Avoid Raw Oysters, Clams from Pacific Northwest

The Food and Drug Administration is advising consumers not to eat raw clams harvested in the Pacific Northwest because of reports of a significant increase in gastrointestinal illnesses caused by Vibrio parahaemolyticus (Vp). This advisory updates a July 31, 2006, advisory to consumers on eating raw oysters harvested in the Pacific Northwest.

“FDA is working with the U.S. Centers for Disease Control and Prevention (CDC) and our state partners in this continuing investigation,” said Dr. Robert Brackett, Director of FDA’s Center for Food Safety and Applied Nutrition. “We will continue to update the public as more information becomes known.”

In recent months, there has been an unusual increase in bacterial illness associated with eating raw oysters and raw clams from the Pacific Northwest. The illnesses are associated with the naturally occurring bacterium Vp, which is most prevalent during summer months when water temperatures in the Pacific Northwest are most favorable for its growth. While Vp can cause mild gastrointestinal disorders in healthy individuals, older persons and those with weak immune systems are at greater risk for serious illness, such as septicemia (infection of the blood system).

Until the threat of Vp from shellfish harvested in the Pacific Northwest has passed, consumers are advised to thoroughly cook oysters and clams harvested from that area before eating. They also should thoroughly cook oysters and clams if they are not certain of their origin, or if they wish to further reduce their risk of infection from bacteria that may be found in raw oysters and clams.

Pacific Northwest oysters and clams are distributed nationally. To date there have been 72 laboratory confirmed and an additional 105 probable Vp illness reported from Washington State, Oregon, and New York linked to contaminated oysters and clams.

In Washington State, shellfish control authorities are identifying and closing harvest areas where oysters and clams associated with the illnesses originated. Washington State has initiated a recall of all shell stock 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 is currently working with state shellfish authorities to take appropriate action to address any product that be remaining on the market.

Cooking destroys the bacteria, eliminating the risk of illness for both healthy and immunocompromised individuals. The majority of illnesses that occur from the consumption of raw shellfish are not life-threatening to the general population and commonly range from mild intestinal disorders of short duration to acute gastroenteritis. The symptoms are watery diarrhea, often with abdominal cramping, nausea, vomiting, fever and chills. Usually these symptoms occur within 24 hours of ingestion and last no more than three days. Severe disease is rare and occurs most commonly in persons with weakened immune systems. Individual who believe they have experienced the same symptoms of illness after consuming oysters or clams should consult their health care provider and contact their local health department.

Persons with weakened immune systems, including those affected by AIDS; persons who chronically abuse alcohol, liver, stomach or blood disorders, cancer; diabetes or kidney disease should avoid raw oyster consumption altogether, regardless of where the oysters or clams are harvested. Consumers can continue to enjoy oysters and clams in many cooked preparations by following this advice.
At Restaurants and other Foodservice Establishments:

* Order oysters and clams fully cooked.

In the shell:

* Purchase oysters and clams with the shells closed.
* Throw away any oysters or shells already opened.
* Never allow raw seafood to come into contact with cooked food.
* Boil oysters and clams until the shells open. Once open boil for an additional 3-5 minutes.
* Steamer – add oysters and/or clams to water that is already steaming and cook live oysters and clams until the shells open, once open steam for another 4-9 minutes.
* Use smaller pots to boil or steam oysters and clams. Using larger pots, or cooking too many oysters or clams at one time, may cause uneven heat distribution, which may cause the oysters or clams in the middle to not get fully cooked.
* Discard any oysters or clams that do not open during cooking.

Shucked Oysters and Clams:

* Never allow raw seafood to come into contact with cooked food.
* Boil or simmer shucked oysters and clams for at least 3 minutes or until the edges curl.
* Fry at 375 degrees for at least 3 minutes.
* Broil 3 inches from heat for 3 minutes.
* Bake at 450 degrees for 10 minutes.

For further information contact:

FDA Food Safety Hotline: 1-888-SAFEFOOD
FDA website: http://www.cfsan.fda.gov/list.html

The material in this press release comes from the originating research organization. Content may be edited for style and length. Want more? Sign up for our daily email.