A teenager in British Columbia was hospitalized in critical condition with the disease, and officials were working to find out how the person was exposed to the virus.

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.

Canadian health officials announced Tuesday that a teenager infected with H5N1 bird flu from an unknown source is in critical condition.According to British Columbia Provincial Health Officer Bonnie Henry,