Massachusetts' deadly mosquito virus threatening local towns: What to know

A deadly – yet rare – disease spread by mosquitoes has officials in several Massachusetts towns urging people to avoid going outdoors at night.

The disease, called eastern equine encephalitis (EEE), was caught by a man in his 80s in what was the first human case found in Massachusetts since 2020.

Here’s what to know about the mosquito-borne disease. 

Massachusetts’ deadly mosquito virus

The town of Plymouth, located about 40 miles southeast of Boston, announced on Friday that it was closing public outdoor recreation facilities from dusk until dawn each day after a horse in the town was infected with the disease.

Meanwhile, state health officials warned that a cluster of four towns south of Worcester — Douglas, Oxford, Sutton and Webster — are at "critical risk" after a man from Oxford caught the virus.

State and local health officials urged people in those towns to avoid the peak mosquito biting times by finishing outdoor activities by 6 p.m. until Sept. 30 and then by 5 p.m. after that, until the first hard frost.

They also recommend that people across Massachusetts use mosquito repellents when outdoors and drain any standing water around their homes.

Jennifer Callahan, Oxford's town manager, wrote in a memo that the family of the man who caught the virus in mid-August had reached out to her office.

"They want people to be aware this is an extremely serious disease with terrible physical and emotional consequences, regardless if the person manages to live," Callahan wrote.

She said the infected person had often recounted to his family how he never got bitten by mosquitoes. But just before he became symptomatic, he told them he had been bitten. She said the man remains hospitalized and is "courageously battling" the virus.

Callahan said the family is urging people to take public health advice seriously and to do their utmost to protect themselves.

RELATED: Dr. Anthony Fauci hospitalized for West Nile virus

What to know about eastern equine encephalitis (EEE)

The presence of EEE in Massachusetts this year was confirmed in July in a mosquito sample, and has been found in other mosquitoes across the state since then. 

In a 2019 outbreak, there were six deaths among 12 confirmed cases in Massachusetts. The outbreak continued the following year with five more cases and another death.

There are currently no vaccines to prevent EEE, nor medicines to treat it.

According to the U.S. Centers for Disease Control and Prevention, EEE is rare – but it is very serious. About 30% of people who become infected die, and many survivors have ongoing neurologic problems, the agency says.

Only a few cases of EEE are reported in the U.S. each year, with most infections found in the eastern and Gulf Coast states, according to the CDC.

It’s spread to people through the bite of an infected mosquito. The disease is prevalent in birds, and although humans and some other mammals can catch EEE, they don't spread the disease, the CDC says.

Symptoms of EEE include fever, headache, vomiting, diarrhea and seizures.

Fauci hospitalized for West Nile virus symptoms

Meanwhile, Dr. Anthony Fauci, the public face of the U.S. coronavirus pandemic response, was hospitalized earlier this month with the West Nile virus (WNV), a spokesperson for Fauci told FOX News last week.

Fauci, 83, was hospitalized before he returned home where he is now recovering, the spokesperson added.

He's expected to make a full recovery from the virus, which is most commonly spread through the bite of an infected mosquito, according to the CDC. Fauci was in hospital for six days. 

The virus first entered the U.S. in 1999, and it has become the leading cause of mosquito-borne disease in the country, per the CDC.

Symptoms include fever, headache, body aches, vomiting, diarrhea or rash, although a vast majority — around 80% — of the people who contract WNV will not experience any symptoms. 

Similar to EEE, there are no vaccines or treatments for the virus.

In most cases, the virus is spread when Culex mosquitoes bite infected birds and then bite people and other animals, per the CDC’s website. More than 1,800 people were hospitalized with the virus last year in the U.S., leading to 182 deaths, per CDC data.