Deadly Mosquito Virus Detected In MI: How To Protect Yourself

MICHIGAN — State health officials have detected another deadly mosquito virus in Michigan.

Members of the Michigan Department of Health and Human Services said mosquitos recently collected in Bay County tested positive for Eastern Equine Encephalitis.

As of Monday, there have been no confirmed human cases, but officials urged Michiganders to protect themselves from mosquitos as the virus can be transmitted from a single bite. People under age 15 and over age 50 are at greatest risk of severe disease following an EEE infection.

"This testing information confirms the virus is here in mosquitos in Michigan," Michigan Department of Health and Human Services Chief Medical Executive Natasha Bagdasarian said. "EEE is one of the most dangerous mosquito-borne diseases in the United States, with a 33% fatality rate in people who become ill."

Signs of EEE infection include a sudden fever, chills and body and joint aches that can progress to severe encephalitis, resulting in headache, disorientation, tremors, seizures and paralysis. In some case, permanent brain damage, coma and death can happen.

Anyone who thinks they may be experiencing these symptoms should contact a medical provider.

Officials offered these tips to prevent mosquito bites:

• Apply insect repellents that contain the active ingredient DEET or other EPA-approved products to exposed skin or clothing. Always follow the manufacturer’s directions for use.
• Wear light-colored, long-sleeved shirts and long pants when outdoors. Apply insect repellent to clothing to help prevent bites.
• Maintain window and door screening to keep mosquitos outside.
• At least once a week, empty water from mosquito breeding sites around the home, such as buckets, unused children’s pools, old tires and other water-holding containers where mosquitos can lay eggs.

Horses are also vulnerable to EEE, with a 90 percent fatality rate in horses that become ill. The disease is not spread by horse-to-horse or horse-to-human contact.

Here's how officials said you can protect horses:

• Talking to their veterinarian about vaccinating horses against EEE and other mosquito-borne diseases.
• Placing horses and other livestock in a barn under fans during peak mosquito activity (from dusk to dawn).
• Using an insect repellent on animals that is approved for the species.
• Contacting a veterinarian if an animal shows signs of illness.

As of June 30, more than 600 mosquito pools had been tested in Michigan during 2023. A mosquito pool from Saginaw County tested positive for Jamestown Canyon virus.

In 2022, there were no human cases of EEE, but three horses from Eaton, Roscommon and St. Joseph counties and one bird from Houghton County died from the virus.

In 2021, there was one human case of EEE. In 2020, there were four human cases of EEE, two of which were fatal. In 2019, Michigan had 10 cases of EEE, six of which were fatal.