West Nile Virus is a mosquito-borne disease that can cause encephalitis or brain infection. Mosquitoes can acquire the virus from birds and pass it on to other birds, animals and people.West Nile virus multiplies in the person's blood system and interferes with normal central nervous system functioning and causes inflammation of brain tissue. West Nile virus is a "flavivirus" commonly found in Africa, West Asia, and the Middle East.

West Nile Virus in the United States as of August 09 2005

Source: CDC (Click on the Map to read in detail)