Canadian oysters may be making Americans sick with norovirus: FDA

The U.S. Food and Drug Administration (FDA) has partnered up with its Canadian counterpart to investigate whether contaminated oysters were sold south of the border.

The FDA explained in a press release that it is in communication with the Canadian Food Inspection Agency (CFIA) and looking into a “multi-state outbreak of norovirus” linked to oysters originating from British Columbia.

READ MORE: Norovirus outbreak in Canada — here’s what’s triggering the vomiting bug

“Potentially contaminated” oysters from B.C. were sold in California, Illinois, Massachusetts, and Washington — it’s possible that other states may also be affected.

“FDA and the states are conducting a traceforward investigation to determine where the raw oysters were distributed and ensure they’re removed from the food supply,” the release read.

It warned that oysters harvested from several locations in Baynes Sound, B.C., should not be sold, distributed or eaten.

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“People should not eat any raw oysters from the locations listed above. If they have any of the listed products, they should throw them in the garbage.”

The U.S. food authority did not report how many people, if any, have contracted norovirus from oysters.

Canadian cases

In Canada, the oysters from B.C. farms have led to gastrointestinal illness cases in recent months.

While no deaths have been reported, many individuals reported becoming sick between mid-March to early April after eating B.C. oysters.

According to the public health agency, as of mid-April, there have been 126 reported cases of gastrointestinal illnesses in the country directly related to oysters — 92 in B.C., nine in Alberta and 25 in Ontario.

READ MORE: 9 cases of gastrointestinal illness in Alberta could be linked to raw B.C. oysters

Though not all the cases have been tested, the health agency says that norovirus is the dominant infection.

The most common symptoms of the illness are nausea, vomiting, diarrhea and stomach cramps, but others can include a fever, chills and aches. Those with weaker immune systems, such as pregnant women, young children or the elderly, may develop more severe symptoms.

WATCH: How to avoid picnic food poisoning

How to handle oysters

While the FDA recommends all raw oysters from certain B.C. farms be thrown out, it also warns that consumers should follow food safety precautions all the time while handling the seafood products.

That includes washing hands, utensils and surfaces with hot, soapy water after handling food.

READ MORE: Got norovirus? 5 things you need to know about the ‘winter vomiting bug’

Canada’s Public Health Agency advises that oysters should be fully cooked in order to kill norovirus — partially cooking will not solve the problem. That means they should be cooked to an internal temperature of 90 C, or 194 F.

Oysters that don’t open while cooking should be thrown away, and any leftovers should be refrigerated immediately.