TCS Daily


The Oyster Wars

By Sandy Szwarc - May 13, 2003 12:00 AM

The love affair Americans have with raw oysters may soon be a thing of the past, if special interest groups get their way. As sensationalized "death on the half shell" stories - such as this cover story from D magazine - intensify panic over oysters' safety, spark lawsuits, and call for mandatory post-harvest processing and bans on raw Gulf Coast oysters, consumers have become increasingly afraid to eat oysters and restauranteurs are becoming hesitant to serve them. As a result, the seafood and restaurant industries of the Gulf states have been turned upside down. Clearly, this is the food scare du jour for this summer.

Raw oysters have long been the food of folklore and legends, arousers of passions and fears, and paradigms of fine taste. The legendary Auguste Escoffier (1846-1935), considered the father of fine French cuisine, first introduced the custom of serving raw oysters spread open on crushed ice with their lips quivering in their own exquisite salty juice. Casanova may have been their greatest fan, consuming fifty raw oysters every morning in the bath with his fancied lady; or so the stories go.

As delicious as history and gourmands find these morsels, today's stories are frightening. The old adage - you know the one, about eating oysters only in months with an "r" their names - has been reborn. But today's version isn't one of advice. It's one of alarm. Is there any truth to that old proverb piloting current fears? A look at its origins offers insights into what is legend and what are today's truths.

For M. F.K. Fisher, it was all poppycock. "This is wrong, of course," she wrote in Consider the Oyster (1941), "except that all oysters, like all men, are somewhat weaker after they have done their best at reproducing." Oysters spawn during warm months - without an "r" - which leaves their flesh softer and milkier. Early diners may have been wary of the difference in texture, but for plenty of gourmands nowadays, those slightly sweeter flavors are preferable, especially when served well-chilled.

Fisher speculated a second reason for this proverb. Early oyster fishermen promoted it to better ensure future harvests, she believed, giving female oysters time to give birth to their some twenty million eggs apiece before being plucked from the sea. Not to worry, today plenty of oysters are available year-round, said Chef Russell Scott, an associate professor at the Culinary Institute of America and ten time medal winner at the International Culinary Olympics.

The third possible basis for that old wives' tale was that in the days before refrigeration, refrigerated shipping and science-based safety oversight, bacterial counts - which rise at warm summer temperatures - often meant unwanted illness. Modern versions deduce that since the Gulf is warm, its oysters must also be dangerous. "These days, millions of Gulf oysters are consumed raw without any adverse effects," said Kirk Wiles, Director of the Seafood Safety Division, Texas Dept. of Health. "Instances of infection from Vibrio are really low and good fresh seafood reaches restaurants in cities across the country daily, oftentimes in under 24 hours from boat to your table."

Vibrio vulnificus is the bacterium associated with oyster-related illnesses. It's natural and normal in warm coastal waters and in all oysters. Vibrio is found in clean waters and has no relationship to pollution, Wiles emphasized. For healthy people, Vibrio is generally harmless and infections are not a problem, according to the U.S. Food and Drug Administration (FDA) and Centers for Disease Control (CDC). Rare infections can occur from eating oysters or exposing open wounds to seawater where the bacteria are present, but they're typically mild and self-limiting, resolving within three days. In most cases no treatment is needed.

The risks of getting sick are negligible. The CDC's Foodborne Diseases Active Surveillance Network, which tracks infections in the four Gulf Coast states, found an annual Vibrio infection rate of at least 0.6 per 1 million persons. "No major outbreaks of illness have been attributed to this organism," states the FDA's Foodborne Pathogenic Microorganisms and Natural Toxins Handbook. Cases are sporadic, albeit more common in warm months. Although raw Gulf oysters are being impugned in the media and were banned recently in California, Gulf oysters have been implicated in only about a third of Vibrio cases. "The potential for infections exists whenever raw oysters are consumed," the CDC stated in its June 04, 1993 Morbidity and Mortality Weekly Report. The largest reported outbreak in North America actually occurred in the Pacific Northwest in 1997.

Federal, state and local agencies, and everyone handling oysters from ocean to table have a vested interest in ensuring oyster safety. "The oyster industry has taken a lead in advancing new technologies and educating consumers who may be at risk," said Teddy Busick, Chairman of the Gulf Oyster Industry Council. "We take our responsibility to the consumer very seriously."

"Seafood is the most intensely regulated industry there is, next to milk," Wiles explained. "We follow very strict standards set by the National Shellfish Sanitation Program (NSSP), Gulf Coast states regulate the industry according to its guidelines, and the FDA reviews our regulatory programs to verify compliance." Oysters can only be harvested, and given certification tags, from approved sanitary waters meeting quality standards closely monitored by state health departments. Despite activists' allegations of shady illegal dealings, areas closed to harvest are carefully avoided by harvesters and vigilantly patrolled to guard against illegal catches. "There is absolutely no link between any Vibrio deaths and harvesting from prohibited areas," said Wiles. "No association whatsoever."

FDA research has found significant reductions in the probability of illness not just by controlling Vibrio levels at harvest, but with prompt chilling, so temperature criteria are rigorously enforced. Anyone who buys oysters from a harvester and shucks, ships or packages them, or sells to retailers and restaurants must also be certified and follow the FDA's Hazard Analysis and Critical Control Point regulations. HACCP protocols are now used throughout the food and restaurant industry to ensure food safety and are effectively decreasing cases of foodborne illnesses.

The current seafood guidelines keep Vibrio levels so low that fewer than 0.6-percent of servings offer a risk of infection to most people, according to the FDA's 2001 scientific risk assessment. That's remarkably safer than almost any other food we eat. In contrast, organic chickens are 100 percent contaminated with campylobacter (three times more than conventional poultry) which has an estimated 4 million victims and kills up to 511 each year in this country alone, according to the FDA and the USDA Economic Research Service. The CDC found organic and all-natural produce eight times more likely to be contaminated with the deadly new strain of E.coli 0157:H7, which causes an estimated 250 deaths per year in the United States. [Imagine the outcry if the government banned all organic foods because of these far greater risks.]

The risk of dying from Vibrio in raw oysters is remote. "Raw oysters are safe for the vast majority of people," said Wiles. The FDA puts the annual deaths nationwide at around 12, according to the Texas Department of Health. That pales in comparison not just to campylobacter- or E.coli-related deaths, but to the over 63,000 American lives lost to common pneumonia, 42,000 in car accidents, 36,000 to the flu, and over 12,000 due to simple falls.

Certainly, it's heartbreaking when someone dies unnecessarily due to eating raw oysters, but all shellfish-related Vibrio deaths have been only in people with known preexisting health problems that put them at risk, according to the CDC, International Shellfish Sanitation Council Vibrio vulnificus Subcommittee, and the Texas Department of Health. Tragically, they made the choice to disregard FDA and posted restaurant warnings, and ate raw oysters anyway.

Although of no concern for healthy people, say experts at the FDA and CDC, Vibrio poses a significant risk to people with specific health problems that make them vulnerable to the bacteria, such as those with diabetes, liver disease, low gastric acid (due to surgery or who take antacids regularly), or compromised immune systems. The risk of death is almost 200 times greater in those with liver disease than those without liver disease, according to FDA research.

"The FDA's advice has always been and continues to be that people who are at high risk should not eat raw oysters,'' said Joseph Levitt, FDA's food safety chief. They've also added, that if people are unsure of their health, they should visit their doctor.

In the 1993 case of a Louisiana seafood restaurant sued when a patron with liver disease died after eating raw oysters, after reviewing all of the scientific evidence the Supreme Court stated, "a product is not unreasonably dangerous simply because it cannot be made entirely safe for all consumption....seen in this light, the "defect" is really found in the person rather than the product, much in the same way that sugar is harmful only when used by someone with diabetes." In all lawsuits concerning Gulf oysters between 1984 and 1997, the defendants have won all of the court decisions. The responsibility lies with diners to use common sense.

"Oysters are wonderful things and people have been consuming them for thousands of years," said David Blevins, Shellfish Specialist with the FDA's Dallas regional district office of the Shellfish Sanitation Program. "Just know you're okay before you eat them raw."

For the small subgroup of the population at risk, the only safe oyster is a well-cooked one. To date, research has found no level of Vibrio exposure known to be safe for those susceptible to the bacteria, and there's no known way to render a raw oyster risk-free for them. In the FDA's risk assessment, extremely low numbers of cells were implicated in infections in certain high-risk individuals.

Recently-introduced post-harvest processing methods, such as flash-freezing and low-heat pasteurization, are well-intentioned and sound good to those demanding completely risk-free foods, but could create a false sense of security. The FDA's risk assessment indicated freezing results in a 1 to 2 log decrease in viable Vibrio levels and mild heat pasteurization at least a 4.5 log decrease. Reducing, but not eliminating, Vibrio levels is still no guarantee of a risk-free oyster for those vulnerable to Vibrio. FDA's advisories remain unchanged. And, while issues are focused elsewhere-on bans and processing regulations-fewer people will get the one most vital message that could save their lives. The only assured way to prevent the handful of deaths in high-risk individuals is simply for them to not eat oysters raw.

Meanwhile, for the vast majority of people, who are already not bothered by the low Vibrio levels being maintained, it's unclear how expensive processing will significantly benefit them. Of concern to them isn't so much the added costs, or the impact that mandated post-harvest processing will predominately have on small restauranteurs and seafood companies, but taste. Freezing or heat-processing won't let them enjoy the raw, fresh, and all-natural oysters they love. And raw oyster-lovers are a pretty passionate bunch.

"Some gourmands say that any oyster worthy of its species should not be toyed with and adulterated," wrote Fisher. "Of those who will eat their oysters raw and only raw, they would die before denying that a perfect oyster, healthy, of fine flavor, plucked from its chill bed and brought to the plate unwatered and unseasoned, is more delicious than any of its modifications."

The bottom line: If you have a health condition that puts you at risk to Vibrio, don't eat raw oysters. Period. If you're unsure of your health, visit your doctor. Everyone else, relax and enjoy your oysters, well-chilled.
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