Even some of the bacterial infections are getting smarter and treating them is becoming harder. I think that's the case with gonorea.
Probably a combination of environmental factors and previous bacteria which evolved with Humans.
Given the right environmental stimulus, the Human body will adapt to this stimulus.
Certain bacteria and viruses could have undergone changes in such an environment.
What I did notice however is that 'modern medicine' seems to be effective for a wide range of bacterial infections, but is relatively ineffective when it comes to viral ones.
I have been doing some research online about this. One theory is that HIV got into humans via bushmeat. People are exposed to a kind of virus SIV from bushmeat, which would have evolved to HIV. How STDs got so common is still confusing. May be natures way of controlling population.
How did any bacteria or virus start? Things could have been around for millions of years and just like anything evolve. There is no time line or way to find out.
HIV as it is "newer" has some roots, but reports of cases as early as the 50's exist in Africa. It is believed that it was transfered from monkeys to humans. Several tribes eat monkey brains uncooked and believe that is where the transfer happened.
That's actually something I've been asking myself.
Its an intriguing question and would be nice if someone could provide an insight into the topic.
Hi, may be ask dr hh about this