RESUMO
West Nile virus is a flavivirus transmitted by mosquitoes, mainly of the genus Culex. In Brazil, serological studies have already indicated the circulation of the virus since 2003, with the first human case detected in 2014. The objective of the present paper is to report the first isolation of WNV in a Culex (Melanoconion) mosquito. Arthropods were collected by protected human attraction and CDC light bait, and taxonomically identified and analyzed by viral isolation, complement fixation and genomic sequencing tests. WNV was isolated from samples of Culex (Melanoconion) mosquitoes, and the sequencing analysis demonstrated that the isolated strain belonged to lineage 1a. The finding of the present study presents the first evidence of the isolation and genome sequencing of WNV in arthropods in Brazil.
RESUMO
Introducción: las primeras infecciones por el virus del Nilo Occidental en Cuba se reportaron en 2004. Objetivo: monitorear y conocer la prevalencia del virus del Nilo Occidental en áreas con casos confirmados de este. Métodos: el estudio se llevó a cabo en la municipalidad de Jatibonico y en la ciudad de Sancti Spiritus. Un total de 14 personas, 8 caballos y 41 aves se estudiaron para la detección de anticuerpos a flavivirus y específicos al virus del Nilo Occidental. Resultados: se confirmó la presencia de anticuerpos específicos a virus del Nilo Occidental en 4 muestras de suero de aves y 4 de caballos. Una persona se confirmó como 1 caso de infección por virus del Nilo Occidental asintomático. Conclusiones: la presencia de anticuerpos específicos al virus del Nilo Occidental en aves residentes, caballos y humanos en áreas con casos confirmados demuestran el establecimiento de un ciclo de amplificación local establecido en Cuba antes de este estudio.
Introduction: First infected cases caused by West Nile virus were reported in Cuba in 2004. Objective: to monitor and learn about the prevalence of the West Nile virus in those areas with confirmed cases. Methods: the study was conducted in Jatibonico municipality and in the city of Sancti Spiritus. A total number of 14 persons, 8 horses and 41 birds were researched to detect antibodies to flavivirus and specific antibodies to West Nile virus. Results: the presence of specific antibodies to West Nile virus was confirmed in 4 samples of sera from birds and in 4 from horses. One person was confirmed as one case of asymptomatic West Nile virus infection. Conclusions: the presence of specific antibodies to West Nile virus in birds, horses and persons residing in areas where there are confirmed cases showed that a local amplification cycle had been established in Cuba before this study.