Venereal transmission of chikungunya virus by Aedes aegypti mosquitoes (Diptera: Culicidae).

Experiments were conducted to demonstrate the role of male Aedes aegypti mosquitoes in the maintenance and transmission of chikungunya virus (CHIKV) to female mosquitoes. We demonstrated that infected male mosquitoes are capable of infecting females during mating. The infection rate in female mosquitoes was 11% when virgin female mosquitoes were allowed to coinhabit with infected males. The body suspension of venereally infected female mosquitoes induced illness in infant Swiss albino mice, which demonstrated the infectivity of the venereally transmitted virus. The presence of CHIKV in the brains of the ill mice was confirmed by a reverse transcription-polymerase chain reaction specific for partial sequences of nonstructural protein 4 and envelope 1 genes. In the light of the recent report of transovarial transmission of CHIKV in mosquitoes, although at a lower level, this finding has significance because it may help in transmission of the virus to females venereally to start a new infection cycle.