The Michigan Department of Agriculture and Rural Development (MDARD) reported Michigan’s first case of Eastern equine encephalitis (EEE) in a domestic animal for 2024.
The disease was detected in a Standardbred filly from Van Buren County; the horse was unvaccinated against EEE. This case highlights the importance for all Michiganders to take precautions to protect their animals and themselves from mosquito bites.
”While this is the first case of EEE detected this season, other mosquito-borne diseases have been discovered throughout Michigan, including one human case of West Nile virus,” said State Veterinarian Dr. Nora Wineland, DVM, MS, DACVPM. “These detections clearly indicate disease is circulating in the state’s mosquito population, making it crucial to protect animals and people against these insects. Preventing mosquito bites will prevent mosquito-borne diseases.”
EEE is a zoonotic, viral disease transmitted through the bites of mosquitoes to both animals and people. Cases of the disease are typically seen in late summer to early fall each year in Michigan. Mosquito-borne diseases, like EEE, are not spread by horse-to-horse or horse-to-human contact.
”It only takes one bite from an infected mosquito to cause a severe illness,” said Dr. Natasha Bagdasarian, MDHHS chief medical executive. “We urge Michiganders to take precautions such as using an EPA-registered insect repellent when outdoors, avoiding areas where mosquitoes are present if possible, and wearing clothing to cover arms and legs to prevent bites. EEE is one of the most dangerous mosquito-borne diseases in the United States, with a 33% fatality rate in people who become ill.”
This year in Michigan, while there are no additional detections of EEE in animals or humans, West Nile virus (WNV) was detected in 48 mosquito pools, 12 wild birds, and one human. For the latest information on cases of mosquito-borne diseases in Michigan, please visit michigan.gov/emergingdiseases for weekly summaries.
To prevent the occurrence of mosquito-borne diseases in horses and other animals, owners can:
- Talk to a veterinarian about vaccinating horses against EEE, WNV, and other mosquito-borne diseases.
- Eliminate standing water—i.e., fill in puddles, repair eaves, and change the water in buckets and bowls at least once a day.
- Place livestock in a barn under fans (as mosquitoes are not strong flyers) and pets inside the home during peak mosquito activity from dusk to dawn.
- Use an insect repellant on animals that is approved for the species.
- Contact a veterinarian if an animal shows signs of illness.
- If a Michigan animal is suspected of having EEE or WNV, funding is available under an arbovirus grant to cover these testing costs. Please contact MDARD at 800-292-3939 for more details.
Also, Michiganders can stay healthy by using simple, effective strategies to protect themselves and their families. The following steps are recommended to avoid mosquito-borne diseases:
- Apply insect repellents that contain the active ingredient DEET or other EPA-approved products to exposed skin or clothing. Always follow the manufacturer’s directions for use.
- Wear light-colored, 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, and other water-holding containers where mosquitoes can lay eggs.
For more information about EEE, please visit www.michigan.gov/EEE.