An adult resident of DuPage County has died from causes related to West Nile virus, marking the county's first human death tied to the mosquito-borne disease in 2026. The death brings DuPage's total reported human cases this year to six.
The DuPage County Health Department confirmed the fatality this week, saying it was reporting the first human death related to West Nile virus in DuPage County in 2026 in an adult resident, according to the health department's News Flash. The department said there have been six human WNV cases reported to date in DuPage County in 2026. As reported by the Daily Herald, the case was among six confirmed in the county so far this year, and the person who died was not otherwise identified.
The Daily Herald reported that the DuPage fatality is the third death attributed to the virus in Illinois this year, a count the paper attributed to state figures. That statewide toll underscores how the virus has moved through the region this season; activity typically decreases in the fall.
How the Virus Spreads and Who's at Risk
West Nile virus reaches humans through bites from mosquitoes that picked up the virus by feeding on infected birds, the health department's notice explains. Most people who become infected experience mild symptoms or none at all, and the same source noted that approximately one in five people with WNV will develop symptoms. Individuals over the age of 60, and those with medical conditions, face higher risk for serious illness, according to the department.
DuPage County's mosquito surveillance data shows the virus remains active locally. The current positive pool rate stood at 13 percent for the week of September 21 to 27, per the health department. The county also maintains surveillance maps showing where mosquitoes have tested positive, with red circles indicating an area with a positive test for WNV, the county's mapping page notes.
A Tough Year for Mosquito-Borne Illness in the Region
This year's death follows a 2025 in which DuPage recorded a total of 14 WNV human cases including one related death, according to the health department. Virus activity typically decreases in the fall when cooler temperatures arrive, especially after the first frost, the Hinsdalean reported earlier this fall, offering some hope that the season's risk window is closing.
DuPage isn't alone in confronting the virus this year. Chicago's public health department reported the city's first two human cases and first death from West Nile virus in 2026 in a statement posted to the city's website. Downstate, the Shelby County Health Department said an 86-year-old man's recent death was due in part to contracting the West Nile virus, according to WAND-TV.
Precautions Health Officials Recommend
DuPage County Health Department officials are urging residents to take basic precautions as mosquito season winds down. Recommendations include using insect repellent, maintaining screens, and limiting time outdoors at dusk and dawn.
