Policemen wearing surgical masks monitor the entrance to the General Hospital in Mexico City, Friday, April 24, 2009, where people were lining up in droves. (AP Photo/Dario Lopez-Mills)

And here we go. Since I first posted yesterday about swine flu, the number of U.S. cases has more than tripled from two to seven, plus another nine suspect cases, and Texas has been added to the list of states reporting swine flu infections.

Authorities from the Centers for Disease Control and Prevention are promoting basic public health measures to contain the U.S. spread, since swine flu is, in fact, contagious and spreading from person to person. You know the drill: wash your hands, don’t hang out with sick people and, if you are sick, throw away your germ-filled tissues instead of leaving them on your desk. You can see more about the agency’s guidance and ongoing investigation here.

Compare that somewhat measured response with what’s happening in Mexico where classes were cancelled in Mexico City. Sixteen people (and counting) have died from the swine flu outbreak and several hundred more are suspected ill, according to the New York Times. The country has also seen influenza cases spike in recent weeks, which is kind of weird considering that the flu season is usually over by now. The other piece of the puzzle is that the Mexican cases seem to be affecting young adults, as opposed to influenza’s favorite targets: the elderly and little kids. In a statement released today, the World Health Organization has said “these events are of high concern.”

Do you guys think this is the latest version of avian flu or SARS? Is it still too early to tell? It seems like it, but I’ll doubtless be demanding details from my husband, a medical epidemiologist. In the meantime, wash your hands and read more infectiously readable stuff at HowStuffWorks.com:
How the Flu Works
How Bird Flu Works
Why are British scientists creating a human-pig hybrid?
10 Worst Epidemics