PT - JOURNAL ARTICLE AU - James J. Sejvar TI - West Nile Virus: An Historical Overview DP - 2003 Jun 20 TA - Ochsner Journal PG - 6--10 VI - 5 IP - 3 4099 - http://www.ochsnerjournal.org/content/5/3/6.short 4100 - http://www.ochsnerjournal.org/content/5/3/6.full SO - Ochsner J2003 Jun 20; 5 AB - West Nile virus (WNV) has quickly established itself in North America since its recognition in New York City in 1999. Historically, WNV has been associated with temporally dispersed outbreaks of mild febrile illness. In recent years, the epidemiology and clinical features of the virus appear to have changed, with more frequent outbreaks associated with more severe illness being noted. The 2002 outbreak in North America was unprecedented in terms of the number of cases and geographic spread of the virus. Historical patterns of WNV provide few indications as to the future behavior of WNV in North America.