[Estimation of the incidence of human trypanosomiasis due to Trypanosoma brucei gambiense using epidemiological parameters essentially linked to the vector: case of a focus in the Ivory Coast].

The entomo-epidemiological studies carried out from 1980 to 1985 in the human trypanosomiasis focus at Bouaflé (Ivory Coast) were designed to estimate the main epidemiological parameters related to G. palpalis palpalis, the sleeping sickness vector in the zone considered. This paper defines the mathematical relationships which can exist between these parameters leading to the production of a simple model enabling estimates to be made of the incidence of human trypanosomiasis caused by T.b. gambiense in this focus. The model predicted a mean annual incidence of 1.50% in the Bouaflé focus. In the zones with high pig densities which were characterised by high densities of tsetse flies with weak anthropophily, the model predicted an incidence of 1.22%. However, a disease incidence of 1.76% was estimated for zones where domestic pigs were absent or at low density and characterised by low densities of tsetse flies with strong anthropophily. The author also emphasizes the relationships between mathematical models and realities in the field and the usefulness of these models to the field worker in planning control campaigns.