FDA Warns About Raw Pacific Northwest Oysters

ROCKVILLE, Md., Aug. 2 -- The FDA has issued a nationwide warning to fans of Pacific northwest oysters to refrain from eating them raw, on pain of gastrointestinal distress, until the waters where they are harvested cool off.

Oysters harvested in the Pacific Northwest have been linked to several reported cases of gastrointestinal illness, which prompted the agency to issue its advisory on eating them raw.

The oysters were contaminated with Vibrio parahaemolyticus, naturally occurring bacteria that thrives during summer months when Pacific Ocean waters are warmest. The bacteria does not, however, survive cooking so the warning did not extend to cooked, broiled, steamed, fried or stewed oysters.

The FDA warned that until the threat of Vibrio parahaemolyticus has passed, consumers should only eat thoroughly cooked Pacific northwest oysters. They also should thoroughly cook oysters if they are not certain of the oysters' origin, or if they wish to further reduce their risk of infection from bacteria that may be found in raw oysters.

Among healthy individuals, Vibrio parahaemolyticus infection usually causes mild symptoms such as diarrhea, abdominal cramping, nausea, vomiting, fever that occur within 24 hours of ingestion and last no longer than three days.

But among the elderly or those with compromised immune systems the bacterium can trigger septicemia.

Pacific northwest oysters are distributed nationally. Although most of the illnesses reported have occurred in the Pacific northwest, some have been reported in New York State as well.

In Washington State, shellfish control authorities are identifying and closing areas where people have become sick from eating oysters. Washington State has initiated a recall of all shell stock oysters (oysters in the shell) harvested from areas closed within the state. Because of the potential for nationwide distribution, consumers are advised to follow recall instructions and return associated shell stock oysters to the retailer from which they were purchased.

The FDA advisory also included these recommendations:

At restaurants:

• Order oysters fully cooked.

In the shell:

• Purchase oysters with the shells closed. Throw away any oysters with shells already opened.
• Boil oysters until the shells open. Once open boil for an additional three to five minutes.
• Add oysters to water that is already steaming and cook live oysters until the shells open, once open steam for another four to nine minutes.
• Use smaller pots to boil or steam oysters. Using larger pots, or cooking too many oysters at one time, may cause uneven heat distribution, which may cause the oysters in the middle to not get fully cooked.
• Discard any oysters that do not open during cooking.

Shucked oysters:

• Boil or simmer shucked oysters for at least three minutes or until the edges curl.
• Fry at 375 degrees for at least three minutes.
• Broil three inches from heat for three minutes.
• Bake at 450 degrees for 10 minutes.