Recently introduced Aedes albopictus in Corsica is competent to Chikungunya virus and in a lesser extent to dengue virus

Aedes albopictus has been established in Europe for some decades rendering temperate countries vulnerable to tropical diseases. The Italian chikungunya (CHIK) outbreak in the summer of 2007 demonstrated that indigenous transmission of CHIK was possible in Europe. To estimate the risk of a CHIK outbreak in Corsica, we assessed the vector competence of A. albopictus established in the island since 2006 towards a CHIK variant (E1-A226V). A dengue serotype 2 virus was also tested. Experimental infections showed that A. albopictus was highly competent to CHIK virus (disseminated infection rates ranging from 75% to 100%) and to a lesser extent, to dengue virus (12.5–68.8%). Moreover, A. albopictus ensured a high level of viral replication and was able to transmit the virus as early as 2 days after ingestion of infected blood with around 1 000 viral RNA available in salivary glands. The risk for a local transmission of CHIK is thus likely in Corsica, if other parameters determining the vector capacity of A. albopictus are suitable.