I'm calling BS. We've known of 6 STD's for at least 100 years: Syphilis, gonorrhea, chancroid, granuloma inguinale, lymphogranuloma venereum, and pediculosis.
I only know of two STDs that are incurable - HIV and Herpes; and they're both treatable.
Could you please name just two other allegedly "incurable" STD's?
I’m confused, are you disputing the idea that cohabitation is bad or are you simply questioning the statistics of curable vs. incurable STDs and when they first appeared?
Hepatitis B and HPV are both incurable, though there are some effective treatments and vaccines.