IDPH Reports First Human Case and First Death From West Nile Virus in Illinois of 2022

CHICAGO – The Illinois Department of Public Health (IDPH) has confirmed the first human case and first human death of West Nile virus (WNV) reported in Illinois for 2022. A person in their late 70’s in Cook County became ill at the beginning of August and subsequently died. WNV was a contributing factor in the death.  Laboratory testing at CDC has confirmed the diagnosis of WNV.

“This unfortunate first reported death of the year from West Nile virus in Illinois is a reminder that this disease poses a risk, especially to those who have weakened immune systems,” said IDPH Director Dr. Sameer Vohra. “While the weather is warm and mosquitos are breeding, we should all take precautions to protect ourselves from mosquitoes and the viruses they carry by wearing insect repellent and eliminating standing water around our homes where mosquitos breed.”

The first human case of WNV in Illinois was reported last year on August 3, 2021. For the 2021 season, IDPH reported 65 human cases (although human cases are underreported), including five deaths. Last year, 48 counties in Illinois reported a WNV positive mosquito batch, bird and/or horses.  So far in 2022, there have been positive mosquito batches in 30 counties and eight birds have tested positive in six counties.

This year, the first mosquito batch to test positive for West Nile virus was collected on May 17, 2022, in Will County. The first bird to test positive for West Nile virus this year was collected in Logan County on July 5.

Surveillance for West Nile virus in Illinois includes laboratory tests on 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. People who observe a sick or dying crow, blue jay, robin or other perching bird should contact their local health department, which can determine if the bird will be picked up for testing.

West Nile virus is transmitted through the bite of a Culex pipiens mosquito, commonly called a house mosquito, which has picked up the virus by feeding on an infected bird. Common symptoms of WNV include fever, nausea, headache and muscle aches. Symptoms may last from a few days to a few weeks. Four out of five people infected with West Nile virus will not show any symptoms. However, in rare cases, severe illness including meningitis or encephalitis, or even death, can occur. People older than 50 and immunocompromised individuals are at higher risk for severe illness from West Nile virus.

IDPH encourages the public to Fight the Bite by practicing the three “R’s” – reduce, repel, and report:

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.

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 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.

For additional information about WNV in Illinois can be found at: West Nile virus.