CHICAGO, July 6 (UPI) -- A sample of mosquitoes taken from pools in Will County, Ill., west of Chicago has tested positive for West Nile virus, Illinois state health officials said.
The Illinois Department of Public Health Tuesday said West Nile virus has been confirmed in 40 mosquito pools and 57 birds in 23 counties since local health departments began stepped up surveillance May 1.
West Nile was confirmed in 75 of the state's 102 counties last year, with 54 human cases and one death. In 2002, Illinois led the nation with 884 human cases and 66 deaths.
West Nile virus is spread through the bite of a Culex mosquito that has fed on an infected bird.
Symptoms include headache, high fever, neck stiffness, stupor, convulsions, muscle weakness and paralysis. Most people show no symptoms, which occur three to 14 days after infection, said Dr. Eric Whitaker, state public health director.
