Health officials in several Gulf states are warning about a rise in cases of the “flesh-eating” bacteria Vibrio vulnificus. So far this year public health officials have linked Vibrio infections to eight deaths around the Gulf Coast, along with dozens of hospitalizations.
In Louisiana, health officials have reported 17 cases of Vibrio vulnificus and four deaths due to the bacteria so far in 2025. Officials said cases are significantly higher than usual — the yearly average has been seven cases and one death over the past decade.
Of the 17 cases, 75 percent were linked to exposure of wounds to seawater.
Health officials in Florida have reported 13 cases of Vibrio vulnificus and four deaths from the bacteria in 2025 to date.
“Vibrio vulnificus is by far most common in the Gulf states, but it’s been expanding northwards,” says Thomas Russo, MD, a professor and the chief of infectious disease at SUNY University in Buffalo, New York. “As its range expands, the number of cases are likely to expand as well.”
What Is Vibrio vulnificus?
Vibrio is a type of bacteria that live in coastal waters. There are about a dozen species that can cause a potentially lethal infection called vibriosis. Vibrio parahaemolyticus, Vibrio vulnificus, and Vibrio alginolyticus are the most likely to make people sick in the United States.
The Vibrio cases making headlines right now are from Vibrio vulnificus.
“Vibrio is a germ that likes to live in warm, salty waters,” says William Schaffner, MD, an infectious disease specialist and professor at the Vanderbilt University School of Medicine. “It can contaminate beachfront areas.”
Vibrio vulnificus is found nearly everywhere in warm aquatic environments, according to Amesh Adalja, MD, a senior scholar at the Johns Hopkins University Center for Health Security. “For example, almost all oysters in the Chesapeake Bay harbor the organism,” he says.
How People Get Exposed to Vibrio
People usually contract Vibrio vulnificus if an open wound comes into contact with saltwater or brackish water (a mix of fresh and saltwater). In about 10 percent of cases, people get infected after eating raw or undercooked shellfish.
Some people are at a higher risk for wound infections than others, including those with underlying health conditions like diabetes and liver disease, Dr. Schaffner says. People who are immunocompromised are also especially vulnerable. “But everybody has to be concerned if they go into the water and have cuts,” he says.
Cases of Vibrio vulnificus Are Quickly Rising in the U.S.
An estimated 80,000 cases of Vibrio are diagnosed in the United States each year, but Vibrio vulnificus accounts for only between 150 and 200 of those.
Those numbers are increasing, though. While Vibrio vulnificus infections have historically been most common in Gulf Coast states, cases in the eastern U.S. increased eightfold between 1988 and 2018. The northern range of infections has expanded by nearly 30 miles a year.
“The reason it’s spreading is global warming,” Schaffner says. “This used to be an infection that was largely confined to the Gulf Coast. Now the bacteria is comfortable moving up the East Coast.”
Some Vibrio Symptoms Can Be Confused With Stomach Bugs and Flu-Like Illnesses
Symptoms of a Vibrio vulnificus infection vary depending on whether someone gets sick from eating oysters or contracts it through an open wound.
These are the main symptoms in people who get Vibrio vulnificus from eating raw oysters or other raw shellfish:
Vomiting
Diarrhea
Stomach pain
People who are infected through an open wound may have these symptoms:
Fever
Chills
Drop in blood pressure
Skin breakdown
Skin ulcers
“You can quickly develop fever, chills, and feel very poorly, very, very quickly,” Schaffner says. Vibrio vulnificus wound infections are unlikely to go undiagnosed, given how severe these illnesses usually are, he says.
Dr. Russo says Vibrio vulnificus infections from ingestion of contaminated food or water may go underdiagnosed, given that they can be confused with other gastrointestinal illnesses.
Vibrio Is Treatable, but Can Quickly Turn Fatal
Vibrio vulnificus can cause life-threatening infections, and 1 in 5 cases is fatal — sometimes within one to two days. That’s why a fast response and treatment is important, Russo says.
Treatment involves oral or IV antibiotics, along with careful monitoring of the wound, if there is one. “You have to assess the local site of infection very carefully because it can be subtle,” Schaffner says. “Much of what is going on is underneath the skin, and doctors have to be aware that this ‘flesh-eating’ bacteria could be tunneling under the skin.”
Skin that has died from the infection should be removed and, in severe cases, people may need amputation of the infected limb, Russo says.
How to Lower Your Risk of Vibrio
There are a few things you can do to keep from getting Vibrio vulnificus, the experts say.
Don’t swim with open wounds. Obvious cuts and scrapes, as well as new tattoos and piercings increase your vulnerability. “If you have an open wound, you should really avoid going into brackish water,” Russo says.
Avoid raw or undercooked oysters. “Don’t eat raw oysters,” Russo says, noting that these mollusks can also carry viruses like norovirus. “Certainly, if you fall into a high-risk group, definitely avoid eating raw oysters,” he adds.
Check local water alerts. Local health or environmental departments regularly update water quality reports, Russo points out. He suggests checking these before swimming, especially if you’re considered high risk for a Vibrio vulnificus infection.
Wash up after swimming. “It’s a good idea when you get home to take a shower,” Schaffner says. If you get a cut while swimming, he recommends rinsing the area well with fresh water immediately afterward, too.
“Doctors who work in emergency rooms along the Gulf Coast are aware of Vibrio vulnificus. But now that it’s sneaking up the Atlantic seaboard, lots of doctors in emergency rooms up the East Coast need to learn about this infection, too,” Schaffner says.
EDITORIAL SOURCES
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Resources
Louisiana Department of Health Urges Caution to Prevent Vibrio Vulnificus Infection. Louisiana Department of Health. July 31, 2025.
Parveen S et al. Seasonal and Geographical Differences in Total and Pathogenic Vibrio parahaemolyticus and Vibrio vulnificus Levels in Seawater and Oysters from the Delaware and Chesapeake Bays Determined Using Several Methods. Applied and Environmental Microbiology. November 2020.
Emily Kay Votruba has copyedited and fact-checked for national magazines, websites, and books since 1997, including Self, GQ, Gourmet, Golf Magazine,Outside, Cornell University Press, Penguin Random House, and Harper's Magazine. Her projects have included cookbooks (Padma Lakshmi's Tangy Tart Hot & Sweet), self-help and advice titles (Mika Brzezinski's Know Your Value: Women, Money, and Getting What You're Worth), memoirs (Larry King's My Remarkable Journey), and science (Now You See It: How the Brain Science of Attention Will Transform How We Live, Work, and Learn, by Cathy Davidson). She started freelancing for Everyday Health in 2016.
Korin Miller is a health journalist with more than a decade of experience in the field. She covers a range of health topics, including nutrition, recent research, wellness, fitness, mental health, and infectious diseases.
Miller received a double bachelor's in international relations and marketing from The College of William & Mary and master's in interactive media from American University. She has been published in The Washington Post, Prevention, Cosmopolitan, Women's Health, The Bump, and Yahoo News, among others.
When she's not working, Miller is focused on raising her four young kids.
