Vancouver Coastal Health has issued a public service announcement, stating that restaurants in that province must cook oysters harvested in British Columbia before serving. Only oysters harvested outside of that province may be served raw at this time.
An ongoing outbreak of Vibrio parahaemolyticus relating to the consumption of raw oysters is ongoing in Canada. This bacteria is naturally occurring in coastal waters. This illness increases in the summer months, but the outbreak is large enough this year to warrant this preventative measure.
Thirty-one people have been sickened with Vibrio infections so far in Vancouver. The actual number of Vibrio illnesses is probably much higher, since most cases of foodborne illness are not reported to authorities. Only 16 cases were reported in 2014.
The symptoms of a Vibrio illness include watery diarrhea, cramps, vomiting, and fever. People who are at high risk for serious complications can suffer sudden chills, fever, and shock. If you have eaten raw oysters and have experienced these symptoms, see your doctor for treatment. The incubation period is short: about 2 to 48 hours. Most illnesses last for about a week.
People with liver disease, diabetes, stomach disorders, HIV, cancer, or other immune-suppressing illnesses can develop life-threatening complications if they contract a Vibrio infection. About half of Vibrio bloodstream infections are fatal.
Consumers should follow this advice too. If you eat raw oysters, do not buy oysters harvested in British Columbia. Cooking raw oysters will kill the bacteria and make the shellfish safe to eat.