The bacteria that causes gonorrhea, Neisseria gonorrhoeae, is notoriously good at adapting to avoid our attempts to kill it, said Dr. Robert Bonomo, professor of medicine, pharmacology, molecular biology and microbiology at Case Western Reserve University.
"Superstrains" of gonorrhea resistant to penicillin and tetracycline cropped up in the 1970s and '80s and to a class of drugs called fluoroquinolones, such as Cipro, in 2007.And why, oh why, do you think that these superstrains showed up in the 1970s and 1980s? Might it have been related to the replacement of traditional notions of sexual morality (backed up by not only social pressure but laws as well) with "If it feels good, do it"? The rate of STD infection of a population increases with the square of the number of sexual partners per time. Double the number of sexual partners per month and you quadruple the number of people infected; quadruple the number of partners per month, and you increase the infection rate by 16.
I don't have any illusions that in 1950s America, people stayed virgins until marriage, and never strayed. But the social pressure, fear of pregnancy, and a notion that some things were morally wrong at least kept the situation a bit in check.