Michigan health officials confirm first West Nile virus human case in 2025
The Michigan Department of Health and Human Services confirmed the state's first West Nile virus human case in 2025.
Health officials say the virus was detected in a Livingston County resident. MDHHS did not release any additional information on the resident. The first human case in 2024 was also detected in Livingston County.
"It only takes one bite from an infected mosquito to cause a severe illness. Use insect repellent and wearing long-sleeved shirts and long pants when outdoors during times when mosquitoes are active," said Dr. Natasha Bagdasarian, Michigan's chief medical executive. "These precautions are especially important during peak mosquito-biting hours, which are from dusk to dawn."
Health officials have found mosquitoes with the virus in Bay, Kalamazoo, Kent, Macomb, Midland, Saginaw, Tuscola and Wayne counties. Additionally, mosquitoes were found with the John Cunningham virus in Bay, Kalamazoo, Macomb, Ottawa, Saginaw and Washtenaw counties.
What are the symptoms of West Nile virus?
Most people who are infected with WNV do not experience any symptoms or have a mild illness that could include a high fever, muscle weakness, confusion and severe headache. However, in some people, WNV can cause serious disease-causing inflammation and swelling of the brain.
People over 50 are more likely to develop serious or life-threatening symptoms of WNV.
How you can protect yourself against mosquito-borne viruses
Health officials recommend the following tips to protect you and your family from mosquito-borne illnesses like WNV.
- Use Environmental Protection Agency (EPA) registered insect repellent. All EPA-registered insect repellents are evaluated for safety and effectiveness and will contain DEET, picaridin, IR3535, Oil of Lemon Eucalyptus or para-menthane-diol as the active ingredient. Repellents containing a higher percentage of the active ingredient typically provide longer-lasting protection. Always follow the product label instructions.
- Be careful using repellent on the hands of children, as it may irritate the eyes and mouth.
- Get rid of mosquito breeding sites by removing standing water around your home.
- Turn over any type of container that can collect water. Once a week, empty out items that hold water, such as tires, buckets, planters, toys, pools, birdbaths, pet bowls, flowerpots, and trash containers.
- Clean clogged roof gutters, particularly if leaves tend to plug up the drains.
- Treat standing water that cannot be eliminated, such as retention ponds or drainage ditches, with a mosquito larvicide. Mosquito larvicide is easy to use and can be purchased at most home improvement stores.
- Wear protective clothing such as long-sleeved shirts and pants.
- Limit outdoor activity from dusk to dawn when mosquitoes are most active.
- Maintain window and door screens to keep mosquitoes out of buildings. Do not prop open doors.