Massachusetts DoH confirms first case of positive EEE mosquito sample from recent test in Carver

“BOSTON — The Massachusetts Department of Public Health (DPH) today announced that Eastern equine encephalitis (EEE) virus has been detected in mosquitoes in Massachusetts for the first time this year. The presence of EEE was confirmed in mosquito samples collected on June 30 in the town of Carver in Plymouth County. No human or animal cases of EEE have been detected so far this year.

Today’s finding increases the risk level of EEE to moderate in the communities of Carver, Kingston, Middleborough, Plymouth, Plympton, and Wareham.

“The last EEE outbreak cycle in Massachusetts occurred in 2019-2020 and since then, there have been no human cases of EEE reported in the state,” said Public Health Commissioner Robbie Goldstein, MD, PhD. “Today’s finding alerts us to the presence of EEE in Massachusetts this year. Combined with yesterday’s announcement of West Nile virus in mosquitoes in Massachusetts, we are asking everyone to take the necessary precautions to prevent mosquito bites. We recommend that people use mosquito repellent when they are spending time outdoors so they can celebrate the July 4th holiday and enjoy the rest of the summer without being bitten.”

EEE is a rare but serious and 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; in 2020, there were five human cases and one death. There were no human cases of EEE in Massachusetts in 2021, 2022 or 2023.

“EEE activity in Massachusetts tends to occur in outbreak cycles,” said State Epidemiologist Dr. Catherine M. Brown. “When EEE is found in mosquitoes like this at the start of the season, the risk may increase throughout the rest of the summer. We rely on our mosquito surveillance program to monitor for the presence of virus to let people know when and where the risk is occurring.”