Structure of West Nile Virus

摘要

West Nile virus (WNV) is found throughout Africa, Europe, Central Asia, and, most recently, in North America. The first outbreak in the United States was in New York City during the summer of 1999, and the virus subsequently spread across the United States . In 2002, there were 4156 reported cases of human illness associated with WNV and 284 deaths. WNV is a flavivirus transmitted primarily by Culex mosquitoes to vertebrate hosts. Flaviviruses include members such as dengue virus, yellow fever virus, and tick-borne encephalitis virus and are positive-strand RNA viruses that contain three structural proteins and a host-derived lip-id bilayer. Two lineages of WNV (Ⅰ and Ⅱ) have been identified. All isolates that cause severe human disease fall into lineage Ⅰ.