In order to really understand PID, we really have to step back from those statistics and think about sexually transmitted diseases in general, and particularly those bacterial STDs, Gonorrhea and Chlamydia. These two STDs are exceedingly common worldwide. One third of a billion new cases of curable STDs occur every year. Unfortunately, the U.S. has nothing to brag about in this respect; our rates are 50 to 100 times higher than other industrialized nations.