Analysis Of Data Collected By Epidemio-Surveillance Network For Animal Diseases In Chad During The Period 1996 - 2002: Case Of Pasteurellosis

Summary During the period 1996 - 2002, 82 suspected cases of pasteurellosis were recorded and 88 samples taken from suspected animals were collected and analysed by the national laboratory Laboratoire de Recherches Vétérinaires et Zootechniques de Farcha. Out of 82 suspected cases, only 7 % were confirmed by laboratory diagnosis. Following the verification of samples recorded, it was deduced that the cause of negative suspicions could be due to inadequate samples coming mainly from blood taken from animals with chronic forms of Pasteurellosis. Data mentioned in this article are not able to give an pidemiological picture of the disease in the country. Therefore, it is preferable to undertake serological survey in sensitive populations combined with clinical surveillance followed by samples taken from suspected animals. Key words: Epidemio-surveillance, Pasteurellosis, Chad Analyse Des Donnees Collectees Dans Le Cadre Du Reseau D\'epidemiosurveillance Des Maladies Animales Au Tchad Durant La Periode 1996 - 2002: Exemple De La Pasteurellose Résumé Durant la période 1996 - 2002, 82 suspicions de la pasteurellose ont été enregistrées et 88 prélèvements réalisés sur des animaux malades et/ou morts ont été collectés et analysés au laboratoire national (Laboratoire de Recherches Vétérinaires et Zootechniques de Farcha). Sur les 82 suspicions enregistrées, seulement 7 % ont été confirmées par le diagnostic du laboratoire. Suite à la vérification des prélèvements reçus, Il en résulte que la cause de fortes suspicions négatives aurait été liée aux prélèvements inadéquats, constitués majoritairement de sang des animaux manifestant des signes de pasteurellose chronique. Les données indiquées dans cet article ne permettent pas de connaître la situation épidémiologique de la maladie dans le pays. Pour cela, il serait préférable de mener une enquête sérologique au sein des populations sensibles, combinée avec la surveillance clinique, suivie des prélèvements réalisés sur les animaux suspects. Mots-clés: Epidémiosurveillance, pasteurellose, Tchad Bull Anim. Hlth. Prod. Afr. Vol. 53 (3) 2005: 167-17

Comparison between active and passive surveillance within the Network of Epidemiological Surveillance of Animal Diseases in Chad (REPIMAT)

A comparative study between passive and active surveillance based on herd visits (villages) was conducted over a period of 24 months. It included 106 surveillance stations of the animal disease epidemiological surveillance network in Chad distributed randomly into 52 stations of active surveillance and 54 stations of passive surveillance. Nine diseases of various vaccination and expected prevalence status were monitored. The active surveillance stations carried out four herd visits monthly to look for the diseases under surveillance and organised four farmers awareness-raising meetings to stimulate them to make disease notifications. The passive surveillance stations held each month four farmer awareness-raising meetings. The suspicions recorded by the stations were consigned to a suspicion form specific to each disease, indicating whether a call from the farmer, a visit to the herd or a awareness-raising meeting was the source. The results showed that, irrespective of surveillance type, all diseases under surveillance, except the rare diseases (Rinderpest and Rift Valley fever) were reported by the surveillance agents. However, suspicions recorded following farmer calls are significantly more important than suspicions carried out during herd visits or meetings. Nevertheless, a considerable number of suspicions is recorded during awareness-raising meetings. Finally approximately 83% of the herd visits realised by the active surveillance stations showed negative results (no suspicion identified). Passive surveillance stimulated by awareness-raising meetings appears to be better adapted to Chads conditions and less expensive for the surveillance of existing diseases. However, for the rare diseases, other methods of specific active surveillance (such as for example sentinel herds) remain important to complete passive surveillance