IDPH reports first human case of West Nile Virus in Illinois this year

(WAND) - The Illinois Department of Public Health announced the first human case of West Nile virus in the state this year.

The illness is mosquito-borne.

IDPH routinely sends the first positive case to CDC for confirmatory testing, which is pending. Commercial testing and clinical symptoms do indicate a positive case.

The person is in their 60’s and lives in suburban Cook County. The onset of WNV symptoms was in mid-June.

IDPH is tracking positive batches of birds and mosquitos on its West Nile virus dashboard and has reported 33 Illinois counties this year with positive results, an early warning of the presence of WNV in an area.

“Summer in Illinois means mosquitos, and these mosquitos increase our risk of contracting vector-borne illnesses like West Nile Virus,” said IDPH Director Dr. Sameer Vohra. “We encourage all Illinois residents to ‘Fight the Bite’ and protect themselves and their loves ones from insect bites that can cause potentially serious illnesses."

There were 119 human cases of WNV reported in Illinois in 2023, up from 34 human cases in 2022. There were six human deaths attributed to West Nile virus in the state in 2023, compared to seven in 2022. The first 2023 human case in Illinois occurred in late June.

West Nile virus is transmitted through the bite of a Culex mosquito, commonly called a typical 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 can occur, including brain infections such as meningitis or encephalitis and paralysis or even death. People older than 50 and immunocompromised individuals are at higher risk for severe illness from West Nile virus.

There is no specific treatment for WNV nor is there a vaccine.

IDPH encourages the public to Fight the Bite and take steps to prevent WNV by practicing 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. The CDC does not recommend use of products containing oil of lemon eucalyptus or para-menthane-diol on children under 3 years old. Consult a physician before using repellents on children under 3.
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.