British Columbia health officials have yet to identify a likely source of the infection, though none of the teen's contacts have tested positive for the virus so far.

A teenager has been left in critical condition after contracting the first presumptive human case of avian influenza in Canada. Expert Sam Scarpino discusses the health risk and potential for spread.

OTTAWA (Reuters) -Canada has detected its first presumptive case of H5 bird flu in a person, a teenager in the western province of British Columbia, health officials said on Saturday. The teenager likely caught the virus from a bird or animal and was receiving care at a children's hospital, the province said in a statement.