Distribution and diversity of mosquitoes and the role of Aedes in the transmission of arboviruses in selected districts of Tanzania

摘要

Arboviruses belong to various families of viruses that are transmitted by arthropods, mainly mosquitoesand often cause diseases in humans. The objective of this study was to determine mosquito diversity andtransmission of arboviruses by Aedes in selected ecosystems in Tanzania. Adult mosquitoes werecollected from rural and urban settings using carbon dioxide-baited CDC light traps, Biogent sentineltraps, and the Mosquito Magnet traps. Reverse Transcription-Polymerase Chain Reaction assay wasperformed on pooled adult Aedes mosquitoes to detect the presence of Chikungunya, Dengue, RiftValley fever (RVF) and Yellow fever (YF) viruses. A total of 42, 77 mosquitoes belonging to five genera(Aedes, Anopheles, Culex, Mansonia and Mimomyia) and 18 species were collected. Culex accountedfor the largest (62.7%; n= 2,682) proportion of the mosquitoes while Anopheles for the lowest proportion(5.7%; n=245). Of the total mosquitoes collected, Culex quinquefasciatus accounted for more than a half(53.4%; n=2692), followed by Aedes aegypti 12.1% (n=520). Of the 34 adult Ae. aegypti pools tested,arboviruses were detected in 33(97%) pools. Dengue virus was detected in 47.6% (10/ 21) pools whichtested positive for Flaviruses. Chikungunya virus was detected in 30% (3/ 10) pools which were positivefor Alphavirus genera. Of 2 pools tested positive for Bunyavirus genus, Rift Valley fever virus wasdetected in 1 pool (50%). The presence of various mosquito vectors and detection of arboviruses in aedesmosquitoes leave the population of Tanzania at great risk of transmission of different pathogens andhighlight a need for vector control measures in the country.