A flesh-eating bacteria killed a Louisiana man and infected three other people who swam in the Gulf of Mexico earlier this summer. According to a press release, the fatality was an 83-year-old man from Terrebonne Parish, La.

Health officials said that sea water had splashed onto the victim’s open wound while he was fishing, resulting in an infection that led to his death. According to the Epoch Times, the bacteria that infected all four of the victims was Vibrio vulnificus, a gram-negative bacterium that naturally resides in warm brackish and salt water.

The pathogen primarily infects people who consume contaminated seafood, especially raw oysters, or those with open wounds that get exposed to contaminated sea water. The mortality rate for those with infected wounds is approximately 25 percent. “You get bacteria into certain wounds, and they can cause a lot of tissue destruction by virtue of the fact that these bacteria produce enzymes that break down the tissue,” Dr. Peter Hotez, an infectious and tropical disease expert at Baylor College of Medicine, told ABC-13 in Houston.

The other three victims were a 71-year-old man from Iberville Parish, a 43-year-old Calcasieu Parish man, and a 76-year-old man from St. Bernard Parish. One of the men has been released from the hospital, while the other two remained under care as of Monday, the Inquisitr reported. All of the men had open wounds that came into contact with seawater.

The four cases evidently led the Louisiana Department of Health and Hospitals to issue a warning to swimmers ahead of the July 4 weekend. The DHH warned swimmers to be cautious about swimming in the ocean with open wounds and to avoid areas that were known sites of contamination.

“We know people are venturing into our state’s waterways to cool off this summer, so we advise them to be careful and exercise health precautions,” Kathy Kliebert, department secretary, told the Town Talk. “We certainly do not mean to discourage people from enjoying water activities, but we want them to understand the potential risks involved.”

Kliebert added that the advisories were part of an ongoing state effort to test beach water. “DHH works with other state and local partners to monitor and test beach water to inform residents of the water quality, and we hope residents will heed posted beach advisories when they see them,” she said.