West Nile encephalitis

From Freepedia

West Nile encephalitis (West Nile fever) is a febrile illness caused by the West Nile virus, a member of the family Flaviviridae, that is transmitted from birds to the common Culex mosquito and then to people. The virus is named after the fact that it was first found in Uganda.

West Nile encephalitis occurs in parts of Africa and Asia and, infrequently, in Southern Europe and the Middle East. The West Nile virus had never been seen in birds or people in the Western Hemisphere prior to an outbreak in the summer of 1999 in New York City. It has since spread throughout the United States and Canada.

Signs and symptoms include the sudden onset of drowsiness, headache and nausea due to encephalitis, pain in the abdomen, a rash, and swollen glands (lymphadenopathy). These features are usually but not always mild. Fatal cases tend to involve infants and small children under age 5, the aged, and people with an impaired immune system.

The virus is closely related to other flaviviruses including those responsible for St. Louis encephalitis, Japanese encephalitis and Murray Valley encephalitis.