(Nature) – Mysterious US bird flu case in person without any known contact with an infected animal raises spectre of human-to-human transmission.

All eyes are on Missouri. Researchers are anxiously awaiting data from the midwestern state about a mysterious bird flu infection in a person who had no known contact with potential animal carriers of the disease. The data could reveal whether the ongoing US bird flu outbreak in dairy cattle has reached a dreaded turning point: the emergence of a virus capable of spreading from human to human. (Read More)