DEAR DOCTOR K: I heard that a dangerous new kind of "bird flu" was recently discovered in China. Should we in the United States be worried?
DEAR READER: You're right: In March 2013, cases of a brand-new kind of bird flu were discovered in China. One of the hardest things to predict is what will happen when a new strain of the influenza ("flu") virus first infects humans. I'm not exaggerating when I say it could turn out to pose no threat at all in the U.S., or it could be truly terrible.