Hurricane Ian hit Florida as category 4 storm in late September, bringing torrential rains and a storm surge that left much of coastal and central Florida underwater. But while the immediate dangers involved drowning and injuries, an invisible threat would soon sicken some people who came in contact with the water: flesh-eating bacteria.
After the storm, coastal Florida saw a spike in infections by Vibrio vulnificus, a flesh-eating bacteria. People often catch it from uncooked seafood, but it can also live in warm, brackish water. According to the Florida Department of Health’s website, the state has seen 64 confirmed cases of flesh-eating bacteria infections so far this year, with 11 deaths. That’s almost double the cases reported in all of 2021. Lee County, which contains hard-hit Fort Myers, alone has confirmed a whopping 28 cases and four deaths as of October 21.
Flesh-eating bacteria is just one of several health risks that come with floodwaters. Inundated streets, roads, and homes become covered by polluted water that threatens residents and emergency responders. Gastrointestinal illnesses and skin infections often spike after flooding events.
Other floods in recent history have also yielded a spike in disease. A 2019 report that studied floods in Iran also looked at other major flooding events worldwide, including 1988 floods in Sudan that led to a spike in hepatitis A infections, caused by sewage-contaminated waters.
Brian Labus, an assistant professor in the School of Public Health at the University of Nevada, explained that the pollutants in floodwater may differ depending on where you are. Urban centers may be more likely to deal with sewage, while rural areas may see animal waste, fertilizer, or pesticide runoff.
“The diseases we see most often occur from sewage are gastrointestinal infections, things like norovirus, or salmonella, E. coli,” he said. “You get sick from these things typically from swallowing. It’s going to be on your hands…they could be covered in bacteria, which, you then grab a sandwich or grab something to drink and wind up swallowing [the bacteria].”
The contaminants in water also depend on the level of damage to local infrastructure, such as chemical treatment plants and wastewater treatment facilities. Oil spills can also spread, and if oil-contaminated floodwater enters a home, the fumes can pollute indoor air and lead to various health effects, including harm to the nervous and respiratory systems.
During Hurricane Ian, a water treatment plant just off Highway 27 reported a leak of more than 2,000 gallons of sodium hypochlorite, according to the Tampa Bay Times. The chemical is a harsh disinfectant that causes blistering and burns on skin and even eye damage. The damage also released sewage into some of the state’s floodwaters and waterways. In Brevard County, the flooding caused more than 357,000 gallons of waste to flow up from manholes and onto beaches, Florida Today reported.
And as flooding becomes more widespread and more intense, areas that are not accustomed to floods may not know to reinforce places like gas stations, sewer systems, or chemical processing facilities.
“Whether it’s the storm surge or just the vast amounts of rain, there is not a sewer system on the planet that can take that kind of hit without having some sort of overflow,” Nathan Gardner-Andrews, the chief advocacy officer for the National Association of Clean Water Agencies, told Bloomberg earlier this month. “As storms get more intense you are going to see unfortunately more incidents where systems get overwhelmed.”
Byomkesh Talukder, a public health researcher at York University, explained that many of the gastrointestinal infections and illnesses caused by flood waters tend to clear up on their own. But if someone has allergies or a weaker immune system, those small infections can turn into a life-threatening emergency.
“Obviously, if there is flooding, the healthcare system is disrupted. You cannot expect an ambulance at that point,” he said. “Drugstores will also be closed. In Canada and in the U.S., we don’t always keep essential medicines that are not prescribed in the household. My suggestion is to keep this kind of primary care medicine around.”
Talukder especially recommended keeping pain relievers and fever reducers like acetaminophen or aspirin at home, especially if you know that a storm or potential flooding event is possible. Pharmacies also carry over-the-counter anti-nausea and antidiarrheal medications, which can help avoid dehydration.
He and Labus both recommended storing as much water as possible to ensure access to clean drinking water after a storm. The extra water can also be used for hand washing—this is especially important for first responders and anyone who has no choice but to come in contact with floodwater. Anyone who has to go into floodwaters to help others should cover their skin as much as possible. If they have any cuts or scrapes, those wounds should be cleaned as best as possible and monitored for signs of infection. Any clothing that has come in contact with floodwaters should be washed with hot water and a disinfectant.
Even if someone has not been injured while in contact with floodwaters, many viruses and bacterias can be ingested. Medical professionals often recommend that people who have been exposed to floodwaters should make sure they’re up to date on their shots, like tetanus and hepatitis vaccines.