Health officials say the number of gastrointestinal illnesses associated with raw oysters that made over a hundred people sick in three provinces appears to be dropping.
The Public Health Agency of Canada says there’s been a decrease in the number of cases reported to the investigation team, which it says indicates the outbreak may be slowing.
A total of 172 cases of gastrointestinal illness, suspected to be norovirus, linked to oyster consumption have been reported in British Columbia, Alberta and Ontario.
Most people reported eating raw oysters from the south and central parts of Baynes Sound, B.C., before they got sick.
The BC Centre for Disease Control says four shellfish farms linked to illnesses have been closed.
The Public Health Agency of Canada says people should fully cook oysters before eating them.
“Lightly cooking oysters does not kill norovirus,” the agency says.
The exact source of the contamination has not been determined, but the agency has said that human sewage in sea water is a possible cause.
No deaths have been reported.
Illnesses associated with raw oysters or shellfish contaminated with viruses or bacteria commonly cause vomiting, watery diarrhea and abdominal cramps.
Other symptoms can include nausea, fever, headache and bloody stools.