Isolations of West Nile and Bagaza viruses from mosquitoes (Diptera: Culicidae) in central Senegal (Ferlo).

During October-November 1990, 31,497 mosquitoes consisting of 25 different species were collected in Barkedji, Ferlo area (Senegal), and tested for virus infection. Viruse were isolated from 55 of 407 pools. Eighteen pools were found positive for both Bagaza virus (BGA) and West Nile virus (WN). One alphavirus (Babanki [BBK] and 72 flaviviruses (19 BGA, 53 WN) were isolated from Culex poicilipes Theobald (29 WN, 8 BGA), C. neavei Theobald (3 WN, 1 BGA), Mimomyia hispida Theobald (8 WN, 6 BGA, and 1 BBK), M. lacustris Edwards (4 WN, 1 BGA), M. splendens Theobald (6 WN, 2 BGA), Mimomyia. spp. (2 WN), and Aedeomyia africana Neveu-Lemaire (1 WN). These were the first isolations of arboviruses from A. africana and Mimomyia species. C. poicilipes and possibly Mimomyia spp. may be involved in an avian-mosquito cycle of West Nile virus transmission in Senegal.