Differential Infectivities of O'nyong-nyong and Chikungunya Virus Isolates in Anopheles Gambiae and Aedes Aegypti Mosquitoes

O'nyong-nyong virus (ONNV) and chikungunya virus (CHIKV) are closely related alphaviruses that cause human disease in Africa and Asia. Like most alphaviruses, CHIKV is vectored by culicine mosquitoes. ONNV is considered unusual as it primarily infects anopheline mosquitoes; however, there are relatively few experimental data to support this. In this study, three strains of ONNV and one strain of CHIKV were evaluated in Anopheles gambiae and Aedes aegypti mosquitoes and in four cell lines. As predicted, CHIKV was not infectious to An. gambiae, and we observed strain-variability for ONNV with respect to the ability of the virus to infect An. gambiae and Ae. aegypti. The species specificity in vivo was reflected by in vitro experiments using culicine and anopheline-derived cell lines.