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Very few people actually contract an infection from the dangerous Vibrio vulnificus bacteria. Getty Images
  • Only about 205 people in the United States will get an infection from Vibrio vulnificus — also called the “flesh-eating bacteria” — this year.
  • People with certain underlying conditions may be more prone to contracting the infection.
  • The bacteria can also cause symptoms when ingested, such as through raw oysters.

This summer millions of people will head to the beaches to enjoy some time on the coast.

However, there’s a looming concern of flesh-eating bacteria in the waters.

Headline after headline has touted people suffering from an infection caused by bacteria described in graphic terms as “flesh eating.”

For those who love warm water, the headlines may bring up fears that the local lake or ocean beach isn’t safe. But experts say that’s not the case for the vast majority of people.

Here’s what to know:

Multiple types of Vibrio bacteria can cause tens of thousands of infections in the United States every year.

But it’s Vibrio vulnificus, one of a dozen species of this Vibrio bacteria, that has been making headlines this summer. It’s found in the coastal waters according to the Centers for Disease Control and Prevention (CDC).

There are higher concentrations of the bacteria during the warmer months as warm water temperatures — greater than 68°F — allow the species to thrive.

Most commonly, people become infected with the bacteria by eating raw and undercooked shellfish, particularly oysters. Others encounter the bacteria through open wounds while swimming in infected waters.

In rare cases, the Vibrio infection can cause necrotizing fasciitis. This is a soft tissue infection that progresses to the muscles and organs resulting in rapid destruction of tissues. However, if caught early, this infection can be promptly treated with antibiotics.

Although you can find Vibrio vulnificus in all coastal waters of the United States, it’s usually found in the warmer waters in the Southeast regions of the United States and the Gulf of Mexico.

While the bacteria has been making headlines across the United States, the CDC estimates that Vibrio vulnificus causes only about 205 infections in the United States each year.

“People are concerned because this is a very dramatic infection. It affects people of all ages — you can be healthy and get the infection. Despite this, it is rare,” said Dr. William Schaffner, an infectious disease specialist at Vanderbilt University Medical Center.

If ingested, usually through eating raw or undercooked oysters, the symptoms of diarrhea, cramping, fever, chills, and vomiting usually appear within 24 hours. The symptoms usually last only 3 days.

If Vibrio vulnificus is exposed to open wounds, it can cause a rash that changes skin color. There’s also bruising and localized swelling, and it can be painful to the touch.

Although anyone is susceptible to a vibrio illness, those with the following conditions are particularly vulnerable:

  • liver disease
  • alcohol use disorder
  • diabetes
  • cancer or malignancy
  • kidney disease

“Although anyone could be infected with an open wound, patients with cirrhosis or other immune compromising conditions are particularly vulnerable,” said Dr. Christopher Greene, an assistant professor of Emergency Medicine at the University of Alabama at Birmingham.

In a recently published study in the Annals of Internal Medicine, researchers found that between 2008 and 2016 there was only one case of Vibrio vulnificus infection reported at a hospital in the Delaware Bay region, where the water is often colder than ideal for the bacteria.

However, the study authors found that after further investigation, there were at least five cases in the same Delaware Bay region, just between 2017 and 2018.

In all 5 cases, the patients were men between the ages of 38 and 64 who presented to the hospital with necrotizing fasciitis after marine life exposure at work and through consumption.

All of the men involved had preexisting conditions. Two had hepatitis, two had previous injuries while crabbing, and another had diabetes — all things that put you at higher risk for infection from Vibrio vulnificus.

While risk factors do increase your chances of contracting Vibrio vulnificus, the authors attribute the increase in cases in the Delaware Bay partly to climate change.

Despite the news headlines, you can still enjoy the beach, oysters, and the coastal waters. However, a few safety tips can decrease the chance of you contracting the illness.

The CDC offers the following tips to reduce your risk of vibriosis:

  • Don’t eat raw or undercooked oysters.
  • Always wash your hands with antimicrobial soap after handling raw oysters.
  • After cooking seafood, properly refrigerate leftovers to prevent warming.
  • Avoid salt and brackish waters if you have an open wound including simple scrapes and open cuts. If you’re going to go into the water, use a waterproof bandage to prevent wound contamination.
  • If the wound does get exposed to potentially infected waters, wash all wounds with antimicrobial soap and clean water. If the wound becomes red or appears infected, seek immediate medical care.

“People should avoid swimming in any type of water with open wounds, and wear protective clothing including footwear to protect from injuries and abrasions,” Greene told Healthline.

Although everybody should be cautious of the risk factors for contracting vibriosis, those with conditions that put them at a higher risk should be especially careful.

If you or someone you know have recently been exposed to raw or undercooked oysters and started to experience nausea, vomiting, diarrhea, and the characteristic rash, you should seek immediate medical attention.

Although early symptoms of vibriosis from Vibrio vulnificus can be treated with oral antibiotics and antiemetics, more severe cases may require hospitalization, IV antibiotics, and if wounds are present, surgical evaluations.

“Any wound should be gently cleansed with soap and water,” said Greene. “Signs of infection include redness (erythema) that spreads from the wound edge, severe pain in the wound, visible swelling in the tissues surrounding the wound, or fever/chills” which should prompt a visit to your local emergency department.

Those who may need more intensive treatment are those with worsening symptoms.

Vibriosis is a condition that can be difficult to spot. It occurs underneath the skin. So, if there’s pain with gentle touch that’s beyond what you would expect just by looking at the skin’s surface, you may be experiencing the later symptoms of this illness.

Early medical intervention can promote favorable outcomes and can prevent surgical procedures and the late life-threatening manifestations of the illness.

Schaffner believes that everyone “should go out and enjoy themselves this summer. Go swimming, boating, and eat carefully. If we are all a little bit prudent with understanding this infection, we will all do just fine.”

Rajiv Bahl, MD, MBA, MS, is an emergency medicine physician and health writer. Learn more about him at his website.