Genetic diversity of Dengue virus serotypes circulating among Aedes mosquitoes in selected regions of Nigeria
Abstract The DENV mosquito vector is endemic to tropical and subtropical climates, placing ∼40% of the world’s population at direct risk of dengue infection. Currently, in Nigeria the status of DENV serotypes circulating among mosquitoes’ vectors is unknown. Our study was designed to identify and characterize the DENV serotypes circulating in Aedes mosquito populations collected in selected sites in Nigeria. The mosquitoes were collected, identified morphologically to species level using colored identification keys of Rueda. Generally, each species identified was tested in pools of 20 individuals of each Aedes species. RT-PCR and nested PCR were used to detected DENV serotypes in mosquitoes and characterized using Sanger sequencing methods. The results show that DENV serotypes were detected in 58.54% of the pools of mosquitoes screened. This corroborates with our unpublished report on the presence of DENV IgM antibodies in humans in the same study area. All DENV1-4 serotypes were detected in Ae. aegypti, Ae. albopictus and Ae. gaillosi with DENV4 serotype being reported for the first time in Nigeria. DENV2 (37.8%) was the most detected serotypes, while double and triple co-infections of serotypes were detected in 24.4% of the pools. Phylogenetic analysis revealed a strong evolutionary relatedness of DENV serotypes in our study with that of South and Southeast Asia, North America, and other African countries. This is the first reports on the co-infection of natural DENV in Aedes species pools in Nigeria. Thus, our study speculates a possible linkage between DENV serotypes and febrile flu-like disease burden being experienced by host communities in northern Nigeria.