Beach Lovers: How Dangerous Is the "Flesh-eating” Vibrio Vulnificus Bacterium?
Its reputation is misleading, but you better protect yourself against this seafaring bug
The bacterium, Vibrio vulnificus, is found in warm brackish (unpleasantly salty) seawater and has been blamed for nine infections and three deaths in Florida.
Some press accounts have referred to the germ as a “flesh-eating bacterium.” That’s because its enzymes and toxins can cause blistering and sometimes fatal ulcerations in open wounds. Experts, however, say the term is inaccurate.
“News stories characterizing V. vulnificus as flesh-eating are misleading,” says Mara Burger, a spokeswoman for the Florida Department of Health. The bacterium can destroy soft tissue and lead to serious complications, but does most of its damage by infecting the bloodstream.
A rare cause of illness, V. vulnificus infects about 95 people in the United States each year and causes 35 deaths, according to the Centers for Disease Control and Prevention (CDC).
About half of cases occur in the Gulf Coast region. But thanks to climate change, we may be hearing more about the salt-loving bacterium.
Global warming has brought the threat of V. vulnificus to new regions as melting ice reduces the salinity of seawater and rising temperatures warm the waters, according to James Oliver, PhD, a professor of microbiology at the University of North Carolina at Charlotte. This means you may need to take precautions even in countries where you wouldn’t expect the bacteria to flourish, such as Finland, Sweden and Germany.
A raw deal
Swimming in warm seawater isn’t the only way to encounter V. vulnificus. It’s also found in raw shellfish. Scientists have long known that the bacterium, which is related to the bug that causes cholera, can infect people who eat raw or undercooked shellfish — especially oysters.
Healthy people who ingest V. vulnificus may develop vomiting and abdominal pain. Folks who have liver problems or a compromised immune system, however, can suffer a life-threatening infection that brings on fever, chills, shock and skin lesions. In fact, raw shellfish was linked to one of the three deaths from V. vulnificus in Florida.
How to protect yourself
How concerned should you be about V. vulnificus? If you’re an average healthy person and you have no open wounds, you can swim in warm coastal waters with virtually no fear of infection, according to the CDC.
By taking a few precautions, “people can enjoy the water safely,” said Karen Wong, MD, a medical officer with the CDC. In the rare event you develop a skin infection after being in the water, she says, seek medical attention immediately (and let the doctor know you’ve been in the ocean).
If you have cuts or open sores, a weakened immune system or chronic liver disease, though, you’re more vulnerable to the bacterium. A recent study suggests that a person with an immune system disorder is 80 times more likely to develop a V. vulnificus bloodstream infection than someone who’s healthy. For half of people with liver disease, a V. vulnificus blood infection is fatal.
Follow these tips from experts at the CDC and elsewhere to protect yourself from V. vulnificus:
- Do not eat raw oysters or other raw shellfish; cook shellfish thoroughly and eat it right away. Refrigerate leftovers promptly.
- Wear gloves when handling raw shellfish. If you have a cut on your hands, don’t handle it at all.
- Avoid cross-contamination of raw seafood with other foods.
- Stay out of warm brackish seawater if you have an open wound or a break in your skin.
- If you have chronic liver disease or a weakened immune system, don’t swim in warm seawater.
- If you cut yourself while swimming in warm seawater, get out, advises Oliver. Tend to the wound right away and cover it with a clean bandage.
If you’ve been in the ocean and notice a painful wound, see a doctor right away, Oliver adds. An infection with V. vulnificus can be diagnosed from blood, stool or wound cultures and is easily treated with antibiotics. But if an infection goes untreated, the bacteria could release enough toxins to be dangerous.