Horse Tests Positive for EEE Virus in Town of Vienna
A yearling horse has tested positive for Eastern equine encephalitis virus (EEE) in the Town of Vienna. The horse developed neurological symptoms on August 27, 2025, a blood sample was sent to Cornell Lab for testing, and positive test results were reported on August 28, 2025. The horse was euthanized; it was up to date on vaccinations.
Oneida County Health Department (OCHD) conducted mosquito surveillance this summer to track EEE and other mosquito-borne diseases. No positive samples were found.
EEE is a rare but serious viral disease. EEE is transmitted by the bite of an infected mosquito to horses and humans. EEE is not spread person-to-person, from people to animals or from animals (other than mosquitoes) to people.
Anyone can be infected with EEE if bit by an infected mosquito. Symptoms range from mild to severe. Some do not experience symptoms and others could experience headache, fever, chills, body aches, vomiting and may progress into disorientation, seizures, encephalitis (inflammation of the brain), coma and death. People under the age of 15 and over the age of 50 are at higher risk for severe illness if infected.
“There is no human vaccine for EEE, so people should take measures to reduce exposure around their homes and the chances of being bitten by mosquitoes,” said Oneida County Public Health Director, Daniel W. Gilmore, Ph.D., MPH. “OCHD recommends being vigilant when outdoors during dawn and dusk, as that is when mosquitoes are active. Use insect repellents and wear long pants, long-sleeved shirts, shoes and socks and eliminate standing water around the home.”
OCHD has water soluble pouches, available for Oneida County residents. These pouches help reduce mosquitoes near your home by treating standing water. They can be picked up at the Environmental Health office located on the 4th Floor at the Adirondack Bank Building, 185 Genesee Street, Utica between the hours of 8:30 a.m. and 4:30 p.m.
Vaccines are available to help protect horses from getting sick and horse owners should talk with their veterinarian. In addition, exposure can be reduced by frequently changing water in troughs and buckets and eliminating other standing water sources.
For more information, visit https://oneidacountyny.gov/departments/health/programs-and-services/environmental-health/vector-borne-disease-surveillance/.
