Dengue virus infection in Aedes mosquitoes at the interface of human-livestock-wildlife ecosystem in Kilosa District, Morogoro, Tanzania.

Abstract

Abstract Background Arboviruses are an important cause of human and animal diseases worldwide. The aim of this study was to determine mosquito abundance and screen for the presence of dengue virus in Aedes mosquitoes at the interface of human-livestock-wildlife ecosystem in Kilosa district, Morogoro, Tanzania. Methods In this cross-sectional study, adult mosquitoes were collected outdoors using propane-powered Mosquito Magnet® Liberty Plus traps. Reverse transcription polymerase chain reaction (RT-PCR) was conducted on pooled adult Aedes mosquitoes to screen for the presence of dengue (DENV). Nucleotide partial sequencing of the structural polyprotein region of DENV was done to confirm and characterize DENV virus using Sanger sequencing. Results A total of 1,340 mosquitoes belonging to four genera (Aedes, Anopheles, Culex, and Mansonia) were collected. Aedes aegypti accounted for the majority of collected mosquito species (46.0%; n = 613). Thirty-six pools of female Ae. aegypti were screened for the presence of selected arboviruses using RT-PCR. Dengue virus was detected in 3% (1/36) of the tested Aedes mosquito pools. Nucleotide partial sequencing of the structural polyprotein region of DENV followed by phylogenetic analysis showed that the strain (Accession no. MW133786) clustered with DENV-3 strains previously reported in China and Kenya. Conclusion The findings of this study indicated that Ae. aegypti was the most abundant mosquito species at the interface of human-livestock-wildlife ecosystem in Kilosa district, Tanzania and DENV was detected in tested Aedes mosquitoes which signifies that local transmission of DENV may be taking place. This indicates that the human population in the area is at risk of acquiring dengue infection.