EPIDEMIOLOGICAL SITUATION DURING 1988
From the technical data recorded by the departmental veterinary Service officers, the authors gave the status of bovine brucellosis for 1988. Even if some local situations are still a little weak, at the national level, the overall situation did improve. This gave to the French cattle industry the opportunity to maintain its level of trade for exportation, including within the 1993 European Market perspective. A synthesis of data technical indicators was assed to this paper.
The accelerated national eradication scheme against enzootic bovine leucosis started in France on January 1st, 1988. Departmental programs, agreed by the Agriculture and Forest Ministry, were managed by Veterinary Services and representative professional organisations working in the sanitary field and led to a dramatic mobilisation. The government did an exceptional grant for the running of this new program. At the end of 1988, nearly 80% of the herds were surveyed and 70% of them got an official qualification. Nearly 110.000 heads of cattle have been culled altogether. More than 16.000 farmers subscribed for eradication contracts against chronical leucosis. This success brought the Agriculture and Forest Ministry to continue the action in the same direction for 1989.
The situation of Hog cholera and African swine fever, and its evolution in the twelve EEC countries during 1988 were described and compared to those of previous years.
Blancou (J) & Barrat (J)
The epidemiological situation of rabies in France and in Europe during 1988 was presented from tables, maps and graphs. Some new scientific and technical information’s, in the field of epidemiology or control of rabies, was documented.
Toma (B), Mollard (M), Lorant (J-M), Goyon (M), Lery (L), Vigouroux (A), Eloit (M), Rose (R), Maire (C), Protin (P) & Guilbert (M)
This paper presented the epidemiological situation for Aujeszky’s disease in France during 1988 using tables and figures. The tracers used lead to the idea that the improving of the situation noticed these last years was slowing down in 1988.
In 1988, the prophylaxis of bovine tuberculosis concerned 19.7 million heads of cattle, representing 540 000 herds. The rate of infected herds is still decreasing: annual prevalence is 0.58%, point prevalence (on December the 31st) is 0.29, and incidence rate is 0.30. Except some countries from South of France of low density of cattle, highest rates of infection (over 0.8) are seen in North-East of the country. The rate of non-marked cattle amongst those with any kind of seizure is still decreasing from 36% to 25%) showing a better efficacy of screening. 68% of marked cattle were non visible lesions reactors. The situation needs now to use systematically auxiliary diagnosis methods such as histology, or comparative skin test in case of positive results.
Ducrot (C), Arnould (B), Berthelon (C) & Calavas (D)
In order to determine factors associated with lamb perinatal mortality, an eco-pathological survey was carried out on 92 sheep farms in the South East of France (Rhône-Alpes and Provence Alpes Côte d’Azur). This study was conceived by veterinarians, sheep breeding advisers and stock breeders. Seventy per cent of the farms were specialized in raising sheep and the number of sheep in the flocks averaged 273. During 7 months, from the 1985 fall breeding season to the end of the lambing season in spring 1986, perinatal mortality, raising practices and several environmental factors were recorded. Altogether, 4000 ewes and 6000 lambs were followed-up. Data were analysed using multivariate methods. Perinatal mortality averaged 10 per cent and reached 35 per cent in one flock. Results confirmed the influence of abortive infection on lamb perinatal mortality. They also showed the influence of the following factors: replacement practices, management practices during gestation and especially stress factors, bad body conditions of ewes, parasitism and absence of shearing, birth weight of lambs: perinatal mortality was four times higher for lambs weighing less than 2.5 kg at birth than for lambs weighing more than 2.5 kg, environmental conditions during the lambing season and especially temperature, hygiene of the sheep pen and use of lambing boxes. Various group of herds were observed, characterized on one hand by associations of different risk factors and, on the other hand, by different perinatal mortality rates. A further study of these groups of farms should permit to specify their socio-economic features. A lamb perinatal mortality “prevention plan” was designed from the results of this study. It is now delivered in about one hundred farms by technicians and veterinarians and veterinary practitioners and it will be evaluated.
Manet (G), Guilbert (X), Roux (A), Dronka (T), Vuillaume (A) & Parodi (A-L)
A prospective survey of seasonal incidence of enzootic bovine leucosis was undertaken on 225 cattle herds from the “Landes” district. During a 2-years period, 157 new infections were recorded. Prevalence rates were 41% of the herds and 32% of the animals. The average herd size was 15 cattle. The 2-months incidence varied between 0 and 13.6 %, and average 2.6%. The highest incidence was in summer, the lowest in spring. It depended of territory, grazed surfaces, and size of the herd. It did not seem to be associated with type of production, length of grazing time, presence of other diseases and housing. The Reed-Frost model was sufficient to simulate prevalence. The importance of horseflies was not statistically proved although there were strong theoretical and practical arguments for it. Risks factors were different for prevalence and incidence.
The author describes the epidemiological situation of African Horse sickness in Spain from 1987 to 1989 and presents the hypothesis about the origin of the disease.