Korean shellfish imports have been blocked by the U.S. since May 1 because Korean waters may have been polluted with human fecal waste, the U.S. Food and Drug Admnistration (FDA) said on Friday. Oysters, clams, mussels and scallops harvested in Korea have the potential to be contaminated with norovirus, the agency said.

The Washington State Department of Health had reported the ban more than a week ago, but FDA had not publicly announced the reason for the action.

In a constituent update, FDA said all Korean certified shippers of molluscan shellfish were removed from the Interstate Certified Shellfish Shippers List (ICSSL), following an evaluation that determined “the Korean Shellfish Sanitation Program (KSSP) no longer meets the sanitation controls spelled out under the National Shellfish Sanitation Program.”

 

FDA said its evaluation found significant problems with Korean shellfish growing areas, including the discharge of human fecal waste from nearby fish farms and commercial fishing and aquaculture vessels. Norovirus was detected in shellfish growing areas during the evaluation.

Korean molluscan shellfish that entered the United States before May 1 and any product made with Korean molluscan shellfish are considered adulterated, the agency stated.

FDA said food distributors, retailers and food service operators should “remove from sale or service, all fresh, frozen, and processed Korean molluscan shellfish and any product subsequently made with them.” Consumers who have recently bought molluscan shellfish and are concerned that it may have come from Korea, should contact the seller and ask where the shellfish were harvested, the agency added, advising,  “Product from Korea should not be consumed.”

Canada, Chile, Mexico and New Zealand are the other countries that have shellfish sanitation agreements with FDA. Oysters, clams, mussels and scallops from the Republic of Korea are only a small fraction of the U.S shellfish market. 

Three cases of norovirus illness linked to frozen oysters from Korea were reported in Washington state last year, and a subsequent illness was reported in Pennsylvania.

That led to a series of recalls of frozen oysters from Korea, on Nov. 4 and 18, 2011, and on Jan. 23, 2012.