A suburban Cook County resident in their 60s has died after contracting West Nile virus, marking the first virus-related death reported this year in Illinois, health officials announced Wednesday.
Lab testing has confirmed that the virus was a contributing factor in the resident’s death, the Cook County Department of Public Health said in a statement.
The health department did not provide details about what community the resident lived in, their name, or how they contracted it.
Since the start of the surveillance period on May 11, suburban Cook County has recorded 33 human cases of West Nile virus, which the department said is nearly double last year’s count. Of those cases, 22 were neuroinvasive, meaning the virus impacted a patient’s central nervous system.
By comparison, 19 cases and five deaths were reported in suburban Cook County last year. Statewide, Illinois logged 69 cases and 13 fatalities related to the virus in 2024.
Chicago reported its first human cases of West Nile virus for 2025 in August.
The majority of West Nile virus cases involve little to no symptoms and may go unreported, so the health department emphasizes that case counts are underestimates.
“The year’s first death from West Nile virus in Illinois is a sobering reminder that mosquito-borne illnesses are still with us,” said Illinois Department of Public Health Director Dr. Sameer Vohra. “It’s important to take appropriate precautions as the weather remains warm.”
CCDPH’s Dr. Kiran Joshi said in a statement all residents should take steps to protect themselves from the virus, especially seniors, who face a higher risk for severe illness and death.
“As long as mosquitoes are flying around, people are at risk of mosquito bites and of contracting West Nile virus,” Joshi said in the statement.
Health officials are urging residents to “Fight the Bite” by reducing mosquito exposure, using insect repellent and reporting problems with standing water. Residents should look for EPA-registered insect repellents that contain 20% to 50% DEET for adults and 20% to 25% DEET for children.
While most people who become infected experience no symptoms or mild ones, health officials said severe cases can cause high fever, neurological damage or death. Symptoms that do occur may show up within three to 15 days after infection, according to the health department.