Vector Competence of Aedes Albopictus from Virginia and Georgia for Chikungunya Virus Isolated in the Comoros Islands

Abstract

We evaluated recently colonized samples from Virginia and Georgia (USA) of Aedes albopictus, an important vector of chikungunya virus (CHIKV), to determine whether they became infected with and transmitted COM125, a CHIKV isolate from the Comoros Islands. Seven days after imbibing an infective blood meal containing a minimum of 8.5×10⁴ plaque-forming units (pfu)/mL, 31–86% of A. albopictus from the counties of Fairfax, Loudon, Rockingham, and Suffolk, Virginia, and Fulton, Georgia were infected. The average viral titer per mosquito was 1.1×10⁴ pfu/mL (2×10²–3.3×10⁴). We detected CHIKV in salivary expectorate of infected mosquitoes from Rockingham (8%), Fulton (22%), and Loudon (48%) counties 7 days after blood feeding. Because CHIKV has no vaccines or specific antiviral treatments, vector control and education are critical to prevent its transmission. We discuss how local populations of A. albopictus could transmit CHIKV introduced to the southeastern USA from the Indian Ocean or Indian Subcontinent.