Mosquito diversity and virus infectivity in Kinshasa, Democratic Republic of Congo

Abstract

Mosquito species distribution patterns and their ecology is gaining importance, because global climate changes are thought to lead to the emergence of mosquito-borne diseases; which are of considerable medical and veterinary importance because of their high morbidity and mortality. This study was conducted in five municipalities of Kinshasa to determine mosquito diversity, and arboviruses infection within. Mosquitoes were collected using BG-Sentinel traps, battery-powered aspirator for adult and a dipping technique for larvae. One part (adults and larvae-hatched adults) served for species identification, using morphological keys and Ae. aegypti were further identified by PCR using primers targeting the guanylate cyclase (GUA) and phosphoglycerate kinase (PGK) genes. Another part (adults only) was pooled into groups according to mosquitoes’ genus and sampling sites. Each group was preserved in RNA later and screened for bunyaviruses, alphaviruses and flaviviruses. Positive groups were then tested for the presence of specific viruses using reverse transcriptase polymerase chain reaction (RT-PCR) assays. In total, 5714 mosquitoes were collected. Of these, 2814 adults and larvae-hatched adults were identified and belonged to 4 genera (Culex, Aedes, Anopheles and Mansonia), representing 12 mosquito species. Culex quiquenfiasciatus was the most predominant species, followed by Ae. aegypti, while Ae. luteocephalus seems to be reported for the first time in Kinshasa. 2900 mosquitoes were pooled in 29 groups of 100 mosquitoes and 12 pools were positive either for alphavirus or flavivirus or bunyavirus including mixed infection. Chikungunya, O’nyong’nyong and Rift valley fever viruses were mainly found in Aedes groups. A high frequency of arboviruses was found in agricultural areas around Ndjili River. The present study shows that mosquitoes in Kinshasa carry several arboviruses that may have serious public health implications. Such study in the human population of Kinshasa is needed.