Bird Flu's Latest Talons Force Fresh Defense

A surprise attack by a new strain of the bird flu virus has forced Chinese authorities into the trenches for a two-pronged defense against unseen enemies.

The primary threat is the deadly virus that scientists identified as a new strain of H7N9. It first surfaced in February in Shanghai and, as of April 16, had infected 66 people in six provinces and municipalities nationwide, claiming 14 lives.