I know that question sounds so kiddy and probably stupid but im only 16 and curoise, i know Std names and what they do to the human body and how there spread around the human population. but where did all of them come from?? I know where HIV / AIDS came from, but where did the rest come from?? I know, and ive asked if two people can create an std between eachother and they said no, and the only way you can get it is from another infected person. So im really wondering, where did these diseases and viruses come from? Where they formed from certian bacteria and viruses mixing by accident? or was it somthing else..?