Transmission cycle of West Nile virus in the United States

West Nile virus (WNV) is transmitted to persons by mosquitoes. It causes a rapid fever sometimes associated with neurological complications can be severe in many animal species. Since its first identification in East Africa the virus has been identified on all continents. Today it is endemic in the Mediterranean Central Europe and North America where he is responsible for fatal human case was observed in Greece continental in southern Italy and the US. This paper provides a review of the virology of WNV history epidemiology clinical features pathology of infection the innate and adaptive immune response host risk factors for developing severe disease clinical squeal following severe disease chronic infection and the future of prevention. This article summarizes our current understanding of WNV with particular emphasis on its transmission dynamics and changing epidemiology.