Swine flu: FAQ
Human infection with swine flu viruses are most likely to occur when people are in close proximity to infected pigs, such as in pig barns and livestock exhibits at fairs. (Kiichiro Sato/Associated Press)
A flu outbreak affecting more than 900 people in Mexico, including at least 16 who died, was caused by a new strain of swine influenza "that can attack anyone," Mexico's health minister said Friday.
"It is a virus that mutated from pigs and then at some point was transmitted to humans," Jose Angel Cordova Villalobos said.