We recently reported on the Louisiana Department of Health's warning about Vibrio vulnificus, the flesh-eating bacteria that Boing Boing's Séamus Bellamy so beautifully describes as "living its best life in the waters slopping up against the beaches of America's east coast." Well heads' up, everyone, because while most of the 150 to 200 annual cases in the United State occur along the Gulf Coast, a new case of the flesh-eating bacteria was recently confirmed, this time at a beach in Cape Cod, Massachusetts.
Vibrio vulnificus is a bacteria found in coastal and estuarine waters (where fresh water mixes with salt water), including the Gulf Coast and the Atlantic Coast. The bacteria thrive when water surface temperatures rise during heat waves, and are typically at their peak from May through October. Cape Cod Times quotes Massachusetts Public Health Commissioner Robbie Goldstein, who stated that Vibrio vulnificus infections "can spread through the bloodstream and cause severe, even life-threatening illness" including necrotizing fasciitis, or flesh-eating disease.
As of July 30, Louisiana has seen 17 cases of Vibrio vulnificus in 2025 alone. All seventeen patients were hospitalized and four died. The Louisiana Department of Health reports that 75% of those cases were linked to "wound/seawater exposure." This is an unusually high number of cases — Cape Cod Times reports that, in comparison, during the last decade, Louisiana averaged seven cases and one death per year. Cases have also been showing up this year in Florida. As of July 24, the state has reported 13 cases and four deaths, numbers which are more in line with previous years, albeit still alarming.
This year in addition to the Gulf Coast cases, a new case has recently been confirmed at Old Silver Beach in Falmouth, a town on the southwestern tip of Cape Cod, Massachusetts. According to Cape Cod Times, the case was confirmed by both local and state officials on August 8, shortly after the patient, who had been swimming in the water at the Cape Cod beach, became ill.
So far in 2025, Massachusetts has seen 71 confirmed and probable cases of Vibrio, which includes all of the dozen or so types of Vibrio, not just Vibrio vulnificus. According to Cape Cod Times, thirty percent of those cases included hospitalization, and no deaths have been reported. During the time period 2015 to 2024, Massachusetts reported, on average, 88 cases of Vibrio infection (of all kinds) per year. While Vibrio vulnificus cases are, according to the Falmouth Public Health Department, "extremely uncommon" in Massachusetts, they are starting to be reported further and further north than in previous years, because of warming ocean temperatures. So, I'd expect to see more cases in both the Gulf Coast states and in more northern Atlantic Coast locations.
Cape Cod Times reports that while Cape Cod beaches such as Falmouth are monitored for fecal bacteria, there's no good way to monitor bathing water for the virus. They further explain:
The bacteria is rare in Massachusetts, but is slightly more likely in late summer and early fall when water temperatures are warmest, according to the statement. More cases of Vibrio vulnificus are being reporting in the north than in previous decades, which scientists attribute in part to climate change.
The town asked individuals to avoid swimming or going into water with open cuts, scrapes, or fresh tattoos or to cover the wound with a waterproof bandage. Also rinse any wounds with soap and fresh water after contact with coastal waters and seek medical care quickly if the wound becomes red, swollen, painful or is accompanied by fever after seawater exposure.
People usually get the virus by swimming in sea water with open wounds, so you really should avoid doing that. You can also get the virus by eating raw or undercooked seafood such as raw oysters, so it's good practice to thoroughly cook your seafood, especially in the warmer months of the year. The Massachusetts Department of Public Health advises that immunocompromised people are more at risk for severe disease following exposure to Vibrio vulnificus through open wounds, and that folks who are on medicine that decreases levels of stomach acid or who have had recent stomach surgery have an increased risk of developing gastrointestinal infections from eating shellfish or seafood infected with Vibrio vulnificus. Stay safe out there, friends!
Previously:
• Flesh eating bacteria increasingly common at America's beaches
• 'High amounts' of flesh-eating bacteria and ocean plastics create 'perfect pathogen storm' in Florida seaweed
• Florida man infected with flesh-eating bacteria after being bitten by family member
• Oysters and other sea-boogers carry disease
• Two dead after eating raw oysters from Louisiana
