***Note: As of September 7, seven people in the area affected by Hurricane Katrina have been reported to be ill from the bacterial disease, Vibrio vulnificus. Four have died.
Vibrio vulnificus is a bacterium in the same family as those that cause cholera. It normally lives in warm seawater and is part of a group of vibrios that are called "halophilic" because they require salt.
V. vulnificus can cause disease in those who eat contaminated seafood or have an open wound that is exposed to seawater. Among healthy people, ingestion of V. vulnificus can cause vomiting, diarrhea, and abdominal pain.
In immunocompromised persons, particularly those with chronic liver disease, V. vulnificus can infect the bloodstream, causing a severe and life-threatening illness characterized by fever and chills, decreased blood pressure (septic shock), and blistering skin lesions. V. vulnificus bloodstream infections are fatal about 50% of the time.
V. vulnificus can also cause an infection of the skin when open wounds are exposed to warm seawater. These infections may lead to skin breakdown and ulceration. Persons who are immunocompromised are at higher risk for invasion of the organism into the bloodstream and potentially fatal complications.
V. vulnificus is a rare cause of disease, but it is also underreported. Between 1988 and 1995, CDC received reports of over 300 V. vulnificus infections from the Gulf Coast states, where the majority of cases occur. There is no national surveillance system for V. vulnificus , but CDC collaborates with the states of Alabama, Florida, Louisiana, Texas, and Mississippi to monitor the number of cases of V. vulnificus infection in the Gulf Coast region.
Persons who are immunocompromised, especially those with chronic liver disease, are at risk for V. vulnificus when they eat raw seafood, particularly oysters. A recent study showed that people with these preexisting medical conditions were 80 times more likely to develop V. vulnificus bloodstream infections than were healthy people. The bacterium is frequently isolated from oysters and other shellfish in warm coastal waters during the summer months. Since it is naturally found in warm marine waters, people with open wounds can be exposed to V. vulnificus through direct contact with seawater. There is no evidence for person-to-person transmission of V. vulnificus .
V. vulnificus infection is diagnosed by routine stool, wound, or blood cultures. The laboratory should be notified when this infection is suspected by the physician, since a special growth medium can be used to increase the diagnostic yield. Doctors should have a high suspicion for this organism when patients present with gastrointestinal illness, fever, or shock following the ingestion of raw seafood, especially oysters, or with a wound infection after exposure to seawater.
V. vulnificus infection is treated with antibiotics. Doxycycline or a third-generation cephalosporin (e.g., ceftazidime) is appropriate.
V. vulnificus infection is an acute illness, and those who recover should not expect any long-term consequences.
Although oysters can be harvested legally only from waters free from fecal contamination, even legally harvested oysters can be contaminated with V. vulnificus because the bacterium is naturally present in marine environments. V. vulnificus does not alter the appearance, taste, or odor of oysters.
Timely, voluntary reporting of V. vulnificus infections to CDC and to regional offices of the Food and Drug Administration (FDA) will help collaborative efforts to improve investigation of these infections. Ongoing research may help us to predict environmental or other factors that increase the chance that oysters carry pathogens.
Some tips for preventing V. vulnificus infections, particularly among immunocompromised patients, including those with underlying liver disease:
Source:
Centers for Disease Control and Prevention, September2005
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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