The number of Vibrio vulnificus cases in Florida have reached 20 this week after an additional case was reported from Bay County. The death toll due to the bacterial infection remains at 10.
In 2014, Florida reported 32 cases of V. vulnificus with 7 deaths.
Vibrio vulnificus is a bacterium that is found in all coastal waters of the United States. It has also been found in brackish waters of some interior states. It may be normal flora in salt water and acquiring this organism from shellfish or water exposure does not imply that the water is contaminated by sewage. Most infections that happen are attributed to consuming raw oysters harvested in the Gulf of Mexico during the summer. Because the oysters are shipped all over the country, infections are not limited to the Gulf States.
Oysters are sedentary bivalve mollusks that feed by filtering plankton (small plants and animals) from estuarine water. Because Vibrio vulnificus occurs naturally in the same waters that oysters feed, the bacteria is ingested and becomes assimilated and concentrated in the animal’s tissues.
Healthy, non at-risk individuals are not at risk for serious infection. Non at-risk patients with gastroenteritis have a relatively mild illness consisting of vomiting, diarrhea and abdominal cramps and rarely require hospitalization.
However, there are certain medical conditions that can put you at risk for very rapid, serious and possibly deadly disease. Individuals with diabetes, liver disease like cirrhosis, leukemia, AIDS or those who take immunosuppressive drugs or steroids are particularly susceptible to primary septicemia, a serious “blood poisoning”. In these individuals the bacteria gets into the bloodstream resulting in septic shock and death in more than 50% of those infected.
Wound infections are another problem with Vibrio vulnificus. These infections result either from contaminating an open wound with sea water harboring the organism, or by lacerating part of the body on coral, fish, etc., followed by contamination with the organism.
This infection can be diagnosed by isolating the organism in stool, wound or blood cultures. It can be treated with a antibiotic regimen and supportive care.
What can you do to prevent this infection? Patients with chronic liver disease or immunocompromising conditions are particularly vulnerable to infection and are advised to avoid raw or undercooked seafood. Persons with open wounds should avoid contact with warm seawater.
Here is a list of preventive measures recommended in the journal American Family Physician:
o Avoid contact with raw seafood juices; use separate cutting boards and knives for seafood and nonseafood
o Avoid eating raw oysters or seafood, especially if an immunocompromising condition or chronic liver disease is present; the risk is highest with seafood harvested in the summer
o Cook shellfish thoroughly:
o In the shell: boil until the shells open, then boil for another five minutes; or steam until the shells open, then steam for another nine minutes (do not eat shellfish that do not open during cooking)
o Shucked oysters: boil for at least three minutes, or fry for at least 10 minutes at 375°F (191°C)
o Promptly refrigerate leftover seafood
o Wear gloves when handling raw oysters or shellfish
Persons with open wounds:
o Avoid contact between open wounds and seawater, especially if water temperature is more than 68°F (20°C), or raw seafood
o Wash any wound that is exposed to seawater with soap and clean water
o Immediately seek medical care for any wound that appears infected