The Vibrio vulnificus species of bacteria thrives in warm salty or brackish water. This type of bacteria, along with Streptococcus, can cause a flesh-eating disease that sometimes results in amputations or death.

People can contract a Vibrio infection after wading in contaminated water with an open wound or eating raw shellfish from the water.

The Vibrio flesh-eating bacteria species is spreading beyond its traditional region, in part because of warming ocean temperatures caused by climate change.

In the past two months, at least five people have been infected with flesh-eating bacteria, two of whom passed away.

Today, a 50-year-old Florida man also died after a two-week battle with flesh-eating disease, during which he lost 25% of his skin.

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David Ireland, a 50-year-old Florida man, passed away today after a two-week battle with necrotizing fasciitis, a flesh-eating disease caused by bacteria.

Ireland started exhibiting flu-like symptoms on August 16, and his family rushed him to the hospital five days later, after he started complaining about pain in his leg and groin. Doctors removed about 25% of Ireland's skin "from ankle to torso, butt, and scrotum," during the course of three surgeries, his wife Jody told Newsweek. But the infection proved fatal.

Ireland isn't the only casualty from flesh-eating bacteria this year. In a July 10 Facebook post, Cheryl Bennett Wiygul wrote that her father had contracted necrotizing fasciitis and died after visiting her in Okaloosa County, Florida.

And in June, 77-year-old Lynn Fleming died from health complications related to the same type of infection, NBC News reported. Cases of necrotizing fasciitis have also been reported in two children and an Alabama man this summer, though all three survived.

These flesh-eating infections are rare in the US, but a case report published in June suggests that rising ocean temperatures may be allowing the bacteria to spread to previously unaffected waters.

Cases of flesh-eating bacteria were documented in a new area

A range of bacteria can cause necrotizing fasciitis. In Ireland's case, the bacteria involved was Streptococcus A. But the five other cases in the US this year have all involved a species of bacteria called Vibrio vulnificus.

People can contract Vibrio infections in the Chesapeake Bay and along the Gulf Coast after eating or handling raw shellfish or swimming in contaminated water. The infections can necessitate limb amputations and lead to death, even with treatment.

In the past, Vibrio infections have arisen after people swam in the Chesapeake Bay or came into contact with seafood from those waters. But in the June case report, published in the journal Annals of Internal Medicine, Dr. Katherine Doktor documented five cases in people who were exposed to water in the cooler Delaware Bay or consumed crabs in that area.

"In 2017, we saw three cases of severe skin infections, which raised some flags," Doktor, an infectious-disease specialist at Cooper University Hospital, told Business Insider. "In 2018, we saw two more. These five cases are significant because in the eight years prior to 2017, we only saw one case of Vibrio vulnificus at our institution."

A Maryland blue crab tries to escape from a basket aboard the vessel Tempest in Chesapeake Bay, June 6, 2012. Flickr/U.S. Air Force photo/Staff Sgt. Benjamin Wilson

According to Doktor and her case report co-authors, climate change is partially responsible for the growing range of this type of deadly bacteria. "The bacteria likes warm salty water," she said, adding that cases usually peak between late July and early October, when the Gulf of Mexico and the Chesapeake Bay are warmest. Last year was the warmest year on record for Earth's oceans, however, and warmer waters "are associated with alterations in the quantity, distribution, and seasonal windows" of V. vulnificus, the authors wrote.

Vibrio infections have also been reported in Europe, and in 2018 a South Korean man had to have his left forearm amputated after contracting the infection from eating raw seafood.

Read more: A man had his arm amputated after eating raw seafood contaminated with a potentially flesh-eating bacteria

People can catch the bacteria by handling or consuming raw shellfish

An oyster farmer opens a diseased oyster in Sydney, Australia, in 2005. Ian Waldie/Getty Images

There are multiple species of Vibrio bacteria, and most make us sick, causing diarrhea, cramping, nausea, vomiting, and fever. Usually such symptoms pass in about three days.

But V. vulnificus can cause serious bloodstream infections that are accompanied by blood-filled blisters and necrotizing fasciitis, or flesh-eating disease, which kills body tissue.

People can get infected with V. vulnificus by eating raw or undercooked shellfish, especially oysters, according to the Centers for Disease Control and Prevention. It can also infect the skin if an open wound is exposed to brackish water or saltwater. Some people get infections after wading through storm floodwater. There were several Vibrio-associated deaths after Hurricane Katrina, for example.

"The infection courses through the entire body, kind of like a hurricane or tornado that ravages everything," Doktor said.

Often, these infections can be treated with antibiotics, but the dead tissue must sometimes be removed or the associated limb amputated to keep the infection from spreading. Of the five patients mentioned Doktor's case report, three had to get infected tissue removed, one man had his hands and feet amputated, and one person died in the hospital. The bloodstream infection leads to death in 20% of cases.

Vibrio infections come on quickly

A Vibrio vulnificus infection caused swollen blisters on a man's hand. The limb later had to be amputated. The New England Journal of Medicine, 2018.

In early July, about a week before Cheryl Bennett Wiygul's father swam near Destin Beach, news about a 12-year-old girl who contracted necrotizing fasciitis in the same area began to spread on social media.

Kylei Brown had waded in the water in Destin Beach in early June. Soon after, she started complaining about pain in her leg that traveled throughout her body and became more intense over time, according to a Facebook post by her mother.

Three days after their trip to the beach, Brown's family rushed her to the emergency room, where doctors diagnosed her with necrotizing fasciitis. The doctors were able to save Brown's leg in an emergency surgery.

The other child infected with flesh-eating bacteria this summer was the son of Brittany Carey, who went swimming in Maryland's Sinepuxent Bay on June 29. Two days later, he started developing "little spots" all over his body, Carey said in a Facebook post. Those spots turned into gaping, red wounds, which led doctors to diagnosed the boy with the same type of flesh-eating bacterial infection.

Doktor said she wrote the case report to alert clinicians in the Delaware Bay area that they might see more of this type of infection than they once did, and to urge them to consider it as a diagnosis.

But she noted that patients who contract severe Vibrio infections — like those in the case report — typically had other risk factors like liver disease, diabetes, or hepatitis.

"People who don't have any health problems who are exposed to bacteria may feel a little sick," she said, though she added that it's still a good idea to avoid consuming raw or undercooked shellfish.