Rare, flesh-eating bacteria kills 4 in Florida. What is Vibrio vulnificus?

Four people in Florida are dead after being infected with a rare, flesh-eating bacteria found in coastal waters.

According to the latest data from state health officials , there have also been 11 non-fatal cases of Vibrio vulnificus reported in 2025. The deaths occurred in Bay, Broward, Hillsborough and St. Johns counties. The report does not say how the people came into contact with the bacteria, but it can be transmitted when an open wound is exposed to infected seawater or by eating raw shellfish that has been infected.

Florida health officials have warned anyone with fresh cuts or scrapes to avoid going into the water, saying “water and wounds do not mix.”

Here’s what to know.

Vibrio vulnificus is part of the Vibrio group of bacteria that can cause illness in humans, according to Health Canada. Although the illness can be mild, it is “more often severe with rapid progression requiring intensive care.” It often causes septicemia, an infection of the bloodstream, that can be fatal.

Symptoms include fever, chills, skin lesions and low blood pressure, and can appear 12 to 72 hours after exposure.

It can also cause skin infections if it comes into contact with an open wound, which can lead to skin breakdown and ulcers, according to Florida Health. If it is ingested, it can cause vomiting, diarrhea and abdominal pain.

Vibrio vulnificus infections can be especially harmful for those with weakened immune systems, in particular, those with chronic liver disease, Florida Health says. Those who get infected with Vibrio vulnificus may even need limb amputation in order to recover. Infections are fatal 50 per cent of the time.

It has been called “flesh-eating” because some Vibrio vulnificus infections can lead to necrotizing fasciitis, described as a “severe rapidly spreading bacterial infection that can cause death” by the Cleveland Clinic. It is when the flesh around the open wound dies, the U.S. Centers for Disease Control and Prevention (CDC) explains.

Vibrio vulnificus lives in warm, brackish seawater, according to Florida Health. The CDC says that the bacteria is more likely to be found in high numbers in May through October, due to warmer water temperatures.

There was a surge of Vibrio vulnificus-related deaths in Florida last year, with 19 fatalities reported. Florida Health noted that the “unusual increase” was due to the impacts of Hurricane Helene. In 2022, officials noted that there was another surge due to Hurricane Ian.

The concentration of the bacteria can rise due to heavy rain or flooding, CNN reported when the cases increased last year.

Outbreaks in Canada have been linked to eating raw or undercooked shellfish, particularly oysters, Health Canada said.

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