Bird flu H5N1 has infected dozens of people in the U.S. this year. Could it be the next pandemic? Experts explain the threat and symptoms to watch for.

A Canadian teenager hospitalised with suspected H5N1 bird flu is now in critical condition, health authorities said on Tuesday.The patient, Canada’s first presumed human case of H5N1, was previously healthy and had no underlying conditions,

Cases of H5N1 bird flu in U.S. dairy and poultry workers have largely been mild. However, a new case in a British Columbia teenager has experts worried.

A Canadian teenager infected with bird flu — that country’s first case involving a locally acquired infection — is in critical condition and experiencing difficulty breathing, health officials said Tuesday.

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.

Canadian health officials have confirmed bird flu in a British Columbia teen. The Public Health Agency of Canada said Wednesday that tests showed the virus involved was related to a bird flu outbreak in poultry in the province.

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.

Canada has reported H5N1 bird flu in wildlife and domestic birds. This year, there have been at least 24 reports of the virus in domestic bird facilities, including at least 10 infected premises in BC in October, according to data from the Canadian Food Inspection Agency.

Amid an ongoing outbreak of bird flu in American dairy herds and poultry flocks, Canadian officials have announced that a teen in British Columbia has been hospitalized in critical condition with what is believed to be bird flu.