Feds issue norovirus alert as 279 people get sick after eating raw BC oysters

Federal health officials have provided an update on a norovirus outbreak linked to raw BC oysters that they now believe has sickened 279 people.

The Public Health Agency of Canada (PHAC) said recalls of BC oysters have been issued on four dates since March 18 and that more may be issued.

Some coastal British Columbia oyster fishing areas have also been closed as federal and provincial health and food inspectors investigate.

The bulletin did not specify which areas were closed, but the recalls related to crop areas 14-15 and 14-8 between Denman Island and Vancouver Island.

Most norovirus cases associated with the outbreak (262) were reported in BC, however cases have also been documented in Alberta, Saskatchewan and Ontario. No deaths were reported.

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Source of BC-based norovirus outbreak traced

Earlier this month, Vancouver Coastal Health issued its own raw BC oyster alert after 50 cases were linked to shellfish.

Norovirus can cause severe gastrointestinal problems with symptoms such as diarrhea, vomiting, nausea and stomach cramps. According to PHAC, symptoms usually develop within 24 to 48 hours after consuming the affected product. Symptoms resolve in most people within a day or two and have no lasting health effects.

People who are pregnant or have a weakened immune system, as well as young children and the elderly are at higher risk.

People with severe symptoms should contact their doctor.

The public is urged not to eat any of the recalled oysters and to avoid eating raw or undercooked oysters.

According to PHAC, oysters should be cooked to an internal temperature of 90°C/194°F for at least 90 seconds before consumption.

BC experienced another raw oyster-related norovirus outbreak in 2016 and 2017, sickening an estimated 400 people across Canada.

Researchers at the BC Center for Disease Control later linked this outbreak to norovirus in sewage carried by ocean currents, along with colder-than-usual weather that helped the virus survive.