The Public Health Agency of Canada collaborated with federal and provincial public health partners, the United States Centres for Disease Control and Prevention (U.S. CDC), and the U.S. Food and Drug Administration to investigate an outbreak of norovirus and gastrointestinal illnesses involving five provinces: British Columbia, Alberta, Saskatchewan, Manitoba and Ontario. The outbreak appears to be over and the outbreak investigation has been closed.

Investigation findings identified consumption of raw oysters from British Columbia as the source of the outbreak. As a result, some oyster harvesting areas in British Columbia that were associated with the outbreak were closed as a part of the investigation.

The Canadian Food Inspection Agency (CFIA) issued several food recalls throughout February, March, and April. Links to each food recall associated with this investigation can be found at the end of this public health notice.

The outbreak investigation is an important reminder to Canadians and businesses that raw oysters can carry harmful germs that can lead to foodborne illness if not properly handled and cooked prior to consuming.

In total, 339 confirmed cases of norovirus and gastrointestinal illness were reported in the following provinces: British Columbia (301), Alberta (3), Saskatchewan (1), Manitoba (15) and Ontario (19). Individuals became sick between mid-January and early April 2022, and no deaths were reported.

Some oyster harvest areas in British Columbia that were associated with illnesses in the outbreak were closed as a part of the investigation. The CFIA issued several food recalls throughout February, March, and April. For more information on the recalled products, please consult the Government of Canada’s Recalls and Safety Alerts website.

The U.S. CDC also investigated a multistate norovirus outbreak linked to raw oysters from British Columbia.

Illnesses: 103 illnesses* have been reported as of April 6, 2022

States affected: CA, CO, FL, HI, IL, MA, MN, NJ, NV, NY, OR, TX and WA

Recall: No

Investigation Status: Active

*This number is an estimate based on the information we have at this time. CDC is working with state and local partners to determine a more accurate number of illnesses in this outbreak and will update this number as more information is gathered.