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Aerial treatment begins tonight to combat Eastern Equine Encephalitis Additional EEE animal cases confirmed in Cass, Calhoun; total is now 9 people, 33 animals

FOR IMMEDIATE RELEASE: Sept. 29, 2019           

CONTACT: Lynn Sutfin, 517-241-2112

LANSING, Mich. – Aerial treatment to combat Eastern Equine Encephalitis (EEE) is scheduled to begin tonight in several Michigan counties after being postponed due to inclement weather on Sept. 29, the Michigan Department of Health and Human Services (MDHHS) has announced.

The areas slated for treatment are identified in the Aerial Treatment Zones Map and include:

  • Area 3-1 in Berrien County.
  • Areas 5-1 and 5-2 in Cass County.
  • Areas 12-1, 12-2 and 12-3 in St. Joseph County.
  • Area 13-1 in Van Buren County.

Please refer to the County-level Aerial Treatment Maps for more details of the identified zones’ locations. 

These schedules are weather dependent and may change. Visit for the most up-to-date information. All other treatment zones will not be treated this evening.

As of Sept. 30, EEE has been confirmed in nine people, with three fatalities, in Barry, Berrien, Calhoun, Cass, Kalamazoo and Van Buren counties. In addition, cases have occurred in 33 animals from 15 counties: Allegan, Barry, Berrien, Calhoun, Cass, Genesee, Jackson, Kalamazoo, Kent, Lapeer, Livingston, Montcalm, Newaygo, St. Joseph and Van Buren. The mosquitos that spread EEE are still active and were caught in traps set Sept. 26 in southwest Michigan. 

“The addition of three new animal cases and recent discovery of mosquitos that carry this virus show this is an ongoing threat to the health and safety of Michiganders and the need for continued actions to prevent exposure, including aerial treatment,” said Dr. Joneigh Khaldun, MDHHS chief medical executive and chief deputy for health.

Aerial treatment is conducted by low-flying aircraft, beginning in the early evening and continuing up until 4:30 a.m. the next morning, in areas of concern. Mosquito control professionals will apply approved pesticides as an ultra-low volume (ULV) spray. ULV sprayers dispense very fine aerosol droplets that stay suspended in the air and kill adult mosquitoes on contact.

EEE is one of the most dangerous mosquito-borne diseases in the United States, with a 33 percent fatality rate in people who become ill. People can be infected with EEE from the bite of a mosquito carrying the viruses.

More information, including a Frequently Asked Questions document, are available at  

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