Mosquito-Borne Virus Detected In Michigan Mosquitoes, State Says

LANSING, MI — The first mosquito-borne virus of 2021 has been detected in Michigan mosquitoes, the Michigan Department of Health and Human Services confirmed Friday afternoon.

Mosquitoes recently collected in Bay, Oakland and Saginaw counties have tested positive for Jamestown Canyon virus (JCV) at the MDHHS Bureau of Laboratories, officials said. These are the first infected mosquito pools detected for 2021.

“It only takes one bite from an infected mosquito to cause a severe illness,” said Dr. Joneigh Khaldun, Michigan's chief medical executive and chief deputy director for health at MDHHS. “We urge Michiganders to take precautions such as using an EPA-registered insect repellent when outdoors, avoiding areas where mosquitoes are present if possible and wearing clothing to cover arms and legs to prevent bites.”

Every summer in Michigan, bites from mosquitoes carry the risk of spreading diseases to people and animals, officials said in a news release Friday. JCV sickened three Michiganders in 2020; 32 cases of the West Nile Virus and four cases of Eastern Equine Encephalitis also were reported, resulting in two deaths.

Authorities said the best way to protect against mosquito-borne illnesses is to prevent mosquito bites.

The JCV virus is spread to people through bites from infected mosquitoes. Most cases occur from late spring through mid-fall.

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

JCV can be spread by mosquitoes that become infected when they feed on deer or other animals that have the virus in their blood. Infected mosquitoes spread the virus to other animals or people through bites. Arboviruses including WNV and EEE virus spread when mosquitoes contract the virus from biting infected birds then biting a human.