Once in a while I read somewhere online an article that tells people not to worry about sexually transmitted diseases, because they are rare, and most of them can be easily cured by antibiotics anyway, so the dangers of having a lot of sex with random people are exaggerated. (And then the article often becomes political and starts explaining why the bad guys -- the conservatives -- want to scare you into having less happiness in your life. Because they are stupid and evil, duh.)

How realistic is this? The argument about frequency of diseases in population ignores the fact that the risk is not distributed evenly. For reasons similar to "why your average Facebook friend has more friends than you (because having a lot of friends makes them also more likely to become your friend)", having a lot of sex with random people will make you more likely to have sex with partners who also have a lot of sex with random people, therefore the risk is higher than the statistics calculated for people with average behavior would suggest. (Seems to me that the usual hypocrisy could actually be a good strategy here: if you decide to have sex with many partners, it still makes sense to avoid people known to have sex with many partners.)

However the part "can be cured by antibiotics" also deserves some attention. The words "can be" do not necessarily imply ~100% success, although the article can make such impression. If I understand it correctly, using antibiotics is like carpet bombing the microorganisms in your body: you will do a lot of damage to your gut flora, but the intended target is likely to survive. Also here is the evolutionary arms race against the diseases: the more people rely on the "antibiotics can cure anything" strategy, the greater evolutionary pressure there is on bacteria to mutate into variants resistant to the known antibiotics. And the bacteria can mutate much faster than we can invent new antibiotics. This seems like a "tragedy of commons" scenario.

I'm interested in your opinions in general, but especially whether my reasoning about the antibiotics is more or less correct.