Mosquitoes in Michigan Spread Dangerous EEE Virus

The virus has been confirmed in one person and 32 animals.

Mosquito on human skin
The EEE virus can only be spread through the bite of an infected mosquito. Renaud Visage / Getty Images

As if the coronavirus weren’t enough, another disease is making headlines in Michigan. The Eastern equine encephalitis (EEE) virus has been confirmed in 13 counties in the state. The rare virus causes one of the most dangerous mosquito-borne illnesses in the U.S., with a 33% fatality rate for people who become sick.

As of Sept. 22, health professionals in Michigan have confirmed EEE in one person in Barry County. There also have been 32 animal cases in 30 horses and two deer. There is a vaccine for horses, but not for people. The disease has a 90% fatality rate for horses that become infected.

In making the announcement, the Michigan Department of Health and Human Services (MDHHS) urged residents to take precautions to protect themselves from mosquito bites, including staying indoors after dusk. 

“This suspected EEE case in a Michigan resident shows this is an ongoing threat to the health and safety of Michiganders and calls for continued actions to prevent exposure, including aerial treatment,” said Dr. Joneigh Khaldun, chief medical executive and chief deputy for health at MDHHS. 

“MDHHS continues to encourage local officials in the affected counties to consider postponing, rescheduling or canceling outdoor activities occurring at or after dusk, particularly those involving children to reduce the potential for people to be bitten by mosquitoes.”

As of Sept. 23, more than 63,000 acres in high-risk areas of Michigan have been covered with aerial mosquito control treatment. More areas are scheduled to be treated.

How EEE Virus is Spread

According to the Centers for Disease Control and Prevention (CDC), the EEE virus can cause encephalitis, which is a rare inflammation of the brain. Although some people show no symptoms, typically symptoms are similar to the flu, including fever, chills, and joint or muscle pain.

In the U.S., between five to 10 cases are reported each year. Most cases have been reported from the Gulf Coast and Atlantic states, although cases also have been noted in the Great Lakes region. According to MDHHS, more than 25 percent of the nation’s EEE cases in 2019 were diagnosed in Michigan.

As of Sept. 22, seven confirmed cases of EEE have been reported to the CDC in 2020 including the one in Michigan, four in Massachusetts, and two in Wisconsin.

EEE can only be transmitted by the bite of an infected mosquito. Some of the mosquitoes that can spread the virus to humans include the Aedes, Coquillettidia, and Culex species. EEE can't be spread from person to person or from horses to people.

To reduce your chances of getting infected with the EEE virus, the CDC and MDHHS suggest:

  • Use insect repellent containing DEET, picaridin, IR3535, or oil of lemon eucalyptus on exposed skin and/or clothing. Always follow the directions on the package.
  • Wear long sleeves and pants when outdoors. Apply insect repellent to clothing to help repel mosquitoes.
  • Keep screens on windows and doors to keep out mosquitoes.
  • Empty water from mosquito breeding sites around the home, including flowerpots, buckets, unused wading pools, and old tires.
  • Use nets and/or fans over outdoor eating areas.