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Aerial treatment continues tonight; additional cases of EEE in horses expands treatment areas and adds Livingston County

MDHHS CONTACT: Lynn Sutfin, 517-241-2112

MDARD CONTACT: Jessy Sielski, 517-331-1151­­

LANSING, Mich. – With the confirmation of six additional horse cases of Eastern Equine Encephalitis (EEE) – a potentially deadly mosquito-borne virus affecting both people and animals – aerial treatment is slated to continue tonight and additional treatment blocks have been added to the overall plan, the Michigan Department of Health and Human Services (MDHHS) announced today.

The new cases of EEE in horses added Livingston County to the list bringing the total to 28 cases in 11 counties. Impacted counties are now Barry, Clare, Ionia, Isabella, Jackson, Kent, Livingston, Mecosta, Montcalm, Newaygo and Oakland. In addition, there is one suspect case of EEE in a Barry County resident.

“These additional cases of EEE in horses underscores the importance of providing aerial treatment in the affected counties,” said Dr. Joneigh Khaldun, chief medical executive and chief deputy for health at MDHHS. “There is an ongoing threat to the health and safety of Michiganders as we know mosquitoes are carrying this potentially deadly disease in these areas. Last year, 10 families were devastated by this disease and we are trying to protect others from being infected.”

“Horse owners are not required to vaccinate their animals for EEE,” said State Veterinarian Nora Wineland, DVM. “With consecutive years of widespread infection, though, EEE vaccinations should be a routine part of their animals’ veterinary care. Like other diseases – especially mosquito-borne diseases that affect both animals and humans – a multi-pronged approach is needed. Addressing mosquitoes, protecting people, and safeguarding animals are all key and require coordinated actions by animal owners, veterinarians, homeowners, parents, and state and local government.”

The newly discovered EEE cases expand or add treatment blocks in Ionia, Jackson, Kent, Livingston and Montcalm counties. Aerial treatment conducted on Sept. 16, covered more than 157,000 acres in Blocks 4-1, 4-2, 8-1, 9-1, 9-2, 9-3 and 9-4.

Areas slated for treatment tonight are identified in the Aerial Treatment Zones Map:

  • Block 5-1 in Kent County.
  • Block 6-1 in Newaygo, Oceana and Muskegon counties and 6-2 in Newaygo County.
  • Block 7-1 in Mecosta County.
  • Block 10-1 in Ionia County.

If time and weather permit, the following areas will also be treated:

  • Blocks 1-1 and 1-2 in Barry County.
  • Block 2-1 in Jackson 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. The most up-to-date information will be posted on All other treatment zones will not be treated this evening. Aerial treatment is conducted using specialized aircraft, beginning in the early evening and continuing up until the following dawn.

The Michigan Department of Agricultural and Rural Development has issued an emergency rule temporarily amending the rule on notification and participation for community pesticide applications for aerial spraying treatment across affected counties.

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 and a 90 percent fatality rate in horses that become ill. People can be infected with EEE and other mosquito-borne diseases from the bite of a mosquito carrying the viruses.

Signs of EEE infection include the sudden onset of fever, chills, body and joint aches which can progress to a severe encephalitis, resulting in headache, disorientation, tremors, seizures and paralysis. Anyone who thinks they may be experiencing these symptoms should contact a medical provider. Permanent brain damage, coma and death may also occur in some cases.

To reduce the potential for people to be bitten by mosquitoes, MDHHS is continuing to encourage local officials in the affected counties to consider postponing, rescheduling or cancelling outdoor activities occurring at or after dusk, particularly activities involving children. To protect the public health, the recommendation is being made out of an abundance of caution, and applies until the first hard frost of the year.

Residents can stay healthy by following steps to avoid mosquito bites:

  • Apply insect repellents that contain the active ingredient DEET, or other U.S. Environmental Protection Agency-approved product to exposed skin or clothing, and always follow the manufacturer’s directions for use.
  • Wear long-sleeved shirts and long pants when outdoors.
  • 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 EEE, visit

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