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U.S. Department of Health and Human Services

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Questions and Answers about the Impact of FDA’s New Policy to Prevent Vibrio vulnificus in Gulf Coast Raw, Untreated Oysters


Is FDA banning the sale of all raw oysters?

No, FDA is not banning the sale of any raw oysters but rather calling for the post-harvest treatment of certain raw oysters to make them safer to consume.  FDA has announced its intention to change a policy regarding post-harvest treatment of raw oysters that would be applicable to about 13 percent of oysters harvested in the United States.  The change in policy would apply only to processing of oysters harvested during warm months in the Gulf of Mexico and that are intended to be eaten raw. 

FDA is taking this action to address the approximately 30 Vibrio vulnificus illnesses, with a 50 percent mortality rate, that occur each year as a result of Gulf-produced raw oyster consumption.  The large majority of these illnesses occur in the months that would be affected by this change in policy.  FDA’s revised policy would decrease the number of Vibrio vulnificus illnesses by about two-thirds annually. 

Regarding the percentage of oysters affected, FDA notes that:

  • Half of all oysters sold to consumers are cooked.  These oysters would not be affected by the new policy. 
  • The intended new policy would affect approximately 13 percent of all oysters harvested in the United States. 
    • The Gulf Coast is responsible for approximately 67 percent of all oysters harvested in the U.S. 
    • Of these, approximately 40 percent are harvested during warm months.
    • Of these, only about half of the Gulf Coast oysters are eaten raw.  Therefore, this would affect about one-quarter of Gulf Coast oysters, which is equal to approximately 13 percent of the national total oyster harvest.
  • FDA’s ability to enforce the post-harvest processing requirement would be limited to oysters moving in interstate commerce, but we believe the use of post-harvest processing is the right approach for all raw oysters harvested in the Gulf in the warm weather months and expect it to become the generally recognized standard of care.

Will FDA’s new policy impose prohibitive costs on the oyster harvesting industry on the Gulf Coast?

The Gulf Coast oyster industry is already subjecting about 15 percent of its oysters to post-harvest processing. There are some costs involved with post-harvest processing – approximately 3-4 cents per oyster by one estimate involving the most commonly used technology for summer-harvested oysters, according to a study commissioned by the Interstate Shellfish Sanitation Conference in 2000.  However, there are economic advantages as well.  According to the same study, these advantages include: 

  • Those using post-harvest processing are able to obtain higher prices for treated oysters because of increased safety and other quality-related characteristics of treated oysters, thereby improving the value of Gulf Coast oysters.
  • FDA allows marketers of processed raw oysters to state that they have been processed to improve safety.  The number of consumers of raw oysters may increase as the public understands that the risks associated with Vibrio vulnificus have been largely removed.    

Finally, there are ways to reduce the capital equipment costs associated with post harvest treatment technology.   As described in the study commissioned by the Interstate Shellfish Sanitation Conference, the Gulf Coast shellfish industry could form cooperatives to reduce costs associated with equipment.  The cooperative model was used successfully by the dairy industry in order to reduce their costs for pasteurization equipment and facilities.  And companies already exist in the Gulf Coast with whom harvesters can contract to have their oysters treated. 

Will FDA’s policy cause widespread unemployment in the Gulf Coast region?

Over three-quarters of Gulf Coast oyster production would not be affected by FDA’s policy – because they are not harvested in warm weather months, are not consumed raw, or are already processed.  Additionally, FDA intends to implement its policy in the 2011 harvesting season in order to provide time for the oyster industry to adapt.  FDA will provide technical assistance in support of efforts by individual firms, cooperatives, or economic development agencies to make processing facilities accessible to as many harvesters as possible.     

Will people eat raw oysters that have undergone the post-harvest processing needed to eliminate the threat of Vibrio vulnificus infections? 

Yes.  A study funded by the Interstate Shellfish Sanitation Conference in 2000 found that six of seven restaurants using treated oysters report that their patrons do not notice a difference in the oysters served. 

Aren’t state regulators and the oyster industry addressing this problem well without the need for FDA to intervene?

State regulators and the oyster industry have made efforts to address the problem of Vibrio vulnificus, but they have not been successful.   In 2001, the Interstate Shellfish Sanitation Conference, which is comprised of state regulators and industry (and with the participation of the FDA), developed a control plan, which focused primarily on an education program intended to reduce deaths and severe illnesses by 60 percent in 7 years.  Eight years later, the only real reductions in death and disease have resulted from two actions:  (1) 15 percent of Gulf Coast oysters being treated; and (2) in 2003, the State of California banned the importation of untreated raw oysters from the Gulf Coast during warm months (April through October).  

The illness reduction plan agreed to in 2001 by state regulators and industry through the Interstate Shellfish Sanitation Conference envisioned post-harvest processing if the illness reduction goals were not met.  FDA’s decision to revisit its policy regarding post-harvest treatment was made only after the education program was given the full seven years to achieve results.   FDA is acting after the failure of the education program to make a significant difference in the number of illnesses.

Is the FDA acting abruptly and without providing affected parties an opportunity to comment on the policy?

No.  Over eight years ago, post-harvest processing was anticipated as the likely remedy to prevent severe illness and death from Vibrio vulnificus if the Interstate Shellfish Sanitation Conference’s education campaign failed to achieve results.  FDA intends to implement its policy for the 2011 harvesting season and, in the meantime, will be issuing for public comment a draft guidance document.  FDA will seek comment on such matters as:

  • Where and when the hazard posed by Vibrio vulnificus is reasonably likely to occur, which affects the geographic scope of the policy,
  • The availability of alternatives to post-harvest processing that are equally effective in reducing risk,
  • Ways in which the impact of new control measures on small business can be mitigated – such as through technical assistance, organization of co-ops, or other ways to facilitate economically sustainable access to processing facilities, and
  • How the public can become aware of and value the safety enhancement gained through post-harvest processing.

Isn’t the real problem of Vibrio Vulnificus infections that people with chronic illnesses are eating raw oysters when they should know better?

No.  Many individuals who become ill from Vibrio vulnificus are not even aware that they have a chronic disease that could put them at risk for a fatal infection from eating raw, untreated Gulf Coast oysters in the warm months.  For example, of the nearly 24 million people with diabetes, almost 6 million are not yet diagnosed.

Further, the education effort aimed at getting susceptible individuals to “understand their risk and change their eating behavior” has not been successful in decreasing the level of illness.