I've been wondering along similar lines. I have this thought in the back of my mind that somehow this retrovirus found it's way into humans via immunizations. Both my sisters (that is, all of my siblings) have CFS, and I can remember more than one occasion where we all received the same vaccines at the same time. Mom wasn't big on taking us to the doctor so much and we were commonly seen all together for the sake of convenience. It's hard to explain how all of my siblings and myself have CFS and our mother has no signs of any neuro-immune pathology going on at all. I have a few other theories as well; this is just one of them. I remember reading an article about 18 years ago on how the HIV virus jumped into humans. I can't remember every detail of the article because it was so long ago, but as I recall the article proposed that this happened when Dr. Jonas Salk was working on the polio vaccine. He injected polio virus into monkeys and then harvested their organs and made different trial versions of the vaccine. The human polio virus did not survive in the monkeys of course, but the monkeys' immune systems did produce antibodies that were close enough to be effective, or something like that. He actually tested it on humans by spraying it into the throats of tribal peoples and then waiting to see if they developed immunity to polio (remember this was the 1950's). Little did he know that he was also introducing all sorts of live simian viruses at the time and just a few little mutations later, there was HIV. This was in a very long article in a laboratory science magazine. It wasn't a scientific journal per se, but it was a magazine for pathologists, medical technologists, biochemists and other laboratorians. Like a Rolling Stone for lab geeks. I wonder sometimes if any of the vaccines that were used in the 1960's were similarly made using mice, or if something that could fit a similar scenario could have possibly taken place. It could happen even if vaccines were simply manufactured in the same room/facility or with the same equipment that research with mice had been done. I'm also reasonably certain that if a company that may have unknowingly (at the time) done this would not be eager for this information to come out. I'm not big on conspiracy theories myself, but for those who are, there's one for you.