US health authorities have urged restaurants and food outlets to stop selling all fresh, frozen and canned oysters, clams and mussels that came from South Korea over contamination fears.
"These products and any products made with them may have been exposed to human fecal waste and are potentially contaminated with norovirus," the Food and Drug Administration said in a statement issued late Thursday.
The FDA said the measure also applies to any scallops that arrived in the United States before or after May 1 when the FDA removed such products from the Interstate Certified Shellfish Shippers List.
The United States documented some cases of norovirus linked to the consumption of South Korean oysters as recently as 2011, but there have been no such cases reported this year.
Norovirus typically causes nausea, vomiting and stomach cramps. The accompanying dehydration can cause some to seek medical treatment.
The latest move came after an FDA evaluation found that "the Korean Shellfish Sanitation Program (KSSP) no longer meets the sanitation controls specified under the United States' National Shellfish Sanitation Program," it said.
The FDA cited "significant deficiencies" that include poor sanitary controls, ineffective management of land-based pollution sources and detection of norovirus in shellfish growing areas.
Korean shellfish makes up a small fraction of the oysters, clams, mussels and scallops sold in the United States.
Health authorities in Taiwan on Friday said they had intensified checks on oysters imported from South Korea following at least 62 cases of food poisoning cases in recent weeks.
About one-third of Taiwan's imported oysters come from South Korea.
[Oysters via AFP Photo / Lionel Bonaventure]