west Nile virus Illinois: West Nile virus emerged within us within the NY metropolitan area within the fall of 1999. Since then, the virus, which may be transmitted to humans by the bite of an infected mosquito, has quickly spread across the country.

In Illinois, West Nile virus was first identified in September 2001 when laboratory tests confirmed its presence in two dead crows found within the Chicago area.

The subsequent year, the state’s first human cases and deaths from West Nile disease were recorded and everyone but two of the state’s 102 counties eventually reported a positive human, bird, mosquito or horse. By the top of 2002, Illinois had counted more human cases (884) and deaths (64) than the other state within us.

A blood-engorged female Aedes albopictus mosquito feeding on a human host, 2001. Under experimental conditions the Aedes albopictus mosquito, also known as the Asian Tiger Mosquito, has been found to be a vector of West Nile Virus. Aedes is a genus of the Culicine family of mosquitoes. Image courtesy CDC/James Gathany. (Photo by Smith Collection/Gado/Getty Images).

The Illinois Department of Public Health (IDPH) maintains a classy disease closed-circuit television to watch animals and insects which will potentially carry the virus: dead crows, robins, blue jays, mosquitoes and horses. Mosquitoes can either carry the virus or catch on by feeding on infected birds.