The virus has been found in 92 mosquito samples this year, the Massachusetts Department of Public Health said Wednesday, and one-third of them are from a species that can spread the virus to people.
“We’re raising the risk level because there is more activity than we typically see and it is happening early in the season,” Public Health Commissioner Monica Bharel said in a statement.
Although no human or animal cases of EEE have been detected in the state this year, officials are cautioning people to avoid getting bitten by mosquitoes.
“We take EEE very seriously and this year we are concerned about the risk,” state epidemiologist Catherine Brown said in the statement. “It is important for residents to know that in communities at high risk for EEE, we strongly encourage rescheduling evening outdoor events to avoid the hours between dusk and dawn when mosquitoes are most active.”
Last week, Florida health officials also issued a warning about the virus after several sentinel chickens tested positive.
The disease is rare
Only about seven cases of the EEE virus in humans are reported in the US every year, the US Centers for Disease Control and Prevention says. However, the disease can be fatal: About 30% of those who contract it die, according to the CDC. Many survivors have ongoing neurologic problems.
Infected people develop symptoms about four to 10 days after they are bitten by an infected mosquito, the CDC says. Signs include sudden headache, high fever, chills and vomiting. More severe symptoms include disorientation, seizures and coma.
How to stay safe
Freetown, one of the affected communities, has closed all public spaces from dusk through dawn, when mosquito activitiy is at its peak.
Health officials urge people to apply insect repellent and wear protective clothing when outdoors, drain standing water around their homes and install screens in windows.