Federal health officials are urging consumers to refrain from eating raw oysters from the Gulf of Mexico for much of the year because of possible bacterial contamination.
The U.S. Food and Drug Administration recently recommended thorough cooking of any Gulf Coast oysters that are harvested between April and October. The advisory, however, is likely to lessen enthusiasm for the shellfish because many are eaten, in fact, on-the-half-shell or raw.
This latest action is yet another setback for the seafood industry, which has repeatedly faced questions from Congress and consumer groups about the safety of fishery products.
According to food folklore, it was thought safe to eat the uncooked, tangy bivalves in any month containing the letter r . Now, however, the emergence of Vibrio vulnificus , has led the agency to partially amend that conventional wisdom for, at least, the Gulf species, according to a report in FDA Consumer magazine.
A 'Mortal Threat'
" V. vulnificus can cause illness in normally healthy individuals and poses the mortal threat of septicemia, or blood poisoning, to high-risk people," the article stated.
Groups who are particularly vulnerable to the bacterium are those with liver diseases and related problems such as alcohol abuse, people suffering from iron imbalances and individuals with weakened immune systems such as cancer or AIDS patients.
The organism, first identified in 1975, was responsible for 60 illnesses and 36 deaths in the last decade. The number of cases, however, is "significantly underreported," according to FDA officials.
Known symptoms of the illness include abrupt onset of chills, fever, nausea, vomiting and abdominal pain.
More than half of the nation's supply of these increasingly popular shellfish, or about 20 million pounds of shucked meat, come from the Gulf of Mexico. Sales of oysters from the region were estimated at about $46 million last year.
What impact the government's recommendation will have is uncertain. However, one federal estimate claimed that as much as 40% of all Gulf oysters harvested during the April-October period contain V. vulnificus.
A New Pathogen
As a relatively new pathogen, there is much about V. vulnificus that's unknown. Still puzzling scientists is why the organism, which is also found in Atlantic and Pacific Ocean oysters, seems to only cause illnesses when present in Gulf oysters. Further, it has yet to be ascertained what role, if any, warm water plays in the bacterium's development.
In addition to its public warning, the FDA is also urging Gulf oystermen to improve handling and processing techniques.
"That . . . means keeping the oysters clean and cool and getting them from the water to the consumer's stomach as fast as possible," according to FDA Consumer.
Health officials believe that improper storage temperatures and long transit periods may contribute to the health risk posed by any V. vulnificus present in oysters.
One possible solution for increasing Gulf oysters' safety would be to purge the shellfish of toxins before they enter retail channels. The method, considered too costly at present, involves placing the bivalves in salt-water tanks long enough so that any contaminants would be removed by continual infusion of clean water.
One health official familiar with the Gulf oyster situation says that healthy individuals are at little risk from eating the shellfish raw.
When to Eat, When Not to Eat
"Use common sense," said Richard Thompson, director of the Texas shellfish sanitation control division. "If you have a health problem then don't eat oysters raw. But if you are healthy and in good shape, then the risk of eating oysters now is no greater than it would be in December."
A spokeswoman for the National Fisheries Institute, a trade group, said that eating any uncooked food may pose a risk.
"We feel strongly that when eating raw seafoods, or any raw foods in general, that the consumer should understand the risk and that they should cook (the items) before they are eaten," said the Institute's Clare Vanderbeek.
In the past, the FDA has also issued statements warning against eating fish or shellfish that is raw or undercooked.
Oyster Warning Label?--The current FDA focus is fueled by a recent court decision in which a judge ruled that the state of Louisiana was liable for damages resulting from a case of septicemia linked to consumption of the state's oysters.
The ruling stated, in part, that Louisiana was "has the power and responsibility to warn, and should have warned, the man (who became ill) and the public about the dangers of eating raw oysters," FDA reported.
A proposal to label shipments of Louisiana oysters with a health warning was, in fact, brought forward at a recent meeting of government and seafood industry officials in Denver, according to Food Chemical News.