A. West Nile encephalitis is a mosquito-borne viral disease which can cause an inflammation of the brain. For the first time in North America, WNV was confirmed to be present in the New York metropolitan area during the summer and fall of 1999. A. WNV is transmitted to people by the bite of a mosquito, primarily the northern house mosquito, Culex pipiens.
Most infections are asymptomatic or mild.
In rare cases, more severe infection may result, with symptoms such as high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, paralysis and, rarely, death. There is no specific therapy. Most individuals recover spontaneously without hospitalization. However, those developing more serious symptoms require hospitalization for supportive therapy. A. Usually 5 to 15 days.