West Nile virus-positive mosquitoes found in Highland Park and Winnetka for first time this year

The Lake County Health Department has officially located West Nile virus-positive mosquitoes in Highland Park.

The virus-mosquitoes confirmed the first presence of West Nile virus in Lake County this year. They were sampled on June 24 from a Southlake Mosquito Abatement District trap set in Highland Park.

“Mosquitoes are an expected part of summer, but they also carry diseases that can lead to serious illness and even death,” said Chris Hoff, executive director of the Lake County Health Department, in a Tuesday news release announcing the local test results.

The government health agency urged residents to practice the four “Ds of Defense:”

• Drain standing water from items around your home, yard, and business 
• Defend with insect repellent when outdoors
• Protect yourself during dawn and dusk, prime times for mosquito activity
• Dress with long sleeves, pants and closed-toe shoes to cover your skin.

Most people infected with West Nile virus have no symptoms of illness, but may become ill three to 15 days after a bite from an infected mosquito, the health agency said. Common symptoms include fever, nausea, headache and muscle ache. Severe illness will include meningitis, encephalitis or even death.

People older than 50 and individuals with weakened immune systems are at higher risk for severe illness from West Nile virus. 

The Lake County Health Department’s Mosquito Surveillance Program tests mosquitoes weekly for West Nile virus, investigates areas of stagnant water for larvae and monitors reports of dead birds — an early sign of the presence of the virus.

The North Shore Mosquito Abatement District announced on Thursday that it found West Nile-virus-positive mosquitoes in Winnetka on June 30. The NSMAD also tested West Nile-positive mosquitoes out of Wilmette and Skokie on June 18. Mosquitoes already tested positive for the virus in Niles and Glenview earlier last month.

The current risk level for West Nile virus in the North Shore is low, but illness prevalence tends to increase later in the summer, the local agency said.

A total of 154 out of 723 batches of mosquitoes tested positive for West Nile virus in Lake County 2024, according to the county health department. Six people tested positive for the virus last year. Since 2002, there have been 86 confirmed human cases of West Nile virus in Lake County and five confirmed deaths.

Residents can find more West Nile virus prevention tips at FightTheBiteNow.com and call the Lake County Health Department’s West Nile hotline at (847-377-8300) to report stagnant water, dead birds and obtain more information on the signs and symptoms of West Nile virus. 

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