First human case of West Nile virus confirmed in southern Illinois
The Illinois Department of Public Health announced Tuesday that a person was hospitalized with the first case of West Nile Virus in southern Illinois for 2025.
Of of 19 Illinois counties where the virus was discovered, the only confirmed human case is in Wayne County, about 90 miles east of St. Clair.
The Center for Disease Control confirmed the case. Michael Claffey, a spokesperson for the Department of Natural Resources, said the person had since been discharged from the hospital.
“About one in 150 people who contract the disease caused by a bite from an infected mosquito develop a severe illness that can affect the brain, spinal cord, nerves and even cause paralysis,” according to a release from the state.
This is the earliest onset of illness observed in Illinois since 2016, the press release said. In 2024, there were 69 confirmed human cases of West Nile Virus, including 13 deaths.
“The fact that we are seeing the first human case of West Nile virus so early in the season serves as a timely reminder – especially for seniors and those with weakened immune systems – to protect yourself from illnesses caused by mosquito bites,” IDPH Director Sameer Vohra said. “I encourage all Illinoisans to ‘Fight the Bite’ and take precautions to protect themselves and their loved ones.”
The press release gave three methods of combating the virus:
- REDUCE - make sure doors and windows have tight-fitting screens. Repair or replace screens that have tears or other openings. Try to keep doors and windows shut. Eliminate, or refresh each week, all sources of standing water where mosquitoes can breed, including water in bird baths, ponds, flowerpots, wading pools, old tires, and any other containers.
- REPEL - when outdoors, wear shoes and socks, long pants and a light-colored, long-sleeved shirt, and apply an EPA-registered insect repellent that contains DEET, picaridin, oil of lemon eucalyptus, IR 3535, para-menthane-diol (PMD), or 2-undecanone according to label instructions. Consult a physician before using repellents on infants.
- REPORT – report locations where you see water sitting stagnant for more than a week such as roadside ditches, flooded yards, and similar locations that may produce mosquitoes. The local health department or city government may be able to add larvicide to the water, which will kill any mosquito larvae.
The press release said a county is considered positive for West Nile virus if a human, horse, or mosquito tests positive. The counties that currently have reported West Nile virus are: Bureau, Christian, Clinton, Cook, DeKalb, DuPage, Fulton, Grundy, Hancock, Henry, Marshall, McDonough, McHenry, Peoria, Scott, Stark, Tazewell, Wayne and Winnebago.
This story was originally published June 24, 2025 at 3:31 PM.
