The U.S. is having its worst year for measles spread in more than three decades, with a total of 1,288 cases nationally and ...

New versions of the H5N1 virus are increasingly adept at spreading. Suggestions to either let it rip in poultry or vaccinate the birds could backfire.

The U.S. Centers for Disease Control and Prevention (CDC) announced the end of the bird flu emergency, at least for now.