More than 120,000 people are expected to travel by air through Raleigh-Durham International Airport this holiday weekend. Millions more Americans will be hitting the roads this weekend, with many North Carolinians headed to lakes or the coast.
But as families head to the water, researchers are reminding swimmers about two rare but potentially deadly risks: Naegleria fowleri, commonly known as the “brain-eating amoeba,” and Vibrio vulnificus, sometimes referred to as “flesh-eating bacteria.”
A North Carolina teen died earlier this week after contracting Naegleria fowleri, according to The North Carolina Department of Health and Human Services. Where the teen came into contact with the amoeba has not yet been publicly identified.
NCDHHS separately reports there have been two deaths so far this year tied to Vibrio vulnificus cases as of September 3, the most recent occurring in the past few weeks. Additionally, the state tells WRAL there have been 29 confirmed cases and 83 probable cases of other Vibrio infections, excluding cholera and Vibrio vulnificus.
About 1 in 5 people with Vibrio vulnificus will die, sometimes in as little as 1-2 days, according to the Centers for Disease Control and Prevention. The agency reports when Naegleria fowleri travels up the nose into the brain, it can cause an infection that is fatal 97% of the time.
The risks are different depending on where you swim. Naegleria thrives in warm freshwater, while Vibrio bacteria are naturally found in coastal waters.
Both are rare, but understanding how they happen can help reduce your risk of infection.
Ashley Moseman, an assistant professor of integrative immunobiology with the Duke University School of Medicine, has studied Naegleria fowleri for about a decade.
“These amoebas are very heat loving,” Moseman said. “They grow faster when it’s warm, and so as water temperatures get higher, they can thrive.”
The amoeba is naturally found in freshwater, including lakes, rivers and ponds. Those conditions are especially relevant during North Carolina summers. WRAL meteorologists forecast an especially hot labor day weekend with triple digit temperatures Friday and temps in the mid-90s Saturday.
The CDC reports in very rare cases, Naegleria fowleri has also been found in poorly maintained swimming pools, splash pads, and other recreational venues, as well as tap water.
Moseman said Naegleria fowleri is so dangerous in part because of how quickly the infection progresses, and because early symptoms can mimic other conditions.
“Your immune system is able to combat this pathogen, but it’s never able to really fully clear the pathogen,” Moseman said. “What happens is, as the amoeba moves deeper into your brain, your body is trying to fight this pathogen, and in doing so it creates a lot of damage to itself.”
Moseman explained that as the body tries to clear the pathogen, dangerous inflammation and swelling can build inside the skull.
Despite the recent fatality in North Carolina, Moseman said exposure to Naegleria fowleri does not typically lead to disease.
“People in general have been exposed to this very commonly. Most of us have been exposed to this. Most of us have had it inside of us. Your body has mounted an immune response, and it was successful,” said Moseman. “It doesn’t want to be inside of people. It just ends up there sometimes, and it sort of accidentally causes disease.”
The infection occurs when contaminated water carrying the amoeba reaches the upper nasal passages, near the brain.
“If you just get water on the outside of your nose, it’s really probably not much of a risk,” said Moseman.
People cannot become infected with Naegleria fowleri by swallowing contaminated water.
To reduce risk of contracting Naegleria fowleri, Moseman said the best protection is keeping freshwater out of the nose.
“If you don’t submerge your head and your nose doesn’t go underwater, then there’s really nothing that the amoeba can do to you,” said Moseman. “You can also wear a nose clip so you can prevent water from going up your nose if you really insist on diving underwater.”
The CDC also recommends avoiding stirring up sediment in shallow fresh water.
Vibrio infections can happen when bacteria enter the body through an open wound exposed to coastal or brackish water, or when a person eats raw or undercooked seafood.
While many Vibrio infections cause gastrointestinal illness, Vibrio vulnificus can cause severe wound infections. Symptoms can include redness, pain, swelling and discoloration around a wound. In severe cases, the infection can spread to the bloodstream and become life-threatening.
To lower risk of Vibrio infection, the CDC recommends cooking seafood to 145 degrees, particularly shellfish like oysters, which are commonly associated with Vibrio vulnificus.
People with open wounds should also avoid saltwater or brackish water, and cover the wound with a waterproof bandage if contact is unavoidable.