Elizabeth Weise of USA Today reported on a speech by “FDA’s Michael Taylor [where he] outlined the agency’s plans to combat the deadly bacteria vibrio vulnificus by requiring Gulf-raised oysters to undergo post-production processing to kill the bacteria. Taylor told the assembled state health department and shellfish industry officials that as of 2011, the agency would no longer allow fresh, live oysters from Texas, Louisiana and Florida to be sold during the warm-weather months unless they were processed.”
Of course, oysters are grown and eaten raw in other parts of the country – and have been linked to vibrio vulnificus illnesses as well – at least twice – 2006 and 2009 – from the State of Washingon. Curious why the requirement is not on all oysters? Of course, I always thought it was a bit unwise to eat raw oysters anyway. Frankly, over the years we have been asked to look at several vibrio cases and we have declined to represent the ill persons.
According to Ms. Weise, “FDA would require that Gulf coast oyster undergo one of four processes to kill potential bacteria:
• Quick freezing
• High pressure treatment
• Mild heat
• Low dose gamma radiation”
V. vulnificus causes disease in individuals who eat contaminated seafood (usually raw or undercooked oysters) or have an open wound that is exposed to seawater. Among healthy people, ingestion of V. vulnificus can cause vomiting, diarrhea, and abdominal pain. Most V. vulnificus infections are acute and have no long-term consequences.
In immunocompromised persons, particularly those with chronic liver disease, V. vulnificus can invade the bloodstream from either a wound or from the GI tract, causing a severe and life-threatening illness called primary septicemia, characterized by fever, chills, septic shock and death. Blistering skin lesions accompany the disease in about 70% of the cases. V. vulnificus bloodstream infections are fatal about 50% of the time.
Although V. vulnificus is a rare cause of disease, it is likely that it is unrecognized and underreported (one estimate of the total number of cases annually in the U.S. is as high as 45,000). Between 1988 and 1995, CDC received reports of over 300 V. vulnificus infections from the Gulf Coast states, where the majority of cases occur.
Persons who are immunocompromised, especially those with chronic liver disease, are at risk for V. vulnificus when they eat raw seafood, particularly oysters. These individuals are 80-200 times more likely to develop V. vulnificus primary septicemia than are healthy people. For this particular risk group, the infection carries one of the highest mortality rates of all bacterial infections.