sheep serum collected in the vicinity of the three cattle outbreaks of 1999 were analysed. 88% of the sera was negative to both structural and non-structural and 12% were positive (cattle and sheep), all belonged to the last outbreak. The sensitivity and specificity the SP ELISA and NSP ELISA were similar, but it is important to note that the Ab to NSP appear later and with a lower titre.
Dr Sanchez-Vizcaino referred to their experiences with NSP ELISAës for serosurveillance (Appendix 9b). The sensitivity and specificity of the ELISA based on 3ABC protein allowed detection of all infected animals and made it possible to distinguish between infected cattle and (multi-)vaccinated cattle. He recalled that the NSP ELISA was already described for pigs in 1994 (Rodriguez et al., 1994, Archives of Virology 136, 123-131).
Dr. Ivanov presented the results of a serosurveillance in Bulgaria in 1998 (Appendix 10). The serosurvey included the 3 Bulgarian provinces bordering Turkey, where 42 villages within 10km of the Turkish border were sampled. The sampling procedure was based on statistical methods. A total of 19.188 samples from 282 small ruminant flocks were analysed by a LPB ELISA for O1 and A22 antibodies. 54 of the 19.188 samples were above the threshold 1:40 but <1:100. Further testing showed that these reactions were not due to specific FMD antibodies.
Dr. Amadori presented the next paper about "Serosurveillance of FMD in the TransCaucasian Countries: Role of the 3ABC-ELISA" (Appendix 11). Cattle and sheep sera from several districts of Georgia and Armenia were tested for Ab to O1 and A22 by LPB ELISA. The results indicate poor and irregular vaccination coverage. The percentage of positive sera in cattle and sheep were far higher in Armenia than in Georgia. 33% of a selection of positive sera, representing all areas, were also 3ABC positive. These sera were clustered in an area of Armenia affected by FMD in 1998. Dr. Amadori concluded that these countries should not be considered as endemic areas but as areas where virus may be introduced from the surrounding and persist for some time in certain sites.
Dr. Donaldson presented a paper on "Antibody to the Non-Structural proteins of FMD virus in relation to the carrier state in cattle" (Appendix 12). Some evidence was provided that seroconversion to NSP was more likely in carrier animals in which virus was recovered consistently and at high titre. Ab to NSP was higher in animals showing clinical signs than in subclinically infected animals and in the latter the response to NSP was delayed. Anamnestic Ab response to NSP seems to be related to the re-establishment of infection. There is no relationship between the titre of Ab to SP at the time of challenge and either seroconversion to NSP or subsequent development of the carrier state.
Conclusions and Recommendations
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Measurement of antibody to NS proteins, particularly 3ABC, should be used as marker of previous infection with FMDV on a group basis. However, it cannot be used as reliable indicator of current virological status of individual animals i.e. whether or not the animal is a carrier. Therefore there is still a need for techniques which identify the agent itself.
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Antibodies to NSP appear later than Ab to SP, at a lower titre and fall below the detectable level earlier. Therefore a required sampling frame, particularly in sheep, has to be determined.
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There is no relationship between the titre of Ab to SP at the time of infection and either seroconversion to NSP or subsequent development of the carrier state.
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A serosurveillance in Bulgaria in 1998 at the Turkish border testing for the presence of antibodies in small ruminants against FMDV O1 and A22 revealed that all samples were negative. It was highly recommended that all serosurveys in the Balkan area should be conducted on the basis of a NSP ELISA. The necessary technology and reagents should be transferred as soon as possible.
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The Transcaucasian countries are at risk for FMD. Further serosurveys for Ab against SP and NSP should provide the data about the efficacy of future vaccination campaigns and previous contact with infectious FMDV.
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Serosurveillance is very useful for directing FMD control in several areas. Kits for detection of Ab to NSP should be made available for national and regional laboratories in Europe as soon as possible.
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Vaccine producers should absolutely avoid the presence of NSP in their vaccines.
Dr Remond presented the epidemiology, diagnostic and research activities regarding viral vesicular diseases in AFSSA-Alfort (Appendix 13).
Viral isolation, ELISA tests, PCR, seroneutralization are currently performed for the diagnosis of vesicular diseases (FMD, SVD, VSV) and for the serological control of animals. Research activities consist in the production of recombinant FMDV 3ABC antigen in insect cell, in the determination of FMDV capsid epitopes recognised by non neutralizing monoclonal antibodies and in the expression of Fab fragments from anti FMDV bovine immunoglobulins on the surface of phage (antibody phage display).
The epidemiology unit of AFSSA-Alfort is the second unit of this laboratory dealing with FMD. Together with AFSSA-Lyon it participates in the surveillance of the disease in France, and is contacted in case of any field suspicion. If the suspicion results in a sampling procedure, then the virology unit is contacted and put on alert. The epidemiology unit is also in charge of the training sessions for veterinary officers, four a year, three days each, held in different locations each time. Research work is also carried out. A thesis has been written on artificial intelligence reproducing an FMD outbreak. Mathematical modelling also concerns airborne spread. Another thesis is currently being prepared covering two subjects: the analysis of the effect of density and the geographical spread of the disease.
Experts from the epidemiology unit have participated in field missions for EU and FAO in Europe.
Under this item seven papers were presented. Dr Amadori reported on the activities of the Working Group on the FMD Monograph of the European Pharmacopoeia appointed by the Executive Committee of the EuFMD in accordance with the recommendations laid down at the Aldershot meeting of the Research Group (Appendix 14). The Working Group consisted of representatives of the EuFMD Research Group, the EU Scientific Veterinary Committee, private companies and the secretariat of EuFMD. The Table of Contents of the present monograph was critically analysed and adapted to a more logical format relating to modern manufacturing practices.
Emphasis was put on validated in vitro rather than in vivo tests. In this light, tests for absence of residual virus carried out in vitro would be more sensitive and statistically more reliable than the in vivo test (application into the tongue of bovines), which should no longer be prescribed.
A similar rationale was taken for the potency test in the monograph. In particular the possibility was envisaged to demonstrate consistency of results in the framework of the Quality Assurance System and thus reduce the need for animal usage.
Dr Haas reviewed the experience of several groups in the use of serology in potency testing of FMD vaccines in pigs (Appendix 15). He highlighted the contradictory results and the discrepancies among the results of the different groups. This could be largely referred to the different tests and challenge conditions. However, he reported that at least two laboratories used the correlation between serology and vaccine potency in pigs for batch release.
Dr Barnett reported on the use of suppressive vaccination as a disease control measure (Appendix 16). Experiments carried out so far with highly potent emergency vaccines indicate that protection can be rapidly achieved. However, the vaccinated animals although without clinical symptoms may excrete virus before being protected. Dr Barnett also reported on the other disadvantages that could arise from suppressive vaccination.
Dr Barteling reviewed the activities carried out in the past to standardise the 146S test (Appendix 17). Since this test is used by the vaccine producers to estimate the content of immunogenic antigen and on this basis to formulate the vaccine, further standardisation is required.
Prof Panina, EU Scientific Veterinary Committee for Animal Helth and Animal Welfare, presented a document adopted by the EU Scientific Veterinary Committee for Animal Health on the strategy for emergency vaccination (Appendix 18). He stressed the importance to carry out the test for antibodies against non-structural proteins on a herd basis and the requirement for testing all vaccinated animals.
Dr M. Danes presented a paper on the long-term storage at 4oC of semi-prepared vaccine and its immunizing properties (Appendix 19). He demonstrated that vaccines based on antigen adsorbed to bentonite did not significantly lose their immunogenic properties over a 7-year period.
Dr C. Griot presented results of a challenge experiment of cattle vaccinated with monovalent FMD vaccine type O Iran 94 from the Swiss Vaccine Bank (Appendix 20). The challenge was carried out with type O Algeria 99. The experiment indicated a value of approximately 2 PD5O against this non-homologous strain.
Conclusions and Recommendations
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The proposals of the Working Group on the European Pharmacopoeia should be endorsed by the Executive Committee and submitted to the EP Committee and, in addition, to the OIE Standards Commission and to EMEA.
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Further studies should be carried out to determine the correlation between in vitro immunological tests and response to challenge in vaccinated pigs. The present collections of sera from pig vaccine tests could be used for this purpose if housing and challenge conditions are taken into account.
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Suppressive vaccination should not be applied unless logistical and/or political reasons dictate it. More experiments using highly potent vaccines under severer challenge conditions would further assist our understanding on the practicalities of suppressive (dampening down) vaccination ; the development of mucosal vaccines may be advantageous to such a control measure.
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A study should be encouraged to achieve satisfactory standardization and, if possible, to evaluate the 146S content of existing vaccines.
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An approved ELISA testing kit for detection of Ab to non-structural proteins should be available for national and regional diagnostic laboratories because the testing of all vaccinated animals is required.
Item 6: Biosecurity and quality assurance in FMD laboratories è environmental aspects of FMD control
Biosecurity
Dr Sanchez-Vizcaino presented a paper (Appendix 21) on the biosecurity procedures at Valdeolmos laboratory, in particular in terms of handling of FMDV.
It was stressed that when setting up any new biosecurity facility, animal rooms should be designed in such a way that they can be used for a wide variety of animals such as cattle, sheep, pigs etc.
Conclusion and recommendation
A well-organised biosecurity procedure is mandatory for any laboratory working with FMD virus. The minimum standards as described in the Security Standards for FMD Laboratories (Report of the Thirtieth Session of the EuFMD 1993 è Appendix 6 pages 67-79 of EuFMD Commission) should be applied.
Quality assurance
Dr Griot, presented a paper (Appendix 22) on experience of introduction of a QA system by IVI, Switzerland. Emphasis was put on the practical experiences of the three-year process.
Conclusion and recommendation
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Accreditation of veterinary laboratories is highly recommended. Several laboratories in Europe are in the process of doing this in 1999.
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An initial external review before start-up is recommended.
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Allocation of sufficient personnel and other resources is necessary.
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In a context where only one part of a laboratory is accredited, the amount of interfaces between accredited and non-accredited units is kept at a minimum.
Disposal of carcasses
Different options for the disposal of carcasses were presented by Dr Ryan (Appendix 23). For each method advantages and disadvantages were discussed. He also outlined some novel approaches to the disposal problem from different industries and suggested some avenues for further research.
Conclusion and recommendation
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A strategic plan should be available for every country in the case of an outbreak. Risk of virus spread by carcasses should be minimised.
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Rendering plants although available now might not be in the future.
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Be prepared before the disease breaks out. Options other than those proposed should be considered.
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Further research is needed to identify feasible alternatives to the current disposal methods or to improve existing methods so that they can deal with larger volumes in an environmentally friendly manner.
Item 7: Swine vesicular disease : information about the request to remove SVD from the OIE List A
The Chairman explained that the 33rd General Session of the Commission held in Rome in April 1999, requested that consideration be given to the possibility of supporting the proposal made by Dr Hallet, CVO, Belgium that SVD should be removed from OIE List A diseases. The 33rd Session following discussion of this issue decided to seek the opinion of the Research Group (Appendix 24). The Chairman asked Dr Donaldson to lead the discussion on the topic.
In his introductory remarks Dr Donaldson stated that diseases are included in OIE List A mainly for historical reasons and because they have the potential to cause major economic losses and not as the result of clearly defined criteria. SVD is included because the clinical syndrome in pigs resulting from infection with the virulent strains of the virus is clinically indistinguishable from FMD and not because the disease causes high productivity losses. Many strains of SVD virus are non-virulent and only cause sub-clinical infections. There is an additional complication which is that in serological surveys of pig populations, including those in SVD-free countries, a small number of pigs will inevitably give false-positive reactions. Consequently considerable time, expense and effort has been spent in EU on the serological aspects of SVD. These considerations have resulted in the state veterinary personnel of some countries, for example Belgium, expressing the opinion that the economic hardships which a country suffers when it declares SVD are too severe and that it should therefore be deleted from OIE List A.
In the discussions the following points were made for and against removing SVD from the OIE List A:
for removing
- Considerable effort and cost of repeated serological surveys.
- Excessive trade and economic penalties result for countries which report outbreaks, especially related to serological findings only.
- Removal would not necessarily result in the cessation of control programmes against SVD.
against removing
- The presence of SVD on List A makes it is easier to defend the cost of SVD control programmes.
- If SVD is allowed to spread there would be a decline in farmer and field veterinarian awareness and possible increased risk of delayed FMD reporting.
- The current position helps to maintain the manpower and infrastructure for vesicular disease laboratory diagnosis.
Conclusions and Recommendations
1) The economic savings of removing SVD from List A would depend on whether there was general international acceptance of the change.
2) The removal of SVD from List A would not necessarily result in the cessation of national control programmes.
3) The laboratory diagnosis of clinical cases of all the vesicular virus diseases should be done within biosecure facilities.
4) If SVD is allowed to spread there would be a decline in farmer and field veterinarian awareness and possible increased risk of delayed FMD reporting.
The Chairman complimented the Group on the very interesting papers which had been presented and expressed regret that the time available for presentation and discussion had been so limited. In order to avoid the constraints of time it was suggested that instead of long scientific papers posters and summaries could be presented. The Group did not agree with this and recommended that instead adequate time be made available for the discussion of each item on the agenda. The Secretary pointed out that the timeframe for this Session had been particularly tight due to the fact that the meeting on proposed amendments to the Pharmacopoeia Monograph had been held just prior to the Research Group meeting. The Group recommended that future meetings should allow for a minimum of two and half days for discussions and a half day for adoption of the Report.
Agenda and venue for next meeting
The Chairman invited the Group to make proposals for the Agenda for the next Session (open), which would be held in Bulgaria from 5 to 8 September 2000.
Drs Griot and GÕrhan extended informal invitations to the Group to hold the meetings for the years 2001 and 2002 in Switzerland and Turkey respectively. The Chairman thanked them for their proposals.
The draft report of the meeting was discussed by the Group and accepted with some amendments.
The Chairman informed the Group that he would be reporting the outcome of the meeting to the 63rd Session of the Executive Committee scheduled to take place in Greece on 4 and 5 November 1999.
He extended thanks to the members and observers for their contributions, to the staff of AFSSA, in particular Dr Michelle Remond, for their generous assistance to and participation in the meeting and finally to the secretariat for coordination of the preparatory work.
Dr Sanite, on behalf of the Director General of AFSSA, and Dr Plateau, Director, AFSSA-Alfort, wished the members and observers who were staying over the weekend a pleasant stay in Paris and bon voyage to everybody. He complimented them on their perspicacity and the fruitful results of their discussions.