Laboratory transmission of Sindbis virus by Aedes albopictus, Ae. aegypti, and Culex pipiens (Diptera: Culicidae).

The susceptibility of Aedes albopictus (Skuse) for Sindbis (SIN) virus was examined in the laboratory. Ae. albopictus, Ae. aegypti (L.), and Culex pipiens (L.) became infected with and subsequently transmitted SIN virus by bite to chicks after feeding on viremic 1-d-old chicks. After ingesting 10(5.3) plaque-forming units (PFU)/ml, Ae. albopictus had the highest transmission rate (30%) of the 3 species. Transmission by Ae. aegypti was less efficient (7%), whereas none of the Cx. pipiens transmitted virus. Transmission rates were higher for Ae. albopictus (53%) and Cx. pipiens (37%) when they fed on chicks with a viremia of 10(8.4) PFU/ml. Ae. aegypti was not tested at this dose. Based on these studies, the increased geographic distribution of Ae. albopictus, and its opportunistic feeding behavior, this species should be considered as a potential bridge vector of SIN virus.