A Suburban Resident Is Illinois’ 1st West Nile Death In 2025

Mosquito season in Illinois usually starts in early April and runs through late September into early October, so we're pretty much right in prime mosquito-biting time here in late September, 2025.

If you haven't really been paying attention to the little bloodsuckers, now would be a good time to start making sure you're covering your skin or spraying it down with bug spray when you're out early in the morning or evening when they're most likely to bite, because you'll want to avoid picking up a case of West Nile virus.

West Nile virus is a mosquito-borne virus most commonly spread to humans through the bite of an infected mosquito. Most people who get it have no symptoms, or only mild ones like fever, headache, or body aches.

In rare cases though, especially in older adults or those with weakened immune systems, it can cause serious illness affecting the brain and nervous system. There is no vaccine or specific treatment for WNV in humans, so prevention focuses on avoiding mosquito bites.

According To The Illinois Department Of Public Health (IDPH), Illinois Has Around 80 Reported Cases Of West Nile Virus So Far In 2025

That number is already ahead of 2024's total count of West Nile virus cases in Illinois, which was 69 cases. Some West Nile numbers from IDPH:

• Human cases: 79
• Median age of human cases: 64 years
• Youngest documented human case: 4 years old
• Oldest documented human case: 91 years old
• Number of counties with positive WNV in humans, birds, mosquitoes, or animals: 67 of 102

In Cook County and suburban Cook, there have been multiple neuroinvasive cases this year. “Neuroinvasive” means the virus has reached the brain or nervous system. In West Nile cases, that can lead to serious illnesses like brain swelling, meningitis, or paralysis. For example, as of September 6th, there had been 33 WNV cases in suburban Cook County, 22 of which were neuroinvasive.

Illinois May Have Be Seeing More Cases Of West Nile Virus Than Last Year, But The State's First Fatality From WNV Just Happened On Wednesday

In 2024, there were thirteen deaths in Illinois attributed to WNV, with the first occurring in August of 2024, so the timeline between last year and this year is similar.

WTTW:

A suburban Cook County resident has died from the West Nile virus, the Cook County Department of Public Health confirmed Wednesday. It’s the first West Nile virus-related death in Illinois confirmed this year.

The suburban Cook County resident was in their 60s. Laboratory testing confirmed that West Nile virus was a contributing factor to the resident’s death, according to CCDPH.

The risk of West Nile virus in suburban Cook County remains high.

Your best bet to keep yourself and your family safe from these mosquitoes and the WNV they're carrying is to "Fight The Bite:"

Limit outdoor time at peak mosquito hours if possible.