The majority of the infections are based in Lee County, where Ian made landfall in late September as a Category 4 hurricane; however, the Florida Department of Health in Lee County didn’t warn residents about the risks associated with Vibrio vulnificus until early October.

Vibrio vulnificus is a bacterium that typically lives in warm, brackish seawater, but sewage spills in coastal waters, such as those caused by Hurricane Ian, may increase bacteria levels, according to the DOH-Lee press release. While infections are rare, people with open wounds can be exposed to Vibrio vulnificus through direct contact with seawater containing the bacteria. Exposure can lead to skin breakdown and ulcers.

Anyone can get a Vibrio vulnificus infection; however, it can be more severe for people who are immunocompromised or have a weakened immune system. People who have chronic liver or kidney disease are also at risk. Symptoms include watery diarrhea, which is often accompanied by stomach cramping, nausea, vomiting, and fever. 

Vibrio vulnificus can infect the bloodstream and cause severe life-threatening illness with symptoms such as “fever, chills, decreased blood pressure (septic shock), and blistering skin lesions.” 

For wound infections from Vibrio vulnificus, which may spread to the rest of the body, symptoms include “fever, redness, pain, swelling, warmth, discoloration and discharge,” according to the Centers for Disease Control and Prevention.

The infection is treated with antibiotics, though amputation of the infected limb is sometimes necessary. Vibrio vulnificus is not spread person to person. People who are concerned they may have been exposed are advised to seek immediate medical attention.