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West Nile Virus

West Nile encephalitis virus. Encephalitis caused by a virus of the Flaviviridae family. Causes West Nile fever, which is characterized by headache, fever, arthralgia, maculopapular rash, myalgia, lymphadenopathy and leukopenia. Transmitted and/or spread by mosquitoes from the genus Culex (family Culicidae).

Entry terms: Kunjin virus, West Nile flavivirus, WNV (West Nile virus), KUNV (Kunjin virus)



Fact Sheet: West Nile virus

IN1375/ENY-2083by Yasmin Tavares, Amely Bauer, Lawrence Reeves, and Lindsay CampbellOctober 28, 2022Introduced to the United States in 1999, West Nile virus (WNV) is transmitted from mosquitoes to humans and equines. With over 52,000 reported human infections, it is the most frequent cause of mosquito-borne disease in the continental United States. Many mosquito species can transmit WNV, and many wildlife species can be infected with the virus and transmit it to biting mosquitoes, which makes identifying WNV's high risk areas or time periods complex. The US equine industry, domestic pets, and livestock are all at risk from harm from WNV. Many equine WNV epizootics have occurred since 1999, with more than 30,000 equine cases reported in the United States. Since WNV's introduction to Florida in 2001, infections have been reported in a total of 460 people and 757 equines. This publication provides information about WNV to the general public, researchers and stakeholders in mosquito control, and public health professionals.

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