EDITOR'S NOTE (Sept. 26, 2019, 5:35 p.m.): Health officials said Thursday that the fourth death was based on an incorrect report. There have been three EEE-related deaths in Massachusetts so far in 2019.
A fourth person this year has died from EEE in Massachusetts, health officials announced Wednesday.
A man in his 70s from Essex County died from the mosquito-borne illness, according to the Massachusetts Department of Public Health.
The 11th human case diagnosed in the state this year has also been confirmed as a Worcester County resident.
Last week, state health officials said a man in his 70s from Bristol County had become the second person to die from the virus. Officials in Freetown said the patient was a resident of that town.
Massachusetts' second human case of West Nile virus of the year was also announced last week.
Both viruses are transmitted by mosquitoes, and Massachusetts, as well as neighboring states, have been aerially spraying pesticides to tamp down the insect's populations.
There are 35 Massachusetts communities at critical risk for human EEE transmission and 46 at high risk. See a map of at-risk parts of Massachusetts here.
The virus the insects can transmit affects the nervous system and kills about three in 10 people who contract it, according to the U.S. Centers for Disease Control and Prevention.
Many communities at critical or serious risk of EEE transmission in Massachusetts have curtailed outdoor activities at dusk, when mosquitoes are most active, until the first frost hits.
Frosts can seriously diminish mosquito populations, while freezes wipe them out.
This is the first outbreak in Massachusetts since 2012. There were 22 human cases in outbreaks from 2004-2006 and 2010-2012.
CORRECTION (Sept. 26, 2019, 5:41 p.m.): An earlier version of this story misidentified the person health officials had said was the fourth EEE-related death in Massachusetts.