[Prevalence of malaria in the Senegal river basin in 1991].

In order to determine the prevalence of malaria and its epidemiological characteristics, a survey was carried out in 11 villages situated in all the Basin of River Senegal (B.R.S.). 3306 (0-14 years) children are examined. The results show that malaria is hypo-endemic in the B.R.S. with a plasmodic index of 8.6% and a splenic index of 9.9%. But these malariametric indexes change according to the areas visited. Thus, malaria prevails at a hypo-endemic level in Dagana and Podor districts while at a medium if not hyperendemic level in Matam and Bakel districts. The plasmodial index also change according to age reaching a maximum within children from 10 to 14 years. As for the spleen index, it is low among children from 10-14 years. As for the spleen index, it is low among children from 0 to 4 years old, then increases among those aging from 5 to 9 years, before decreasing within children ranging from 10 to 14 years. P.falciparum is the most prevalent species, representing 96% of the cases; it is followed by P.malarioe (3%) and P.ovale (1%). If our results are compared with those obtained before by other authors, we can conclude that the recent hydro-agricultural plannings carried out in the area, have not yet provoked an increase of the cases of malaria. But, in order to avoid this risk, it is necessary to take from now some preventive measures.