Hundreds of norovirus cases now linked to B.C. oysters, PHAC says

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The norovirus outbreak involving raw oysters harvested in B.C. has infected almost 300 people, the Public Health Agency of Canada announced Thursday.

The agency says as of Wednesday, there had been 279 cases of norovirus linked to B.C. oysters, with the vast majority of those cases (262) found in B.C. residents. 

An additional 15 cases have been confirmed in Ontario, as well as one each in Alberta and Saskatchewan.

According to the PHAC, recalls of affected oysters were issued on Feb. 18, March 20, March 23 and March 27.

Those last three recalls came after Vancouver Coastal Health issued a public warning on March 18, noting a rise in reported gastrointestinal illness linked to B.C. oysters. At that time, the health authority said more than 50 cases had been reported, though not all had been confirmed to be norovirus. 

Vancouver Coastal Health also noted that several oyster-harvesting areas had been closed as a result of the surge in norovirus cases.

The Canadian Food Inspection Agency is continuing its investigation, and more products may be recalled, according to the PHAC.

"Do not eat, use, sell, or serve the recalled oysters," the agency's statement reads.

"Also, avoid eating raw or undercooked oysters to reduce your risk of foodborne illness and follow proper food handling practices. Cook oysters to an internal temperature of 90 degrees Celsius (194 degrees Fahrenheit) for a minimum of 90 seconds."

Symptoms of norovirus include nausea, cramping, chills, fever, vomiting and diarrhea, and generally emerge between 12 and 48 hours after exposure. The symptoms typically come on quite suddenly and most people feel better within a day or two.