KALAMAZOO, Mich. — Kalamazoo County health officials are warning that mosquitoes carrying a serious disease have been detected in the county.
A group of mosquitoes captured through the Kalamazoo County Health & Community Services Department’s Environmental Health Division's mosquito surveillance program tested positive for the Jamestown Canyon Virus. The illness is passed to humans by mosquitoes.
That disease is found across much of the U.S. and has been detected in mosquitoes over the past few years in Michigan. In 2024 seven people in the state tested positive for Jamestown Canyon Virus, according to the Michigan Department of Health and Human Services.
So far in 2025 there are no confirmed human cases.
The detection of a mosquito carrying the virus is the first for West Michigan in 2025. Two other counties in the state have captured virus-carrying mosquitoes this year: Bay and Midland counties.
Fever, headache and fatigue are common symptoms of Jamestown Canyon Virus, which can in rare cases cause severe disease, including infection of the brain or the lining around the brain.
“Mosquito surveillance continues to be of great importance in providing early notification to our community of positive virus detection,” said Environmental Health Division Manager Lucus Pols. “Early detection is the key to bringing awareness to our citizens of the continued need to be vigilant in mosquito bite prevention.”
Precautions to avoid mosquito bites include:
- Using EPA-registered insect repellents with one of the following active ingredients: DEET, picaridin, IR3535, oil of lemon eucalyptus or para-menthane-diol and 2-undecanone. Follow the product label instructions and reapply as directed.
- Don’t use repellent on children under 2 months old. Instead dress your child in clothing that covers arms and legs and cover crib, stroller and baby carrier with mosquito netting.
- Wearing shoes and socks, light-colored long pants and long-sleeved shirts when outdoors.
- Making sure doors and windows have tight-fitting screens. Repair or replace screens that have tears or other openings.
- Using bed nets when sleeping outdoors or in conditions with no window screens.
- Eliminating all sources of standing water that can support mosquito breeding around your home, including water in bird baths, abandoned swimming pools, wading pools, old tires and any other object holding water once a week.
