The bacteria is found in raw seafood, like oysters, and warm, brackish waters. Climate change may increase the risk of infections from the deadly bacteria farther north. Three people in the New York City area have died in recent weeks and a fourth person was hospitalized after contracting infections from a flesh-eating bacteria that can be caused by eating raw oysters or swimming in saltwater, health officials in New York and Connecticut said. Infections from the bacteria, called Vibrio vulnificus, are rare but extremely dangerous. The Centers for Disease Control and Prevention estimates that one in five people who become infected die. Many survivors lose limbs to amputations, according to the C.D.C. “We are reminding providers to be on the lookout for cases of vibriosis, which is not often the first diagnosis that comes to mind,” Dr. James McDonald, the New York state health commissioner said in a statement on Wednesday. People with open wounds should avoid swimming in warm seawater, he said. And people with compromised immune systems should be careful with eating or handling raw seafood. One of the New York area deaths was in Suffolk County, on Long Island; two others were in Connecticut. In the fourth case, also in Connecticut, a person was sickened but later released from the hospital. Vibriosis is caused by several species of bacteria, including the Vibrio vulnificus bacteria, which can be found in salt water, especially when the weather is warm, New York health officials said. Symptoms include diarrhea, stomach cramps, vomiting, fever and chills. Exposure can also result in ear infections and cause sepsis and life-threatening wound infections. The flesh around an open wound can die, which is why Vibrio vulnificus is called a “flesh-eating” bacteria. “It gets very nasty,” said Dr. William Schaffner, an infectious disease specialist at the Vanderbilt University School of Medicine. The infection can destroy the soft tissues, he said, before getting into the bloodstream and causing sepsis. Healthy people should not be too concerned, he said. But people with liver problems, he said, should be cautious with seafood: “Eat the shrimp, rather than the oyster.” In the Connecticut cases, two people had open cuts and were exposed to water in the Long Island Sound, according to Christopher Boyle, a spokesman for the state’s health department. A third Connecticut resident became sick after eating raw oysters, though not at a restaurant in the state, and not harvested from the Sound, said Rebecca E. Murphy, a spokeswoman for the state agriculture department. “Nobody has ever been infected with Vibrio from eating shellfish or oysters in the state of Connecticut,” Dr. Manisha Juthani, the state’s public health commissioner, said at a news conference earlier this week. New York officials are still investigating whether the death in Suffolk County was caused by bacteria that was encountered in local waters or elsewhere. The bacteria are more common in the summer months. As ocean temperatures rise, more people may be at higher risk of infection, according to a study published this spring in the journal Scientific Reports. Once, the bacteria were rare north of Georgia, but they have been found farther north in recent years. From 1988 to 2018, wound infections from the virus increased from 10 cases per year to 80 cases a year on the East Coast, the researchers found. “This is showing the interconnectedness of our health and ocean health,” said Elizabeth Archer, the lead author. There have been other national spikes related to coastal surges, as infection-bearing water is pushed further inland. Last fall, after Hurricane Ian struck Florida, the state’s health department recorded what it described as an “abnormal increase” in cases. After Hurricane Katrina, in 2005, at least five people died of illnesses caused by Vibrio bacteria. Connecticut has seen a few cases in recent years. One person died of a Vibrio vulnificus infection in the state in 2019. In 2020, five cases were reported; all recovered. The people who became infected had open wounds and were exposed to salt or brackish water. Partly in response to the 2020 outbreak, the state now tests oysters for Vibrio vulnificus, said Emily Marquis, an environmental analyst with the bureau of aquaculture and laboratory services. Inspectors have never detected it in the state’s commercial oysters, said David Carey, the director of the bureau. Connecticut, which has a thriving oyster industry, also implemented rules about the storage and freezing of oysters after a 2013 outbreak of a similar bacterial strain, Vibrio parahaemolyticus, sickened 23 people there. Connecticut’s protocols are designed to keep oysters cold, below or equal to 50 degrees Fahrenheit. Oysters must be refrigerated or placed in an ice slurry, depending on where they are harvested. The agriculture department said that there have been no Vibrio outbreaks since the protocols were put in place in 2014. “Maintaining cool temperatures is inhibiting bacteria growth,” said Tessa L. Getchis, who trains farmers in seafood cultivation practices with the Connecticut Sea Grant and UConn Extension Program. “Which is what you want. That’s why we refrigerate anything.” News of the deaths have worried some Connecticut residents. But the organizers of the annual Milford Oyster Festival, set for Saturday, say they are confident about safety. “There’s no reason for us to be alarmed over this,” said Trisha Kozloski, who organizes all the oyster sales for the festival. Organizers plan to provide 30,000 oysters, all harvested off the town’s coast. All are put on ice or refrigerated immediately, and festival workers regularly check the temperature of the truck, and of individual oysters, she said. “But we’re shucking to order, so the oysters aren’t sitting around,” she said, adding: “Nothing has changed. There’s no greater risk this year than there ever has been before. And the risk is very, very low.”
