Avian flu typically spreads between wild and domestic birds but can spread to other animals and people. There have now been more than 40 confirmed human cases in the United States, according to the Centre for Disease Control,

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,

Federal health officials have confirmed that a B.C. teen who is currently in hospital has Canada's first human case of H5N1 avian flu.