West Nile Virus

Abstract

JAVMA, Vol 232, No. 9, May 1, 2008 W Nile virus was first identified in Africa in 1937, and subsequently, Africa, Europe, Australia, and Asia were recognized as regions in which the virus was endemic. In 1999, concurrent outbreaks of encephalitis among crows, humans, and horses in New York State triggered an investigation by human and veterinary health officials that led to the initial detection of WNV in the western hemisphere. West Nile virus is now the leading cause of human arboviral encephalitis in the United States. It is found throughout the western hemisphere, including North America, Central America, South America, and the Caribbean.