ILLINOIS (WEHT) – The Illinois Department of Public Health (IDPH) is reminding the public that mosquito season is now underway in Illinois and that positive batches of West Nile virus have been reported in seven counties around the state.

“West Nile virus is a serious illness, and we want to remind everyone to protect themselves from mosquito bites at this time of year when so many of us are spending more time outdoors,” said IDPH Acting Director Amaal Tokars. “The most important things we can do are to wear insect repellent if we are spending time outside and eliminate standing water where mosquitos breed around our homes. These precautions are especially important for those with weakened immune systems”

IDPH says while no human cases of West Nile virus have been reported in Illinois so far this year, there were 64 human cases and five deaths attributed to the disease in 2021. IDPH says the first mosquitoes to test positive for West Nile virus in Illinois in 2022 were reported on May 24 in Roselle in DuPage County. Since then, six more counties – Cook, Will, Logan, Edgar, Macoupin and Washington – have reported mosquitos that tested positive for West Nile. Updates on where cases have been reported can be found on the IDPH West Nile Virus Surveillance page.

IDPH says monitoring for West Nile virus in Illinois includes laboratory tests for mosquito batches, dead crows, blue jays, robins, other perching birds, sick horses and humans with West Nile virus-like symptoms. People who see a sick or dying crow, blue jay, robin or other bird should contact their local health department, which will determine if the bird will be picked up for testing.

The press release says West Nile virus is transmitted through the bite of a house mosquito that has picked up the virus by feeding on an infected bird. Common symptoms include fever, nausea, headache and muscle aches. Symptoms may last from a few days to a few weeks. IDPH says four out of five people infected with West Nile virus will not show any symptoms. In rare cases, severe illness including meningitis, encephalitis, or even death, can occur. People older than 60 and individuals with weakened immune systems are at higher risk for severe illness from West Nile virus.

IDPH encourages the public to practice the three “R’s” – reduce, repel, and report:

  • 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, or IR 3535 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.

More information about West Nile virus can be found on the IDPH website.