How did stds first come about?

Well i've always thought about it. how did something like that first cme to be?
Lots of STDs have been around passed from person to person for thousands of years, like syphillis.

Some STDs (and other diseases, like the plague) may come from animals.But not from sex with animals as people like to say.

AIDs is thought to have originated as a primate disease (i.e. monkeys) but it wasn't fatal to the primates. At some point humans ate primate meat or were exposed to their blood or saliva (through a monkey bite, or butchering them, for example), and were exposed to the virus which later mutated to become a human disease.

Hope this helps!!!!
While many responses would give a timeline of hundreds or thousands of years, given the simplicity of the genetic structure of many STDs, they have been around for more than a few millions years. STDs are simply parasitic organisms which evolved over time to survive and thrive off of many different animal species, humans included.

You can't expect to get an STD from a monkey at the carnival, but over time, a virus or bacteriophage will evolve to find new hosts. HIV is a prime example, as some others mentioned. HIV originated as SIV, Simian Immonudeficiency Virus. Due to blood contamination during research studies on primates in the mid twentieth century, the infection evolved to accept human hosts, and became designated Human Immunodeficiency Virus by Robert Gallo and Luc Montagnier. HIV-1 is believed to have come from the Chimpanzee of the southern Cameroon, and HIV-2 is believed to have come from the Sooty Mangabey, also of southern Africa, including the Cameroon.

But as I said, STDs have spanned millions of years on this earth. For perspective, think about the common cold today. The cold is caused by a multitude of variations of viruses, including Rhinovirus, albeit very weak by some standards. With the advent of medication, we have given diseases and viruses a need to evolve, to become stronger, to fight back, and after many decades we see, that a lot of medications of old do not work anymore, and today the scare is much greater, due to all the preemptive medicating of humans and our food supply.
Well most stds have been around for thousands of years, I would think that it came from a bacterial infection that left untreated in a person developed into a virus and spread from there. More specifically, viruses like AIDS/HIV are synthesized, created by government for various reasons. Nobody will ever know excatly how stds started, all we can do is play guess games.
STD may be a old as mankind itself . Well know for hundreds of years.In English language has shot word for two of the most common the pox (sypillis) and clap (gonorrhea).

en.wikipedia.org/wiki/sexuallytransmit...
www.merck.com/mmpe/sec14/ch/194/ch194a...
www.std-gov.org/stds/std.htm
When we were trying to find the cure to Polio we used monkey blood to cure it, because monkeys were immune to Polio. But what we didn't know is that they carried other diseases, STDS. That is how Aids came about. They came from Monkeys.
std's have been around as long as people have. no way of knowing how it all started.
monkeys