Deadly Mosquito Virus Detected In Michigan For 1st Time In 2024

MICHIGAN — Health officials warned Michiganders on Monday to guard themselves against mosquito bites after a group of mosquitos recently collected in Saginaw County tested positive for Jamestown Canyon virus.

These are the first infected mosquitoes for any virus in 2024 anywhere in the state, according to the Michigan Department of Health and Human Services.

The mosquitoes were found in Saginaw County on May 22. As of Tuesday, no one has tested positive for any mosquito-borne illness, including Jamestown Canyon virus.

"It only takes one bite from an infected mosquito to cause a severe illness," MDHHS chief medical executive Dr. Natasha Bagdasarian said. "We urge Michiganders to take precautions such as using an EPA-registered insect repellent when outdoors, avoiding areas where mosquitos are present if possible and wearing clothing to cover arms and legs to prevent bites."

The Jamestown Canyon virus spreads to people through bites from infected mosquitoes, with most cases occurring from late spring through mid-fall, health officials said.

Although most people do not become ill, initial symptoms can include fever, headache and fatigue, officials said. In rare cases, it can cause severe disease in the brain and/or spinal cord including encephalitis and meningitis.

The Jamestown Canyon Virus sickened six Michiganders in 2021, one in 2022 and four in 2023. There were also 21 cases of the West Nile Virus reported last year, officials said.

While the JCV is found throughout much of the United States, cases have been increasing in the Midwest. Officials believe the increase is due to the presence of the virus in the environment, in addition to an increase in awareness and testing.

The best ways to prevent mosquito bites, health officials say, include:

• 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 help keep mosquitos outside.
• Empty water from mosquito breeding sites around the home, such as buckets, unused kiddie pools, old tires and other water-holding containers where mosquitos can lay eggs.

More information on Jamestown Canyon Virus and how to protect against mosquitoes can be found on the MDHHS website.