Eastern Equine Encephalitis: Vermont Surveillance Shows No Animal or Human Cases

Eastern equine encephalitis (EEE) remains an important One Health threat in Vermont, but current state surveillance does not support reporting a 2026 “resurgence” in human or animal cases.

The Vermont Department of Health’s latest available surveillance update reports no animal cases and no human cases of EEE in 2026. It also reports zero EEE-positive mosquito pools year-to-date through August 1, although surveillance continues during mosquito season.

EEE virus is transmitted by infected mosquitoes and can cause severe neurological disease in both horses and humans. Vermont recorded two horse deaths from EEE in 2024, while that year also saw the state’s first two human cases since 2012.

The current situation therefore warrants continued veterinary and public-health surveillance rather than characterization as a confirmed 2026 resurgence. Vermont conducts regular mosquito testing and monitors human and animal illness throughout the summer and early autumn.

Why it matters for animal health

For horse owners, EEE remains a serious seasonal risk because vaccination is available for horses, while there is no human EEE vaccine or specific antiviral treatment. Mosquito-bite prevention and timely veterinary attention remain central to risk management.