Infection hazard

Four confirmed human cases of West Nile virus have been reported in Cook County.
Experts say West Nile virus cases are not uncommon for this time of year, as the virus is spread by mosquitoes. All four cases were found in adults.
ABC7 talked to an infectious disease expert who says 80% of people with West Nile virus do not develop any symptoms, but there are some to look out for.
Some people may develop mild symptoms such as fever, headache, rash, and body aches three to 15 days after infection.
The Cook County Department of Health says more severe symptoms are called neuroinvasive, meaning the virus has affected the nervous system, including the brain or spinal cord.
Those symptoms can include high fever, stiff neck, confusion, muscle weakness, and inflammation of the brain, which may result in permanent neurological damage or death.
Illinois' first human case was reported last week in Piatt County, near Springfield, and there is another human case in Allen County, Indiana.