MDHHS confirms human eastern equine encephalitis case

LANSING, Mich. - The Michigan Department of Health and Human Services (MDHHS) has confirmed a locally acquired case of eastern equine encephalitis (EEE) in a Roscommon County resident and reminds Michiganders to take steps to protect themselves against mosquito-borne diseases.

This is the first EEE human case reported in Michigan since 2021. No additional information will be provided about this individual.

State and local health departments, along with the Michigan Department of Agriculture and Rural Development and Michigan Department of Natural Resources, have been monitoring and will continue to monitor for signs of EEE in humans, mosquitos, domestic animals and wildlife. Prior to this case, no animal EEE activity has been detected in Michigan this year. Additional mosquito trapping and testing is underway in Roscommon County to assess the level of risk in the area. Information about human, animal and mosquito pool testing is available in a weekly arboviral report.

“It is vital that Michigan residents take precautions against mosquito bites as mosquitoes can carry diseases that can have devastating health effects,” said Dr. Natasha Bagdasarian, chief medical executive. “EEE is one of the most dangerous mosquito-borne diseases in the U.S., with a 30% fatality rate among people who become ill.”

EEE virus is spread to people by the bite of an infected mosquito. EEE is a rare but serious disease. Only a few human cases are reported each year in the United States.  People who become ill with EEE may experience fever, headache, chills and nausea. In some cases, symptoms may progress to inflammation of the brain, signaled by disorientation, seizures and coma. Physicians treating patients with these symptoms should consider testing for EEE and other mosquito-borne viruses and report suspect cases to their local health department. The MDHHS Bureau of Laboratories offers comprehensive testing for the arboviruses of concern in Michigan.

The best way to prevent EEE, or any other mosquito-borne illness, is to reduce the number of mosquitoes around your home and to take steps to avoid mosquito bites, including:

Use U.S Environmental Protection Agency-registered insect repellents with one of the following active ingredients: DEET, picaridin, IR3535, oil of lemon eucalyptus or para-menthane-diol and 2-undecanone. Follow the product label instructions and reapply as directed.

• Do not use insect repellent on children under 2 months old. Instead, dress your child in clothing that covers arms and legs and cover crib, stroller and baby carrier with mosquito netting.
• Wear shoes and socks, light-colored long pants and long-sleeved shirts when outdoors.
• Make sure doors and windows have tight-fitting screens. Repair or replace screens that have tears or other openings.
• Use bed nets when sleeping outdoors or in conditions with no window screens.
• Once a week eliminate all sources of standing water that can support mosquito breeding around your home, including water in bird baths, abandoned swimming pools, wading pools, old tires and any other object holding water.

For more information on the human health impact of EEE, visit CDC.gov/EEE. For updates on EEE activity in Michigan, visit Michigan.gov/EEE.