Massachusetts Mosquito Virus: Eastern Equine Encephalitis Explained

A rare but deadly mosquito-borne disease called eastern equine encephalitis has caused nearly a dozen towns in Massachusetts to shut public parks and restrict outdoor activities at dawn and dusk when the insects are most active.
A 41-year-old man in Hampstead, New Hampshire, has died as a result of the infection, local health authorities report, and another man in his 80s in Worcester County, Massachusetts, has also been hospitalized.
But how worried should we be about this disease?
“Humanity is scared by invisible things, and this is an invisible thing,” Joseph Vinetz, a professor of Medicine, Anthropology and Epidemiology at Yale School of Medicine, told Newsweek.
“It’s a really rare thing, but it’s a thing. You get this mysterious illness when people basically die from brain inflammation, which is what encephalitis is, or recover from it after being symptomatic. It’s a bad, bad disease, but it’s a really rare one.
“We get a couple of cases every year, and people get scared, but it’s maybe out of proportion to the real threat.”
Eastern equine encephalitis, also known as “Triple E,” is a viral infection spread by mosquitoes. In severe cases, the virus can cause inflammation of the brain, which can be fatal. According to the U.S. Centers for Disease Control and Prevention, 30 percent of those who contract the disease die, and many go on to have neurological problems.
However, these figures may not truly represent the actual number of infections.
“When you see an actual case, it’s sort of the tip of the iceberg of all the infections because most cases are not diagnosed,” Vinetz said. “Most cases are either a fever that goes away, or it’s not clear if there’s any apparent infection.”
According to the CDC, symptoms of Triple E include fever, headaches, vomiting, diarrhea, seizures, changes in behavior and drowsiness.
So far, Oxford, Douglas, Sutton and Webster, Massachusetts, have announced that they are at “critical risk” of Triple E, urging residents to avoid outdoor activities during peak biting times.
Until September 30, outdoor activities should finish by 6 p.m., shifting to 5 p.m. in October until the first hard frost.
The town of Plymouth, roughly 40 miles southeast of Boston, is closing outdoor recreation facilities from dusk until dawn every day after a horse was found to be infected with the disease.
But what else can you do to protect yourself from Triple E?
“There’s no vaccine, and there’s no treatment because who is going to spend $500 million developing a vaccine for a disease that is so rare?” Vinetz said.
“[To protect yourself] you have to avoid mosquito bites. So, if you’re in southeastern Massachusetts or Northern Connecticut, you should put on insect repellents if you’re going to sit on your porch at dusk, which is when the mosquitoes like to bite. DEET-containing insect repellents are useful.”
The CDC also recommends wearing long-sleeved shirts and pants and treating gear and clothing with mosquito repellent.
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