A teenager in British Columbia, Canada has been hospitalized with a presumed case of H5N1 bird flu, the first detected human case in the country in the current outbreak.

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.

What's more, the spread of seasonal flu may offer H5N1 a chance to swap DNA with other influenza viruses and potentially get better at infecting humans or causing more-severe disease. With these concerns in mind, officials in both the U.S. and Canada are ...