West Nile virus is commonly found in humans and birds and other vertebrates in Africa, Eastern Europe, West Asia, and the Middle East. West Nile virus was first isolated in the West Nile province of Uganda in 1937 (3, 4). The first recorded large epidemics occurred in Israel from 1951 to 1954, and the largest recorded epidemic to date occurred in South Africa during 1974. Large human outbreaks of WN Encephalitis occurred in Israel in 2000 and have occurred in Southern France (1962), in southeastern Romania (1996), and in south-central Russia (1999) (5,6). Until 1999, West Nile encephalitis had not been documented in the Western Hemisphere. It is not known where the U.S. West Nile virus originated, but it is most closely related genetically to strains found in the Middle East.