I always appreciate your level headedness Cort but I fear in this case you're being a little too generous. Do CDC believe they are right? Well firstly I assume they believe that XMRV exists, I doubt even CDC would try to deny that. Do they believe that XMRV is unlikely to be found in CFS patients and their cohort in particular? Bearing in mind that we started with ME, a neuroimmune disease, and the CDC empirical criteria for CFS purposefully exclude those with any immune or neurological findings, this seems highly likely. Which brings us to the matter or prevalence in the general population. Do they believe that the prevalence rate in the general population is so vanishingly small that they found no trace of it in 100 plus samples? Even the 0.5% rate quoted by Vernon had a 50% chance of being detected. They could argue the geographic case, but they must be aware that the WPI cohort were geographically spread. Do they believe the WPI team, the positive prostate studies and Alter were all wrong and that the positive samples supplied to them were false positives? I'm afraid that's too much self belief for me. As for the fact that XMRV was unknown until a few years ago, this is no excuse. CDC are at fault, not for not finding the bug, but for not even looking for it. Perhaps they did genuinely look for DeFreita's virus and couldn't at the time find it. What they could have done was accept the physiological findings and carry on looking. Instead they disregarded the pathology and instead pushed a psychosomatic model and diluted the disease description which almost guaranteed that if CDC couldn't find the cause, neither could anyone else. Perhaps CDC's reputation as the nation's leading bug hunter was sufficient motivation to bury ME/CFS. After all, if they couldn't find this bug, why trust them with AIDS, Ebola etc. Switzer et al might have believed in their study (which assumes that CDC virology are completely ringfenced from the CFS people) but Reeves certainly didn't.