oystersAn outbreak of norovirus linked to B.C.-harvested oysters is now under Canadian federal investigation.

The Public Health Agency of Canada (PHAC) says it has taken on a leadership role in the investigation, now that cases have been reported in Alberta and Ontario, as well as B.C.

As of Feb. 14, the agency says it’s aware of 221 reported cases of norovirus connected to B.C. oysters.

“We knew in November-December that there were cases popping up in B.C., but it wasn’t until the middle of January or so … that we started seeing or hearing about other cases in Ontario and Alberta,” said Mark Samadhin, director of PHAC’s outbreak management division.

“We know that it’s oysters from B.C., but beyond that, we don’t know what’s contaminated the oysters.”

Samadhin said local investigations are still being carried out by provincial health authorities, the Department of Fisheries and Oceans (DFO) and the Canadian Food Inspection Agency (CFIA), but PHAC has taken on a coordinating role in the investigations now that the outbreak is multi-jurisdictional.

The best way to avoid contracting norovirus from shellfish is to follow proper food safety practices.

This includes ensuring shellfish is cooked all the way through before eating it, keeping raw food separate from cooked food, and to wash your hands thoroughly — particularly if you’ve had contact with someone who is ill themselves.

Symptoms of norovirus include nausea, vomiting and diarrhea. (It’s the same virus that causes the “winter vomiting bug.”)