1st Human Case Of West Nile Virus For 2025 Reported In Lake County

LAKE COUNTY, IL — The first human West Nile virus case of the year has been reported in Lake County, health officials said Wednesday.

The Lake County resident, who is in their 70s, became ill in early July, health officials said.

“Our time spent outdoors typically increases during the summer months, which also increases our exposure to mosquitoes,” said Chris Hoff, Executive Director of the Lake County Health Department and Community Health Center. “Remember to take steps to protect yourself and your family from mosquitoes to reduce your risk of getting West Nile virus.”

So far in 2025, nine out of 214 batches of mosquitoes tested by the health department have been positive for West Nile virus. West Nile virus typically peaks in late summer, usually from July through September when the mosquito population is at its peak.

Lake County residents are reminded to follow these steps to protect your family from the virus:

• Drain: Drain standing water from items around your home, yard, and business
• Defend: When outdoors, use an EPA-approved insect repellent containing DEET, picaridin, oil of lemon eucalyptus, 2-undecanone, or IR3535 and reapply according to label directions.
• Dawn to Dusk: Protect yourself all day and night, and wear repellent outdoors during these prime times for mosquito activity.
• Dress: Wear long sleeves, pants, and closed toe shoes when outdoors to cover your skin.

Most people infected with West Nile virus have no symptoms of illness. However, some may become ill usually three to 15 days after the bite of an infected mosquito, according to a news release from the health department.

These symptoms include fever, nausea, headache and muscle aches. In rare cases, the virus can affect the brain or spinal cord, leading to serious neurological symptoms such as stiff neck, confusion, sudden weakness or numbness on one side of the body, trouble walking or even death.

People older than 60 years and individuals with weakened immune systems or multiple medical conditions are at higher risk for severe illness from West Nile virus.

You can learn more about West Nile virus, and get tips for fighting the virus on the health department's website. Residents can also call the health department’s West Nile hotline at 847-377-8300 to report areas of stagnant water, report locations of dead birds and obtain more information on the signs and symptoms of West Nile virus.