“It’s like something out of a horror movie,” Marcia Funk told the Daily Times of Salisbury, Maryland last week. In September, Funk watched helplessly as her husband of 46 years succumbed to an infection of flesh-eating bacteria in a mere four days.

Michael Funk, her husband, became infected on September 11 while cleaning crab traps in the Assawoman Bay outside their Ocean City, Maryland condominium. The deadly bacteria, Vibrio vulnificus, had slipped into a small cut on his leg as he waded into the bay’s still, warm, and brackish waters—ideal breeding grounds for the bacteria. Within hours, Funk fell ill and went to a nearby hospital where a surgeon removed infected, rotting skin from his leg. But with the flesh-eating bacteria circulating in his bloodstream, his condition quickly worsened. He was flown to a trauma hospital in Baltimore where surgeons amputated his leg. Still, the lesions spread and, on September 15, he died.

Funk’s case is among the more severe examples of V. vulnificus infections—but it still could have been worse. In July, scientists reported that a 59-year-old man showed up at a hospital with a painful ankle lesion that expanded before their eyes (see photo above). His V. vulnificus infection, caught from warm waters in the Gulf of Mexico, turned deadly even faster. Within hours, his whole body was covered in lesions. A little more than 48 hours later, he was dead.

These cases should serve as a chilling warning of the dangers of V. vulnificus and its vibrio relatives (V. parahaemolyticus and V. alginolyticus), according to the editorial board of the Daily Times. Vibrio infections are somewhat rare—about 80,000 in the US each year—but they’re on the rise. In fact, the global number of cases and deaths from V. vulnificus have increased continuously in the last four decades, according to a recent review of scientific literature. In Maryland, the state health department issued a warning in 2014 following an outbreak of nearly 60 cases from the Chesapeake Bay.

Global warming is partly to blame, according to a June study in the Proceedings of the National Academy of Sciences. Warmer ocean surface waters are leading to population booms of vibrio bacteria in waters where they naturally occur. And this is positively correlated with the boost in vibriosis cases in Northern Europe and the Atlantic coast of the US.

Also a factor in rising infection rates is the trend of eating raw oysters and other shellfish, which can collect vibrio from tainted waters. Most of the vibrio infections—an estimated 52,000 out of the 80,000—are thought to be from eating contaminated food. When eaten, vibrio can cause symptoms similar to cholera (also caused by a vibrio species), which includes diarrhea, cramping, and fever. It usually passes in three days, but infections can turn deadly in patients with compromised immune systems and/or if the bacteria get in the bloodstream.

V. vulnificus, the only flesh-eating vibrio, is extremely fast-growing and virulent, researchers note. V. vulnificus wound infections, like Funk’s, carry about a 20 percent mortality. But that rate rises to around 50 percent if the infection spreads to the blood.

The CDC says that vibrio infections can be prevented by not eating raw oysters and other shellfish, plus keeping open wounds covered with waterproof bandages when getting into brackish or sea water. Any exposed cuts or wounds should be washed thoroughly with soap and clean water. The Daily Times editorial board recommends stronger precautions, urging readers to avoid murky, stagnant, brackish water all together—cuts or not cuts.