Highly pathogenic avian influenza, commonly called bird flu, has increasingly spread to mammals and infected hundreds of people, raising concerns that it may lead to human-to-human transmission and turn into a new pandemic.

The detection of bird flu in a sheep is another sign that the H5N1 virus is adapting to hop to new hosts

A United Nations food agency warned that the continued spread of the H5N1 bird flu virus is an unprecedented food security risk that requires a coordinated global response. In a briefing held on