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The disease, known as Triple E, is rare. The mosquitos carrying it tend to live in swampy areas and in places where horses live. Getty Images
  • There have been seven reported cases of Eastern equine encephalitis disease in people in the United States so far this year.
  • The mosquito-borne illness, known as Triple E, is rare but deadly, attacking the brain after it has infected a person.
  • Experts say avoid swampy or brackish water where mosquitoes might live and empty water from items such as old tires and birdbaths.

It might just be one of the most important deadly diseases you’ll never encounter.

But it also may be one you should truly understand, this year more than ever.

In an average year, the United States sees seven confirmed human cases of Eastern equine encephalitis.

However, this year there have already been seven reported cases in people, and some experts are concerned.

“It certainly has appeared on our radar screen (this year),” Dr. William Schaffner, MD, a professor of infectious diseases at Vanderbilt University in Tennessee, told Healthline.

Triple E, as the disease is called, has been reported in humans this year in two states.

Massachusetts has four cases, including one involving the death of a woman over the age of 50. These are the first Triple E cases in that state since 2013.

In Michigan, there are three reported infections.

In Florida, there are cases reported in horses.

Schaffner says that because there will probably never be a time when Triple E is eradicated, it’s smart for the public to understand what the disease is, how it happens, and what people can do to avoid contact.

The odds of a person contracting Eastern equine encephalitis are about the same as hitting the Powerball jackpot, Schaffner notes.

“It really is a bit of rare bad luck,” he said.

What has to happen is this.

The virus itself grows in birds that live in or near freshwater swamps.

A certain type of mosquito called a Culiseta melanura must bite one of those infected birds. These mosquitoes don’t often have a taste for humans.

However, they bite other birds and other animals.

Triple E isn’t transmitted to humans by horses. However, infected mosquitoes often are attracted to horses, meaning there could be a higher chance of coming across one near horses.

When a mosquito with a taste for birds, animals, and humans comes in contact with the virus, there’s a chance the disease will spread to people.

Once a person is infected, Schaffner said, the situation is dire.

“Unfortunately, this virus has an attraction for the central nervous system. It goes through the blood stream, finds the brain, and then says ‘Oh, I’ll get off here,’” he said.

In the brain, Schaffner said, the virus gets to work quickly, multiplying in numbers and eating away at the brain.

The fatality rate for Triple E is about 30 percent. And of those who do survive, a high percentage live on with prolonged disabilities such as spastic muscles and the loss of cognitive function.

It all sounds terrifying to the general public, Schaffner admits.

But he points out that avoiding Triple E is relatively basic, although not everybody takes precautions.

“The actions are very easy, but you have to take them,” he said.

First, he said, know where it might be lurking. Freshwater swamps are ripe for the disease, so it’s a good idea to be extra cautious around any brackish water.

Even in a yard, it’s smart to empty things such as birdbaths, plastic toys that hold water, and old tires that can collect water.

And whenever you are out, particularly in the early and late hours of the day (mosquitoes love the dawn and the dusk), cover up and use bug spray.

Schaffner suggests you wear long sleeves and long pants (even on warmer days), and then cover yourself in bug spray — not just on all your exposed skin, but also over your clothing as well.

“That’s what it comes down to,” he said. “Covering up and protecting yourself.”

Schaffner doubts there will ever been a vaccination for humans for Triple E.

The cases are simply too few to make it profitable.

Plus, he said, some germs are just part of our world for better or worse.

“The common ecological niche (of this virus) does not involve humans for the most part,” he said.

“And the reality is there are all kinds of viruses that live in their own little niches. We will never eliminate them from our environment, and occasionally humans will blunder into it.”