Mosquitoes with West Nile virus identified in DeKalb County for first time since 2019

DeKalb County Health Department reports mosquito samples positive for West Nile virus

Mosquitoes collected in traps in DeKalb and Sycamore have tested positive for the West Nile virus for the first time since 2019, according to a Friday announcement by the DeKalb County Health Department.

Several counties in Illinois have reported West Nile positive mosquito samples this year, which is associated with an increased risk of West Nile virus in people, according to a news release.

There have been no human cases in DeKalb County yet this year, officials said.

West Nile virus is transmitted through the bite of an infected mosquito. Mosquitoes become infected after feeding on an infected bird. It is important to remember that not all mosquitoes, or birds, carry West Nile virus – most do not.

Symptoms to watch for

Most people with the virus have no clinical symptoms of illness, but some may become ill three to 14 days after the bite of an infected mosquito. Illness from West Nile is usually mild and includes fever, headache and body aches, but serious illness, such as encephalitis and meningitis have been known to develop. Persons older than 50 years of age have the highest risk of severe disease.

“The most effective way to prevent you or your family from being infected is to reduce the chances of being bitten by mosquitoes” said Greg Maurice, Director of Health Protection in a statement. “This includes eliminating standing water from around your house and using mosquito repellent when outside.”

Maurice offers these tips:

• Avoid being outdoors when mosquitoes are most active, especially between dusk and dawn.

• When outdoors, wear shoes and socks, long pants and a long-sleeved shirt, and apply insect repellent that includes DEET, picaridin or oil of lemon eucalyptus according to label instructions. Consult a physician before using repellents on infants.

• Make sure doors and windows have tight-fitting screens. Repair or replace screens that have tears or other openings. Try to keep doors and windows shut, especially at night.

• Change water in birdbaths weekly. Properly maintain wading pools and stock ornamental ponds with fish. Turn over any buckets, garbage cans, or other containers that collect water.

For additional information, check the DeKalb County Health Department website at To learn more about the many programs and services of the Health Department, visit or follow on social media.