Seroprevalence of dengue, Zika, yellow fever and West Nile viruses in Senegal, West Africa

West Africa serves as a critical region for the co-circulation of mosquito-borne flaviviruses, which often precipitate sporadic outbreaks. This study investigated the seroprevalence of dengue virus serotypes 1-4 (DENV-1-4), Zika virus (ZIKV), yellow fever virus (YFV), and West Nile virus (WNV) in three regions of Senegal: Sindia, Thies, and Kedougou. We retrospectively analyzed 470 serum samples for flavivirus immunoglobulin G (IgG) using a DENV-2 envelope (E) ELISA. Our findings revealed a seroprevalence of 37.23% for DENV-2 E IgG, indicative of a prior flavivirus exposure rate. The IgG seroprevalence rates for DENV-1-4, ZIKV, YFV, or WNV NS1 were 57.14%, 12.57%, 80.57% and 17.14%, respectively, with 72% of individuals harboring neutralizing antibodies against two or more flaviviruses. We also identified that residing in Sindia (ZIKV, OR, 9.428; 95% CI: 1.882-47.223 & WNV, OR, 6.039; 95% CI: 1.855-19.658) and Kedougou (ZIKV, OR, 7.487; 95% CI: 1.658-33.808 & WNV, OR, 1.142; 95% CI: 0.412-3.164) was a significant risk factor for ZIKV and WNV exposure. In contrast, history of malaria significantly reduced the risk of WNV exposure (aOR, 0.402; 95% CI: 0.203-0.794). This study underscores the complexity of flavivirus epidemiology in West Africa and the necessity for enhanced surveillance to inform public health strategies.