How do people get West Nile virus encephalitis?
WNV is transmitted to people by the bite of a mosquito that has become infectious after feeding on a bird infected with the virus. Birds serve as the reservoir hosts of WNV, and the principal vector in the transmission from one bird to another is the northern house mosquito, Culex pipiens and other Culex mosquitoes. WNV has also been found in several species of Aedes mosquitoes, which could serve as bridge vectors by transmitting it to humans or horses.
