Retroviruses are rare in the general population, whereas most other viruses found in ME/CFS patients are ubiquitous. Most viruses discovered in ME/CFS patients have been common or fairly common herpesviruses such as CMV, Epstein Barr, HHV-6. A finding of a retrovirus in 95 percent of a patient group argues very strongly for causality.

This is why our ME/CFS luminaries — including the doctors who have put their careers on the line for ME/CFS patients — are making strong statements about XMRV being a cause of ME/CFS. Dr. Paul Cheney, who treated patients in the Incline Village cluster outbreak of ME/CFS, wrote, “The finding of antibody or active virus in 95% of CFS and 4% of controls is a result that argues for causality, in my opinion, especially with the associated RNAse-L corruption and NK functional impairment that might predict such an infection.”

Dr. David Bell, who treated a cluster outbreak of ME/CFS in Lyndonville, NY stated in his newsletter,”Now I am not going to be too optimistic — I think XMRV is going to turn out to be the ’cause’ of ME/CFS, and I think treatments will be available from every family physician in America who accepts Medicare. The question is whether this occurs next year or twenty years from now.”