MAN-FLY CONTACT IN THE GAMBIAN TRYPANOSOMIASIS FOCUS OF NOLA-BILOLO (CENTRAL-AFRICAN-REPUBLIC)

A study using bipyramid tetse fly traps in the Nola-Bilolo sleeping si ckness focus (Central African Republic) reveals ecological and behavio ural differences between two vectors, Glossina palpalis palpalis and G . fuscipes fuscipes. The latter species inhabits mainly open water sit es and surrounding forest, whereas G. p. palpalis occurs mainly in cof fe plantations near villages. Consequently, the man-fly contact differ s considerably according to the species. The intensity of trypanosomia sis transmission, estimated by the probable distribution of cases, sho wed significant positive correlation with the density of the flies. An alysis of the fly blood meals in two villages show that, unlike G. g. palpalis, G. f. fuscipes feeds on men more than on pigs. Trypanosoma v ivax infection was observed only in G. fuscipes fuscipes. The differen ces in occupation of the environment between the two vectors must be t aken in account in trapping programmes which may modify this distribut ion.