Deadly Mosquito Virus Detected In Michigan For 1st Time In 2023

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 2023 anywhere in the state, according to the Michigan Department of Health and Human Services.

"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 and one in 2022. There were also 12 cases of the West Nile Virus reported last year, officials said.

While the current dry weather conditions have limited the number of biting mosquitos, spring mosquitos that emerged in early May are still active in portions of Michigan, especially in areas with large tracts of woodland habitat, officials said.

While the Jamestown Canyon Virus is found throughout much of the U.S., cases have been increasing in the Midwest, officials said.

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.