[Evaluation of snake bite incidence in the Sahelian zone of Senegal, example of Niakhar].

An exhaustive household survey was carried out in the study zone of Niakhar, a rural sahelian area in Senegal 150 km east of Dakar. Results were compared with those of the data base updated quarterly since 1983 and to the notifications of snakebites in the 7 health centres of the zone (130 inhabitants per km2). The questionnaire related to the snakebites (identification of victims, circumstances of bite, symptoms and treatment). The annual incidence was low (23 bites per 100,000 inhabitants) as the morbidity (by 20 envenomations per 100,000). The case fatality rate was relatively high (7%) and there were 1.5 deaths per 100,000 inhabitants per year. Males were more often bitten than females (1.8:1). Field work (agriculture and breeding) induced about half of the accidents. Traditional practitioners were systematically consulted by over 93% of victims. This explains why collecting data from health centre registers is not sufficient to estimate the importance of envenomations in this area.