The Illinois Department of Public Health reports the first mosquitoes to test positive for West Nile virus in Illinois in 2017 in Madison County.

Monitoring for West Nile virus in Illinois includes laboratory tests for mosquito batches, dead crows, blue jays, robins and other perching birds, as well as testing sick horses and humans with West Nile virus-like symptoms.

Last year, West Nile was found in 61 counties and infected 152 people. Five of them died.