West Nile Virus Mosquitoes Found In Wilmette, Kenilworth

WILMETTE, IL — Local mosquito control authorities this week confirmed the presence of West Nile virus positive mosquitoes in both Wilmette and Kenilworth.

One batch of mosquitoes collected on July 3 in Wilmette tested positive on Monday, while two batches found on Friday in Kenilworth came back positive for the virus on Tuesday, according to the North Shore Mosquito Abatement District.

And though mosquitos have been more abundant than usual in recent weeks, with more than twice as many collected every trap night, the risk of infection with the virus remains low, according to district officials.

This week, 11 of 98 batches collected tested positive — just over 11 percent — compared to just 3.5 percent of the nearly 440 batches collected this season so far.

In 2024, district traps have also collected West Nile positive mosquitoes in Evanston, Lincolnwood, Morton Grove, Northbrook, Northfield and Skokie.

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The only towns in the North Shore district that have not had a sample test positive yet this year are Glencoe, Glenview, Niles and Winnetka.

Currently, data show the risk level for West Nile virus infection is very low for humans. The vector index measurement of the number of infected Culex mosquitoes currently stands at 0.27, and anything below 1.0 indicates low risk.

District officials advise residents take preventive measures to reduce mosquito bites, including using EPA-registered insect repellent, wearing loose-fitting clothing, avoiding outdoor activities during peak mosquito feeding times around dawn and dusk and eliminating standing water on properties, which can serve as mosquito breeding sites.

Infections with West Nile virus can cause a range of health effects in humans. While most cases are asymptomatic, some can develop severe symptoms, which potentially lead to serious diseases such as encephalitis or meningitis.

According to the Centers for Disease Control and Prevention, about one in every 150 people who get infected with the virus end up suffering a serious illness.

Historically, the last significant human outbreak of West Nile virus in Cook County occurred in 2012, with 20 reported cases. Only 34 cases have been recorded in the North Shore district in the past decade.