The Massachusetts Department of Public Health has said a man in his 60s has been diagnosed with Eastern Equine Encephalitis.
Officials said the man was from the Metrowest area of Middlesex County. He became ill on July 28 after traveling out of state to the mid-Atlantic region of the U.S.
The man told health officials that he received a significant number of mosquito bites while participating in outdoor activities.
The man was hospitalized and released.
Officials said he lives in an area that is considered low risk for EEE.