July 4, 2019

Tyler King was at work in Santa Rosa Beach, Florida, last week, when he noticed his left bicep starting to swell. He tried taking Benadryl but just a few hours later his arm had nearly tripled in size. He rushed to the emergency room.

"When I was a little bit younger, I probably would have tried to tough it out. Well, that would have been the worst thing that I could do," King said. "If I had gone to sleep … and had woke up with it at the rate it was spreading, I might not have an arm right now."

King had contracted vibrio, a bacteria commonly found in warm, brackish water – a mix of salt and fresh water. When exposed to an open wound, vibrio can cause a skin infection. If left untreated, the bacteria can be deadly.

King, who owns a water sports business, says he did not directly touch water the day he was infected. He still doesn't know how it happened but he considers himself lucky.

Similar cases of infection have been popping up on beaches along the East Coast. A Maryland woman says her son is healing after he developed open wounds swimming in a bay last week. A 77-year-old woman who was walking along the Gulf died after developing necrotizing fasciitis when she fell in the water and cut her leg.

"Waters are getting warmer and the bacteria love warmer water, so we're all at higher risk," explained CBS News medical contributor Dr. David Agus.

He says the key to stopping flesh-eating bacteria is to catch and treat infections with antibiotics quickly. Older people with medical conditions like diabetes, cancer or immune deficiencies are more susceptible.

"Once that bacteria has spread in the bloodstream to the organs, sometimes it's too hard to treat … but just pay attention. Don't be afraid of the ocean, but be aware of what's going on," Agus said.

Agus recommended people check themselves and children for cuts and to cover any open wounds with waterproof band-aids before getting in the ocean.

If you do get a cut in the water, clean it with hand sanitizer immediately and keep monitoring cuts for any signs of infection like swelling or redness.