Vibrio vulnificus in Florida: What to know 

Vibrio is the genus name for a bacterial group that naturally lives in coastal waters. It is responsible for a variety of infections known as vibriosis. Vibrio bacteria thrive in warm, brackish waters where freshwater meets the sea. Florida has the highest rate of vibriosis cases in the United States due to this environment. 

Almost a dozen Vibrio species can cause vibriosis, but the most dangerous is Vibrio vulnificus. This species of Vibrio can cause life-threatening infections if swallowed or contracted through an open wound.  

After ingestion or once it has infiltrated a preexisting wound, it can cause necrotizing fasciitis, a condition that kills the flesh surrounding the wound. This has earned it the nickname “flesh-eating bacteria.”  

V. vulnificus basics

The Vibrio genus spans a wide variety of infamous, water-borne bacterial infections. V. vulnificus was first identified in 1976. A series of blood culture samples submitted to the Centers for Disease Control and Prevention showed a gram-negative pathogen yet to be identified. It was initially given the name Beneckea vulnifica, and then finally named Vibrio vulnificus by J. J. Farmer in 1979. 

Today, vibriosis can be caused by several members of the Vibrio genus, other than V. cholerae. Each bacterium has varying ranges of severity, with V. vulnificus being the deadliest. Once V. vulnificus enters the body via ingestion or an open wound, the bacterium can rapidly induce sepsis, a serious condition that occurs when the body’s response to systemic infection becomes uncontrolled and leads to widespread inflammation and tissue or organ damage. If not treated promptly, sepsis can cause organ failure and death. You can also contract V. vulnificus by handling raw shellfish with an open wound.  

V. vulnificus infections are often underreported. From 1988 to 2006, the CDC documented over 900 cases from the Gulf Coast states, the primary locations for these infections. Prior to 2007, there was no comprehensive national surveillance for V. vulnificus. Nevertheless, the CDC collaborated with Alabama, Florida, Louisiana, Texas and Mississippi to track cases in the Gulf Coast region. In 2007, infections from V. vulnificus and other Vibrio species became nationally reportable. 

V. vulnificus in Florida

Florida is a hot spot for V. vulnificus activity. Consistent warm water temperatures create optimal conditions for Vibrio bacteria to flourish. 

Florida also experiences high numbers of V. vulnificus infections because hurricane flooding and storm surge increase exposure to more V. vulnificus. People often get cuts and scrapes during hurricanes, and wading through flood waters puts them at greater risk of contracting harmful forms of Vibrio. In 2022, Collier and Lee counties experienced an unusual increase in cases due to the impacts of Hurricane Ian, with 74 cases and 17 deaths reported. Again, in 2024, after Hurricane Helene, vibriosis cases spiked in Citrus, Hernando, Hillsborough, Lee, Pasco, Pinellas and Sarasota counties. Overall, there were 82 cases and 19 deaths. 

As of August 2025, there have been 20 confirmed cases of V. vulnificus in Florida and five deaths. The deaths were in Bay, Broward, Hillsborough and St. Johns counties. 

V. vulnificus transmission

Luckily, unlike the common cold and influenza, vibriosis is not contagious. The bacterial infection is localized to the patient.  

Ways in which a person can contract a V. vulnificus infection include: 

• Eating raw seafood, especially oysters. 
• Having an open wound exposed to brackish water, raw seafood or raw seafood drippings. 

Symptoms of a V. vulnificus infection

Vibriosis symptoms after ingestion are usually mild, with watery diarrhea typically being the first sign. Other symptoms include abdominal cramping, nausea, vomiting and fever. When the infection spreads beyond the intestinal tract, symptoms become more severe and overlap with a wound infection. V. vulnificus can infect skin tissues, even after ingestion. 

Common signs and symptoms of a Vibrio skin/wound infection include: 

• Fever 
• Redness 
• Pain 
• Swelling 
• Warmth 
• Discoloration  
• Leaking fluids  
• Blood blister skin lesions 

Common signs and symptoms of a Vibrio bloodstream infection include: 

• Fever 
• Chills 
• Dangerously low blood pressure 
• Blood blister skin lesions 

People most vulnerable to V. vulnificus infections

Vibriosis-causing bacteria thrive in salty, warm water. Anyone living in or visiting coastal regions is more at risk of contracting V. vulnificus. These bacteria thrive in brackish water, such as inlets and estuaries, where fresh and saltwater mix. These areas also have large quantities of shellfish filtering water for food and nutrients. 

Those eating raw shellfish or exposing their skin to brackish waters with open wounds are at a higher risk of acquiring V. vulnificus.  

Having a weakened immune system or having certain medical conditions, such as liver disease, cancer, diabetes, HIV or high levels of iron in the blood, can make someone extremely vulnerable to severe vibriosis. This includes the elderly, children and pregnant people. Those also receiving immunosuppressing therapy or taking medicine to decrease stomach acid levels are at a higher risk. 

V. vulnificus diagnosis

A V. vulnificus infection is identified through a wound, blood cultures or stool after ingestion. When a V. vulnificus infection is suspected, quickly informing the laboratory is paramount because a special growth medium can improve detection. Clinicians should consider this organism when patients have a wound infection following seawater exposure or show symptoms like stomach illness, fever or shock after eating raw seafood, particularly oysters. Compared with typical wound infections, the hallmark of a V. vulnificus skin/wound infection is the extremely rapid expansion of the red area. 

V. vulnificus treatment

If  V. vulnificus is suspected, antibiotics should be initiated immediately to improve the patient’s chances of survival. If the bacteria were contracted through an open wound, aggressive attention should be given to the wound site. For patients with wound infections, amputation of the infected limb is sometimes necessary to stop the spread of the infection.  

V. vulnificus prevention

Vigilance is the best form of prevention of V. vulnificus-induced vibriosis. 

Don’t swim or fish in brackish water if you have any fresh cuts, scrapes or burns. This is especially important during the summer months when Vibrio numbers are high. 

Don’t consume raw or undercooked shellfish; thoroughly wash your hands with warm water and soap after handling raw shellfish.  

Make sure to sanitize food preparation surfaces with appropriate disinfectant cleaners to protect yourself from cross-contamination after handling shellfish.  

The Florida Department of Health recommends the following measures to prevent all forms of vibriosis: 

• Do not eat raw oysters or other raw shellfish. 
• Cook shellfish, such as oysters, clams and mussels thoroughly. 
• For shellfish in the shell, boil until the shells open and continue boiling for five more minutes, or steam until the shells open and then continue cooking for nine more minutes. Do not eat shellfish that are not open during cooking. Boil shucked oysters at least three minutes or fry them in oil for at least 10 minutes at 375°F. 
• Avoid cross-contamination of cooked seafood and other foods with raw seafood and juices from raw seafood. 
• Eat shellfish promptly after cooking and refrigerate any leftovers. 
• Wear protective clothing, like gloves, when handling raw shellfish.  
• Avoid exposing open wounds or broken skin to raw shellfish harvested from such waters or warm salt or brackish water. 

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