A mosquito collected in Wayne County has tested positive for West Nile virus, marking the first detection in the county this year and prompting health officials to urge Northville-area residents to take precautions as summer mosquito season continues.
Wayne County Public Health announced the finding on Wednesday, July 22. The infected mosquito was collected in "Out-Wayne County," meaning a community other than Detroit. Officials did not identify the specific municipality.
The City of Northville and Northville Township are both located in Wayne County, placing them within the county where the virus was detected, though the specific collection site was not disclosed. Novi, in neighboring Oakland County, has not reported a detection, though health officials note the virus circulates regionally.
Virus activity in Michigan usually peaks in late August and early September, according to the Michigan Department of Health and Human Services. No human cases of West Nile virus have been confirmed in Michigan so far in 2026, according to the Detroit News and Detroit Free Press.
Wayne County's sample was the 13th positive mosquito test statewide this season, with Bay, Kent, Midland, Ottawa and St. Clair counties also reporting detections.
"We want people to continue enjoying the outdoors this summer," Wayne County Public Health Chief Medical Health Officer Dr. Avani Sheth said Wednesday. "A few simple steps — using insect repellent and emptying standing water around your home — can make a big difference in preventing mosquito bites."
What residents should know
West Nile virus spreads through the bite of an infected mosquito. It cannot pass from person to person. About 20% of those infected develop symptoms, which can include fever, headache, body aches, joint pain, vomiting, diarrhea or rash. Symptoms appear two to 14 days after a bite.
People older than 50 or those with weakened immune systems or chronic illness face higher risk of serious complications, including meningitis or brain infection. No vaccine or specific treatment exist, according to federal health officials.
How to protect yourself
Wayne County health officials recommend these steps:
- Use insect repellent containing DEET when outdoors
- Empty standing water from flowerpots, gutters, buckets, pool covers and birdbaths
- Install or repair window and door screens
- Wear long sleeves and pants at dawn and dusk, when mosquitoes are most active
Statewide and national context
The virus has also been detected in five animals across Michigan this year: four birds in Bay, Charlevoix and Menominee counties, and a squirrel in Delta County. Nationwide, 91 people have tested positive for West Nile virus in 2026, according to the CDC.
Last year, 49 Michigan residents tested positive. Nationally, 2,146 people were infected and 172 died from the illness in 2025, CDC data shows.
Peak virus activity typically arrives in late August. Residents can monitor updates at WayneCountyMI.gov or contact Wayne County Public Health for more information.
