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SHEEP POX SURVEILLANCE IN THE MAGHREB

Outcome of the Second Annual Coordination Meeting on Surveillance for the Eradication of Sheep Pox from the Mediterranean Maghreb

The meeting was held in Tunis, at the FAO Subregional Office, on 17 and 18 February 2000. In addition to the RADISCON Coordinator, Operator and Support Officers, Dr Y. Leforban, Secretary of the European Commission for the Control of Foot-and-Mouth-Disease, RADISCON Support Officer Dr Karim Benjebara and FAO consultant Dr P.C Lefèvre, the meeting was attended by the Chief Veterinary Officers (CVOs) of Morocco and Tunisia, the RADISCON National Liaison Officers (NLOs) of Algeria, Tunisia and the Libyan Arab Jamahiriya, the Alternate NLO of Morocco and the three national experts from Algeria, Morocco and Tunisia who had been involved from the start in the preparation of the background documentation for this programme.

The first part of the meeting addressed the following issues:

The four countries have made considerable advances in their efforts to control the disease in compliance with the recommendations of the last coordination meeting. The annual vaccination programmes, for example, have shown a marked increase in the target animal population even though - with the exception of Morocco - the desired 80 to 85 percent vaccination coverage rate is still far from being achieved. There is a steady reduction in the incidence of the disease, as was highlighted through systematic laboratory differentiation of sheep pox from contagious ecthyma in Algeria and Morocco.

It is now more important than ever to consolidate these efforts if the aim is to suppress definitively the high recurrent annual cost of the disease and vaccination campaigns, which are being progressively replaced by close surveillance of the disease and a stamping out policy. The possible shortcomings that may arise as the programme evolves were discussed and it was felt that they would be easily overcome if the higher decision-makers are more sensitized on the relevance of this ambitious endeavour.

To make the programme known in the farming community, 30 000 posters have been produced and are being widely disseminated in the four countries as well as leaflets which will be distributed to village schools to sensitize children's parents to the programme.

Booklets are also in preparation to indicate the main clinical signs for recognition of the disease and the field action to be taken following the suspicion of a sheep pox outbreak. This is especially important now that the number of within flock clinical cases is diminishing owing to the residual immune status in the sheep populations.

It was decided that the mid-year meeting should take place upon completion of the current vaccination campaign in the four countries to monitor the vaccination results and evaluate the harmonization efforts among countries during the campaign. An expert in vaccinology will be proposed jointly by Algeria and Morocco to assess the production process of the sheep pox vaccine in these two countries where it is being produced. Each country will also update its legislation, rectifying any possible inconsistencies, and adapt it progressively to the control/eradication programme as it evolves.

The second part of the meeting was devoted to reviewing the FMD situation in the four countries and to the preparation of a regional programme for the control of the disease. There has been no report of FMD in any of the Maghreb countries since April 1999. Therefore the question was whether the vaccination which is currently being used for the control of the disease should be pursued and for how long. Another important issue is the role of small ruminants in the epidemiology of FMD and the relevance of immunizing them. With the exception of Tunisia, which has been vaccinating small and large ruminants with bivalent vaccine since 1989, the other countries vaccinate cattle only. This is due to the large population of small ruminants and the incurred costs of such a strategy. The question of which virus strains are to be included in the vaccine was also raised. It was agreed that O type, which is dominant in the Near East, would be the more appropriate type to be included. The other types (A, SAT 2, Asia 1) should also be considered if there is a threat of their introduction in the region.

Surveillance of FMD in the neighbouring countries, and especially in sub-Saharan African countries, should be reinforced so that immediate action can be taken in the Maghreb in case of a specific threat with the new strains.

The four countries recommended that a regional programme for FMD control and surveillance should be established under FAO's coordination, based on the model of the sheep pox eradication programme. Under this programme, all cattle should be vaccinated against O type for a minimum period of three years, preferably using vaccines with a minimum potency of 6 PD50. Meanwhile, surveillance of the disease will be reinforced particularly on the southern and eastern borders of the region. The capacity for diagnosis will be upgraded in the four countries with the establishment or adaptation of one national FMD laboratory in each country. The situation should be re-examined after three years to verify whether vaccination could be progressively abandoned in the countries west of the Maghreb. Active surveillance of FMD is foreseen in the new programme, especially in places where there is a major concentration of animals (souks, markets, abattoirs and oases) and this could be carried out jointly for sheep pox and FMD. A serological survey for FMD antibodies, including detection of the antibodies to the protein 3ABC by ELISA, is also foreseen to monitor vaccination campaigns and verify whether the virus continues to circulate in small ruminants. The meeting also recommended that a vaccine/antigen bank should be set up before deciding to stop preventive vaccination and that a coordination unit of the regional FMD programme should be established.

NATIONAL TADINFO IN THE MEDITERRANEAN MAGHREB COUNTRIES

A tool for decision-makers and an "energizer" for the National Animal Disease Surveillance Systems (NADSSs)

The experience gained from implementing National Animal Disease Databases, using TADinfo in Morocco, Algeria and, recently, in Tunisia and the Libyan Arab Republic, as a tool for CVOs and other decision-makers to manage their animal health situations, may be described as follows:

TADinfo as a national database

TADinfo as a part of a disease surveillance system

TADinfo may serve as a motor to improve the functioning of the NADSSs and the quality of the reporting of disease events in the countries. This will reinforce the coordination role of the Epidemiology Unit within the system. How could this be done?

TADinfo is a geo-referenced database, yes, but ...

In order to have a real geo-referenced database, it is very important to verify the geo-references of some of the villages/localities that are already stored into the database and correct them if needed. In addition, the NADSSs should be able to produce geo-referenced data in order to feed and complete the villages/localities geo-referenced data contained in TADinfo. Therefore, the need for equipment such as the Global Positioning System (GPS) should be implemented gradually in these countries.

In conclusion, TADinfo could be a real driving force to improve the functioning of any NADSS, if its operators are given all the support needed and the full responsibility to gather, follow up and verify data from the different partners of the network. This will help to make the best use of the software capabilities and will assist CVOs and other decision-makers in managing the animal health situation in a more rational and scientific manner.

BLUETONGUE IN TUNISIA

First report of bluetongue in Tunisia

Bluetongue was clinically reported for the first time in Tunisia in December 1999 and there is no evidence of the presence of the infection before that date. The virus responsible was isolated and identified as serotype 2.

Twenty-four serotypes of the virus have been identified worldwide. The virus is present in a wide band of countries, between 40°N and 35°S where certain midges of the genus Culicoides are present to act as vectors. However, clinical disease with confirmation of virus isolation has been observed in only a few countries, possibly because of poor recognition of the disease and its association with other diseases, such as contagious ecthyma.

Clinical surveillance of the disease in Tunisia has been extended to the whole country, in the abattoirs and in animal markets. Professionals who have been sensitized and trained to recognize the disease are also requested to make visual surveillance of the disease during vaccination campaigns. A retrospective study will take place on serum collected before 1999, which is available in the serum bank of the Tunisian Veterinary Research Institute (IRVT). The objective is to study the presence (or not) of bluetongue infection in the country prior to the occurrence of the clinical disease.

Serosurveillance will take place on the animal population that is susceptible to bluetongue, in order to determine the prevalence of the disease and its distribution. It is very important to measure the extent of the problem so to be able to reorient the control programme, such as a better focus of the vaccination programme.

An inventory of Culicoides species present in Tunisia, as well as their geographical distribution, ecology and biology, will be studied exhaustively. Trials will be performed to isolate the virus from the vector.

Tunisia intends to vaccinate the ovine population using an attenuated live vaccine (serotype 2). The vaccination period will take place after the first half of pregnancy and the vector activity. This vaccination programme will be readjusted according to the results of the surveys and the vector study.

Source: Animal Disease Surveillance System of Tunisia, February 1999.

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