A Massachusetts man is the first person this year to be diagnosed with EEE, a rare mosquito-borne virus that can cause personality changes, paralysis, and death

Gabby Landsverk
A female Aedes aegypti mosquito is seen on the forearm of a health technician in a laboratory conducting research on preventing the spread of the Zika virus and other mosquito-borne diseases, at the entomology department of the Ministry of Public Health in Guatemala City, February 4, 2016. REUTERS/Josue Decavele

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  • A man in Massachusetts has been diagnosed with a mosquito-borne virus that causes a rare, life-threatening disease. It's also been found in mosquitoes in Florida, New York, and Delaware.
  • Eastern equine encephalitis, or EEE, kills 3 out of 10 people infected, and can cause permanent brain damage in the form of mental impairment, seizures, and personality disorders in survivors. 
  • There is no known treatment, but certain precautions can help prevent it.
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A rare virus that causes brain damage has just been confirmed in a man in Massachusetts, the first human case in the state since 2013, CNN reported. The virus has also been found this summer in mosquitoes in Florida, New York, and Delaware.

On July 25, Orange County, Florida, officials warned the public about an increase in mosquito activity and said that chickens in the area had tested positive for eastern equine encephalitis virus, or EEE, according to a press release

Just days earlier in New York, Oswego County officials said EEE was discovered in two mosquito pools from a swamp about 20 miles north of Syracuse in a town called West Monroe, according to Syracuse.com.

Meanwhile, in southeastern Massachusetts, a total of 22 communities in Plymouth and Bristol county are at high risk for the virus, according to health officials, WCVB reported. The virus was also confirmed in mosquitoes south of Boston — in Easton, Freetown, and New Bedford, the Boston Globe reported. 

And across Delaware, sentinel chickens (used to monitor for mosquito-borne illnesses) have also tested positive for EEE, according to Delaware Online.

Besides the case in Massachusetts, no other human infections have been reported this season.

Read more: Diseases from ticks and mosquitoes have tripled in the US — and warmer weather means it will probably keep getting worse

EEE is a rare but life-threatening virus that can wreak havoc in livestock and cause permanent brain damage in people, resulting in seizures, mental impairment, and even personality changes in survivors of the disease.  

It is most often found in the northeastern United States in swampy, wooded areas from late spring to early fall. It can also be found in Florida, Mississippi, Louisiana, Alabama, and Texas into the winter months.

There is no cure, but the disease, as well as others transmitted by mosquitoes, can be prevented by taking precautions against mosquito attacks. Here's what you need to know about EEE.

EEE is dangerous because it can inflame the brain

Only about 5 to 10 human cases of EEE are reported in the U.S. each year, according to the Centers for Disease Control and Prevention. But about 30% of cases are fatal, and survivors are often left with permanent brain damage. 

After it's been transmitted via a mosquito bite, the virus can cause inflammation of the brain (encephalitis), which is what makes it so dangerous and potentially fatal. 

If a mosquito with the virus bites you, you can experience symptoms like headache, high fever, chills, and vomiting four to 10 days afterward, according to the CDC. You'll know it's not something like the flu since it suddenly progresses into more serious symptoms like disorientation and convulsions. 

A blood test or spinal fluid sample can diagnose the infection. Although there's no cure, patients should be hospitalized so symptoms can be treated. If the infection doesn't reach the brain, people can make a complete recovery within weeks.

However, if the brain does become inflamed, brain damage can be permanent and cause long-term problems like confusion, memory loss, changes in personality and mood, paralysis, and intellectual impairment. About a third of patients with EEE die, either within weeks of getting this disease or years later as a result of ongoing physical and mental impairment.

bug spray

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Use bug spray with DEET or lemon eucalyptus to protect yourself

Anyone can get the disease, but people who work outside are particularly likely to be bitten by mosquitoes, and children and the elderly are most likely to have severe cases of EEE. 

You can prevent all mosquito-borne illnesses by using effective bug spray (with DEET or lemon eucalyptus) while outside, and wearing long pants and sleeves, according to the CDC.

Health officials also recommend eliminating mosquito habitats where possible. That means getting rid of standing water from containers around the home like flower pots, gutters, recycling containers, wheel barrows, and birdbaths. Also make sure your screens don't have any holes or tears so that they keep mosquitoes outside. 

Read more: 

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Now that it's summer, here's everything you need to know about preventing diseases from ticks and mosquitoes