I love the idea of having a retrovirus. Of course, I am past childbearing age, already married and don't have any children. But if I don't have a retrovirus, as has been said, I might have some other pathogen which would involve the same issues.
I suspect that there are many retroviruses that have yet to be discovered. XMRV seems to have unusual features of disappearing from the blood. It also has "triggers", indicating some periods of little or no activity. All of this, of course, contributes to why it was only discovered in 2006.
How many others are there like this one or with other unusual features? As has been said, someone needs to pull out the DeFreitas work and take another look.
Tina