Correction: Based on an incorrect report filed by a hospital, a previous version of this story improperly reported a fourth death in Massachusetts. Three people have died. The headline and story have been updated.
The Massachusetts Department of Public Health has reduced the number of deaths in the state from Eastern equine encephalitis from four to three, bringing the nationwide total to nine deaths.
“Based on an incorrect report filed by a hospital, DPH has been notified that the fourth death was improperly reported and the official death count remains at three people,” the state reported in a statement Thursday.
Massachusetts health officials also announced the addition of a 12th case of the disease, a woman in her 70s from Hampden County.
There have also been three deaths in Michigan, two in Connecticut and one in Rhode Island.
Eastern equine encephalitis, known as EEE, is a rare virus transmitted by mosquitoes. There are typically only 5 to 10 human cases reported in the United States each year, according to the US Centers for Disease Control and Prevention. About 30% of all cases result in death. This year there has been an uptick in the number of reported cases, nearly 30 among several states.
Tests also confirmed an 11th human case of the mosquito-borne virus in Massachusetts. The patient is a man in his 70s who lives in Worcester County.
With this latest infection, Massachusetts elevated several more communities to high risk. The communities of Auburn, Charlton, Dudley, Leicester, Southbridge and Spencer are now included in the 46 communities considered to be at high risk. There are also 35 communities at critical risk and 122 at moderate risk.
EEE virus has been found in 422 mosquito samples in Massachusetts this year, according to the department, many in species that are capable of spreading the virus to humans. The mosquitoes can also infect animals. There is a vaccine for horses who get EEE, but there is no vaccine for humans.
“Although mosquito populations are declining at this time of year, risk from EEE will continue until the first hard frost,” said State Epidemiologist Dr. Catherine Brown. “We continue to emphasize the need for people to protect themselves from mosquito bites.”
Massachusetts has done some aerial spraying to kill mosquitoes, but the state is done for this season. The spraying helps reduce the risk of EEE, but the risk will persist until that first hard frost.
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The health department encourages people to wear long pants, socks and long sleeves to reduce the amount of skin exposed to the bugs. Use bug spray and limit outdoor activities to an hour before sunset up until dawn. That’s when the bugs bite the most.