A mosquito survey along a transect of urbanization in Dschang, West Region of Cameroon, reveals potential risk of arbovirus spillovers

Abstract

BackgroundWith the advance of globalization and the decline of wild habitats, mosquito-borne viruses are no longer confined to their original sylvatic environments and are emerging or remerging worldwide. However, little is known about the mosquito species implicated in the spillovers of these viruses from their enzootic cycles.\n\nMethodWe conducted an entomological field survey to catalogue the relative abundance of the Culicidae fauna in rural, peri-urban and urban areas in the Dschang locality in West Cameroon. Mosquitoes were collected from March-April and July-August 2019 at both aquatic and adult stages, and identified using stereomicroscopes and morphological identification keys.\n\nResultsA total of 1,401 mosquitoes belonging to 4 genera and 26 species were collected (n=427, 470 and 504 in rural, peri-urban and urban areas respectively). The most abundant species Aedes africanus (45.47%) as well as Culex moucheti (8.92 %) were encountered in peri-urban and rural environments. Species like Culex duttoni (14.49%), Culex quinquefasciatus (2.35%) and Aedes aegypti (1.36%) were solely found in urban area. Aedes albopictus (14.42%), Culex (Culiciomyia) (6.57%), Culex tigripes (1.43%) and Eretmapodites chrysogaster (0.64%) on the other hand were collected in the three study sites. Importantly, all these species have been suspected or incriminated as vectors of many arboviruses.\n\nConclusionThis study identified potential sylvatic, urban and bridge-vectors that can play a role in current or future virus emergence in Cameroon. Further investigations are needed to assess if arboviruses are circulating in these areas and to study the vector role of each mosquito species in arbovirus transmission.