Picture of West Nile Virus
West Nile virus (WNV) is a flavivirus that can cause encephalitis. It is transmitted by mosquitos. West Nile virus is similar to other viruses in the family, including yellow fever, dengue fever, and Japanese encephalitis viruses. WNV is a positive-strand RNA virus, and the genome encodes for three structural proteins and seven nonstructural proteins. The functions of the nonstructural proteins include weakening the host response and regulating viral transcription and replication.