These actually enhance the transmission of viral and bacterial pathogens.
More disease. Lots more disease. That's Public Health!
I'm curious as to how that works (other than encouraging more frequent casual intercourse with strangers). Have you any links to research on the topic?
As noted in another post, much of the increase in VD is among male sodomites. I don't think they're dosing themselves with hormonal contraceptives. They're simply engaged in conduct that's inherently unsafe, unsanitary, and unhealthful.