RESUMO
We report the arthropod-borne pediatric encephalitic agent La Crosse virus in Aedes albopictus mosquitoes collected in Dallas County, Texas, USA, in August 2009. The presence of this virus in an invasive vector species within a region that lies outside the virus's historically recognized geographic range is of public health concern.
Assuntos
Aedes/virologia , Insetos Vetores/virologia , Vírus La Crosse/isolamento & purificação , Animais , Chlorocebus aethiops , Cricetinae , Encefalite da Califórnia/epidemiologia , Encefalite da Califórnia/virologia , Geografia , Humanos , Vírus La Crosse/genética , Filogenia , Saúde Pública , RNA Viral/genética , RNA Viral/isolamento & purificação , Análise de Sequência de RNA , Texas/epidemiologia , Células VeroRESUMO
In 2012, Texas experienced the largest outbreak of human West Nile encephalitis (WNE) since the introduction of West Nile virus (WNV) in 2002. Despite the large number of WNV infections, data indicated the rate of reported WNE among human cases was no higher than in previous years. To determine whether the increase in WNV human cases could have been caused by viral genetic changes, the complete genomes of 17 isolates made from mosquito pools in Dallas and Montgomery Counties in 2012 were sequenced. The 2012 Texas isolates were found to be composed of two distinct clades, both circulating in Dallas and Montgomery Counties despite a 5-fold higher disease incidence in the former. Although minor genetic differences existed between Dallas and Montgomery WNV populations, there was weak support for population subdivision or adaptive changes. On the basis of these data, alternative explanations for increased WNV disease incidence in 2012 are proposed.