Louisiana health officials have confirmed nine Vibrio vulnificus infections and five deaths so far in 2026, a sharp jump from the state's decade-long average of about seven cases and one death per year.
All nine patients were hospitalized, and every one of them had an underlying health condition. Florida has recorded at least 14 cases and two deaths this year.
Vibrio vulnificus, one of the most dangerous flesh-eating pathogens, enters the body through open wounds during contact with warm salt or brackish water, or through raw and undercooked shellfish, especially oysters.
The infection can turn deadly within days
The bacterium can trigger necrotizing fasciitis, a rapid infection that destroys skin, muscle and connective tissue. According to CDC surveillance data cited by Newsweek, 727 US cases were logged over the past five years, with 87 percent of patients hospitalized and roughly one in five dying.
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Warning signs after exposure can appear quickly. Valerie Harwood, a biology professor at the University of South Florida, told Time the first sign is often an "extremely hot and painful wound, but you might not be able to see it initially because it's under the skin."
She urged people to act fast. "If you go in the water and 8 or 24 hours later, your leg hurts and feels hot, go to the doctor right away," she said.
Who is most at risk
The infection is rare in healthy people. Louisiana health authorities flag the highest risk for people with cancer, liver disease, HIV or thalassemia, and for those on immune-suppressing medication. Older adults and people with diabetes also face greater danger.
Anyone with a fresh cut, scrape, surgical wound, piercing or tattoo should keep it out of warm coastal water. Standard CDC guidance is to cover new wounds with waterproof bandages before swimming or wading, and to wash any wound exposed to seawater or raw seafood with soap and clean water as soon as possible.
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Warmer seas are pushing the danger north
Historically clustered along the Gulf Coast, the bacterium is now turning up much farther north. William Schaffner, professor of preventive medicine and infectious diseases at Vanderbilt University Medical Center, told Newsweek the pathogen "thrives in warmer waters," and its habitat has crept up the Atlantic seaboard as far as New England.
Connecticut recorded its first Vibrio vulnificus infection of the year in February, tied to oysters brought in from another state. That fits with earlier research suggesting rising sea temperatures could boost harmful bacteria along coastlines once considered too cool for it.
When to worry after a beach day
Symptoms most often appear within a day of exposure. Red flags include a wound that turns hot, swollen and disproportionately painful, fever, chills, blistering, skin discoloration or a sudden drop in blood pressure. Vomiting, diarrhea and stomach cramps can point to infection from raw shellfish.
Treatment usually involves intravenous antibiotics and surgery to remove dead tissue, and in some cases amputation. Anyone who suspects a Vibrio infection, particularly people in the high-risk groups, should seek emergency care rather than wait to see how symptoms develop.
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This article is made and published by Jesper Bengtson, who may have used AI in the preparation.