For Immediate Release: September 8, 2023

Media Contact:

Ben Truman
Vermont Department of Health 802-316-2117 | [email protected]     

Scott Waterman
Vermont Agency of Agriculture, Food & Markets
802-622-4662 | [email protected]


New York Horse with Eastern Equine Encephalitis (EEE) Virus was Infected in Vermont
The year’s first detection of the virus in a mammal means greater risk to people

BURLINGTON, VT – The Department of Health is advising people in Franklin and Grand Isle Counties to take extra precautions to avoid mosquito bites, after a horse tested positive for Eastern equine encephalitis (EEE), a virus that can cause serious and life-threatening illness.

The Clinton County Health Department of New York on Wednesday announced that a horse in Schuyler Falls tested positive for EEE. Before it was transported to New York, the horse was living in Swanton near where mosquitoes had tested positive for EEE. Test samples taken from the horse after it died identified that it was infected with EEE virus, and the incubation period for the disease places it in Vermont when infection would have occurred.

Last month, Vermont officials announced the state’s first detections of EEE virus since 2015. The virus was found among bird-biting mosquitoes collected in pools from Alburg and Swanton. The finding of EEE in a horse indicates the presence of the virus in mosquitoes that also bite mammals, elevating risk of human and animal exposure. Currently, no human cases of EEE have been reported in Vermont. The last confirmed human cases of EEE in Vermont were in 2012 and resulted in the deaths of two people.

Because of this increased health risk, state officials strongly recommend that schools, families, organizations and campgrounds in the Alburgh and Swanton communities limit outdoor activities and events taking place around dawn and dusk, when mosquitoes are most active.

EEE virus is spread through bites from infected mosquitoes. There is no specific treatment or human vaccine for EEE. Most people who are infected will have no or mild symptoms, such as fever, chills, fatigue, joint and body aches. EEE can result in severe illness − including encephalitis, an inflammation of the brain – and can be fatal in about one-third of people who develop severe EEE disease. People with symptoms or who suspect exposure are encouraged to contact their health care provider as soon as they feel sick.

The Vermont Agency of Agriculture Food and Markets collects mosquitoes at locations throughout the state which are tested at the Health Department Laboratory. So far this season 1805 mosquito pools – groups of up to 50 mosquitoes of the same species collected from the same site – have been tested. There have been 10 pools that tested positive for EEE virus over five sites, all from Alburgh (2) and Swanton (3).

State agriculture and health officials are evaluating options for aerial spraying in areas where the positive pools have been identified, should that be deemed the best course of action to protect public health.

The best way to protect yourself and family is to prevent mosquito bites:

  • Wear long-sleeved shirts and pants when outdoors. 

  • Limit your time outside at dawn and dusk when mosquitoes are more likely to bite.

  • Use insect repellent labelled as effective against mosquitoes. The EPA has a tool to help find the right repellent for you. 

  • Get rid of standing water in places like gutters, tires, play pools, flowerpots and bird baths. Wet weather and flooding have led to larger than usual mosquito populations, which breed in water that has been standing for more than four days.

  • Cover strollers and outdoor playpens with mosquito netting.

  • Fix holes in screens and make sure they are tightly attached to doors and windows.

Horse owners should consult with their veterinarians and make sure their animals are properly vaccinated for EEE, West Nile and other viruses spread by infected insects or ticks. Horses cannot spread EEE or West Nile viruses to humans or other horses. In 2012, two unvaccinated horses died from the virus.

For more information about EEE and to see a map of the areas of risk in Vermont, visit

Learn how to prevent mosquito bites at

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