ROSCOMMON COUNTY, Mich. – Michigan health officials are asking residents across the state to protect themselves against mosquitoes after a Roscommon County resident tested positive for Eastern Equine Encephalitis (EEE).
Michigan Department of Health and Human Services (MDHHS) confirmed the case on Wednesday. It is the first human case of EEE reported in the state since 2021.
EEE is a rare but serious disease that spreads to humans via the bite of infected mosquitoes, with only a few human cases are reported each year in the United States. Considered one of the most dangerous mosquito-borne diseases in the U.S., EEE has a 30% fatality rate among people who become ill, said Dr. Natasha Bagdasarian, the state’s chief medical executive.
“It is vital that Michigan residents take precautions against mosquito bites as mosquitoes can carry diseases that can have devastating health effects,” Bagdasarian said.
People under 15 years old and over the age of 50 are at greatest risk of getting severely ill due to EEE, which can cause symptoms such as sudden fever, chills, nausea and body aches.
Those symptoms can progress to severe encephalitis, headaches, disorientation, tremors, seizures, and paralysis. In severe cases, permanent brain damage, comas, and death are also possible, according to MDHHS.
There is no specific therapy for viral encephalitis except supportive care. Anyone who thinks they might have EEE or any of the above symptoms should call a doctor.
State and local health officials are continuing to monitor for signs of EEE in humans, mosquitoes, pets and wildlife across the state, with additional mosquito trapping and testing underway in Roscommon County to determine the level of risk in the area.
Of the 5,420 mosquito pools the state tested in 2026 for arboviruses — viruses transmitted by mosquitoes or other insects — 73 have tested positive. No animals have tested positive for EEE yet this year.
For more information about human, animal and mosquito pool testing in Michigan, check out the state’s weekly arboviral report.
How to prevent mosquito bites
Here’s more information from MDHHS on how 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.