Swimming with a wound risks serious infection

Swimming with a wound risks serious infection

It sounds like something out of a '50s horror movie, but so-called flesh-eating bacteria are real, and the relatively low risk of contracting such an infection while swimming in coastal waters is apparently rising.

Patrick J. Flynn, MD, PCWC, FAPWCA, medical director of Cape Cod Healthcare's Wound Care Centers in Hyannis and Bourne, said most cases in the United States occur in saltwater and brackish water in the nation's South, but warming of waters around Cape Cod have increased the danger here. He treated a case last summer of a man who swam with a wound in Buzzards Bay off Falmouth and has seen other local cases. He cautioned that any kind of wound, even a seemingly minor scrape or cut, can permit bacteria to enter the skin.

"We don't recommend that patients with any wound go into any water," he said.

Why the Scary Name?

These infections are called 'flesh-eating' because they produce enzymes that break down tissue, a process called necrotizing fasciitis. They can spread rapidly, and extreme cases may require amputation or may be fatal.

"It can go from your foot to thigh in a matter of hours," Dr. Flynn said.

According to the U.S. Centers for Disease Control and Prevention, 20 percent of people with this infection die, which can happen within a day or two of illness. About 10 percent get infected from eating raw or undercooked shellfish. The bacterium Vibrio vulnificus is responsible for infections resulting from swimming in saltwater or brackish water, Dr. Flynn said, but Group A streptococcus causes most cases of necrotizing fasciitis in the U.S., according to the CDC. Approximately 150-200 cases of Vibrio vulnificus infection are reported to the CDC annually. They usually occur from May to October in warm coastal waters where the bacteria naturally grow.

Rising water temperatures and extreme weather related to climate change are expanding the risky areas from the Gulf Coast and spreading it northward up the East Coast, according to the CDC. It noted that in July and August of 2023, North Carolina, Connecticut and New York were among the states with severe and fatal infections.

Symptoms, Treatment, Prevention and Who's at Risk

According to the CDC and Dr. Flynn, symptoms of a Vibrio skin infection include:

• Skin that feels warm, is red or discolored
• Swelling
• Pain
• Fluid leaking from site

If you notice these symptoms and have been swimming recently in saltwater or brackish water, or have been in contact with raw or undercooked shellfish, it's important to seek medical help immediately, especially if the infection seems to be spreading or getting worse.

Removing any unhealthy dead tissue is the first line of treatment, along with antibiotics, said Dr. Flynn. "Really bad cases can result in multiple trips to the operating room," he said.

The genus Vibrio contains several disease-causing species. Some species, including vulnificus, can also cause an illness called vibriosis, if a person eats infected oysters or other shellfish, the CDC notes. Symptoms include fever, chills, nausea, vomiting, watery diarrhea and stomach cramps. In 2024, 3,755 cases were reported nationwide; this doesn't include cases of cholera caused by Vibrio cholerae.

Cases are Still Rare

The chance of getting a skin infection with Vibrio is rare, but some people are more vulnerable. They include older people, people with diabetes and those with weakened immune systems, but young, healthy people can get infected, too, Dr. Flynn said. Any opening in the skin can let bacteria in, even a recent tattoo or piercing, he added.

If you have any kind of wound and still want to go swimming in the ocean or estuary or mouth of a coastal river, you can "try to cover wounds with a waterproof dressing. But they don't always work and we don't recommend it," Dr. Flynn said. "Once out of the water, rinse it with fresh water, or apply antiseptic."

The CDC recommends wearing gloves and washing your hands after touching raw shellfish, and to be aware infection can come from walking on the beach, wading or fishing, even from a pier.