The dangerous bacteria that can hide in floodwaters

Last week, the Florida Department of Health issued an advisory that warned residents to avoid floodwaters to prevent exposure to Vibrio vulnificus, a potentially life-threatening bacteria.

"Vibrio bacteria, commonly found in warm coastal waters, can cause illness when ingested or when open wounds are exposed to contaminated water," the department warned.

Vibrio vulnificus is a bacteria that lives in warm, salty water and can cause infections by coming into contact with wounds, bites, or cuts. It can also infect oysters, mussels, clams, and scallops — however, the foodborne form of Vibrio vulnificus is typically only caused by oysters, since they're not cooked before eating.

The bacteria kills roughly 20% of its victims — sometimes within just a day or two of a person getting sick — and those who get infected can require intensive care, with around 10% needing surgical tissue removal or limb amputations. The bacteria is also capable of causing necrotizing fasciitis, a medical term describing a "flesh-eating" infection.

Symptoms of an infected wound can include swelling, pain, redness, warmth, fever, discoloration, and discharge.

"Vibrio vulnificus is really a nasty one and if it's left untreated and goes systemic it can be fatal," said Rita Colwell, a distinguished professor at the University of Maryland Institute for Advanced Computer Studies. "The bacteria invades the body's tissues and [sometimes] the only way to save the life of these individuals is to amputate [the infected limb]."

Hurricanes Helene and Milton both brough record-breaking storm surges to the Gulf Coast, which causes salt water to mix with fresh water and becomes a breeding ground for bacteria, according to Scott Rivkees, a pediatric endocrinologist and former state surgeon general and secretary of health for Florida.

"Where you have salt water meeting fresh water, this is where vibrio can thrive," he said. "And if individuals are exposed to brackish water and they have an open cut, or they're immunocompromised, such as having cancer, vibrio can take hold."

Rivkees said that vibrio is "one of the most aggressive" types of bacterial infections that exists. Rivkees added that, long after a hurricane is gone, flood water remains the biggest risk to humans.

"People need to recognize that more people will die after a storm than during the storm, and drowning is the major thing that we worry about," he said, adding that driving a car through floodwaters is a major danger.

Rivkees also said that in Florida, septic systems can spill into groundwater during hurricanes, which causes the kind of brackish water that bacteria thrive in.

In Cedar Key, roughly 100 miles from where Hurricane Helene made landfall on Sept. 26, health officials noted a rise in cases of cellulitis, a bacterial skin infection that can occur from exposure to flood water, according to Tami Wilkes, an APRN who works at Cedar Key Healthcare.

Wilkes said the clinic also saw a rise in patients with lacerations, cases of asthma and bronchitis, and people needing tetanus injections.

"The county health department brought a bus to provide tetanus injections and we worked together providing sutures, antibiotics, and nebulizer treatments in effort to meet the needs," Wilkes said.

How to stay safe

CDC recommends that if people "must" enter flood water, they should wear rubber boots, rubber gloves, and goggles. CDC also says people should sanitize after coming into contact with flood water, including using soap and clean water for their skin for 20 seconds, and hot water and detergent for clothes.

Any open wounds that come into contact with flood water should also be cleaned with soap and clean water and checked by a healthcare provider, if necessary, CDC says. Symptoms including redness, swelling or soreness around an open wound, any sign of a foreign object embedded in a wound, or other symptoms like fever, nausea, confusion, extreme pain, shortness of breath, or a high heart rate are serious enough for medical attention, according to CDC.

Rivkees said the most important thing people can do after a hurricane is to listen to public safety officials on when it's safe to return.

"There's always a temptation to get back there as soon as you can, and you're going to have first responders there who are trying to clear the area and make sure that the area is safe and secure," he said. " Individuals should really listen for their public officials to give the all clear when it is safe to return, because otherwise that could help impede the response." (Kindelan, ABC News, 10/9; Dewan, Newsweek, 10/10; Nesi, New York Post, 10/9)

Hospitals must be prepared for a myriad of disasters that can stress health care systems to the breaking point and disrupt delivery of vital health care services.  Our Advisory Board research teams have compiled step-by-step procedures for various threats your facility may encounter.