A horse in West Tennessee has tested positive for eastern equine encephalitis, a virus that can be fatal for horses and humans. The Tennessee departments of Agriculture and Health are advising citizens to take precautions to protect themselves and their livestock.

The horse in Gibson County showed signs of illness. Testing confirmed it was suffering from EEE, and the horse was euthanized.

Mosquitoes transmit EEE. An infected horse cannot directly transmit the virus to other horses or humans through contact. However, mosquito-borne diseases do pose a public health risk. Tennessee had the first documented human case of EEE in a resident of Hamilton County earlier this summer. This recent equine case serves as a reminder that mosquito season is not over yet.

“Mosquitoes may remain active across Tennessee until temperatures fall below freezing,” said Tennessee Department of Health Deputy State Epidemiologist John Dunn, D.V.M., PhD. “The best ways for people to protect themselves from mosquito bites are to wear insect repellent, wear long sleeves and long pants, drain standing water around homes and businesses, and avoid peak times when mosquitoes bite at dusk and dawn.”

Although there is no vaccine for humans, the EEE vaccine for equines is particularly effective to prevent infection in horses. Every horse owner should speak with their veterinarian to develop an appropriate vaccination plan.

“EEE is a devastating illness, with up to 95 percent mortality in infected horses,” State Veterinarian Dr. Samantha Beaty, D.V.M. said. “While you may not be able to completely prevent mosquito bites on your horses, appropriate vaccines are vital to safeguarding their health and protecting them from EEE and other insect-borne diseases.”

Livestock owners should always monitor their animals and contact a veterinarian if an animal appears sick. Equine symptoms of EEE may include lethargy, weakness, loss of appetite, fever, and/or colic.

To minimize risk of insect bites around your farm, use insect repellent for livestock and eliminate sources of standing water where insects congregate and breed.

TDH offers the following tips to protect people from mosquito bites:

Use repellants that contain DEET, picaridin, oil of lemon eucalyptus, or IR3535, following all label recommendations for use. 

Wear closed shoes with socks, along with long-sleeved, light-colored shirts and pants.

Avoid perfumes, colognes, and products with fragrances that might attract biting insects.

The state veterinarian is responsible for monitoring for and preventing the spread of animal disease, as well as promoting animal health in Tennessee. The office works with private veterinarians, animal pathologists and disease diagnostic laboratories to identify diseases and determine the cause of animal deaths.

TDA and TDA work closely together to help protect the health of animals and people as part of the Tennessee One Health Committee. One Health seeks to improve communication and encourage collaboration among veterinarians, physicians, environmental scientists, public health professionals, and others to find solutions to shared challenges such as emerging infectious diseases, antibiotic resistance, and emergency preparedness.