Vectors of Chikungunya virus in Senegal: current data and transmission cycles.

TLDR

Chikungunya fever is transmitted by Aedes mosquitoes, its sylvatic cycle shows ~3‑year silent intervals, and only a few epidemics have been reported in Senegal. The study retrospectively analyzed viral isolates from mosquitoes, wild vertebrates, and humans to characterize Chikungunya transmission cycles in Senegal and compare them with yellow fever. Researchers isolated 178 Chikungunya strains from gallery forest mosquitoes in Kédougou (1972‑1986) and two strains from Ae. aegypti in Kaffrine (1996), using these isolates to map transmission dynamics.

Abstract

Chikungunya fever is a viral disease transmitted to human beings by Aedes genus mosquitoes. From 1972 to 1986 in Kédougou, Senegal, 178 Chikungunya virus strains were isolated from gallery forest mosquitoes, with most of them isolated from Ae. furcifer-taylori (129 strains), Ae. luteocephalus (27 strains), and Ae. dalzieli (12 strains). The characteristics of the sylvatic transmission cycle are a circulation periodicity with silent intervals that last approximately three years. Few epidemics of this disease have been reported in Senegal. The most recent one occurred in 1996 in Kaffrine where two Chikungunya virus strains were isolated from Ae. aegypti. The retrospective analysis of viral isolates from mosquitoes, wild vertebrates, and humans allowed to us to characterize Chikungunya virus transmission cycles in Senegal and to compare them with those of yellow fever virus.