The DuPage County Health Department announced on October 6 that the county has recorded its first human death related to West Nile virus in 2026 — an adult resident, whose age, sex and hometown were not released. Six human cases have been reported in the county so far this year; in 2025, the county recorded 14 cases, including one related death.
County mosquito surveillance shows 13% of tested mosquito pools were positive for the virus during the week of September 21 to 27 — a sign the virus was still circulating in late September. "We are deeply saddened to share news of the first West Nile virus-related death in DuPage County this year," said Adam Forker, executive director of the DuPage County Health Department. "Please remember to take simple steps to stop mosquito bites so you, your family, and your neighbors can stay safe." The Illinois Department of Public Health's statewide dashboard, last updated September 30, listed 50 human cases and three deaths in 2026, along with 3,519 positive mosquito batches and 60 counties with positive findings in humans, birds, mosquitoes, or horses — figures posted before DuPage announced its death.
West Nile virus spreads to people through the bites of mosquitoes that have fed on infected birds. Most infected people have few or no symptoms, but roughly one in five develops fever, headache, body aches, joint pains, vomiting, diarrhea, or a rash. People over 60 and those with conditions such as cancer, diabetes, high blood pressure, kidney disease, or organ transplants face a higher risk of serious illness, which can rarely lead to permanent neurological damage, coma, or death. High fever, neck stiffness, muscle weakness, confusion, or tremors warrant immediate medical attention.
Health officials recommend the "three Rs": Reduce — remove standing water and keep doors and windows screened; Repel — use an EPA-registered insect repellent; Report — notify the county health department of areas where water has sat for more than a week, as well as dead birds. The Chicago Department of Public Health also reported a West Nile death in early September, a sign that transmission season across the Chicago area is not over.
West Nile is the most common mosquito-borne illness in the United States, and there is currently no vaccine and no specific antiviral treatment — care is supportive. Federal data showed nearly 1,000 cases nationally earlier in the season. For families, the practical takeaway this fall: clear leaves and standing water from the yard and wear repellent outdoors.