Illinois confirms first human West Nile virus case of 2026

FOX23 News at 9 p.m

SPRINGFIELD, Ill., (KBSI) — Illinois health officials have confirmed the state’s first human case of West Nile virus this year and are urging residents to take precautions against mosquito bites.

The Illinois Department of Public Health said the confirmed case involves a Piatt County resident. Three additional probable human cases have been identified in northern Illinois.

West Nile virus has been detected in 50 Illinois counties so far this year through positive tests involving mosquitoes, horses or humans.

In 2025, the virus was detected in 73 Illinois counties. The state reported 150 human cases and 10 deaths linked to the virus.

“For many Illinois residents, summer means lots of time spent outdoors enjoying everything our state has to offer,” IDPH Director Dr. Sameer Vohra said. “Before heading outside, it’s important to take steps to protect yourself and loved ones from mosquito bites and the illnesses they can spread.”

West Nile virus is primarily transmitted to humans through the bite of an infected mosquito. Most people who become infected do not develop symptoms, according to IDPH.

About one in five infected people may develop symptoms such as fever, headache, body aches and joint pain. In rare cases, the virus can cause severe illnesses including meningitis, encephalitis or paralysis and can be fatal.

Adults older than 60 and people with weakened immune systems face the highest risk of severe illness.

IDPH is encouraging residents to “Fight the Bite” by reducing standing water where mosquitoes breed, using insect repellent and wearing clothing that covers exposed skin when outdoors.

Residents are also encouraged to report areas where water has remained stagnant for more than a week to their local health department or city government.