Mosquito-Borne Diseases

Mosquito-Borne Diseases West Nile Virus in the U.S. West Nile Virus is a mosquito-borne virus (arborvirus) that can cause encephalitis, an inflammation of the brain. The virus resides in hosts, typically birds. When a female mosquito vector of West Nile Virus feeds on a bird carrying this virus, replication occurs in the mosquito. West Nile Virus then is released in subsequent feedings, spreading West Nile Virus to humans and other birds. The virus is extremely widespread in Africa, the Middle East, Southeast Asia, parts of temperate Europe and now large sections of the United States. As West Nile Virus is now endemic, it has the potential to resurface and spread at any time in the U.S.

Mosquitoes are an all too familiar summer nuisance. Not only are they annoying, they can also transmit encephalitis, malaria, and yellow fever to humans, and heartworm to pets.