The number of fatalities linked to “carnivorous” bacteria is increasing along the southeast coast of the US. Five individuals in Florida, Four in Louisiana, and One in the Outer Banks have succumbed this year to infections that can lead to necrotic wounds.

The culprit, the bacterium Vibrio vulnificus, thrives in warm seawater. According to the state health department, Florida has reported 16 cases so far this year. Louisiana has reported 17 cases, exceeding last year’s average. North Carolina has recorded seven incidents, confirmed by its Department of Health and Human Services, while Mississippi has filed three lawsuits this year, as per the state’s health department.

The initial fatalities in Florida were documented in Bay County along the Gulf Coast, as well as Hillsboro County and regions in Broward and St. John’s Counties, located just south of Jacksonville in southeastern Florida.

Bacteria can enter the body through skin wounds, resulting in tissue necrosis. According to the Centers for Disease Control and Prevention, vibrio vulnificus can also be contracted via the consumption of contaminated food, particularly raw oysters. The exact means of infection for those in Florida remains unclear.

As reported by the CDC, approximately one in five individuals infected with Vibrio vulnificus will die.

Antalpreet Jutt, a professor of engineering at the University of Florida, noted that while infections are still relatively rare, “something feels off this year.” Nevertheless, he mentioned the uncertainty around the reasons behind the spike in infections.

“This is definitely not normal,” Jutt expressed. “We haven’t encountered this many cases early in the summer in quite some time.”

Jutt explained that cases of Vibrio vulnificus tend to rise following hurricanes. Last year, Florida registered a total of 82 cases, potentially worsened by an “extremely active” hurricane season when bacteria can persist in floodwaters.

“This year, it seems there are a higher number of pathogens than usual,” he remarked.

The current hurricane season is still projected to be above average as the US enters its peak period, as reported by the National Oceanic and Atmospheric Administration.

Jutt’s research group is examining why there are elevated concentrations of plankton and chlorophyll (indicators of Vibrio) throughout the Florida panhandle, which he describes as a concerning trend.

What is Vibrio vulnificus?

Rita Colwell, a microbiology professor at the University of Maryland, states that Vibrio vulnificus is one of over 200 species of Vibrio bacteria.

Most Vibrio infections are not harmful to humans, according to Jutt. Some may only impact marine life.

However, Vibrio bacteria are responsible for around 80,000 infections annually, as reported by the Cleveland Clinic. The majority of these cases are gastrointestinal, with only 100-200 cases arising from Vibrio vulnificus. Other Vibrio species, such as Vibrio parahaemolyticus and Vibrio alginolyticus, are more commonly associated with stomach illnesses, while another, Vibrio cholerae, is known to cause cholera.

Vibrio bacteria are primarily found along the southeastern coast of the United States, favoring warmer waters, but are also present on the west coast. With rising sea temperatures, cases have increasingly been reported further north, including areas in New York, Connecticut, and parts of Maryland, Jutt noted.

Who is at risk?

Dr. Norman Beatty, an infectious disease specialist at the University of Florida Health, mentioned that spending time in salty or brackish waters can lead to Vibrio bacteria infiltrating open wounds. Most cases he has encountered are associated with extended exposure to the water, though even short contact can be sufficient.

Visible symptoms of infection can develop within hours, including redness, swelling, and the formation of “bull” blisters. This site can become painful. If the infection progresses, it may enter the bloodstream, potentially leading to sepsis, which can be fatal. According to the CDC, symptoms of sepsis include fever, chills, and dangerously low blood pressure.

Jutt mentioned that individuals with cirrhosis, weakened immune systems, and those over 65 are particularly vulnerable to infections.

Infections caused by Vibrio vulnificus can be treated with antibiotics.

How to prevent Vibrio infection

Beatty advises covering any open wounds before entering the ocean, noting that even waterproof band-aids can be effective.

Individuals who suspect they have an infection should seek immediate medical attention, Beatty cautioned. Delays can significantly increase the risk of severe complications compared to milder cases.

“Late presentations to healthcare are why many individuals suffer more serious consequences than others,” he stated. “Those who seek treatment shortly after the onset of symptoms, and are given antibiotics promptly, are likely to fare better and avoid severe complications.”