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. A. Mosquitoes become infected after feeding on infected birds with high levels of virus in the blood. After a period of 10 days to 2 weeks, the mosquitoes can then transmit the virus to humans or other birds and animals when taking a second blood meal. The disease can only be transmitted by mosquito bite, and not from bird or from birds to people or other animals.