West Nile Virus  Main > Disease States > What is the West Nile
virus? The West Nile virus is spread by the bite of an infected
mosquito.  It can infect people, birds, horses, and other
animals.  Most people infected by the virus will have either no
symptoms or only mild ones.  However, on rare occasions, the
infection can result in severe and sometimes fatal illnesses.
There is no evidence to suggest that West Nile virus can be
spread from person to person or from animal to person.  West
Nile Virus is a flavivirus commonly found in Africa, West Asia,
and the Middle East. It is closely related to St. Louis
encephalitis virus found in the United States. West Nile fever
is a case of mild disease in people, characterized by flu-like
symptoms (mild fever, body aches, a rash, swollen lymph glands).
West Nile fever typically lasts only a few days and does not
appear to cause any long-term health effects.  More severe
disease due to a person being infected with this virus can be
West Nile encephalitis, West Nile meni