"May have been caused by a viral or bacterial infection" is how it is worded in everything I have read on the matter. Surely heredity is a factor, my Rheumatologist assures me of that. An infection could be a trigger, or one of many triggers. Injury and stress are surely other high likelihood triggers or causes.
No, no one is sure right now. We may think that there is nothing on the list, or in addition to the list, that could have triggered our illness, but perhaps there is a flu that we just never really got rid of ?
Yes, Mytoplasmas have been thrown in the discussion ring before, it may have been on the PsA or Fibro site that I first noticed them. They are essentially a bacteria that lacks a cell wall and because of this characteristic most common antibiotics are ineffectual as they target cell wall synthesis. From my take on it, that is the shortest of answers, but someone correct me if I'm not on target here, please.