Mosquito Abundance And Molecular Detection Of Arboviruses In Kyela District, Tanzania

ABSTRACT

Arboviruses belong to various families of viruses that are transmitted by arthropods, mainly mosquitoes and ticks causing clinical disease symptoms in humans ranging from febrile illnesses to hemorrhagic fevers. A systematic vector surveillance spanning two months and covering five sites in Kyela district was carried out in order to determine mosquito abundance and evaluate the potential role of Aedes spp in arbovirus transmission in the study area. Mosquitoes were collected, identified to species levels by using morphological keys, pooled by species and collection sites and screened for arboviruses by RT-PCR. Adult mosquitoes were collected from April to May, 2015 using, three CO2-baited CDC light traps. Additionally, two mosquito Magnet traps were used as well as human landing collection (HLC) was conducted in Kyela town, Kajunjumele, Ipida, Matema and Njisi villages. A total of 1 830 mosquito were collected and identified. The most abundant mosquito collected were recorded in Kyela town 33% (n=601) followed by Kajunjumele 21.3% (n=391). Culex quinquefasciatus was the most collected 40.4% (n=740), followed by Aedes aegypti 26.8% (n=480). Out of these, four genera including Culex 41% (n=750), Aedes 27.2% (n=499), Mansonia 16.5% (n=301) and Anopheles 15.3% (n=280) representing 9 species were identified and shown to be present in Kyela. Aedes mosquitoes were pooled into 24 groups of 20 mosquitoes and among them, nine (37.5%) were positive for both Alphaviruses and Flaviviruses. Chikungunya viruses were the only virus detected in six positive pools of Alphavirus genus (75%) that were collected mostly in the areas where rice cultivation is common. The findings of this study suggest that people from this

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region are highly likely to be exposed to arbovirus infections which may represent significant public health concerns. Further studies to define the risk factors, characterize the circulating viruses and elucidate the epidemiological factors are required in order to institute national interventions to prevent and control these infections.