Cook County Public Health: Don’t Let Your Guard Down Against West Nile Virus
CCDPH encourages residents to take extra precautions, protect themselves from mosquitoes
FOREST PARK, Ill. – Cook County Department of Public Health is urging residents to stay vigilant and take precautions against mosquitoes, which carry the potentially deadly West Nile virus. The risk of human West Nile virus infection remains high in suburban Cook County.
West Nile virus occurs in humans when they are bitten by mosquitoes that contracted the virus by feeding on infected birds.
Since May 11, when the surveillance period for the virus began, through Aug. 30, suburban Cook County has recorded 25 cases of West Nile virus. Of those cases, 17 cases were neuroinvasive, meaning that the central nervous system was affected.
Most cases of West Nile virus infection have either mild or no symptoms and may go unreported, so case counts are underestimates.
“Summer may be ending soon, but this is not the time to be lax about this disease,” said Cook County Department of Public Health Chief Operating Officer Dr. Kiran Joshi. “People should still take steps to prevent mosquito bites. Simple actions can prevent people from getting sick.”
Cook County Department of Public Health encourages residents to take the following extra precautions to protect themselves from mosquito bites and prevent West Nile virus:
- Drain standing water around your home, and don’t allow mosquitoes to breed.
- Apply EPA-registered insect repellents containing 20% to 50% DEET (for adults) and 20% to 25% DEET (for children).
- Take extra precautions or limit time outdoors during dusk and dawn
- Repair torn screens and ensure that they are tight-fitting without gaps.
Although most people never get ill from infection, some may develop mild symptoms, such as fever, headache, rash, and body aches three to 15 days after infection. Severe West Nile virus symptoms could include a high fever, stiff neck, confusion, muscle weakness, and inflammation of the brain, which could lead to permanent neurological damage or death.
Overall, the state of Illinois has recorded 42 human cases of West Nile virus, 34 in Cook County, including the City of Chicago.
Fifty-six percent of mosquito pools tested in suburban Cook County during the week ending August 30 contained West Nile virus. This is down from 66.7% the week prior.
In suburban Cook County, 19 West Nile virus cases and five deaths from the disease were reported in 2024. That was the highest number of West Nile virus deaths reported since eight deaths in 2018.
For more information about Cook County Department of Public Health programs and services, visit www.cookcountypublichealth.org.
Cook County Department of Public Health is the nationally accredited, state-certified local health department serving suburban Cook County. We build healthier, more equitable communities by protecting health, preventing disease, engaging communities, and analyzing and sharing data for action.