Vector competence of rural and urban strains of Aedes (Stegomyia) albopictus (Diptera: Culicidae) from São Paulo State, Brazil for IC, ID, and IF subtypes of Venezuelan equine encephalitis virus.

ABSTRACT

Aedes albopictus (Skuse) is an Asiatic mosquito species that has spread and colonized all continents except Antarctica. It has major public health importance because it is a potential vector of several pathogens. The objectives of our study were to analyze the vector competence of urban and rural strains of Ae. albopictus from São Paulo State (Brazil) for Venezuelan equine encephalitis virus (VEE) subtypes IC, ID, and IF, and to evaluate the effect of infection with subtype IC of VEE on mosquito longevity. Both mosquito strains were susceptible to subtypes IC and ID, but the infection rate for subtype IF was low. Infection and transmission rates of Ae. albopictus for subtype IC were similar to those reported for Ochlerotatus taeniorhynchus (Wiedemann). The high infection, dissemination, and transmission rates for subtype ID reported for Oc. fulvus (Wiedemann) and Culex (Melanoconion) spp. are comparable with those found in this study. We found significant differences in the susceptibility to subtype IC between rural and urban populations of São Paulo. Significant survival rate differences were observed between uninfected and infected mosquitoes, but there were no differences in survival between rural and urban mosquito strains.