A teenager in British Columbia has become the first person in Canada to test positive for the deadly H5N1 bird flu. Health authorities are urgently investigating how the virus spread, but they assure the public that the risk remains low.

A teenager diagnosed with bird flu in British Columbia is the first domestically acquired human case of H5N1 avian influenza, the Public Health Agency of Canada says. Since Influenza A or flu viruses are named after the animal where they are most commonly found,