Health officials are warning residents in Southwest Michigan to try to limit outdoor activities around dusk after four new cases of Eastern Equine Encephalitis in humans have been confirmed. Two of the new cases, in Cass and Van Buren counties, were fatal.

The Michigan Department of Health and Human Services is urging residents of Barry, Cass, Van Buren, Berrien and Kalamazoo counties to be especially careful.

As of September 16, there have been seven confirmed cases in humans with onset dates in July.

There have been nine cases of the disease in horses in Barry, Kalamazoo, Lapeer and St. Joseph counties. Health officials say none of the horses had been vaccinated and all died.

Five deer in Barry, Cass, Genesee, Kalamazoo, and Van Buren counties with EEE were euthanized because of the severity of their symptoms.

The department is urging local officials in the impacted counties to consider postponing, rescheduling or cancelling outdoor activities that happen at or after dusk, including late night sports practices, games or outdoor music practices.

The recommendations are a precaution that applies until the first hard frost of the year.

“Michigan is currently experiencing its worst Eastern Equine Encephalitis outbreak in more than a decade,” said Dr. Joneigh Khaldun, MDHHS chief medical executive and chief deputy for health. “The ongoing cases reported in humans and animals and the severity of this disease illustrate the importance of taking precautions against mosquito bites.”

Here are steps you can take to avoid mosquito bites:

• Apply insect repellents that contain the active ingredient DEET, or other U.S. Environmental Protection Agency-registered product to exposed skin or clothing, and always follow the manufacturer’s directions for use
• Wear 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 mosquitoes outside
• Empty water from mosquito breeding sites around the home, such as buckets, unused kiddie pools, old tires or similar sites where mosquitoes may lay eggs
• Use nets and/or fans over outdoor eating areas

For more information about mosquito-borne diseases, visit Michigan.gov.