A man in his 50s has contracted the state’s fourth confirmed human case of eastern equine encephalitis this year after he was exposed to the mosquito-borne disease, also known as EEE, in a high-risk part of Middlesex County, state health officials said Monday.
The man’s name and the town where he lives were not immediately released.
Last week, the third confirmed human case off EEE was detected in central Middlesex County. In August, a man in his 80s who was exposed in Worcester County, and a woman in her 30s from Plymouth County contracted the disease.
Also last month, a 41-year-old New Hampshire man became that state’s first fatal case of EEE in a decade.
Parts of Middlesex, Worcester, and Plymouth counties remain at high or critical risk for the infection, according to a statement from the Department of Public Health.
“This year’s EEE season has been particularly active and is generating a lot of concern in communities across Massachusetts,” Dr. Robbie Goldstein, the state’s public health commissioner, said in the statement. “While EEE remains a rare disease, the risk level is elevated in multiple communities.”
Residents are asked to reschedule outdoor activities from dusk to dawn to avoid peak mosquito hours, as forecasts call for warm weather in the next few days.
Public health officials have found 91 EEE-positive mosquito samples across the state this year in Bristol, Essex, and Middlesex counties, along with Plymouth and Worchester counties, where the most activity has been focused, officials said.
The last outbreak of EEE in Massachusetts lasted from 2019 to 2020 and led to 17 human cases and seven deaths, officials said.
More information, including all EEE positive results, can be found at www.mass.gov/mosquito-borne-diseases, which is updated daily, or by calling the DPH Division of Epidemiology at 617-983-6800.
Kiera McDonald can be reached at kiera.mcdonald@globe.com.