Massachusetts Health Officials Announce First Human Case of EEE in State Since 2000

BOSTON — The Massachusetts Department of Public Health (DPH) recently announced the first human case of eastern equine encephalitis (EEE) in Massachusetts this year. The person is a male in his 80s who was exposed in Worcester County. As a result, the risk level in the communities of Douglas, Oxford, Sutton, and Webster has been raised to critical, and in Dudley, Northbridge, and Uxbridge, the risk is increased to high.

The neighboring communities of Auburn, Charlton, Grafton, Leicester, Mendon, Millbury, Millville, Southbridge, and Upton are now considered at moderate risk.

The season’s first EEE-positive mosquitoes in Massachusetts were announced on July 3 from Carver. There also have been EEE-infected mosquitoes previously identified in Abington, Halifax, Kingston, Middleborough, Plymouth, Wareham, and Whitman in Plymouth County; Taunton and Westport in Bristol County; Barnstable in Barnstable County; Dedham in Norfolk County; Sudbury in Middlesex County; and Amesbury and Haverhill in Essex County.

“This is the first time we have seen a person infected with EEE in Massachusetts since 2020,” Public Health Commissioner Dr. Robbie Goldstein said. “EEE is a rare but serious disease and a public-health concern. We want to remind residents of the need to protect themselves from mosquito bites, especially in areas of the state where we are seeing EEE activity.”

Though rare, EEE is serious and a potentially fatal disease that can affect people of all ages. EEE is generally spread to humans through the bite of an infected mosquito. There were 12 human cases of EEE in Massachusetts in 2019 with six deaths, and five human cases with one death in 2020. There were no human cases of EEE in Massachusetts in 2021, 2022, or 2023.

“The risk from EEE is high in parts of Plymouth County and critical in parts of Worcester County,” State Epidemiologist Dr. Catherine Brown noted. “In addition to recommending that people use mosquito repellent with an EPA-registered active ingredient and clothing to reduce exposed skin, we also recommend that evening outdoor events be rescheduled to avoid the hours between dusk and dawn. The mosquitoes most likely to spread EEE are most active during the dusk to dawn hours.”