At least three people have died after contracting infections from a rare flesh-eating bacteria that can be caused by eating raw seafood such as oysters or swimming in warm saltwater, New York and Connecticut health officials said Wednesday.

Experts are urging residents to take “critical” precautions to avoid Vibrio vulnificus, a rare but dangerous flesh-eating bacteria, after the recent cases. Officials suggest protecting open wounds from seawater and avoiding raw or undercooked shellfish.

“While rare, the vibrio bacteria has unfortunately made it to this region and can be extraordinarily dangerous,” New York Gov. Kathy Hochul said in a news release Wednesday.

Here’s what we know so far about flesh-eating bacteria and the recent deaths.

HOW DID FOUR PEOPLE IN THE NORTHEAST CONTRACT VIBRIO VULNIFICUS?

Two Connecticut residents were recently infected with Vibrio vulnificus and died after they were swimming with open cuts in separate locations in the Connecticut waters of the Long Island Sound, Christopher Boyle, a spokesman for the state’s Department of Health, told The Washington Post.

A recently deceased resident in Suffolk County, N.Y., was also infected by the flesh-eating bacteria, Hochul announced Wednesday.

Another Connecticut resident was infected after eating oysters at an out-of-state restaurant but was later released from the hospital, according to the state health department.

The three infected people in Connecticut since July 1 were between the ages of 60 and 80 years old, according to the health department. The age of the person who died in New York is unclear. None of the people infected with Vibrio vulnificus have been publicly identified.

WHAT IS VIBRIO VULNIFICUS?

Vibrio vulnificus is a bacteria that causes sepsis, severe wound infections, and stomach flu, according to the National Library of Medicine. Researchers at the Centers for Disease Control and Prevention first identified it as a source of disease in 1976.

Vibriosis is caused by several species of bacteria, including Vibrio vulnificus. It is found in saltwater coastal environments, and more infections usually occur between May and October when the weather is warmer, according to New York state health officials.

Many of the people infected with Vibrio vulnificus require intensive care or limb amputations to survive, according to the CDC. Vibrio vulnificus is described as a flesh-eating bacteria because it can lead to what’s called necrotizing fasciitis, a severe infection in which the flesh around an open wound dies.

The consequences can be deadly.

“About 1 in 5 people with this infection die, sometimes within a day or two of becoming ill,” the CDC said in its description of Vibrio vulnificus.

HOW DO PEOPLE GET INFECTED?

Most Vibrio vulnificus infections are caused by eating raw or undercooked oysters or other shellfish, according to the CDC. People with compromised immune systems are especially susceptible. Anyone can be infected with Vibrio vulnificus, but those with liver disease, cancer, or a weakened immune system, as well as people taking medicine to decrease stomach acid levels, are more likely to get an infection or develop complications during an infection, New York health officials said.

“Particularly during the hottest months of the summer, bacteria are more likely to overgrow and contaminate raw shellfish,” Manisha Juthani, Connecticut’s public health commissioner, said in a July 28 news release. “Given our current heat wave, this may be a time to exercise particular caution in what you consume.”

Juthani emphasized in a news conference this week that “nobody has ever been infected with Vibrio from eating shellfish or oysters in the state of Connecticut.”

Infection can also come from swimming in warm saltwater or brackish water – a mix of fresh and saltwater often found where rivers meet the sea. Those at higher risk include anyone who has an open cut, scrape, or open wound from a recent surgery, piercing, or tattoo.

“If you have wounds, you should avoid swimming in warm seawater,” New York State Health Commissioner James McDonald said in a statement.

WHAT ARE THE SIGNS OF INFECTION? 

Signs and symptoms of a Vibrio vulnificus infection can include watery diarrhea that’s usually followed by a combination of stomach cramping, nausea, vomiting, and fever, or all of the above, according to the CDC.

If the infection is in the bloodstream, then symptoms would range from fever and chills to dangerously low blood pressure and blistering skin lesions, health officials say. An open-wound infection that could spread to the rest of the body would result in signs such as swelling, warmth, discoloration, and leaking fluids, the CDC says.

HOW RARE IS IT TO DIE OF VIBRIO VULNIFICUS INFECTION? 

While it is very rare to die of Vibrio vulnificus infections, there have been multiple instances in recent years of cases and deaths reported.

After Hurricane Katrina devastated the Gulf Coast in 2005, at least five people in two states died after being infected, according to the CDC. In 2016, a Maryland man died days after the bacteria came in contact with a cut on his leg. Last year, Florida health officials said they were experiencing an “abnormal increase” in Vibrio vulnificus infections following Hurricane Ian.

“The Gulf Coast is the epicenter of disease like this,” Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine, told The Post in October. “You have a mix of climate change, poverty, and aggressive urbanization, all contributing to the exacerbation of vibrio infections and an increase of other diseases like dengue, zika, and parasitic infections.”

Connecticut has been the site of several cases in recent years, including a 2019 death from infection. Five other cases were reported in the state in 2020 – all from people with open wounds exposed to saltwater or brackish water – but they all survived, according to the Connecticut Department of Health.

HOW DO YOU CURE OR PREVENT INFECTION? 

If the infection is caught early, it can be treated with antibiotics. The Cleveland Clinic says that providers are likely to prescribe antibiotics such as doxycycline, ceftazidime, cefotaxime, or ciprofloxacin to treat vibriosis.

Other methods to help prevent skin infections include surgical debridement, where a provider cleans dead tissue out of a patient’s wounds, draining fluid from the blisters, and intravenous fluids, according to the Cleveland Clinic.

In terms of prevention, health officials advise people not to eat raw or undercooked oysters or other shellfish.

“Cook them before eating,” the CDC said as part of its prevention tips, which also includes wearing gloves when handling raw seafood.

In addition to food preparation, health officials recommend that people with wounds not swim in saltwater or brackish water. If they still want to swim, officials suggest covering the wound with a waterproof bandage. Washing wounds with soap and water after coming into contact with saltwater or brackish is also suggested.

The tips are crucial to preventing an increase in infections in the region, Hochul said.

“As we investigate further, it is critical that all New Yorkers stay vigilant and take responsible precautions to keep themselves and their loved ones safe,” the governor said.