Sure, sharks are scary. But at least you can see one when it’s coming for you. Bacteria? Not so much. And five cases of infection caused by the very ominous sounding flesh-eating bacteria have been found in the Chesapeake Bay and its tributaries so far this year.

(Just a quick warning to anyone squeamish out there: do NOT google image search flesh-eating bacteria if you’re reading this over breakfast.)

The bacteria, which thrive in warm salty water and are also known as vibrio bacteria, can infect the skin and blood and cause intestinal illnesses, some of which are life-threatening. According to the Baltimore Sun, a 66-year-old man nearly lost a leg to a flesh-eating bacteria infection after a swim in the bay in July. Vibrio infections have long been associated with the Gulf Coast region, but they’re becoming increasingly common in waters off the coast of Maryland.

While flesh-eating bacteria infections are still quite rare–though still about five times as common as shark attacks!–it’s good to be smart about your swimming habits: don’t get in the water if you’ve got open wounds, and shower off after you get out of the ocean. And don’t swim in a Bay tributary after a hard rain. And if your flesh starts, um, decaying, please go to a doctor.