An investigation is underway after more than 70 people have gotten sick since early December from eating raw or lightly cooked oysters, according to the B.C. Centre for Disease Control.
“Testing in several of the cases confirmed the presence of norovirus, and we suspect norovirus in the others,” said Dr. Eleni Galanis, an epidemiologist at the CDC. "We don’t currently have a smoking gun.”
Officials say cases have been reported to Island Health, Vancouver Coastal Health, Fraser Health and the First Nations Health Authority.
Shellfish harvesting closures are being discussed with the Department of Fisheries and Oceans, which is investigating along with Environment Canada, Health Canada and the B.C. health authorities.
The centre has received reports of norovirus since Christmastime, but Galanis said the link between it and raw oyster consumption only became clear this week.
Last year saw an unusually high number of oyster-related norovirus outbreaks, she said, and this particular outbreak is also quite large.
Norovirus can cause constant vomiting and diarrhoea. She said it can be concentrated in oysters because they filter large amounts of ocean water.
The CDC recommends that people abstain from eating raw or lightly cooked oysters, particularly as this outbreak is occurring.
"Cooking at 90 degreees for 90 seconds will kill all microorganisms,” Galanis said.
Anyone who feels ill after consuming any type of shellfish should call B.C. HealthLink at 811 and see a doctor if symptoms are serious. If you suspect that your illness is linked to eating raw or lightly cooked oysters, you should report it to your local health authority.