First Detection Of West Nile Virus In Metro Detroit: What To Know

MACOMB COUNTY, MI — Macomb County health officials said Thursday they have detected the West Nile Virus in a single sampling of mosquitoes.

It is the first detection of the virus in the metro Detroit area, and the fourth in Michigan so far in 2025. The virus was also found in one bird in Saginaw County and two mosquito pools in Bay and Midland counties, according to the Michigan Department of Health and Human Services.

As of Thursday, health officials said there have been no human cases of the virus in Michigan.

"This discovery by our surveillance team is important because it lets us know that this season’s mosquitoes are now carrying the virus – which could spread to humans," Macomb County Health and Community Services Director/Health Officer Andrew Cox said. "We encourage everyone to take steps to prevent mosquito bites to the greatest extent possible."

The virus is spread to humans through the bite of the infected mosquito. Some people who get the virus may develop an illness may experience mild symptoms such as fever, headache and body aches; occasionally, a skin rash and swollen lymph glands may be noticed. These symptoms may last a few days or as long as several weeks.

People who are older than 50 or have immunocompromised conditions can become seriously ill.

There are no vaccines or specific treatments for the infection, according to federal health officials.

Here are recommendations for avoiding exposure:

• Avoid outdoor activities at dawn and dusk, when mosquitoes are most active.
• Empty any standing water and monitor your yard, clearing watering cans, clogged gutters or discarded containers.
• Wear long pants, long-sleeved shirts and hats outside.
• Use an EPA-registered insect repellent according to package directions.