Does the mosquito Culex pipiens represent a potential vector of hepatitis C virus?

Infection with hepatitis C virus (HCV) is a public health burden in several countries. Although transmission through blood is the most likely potential route of HCV infection, other sources warrant exploration. This study was designed to examine the possibility that the mosquito Culex pipiens (Diptera: Culicidae) might serve as a vector of HCV. A series of laboratory experiments were conducted in female Cx. pipiens that were fed on blood taken from HCV patients and tested for the presence of HCV RNAs using a reverse transcription polymerase chain reaction technique. In addition, the ability of the female mosquito to transmit HCV to human blood through membrane feeding or to its offspring (larvae) was tested. Although positive strand RNA was detected on days 1,7 and 14, negative strand HCV RNA was detected in mosquito body homogenate on days 7 and 14. Positive strands were also detected in the head, alimentary canal and salivary glands of mosquito adults at 1 week post-feeding, as well as in their offspring (larvae). An ex vivo assay demonstrated that HCV-infected mosquitoes were able to transmit the virus RNA into naive human blood samples via a membrane feeder. The present data indicate that the mosquito Cx. pipiens may be a potential vector of HCV.