Didn't I read that they only used blood from severely ill CFS patients? I mean, there are many people who have CFS and are not bedridden.
If I remember right, the reason was that if you are severely ill from a virus, likely that virus is very active. Therefore, they are more likely to find the virus in blood of people severely ill. It doesn't mean the others don't have it. Remember even the severely sick showed only 67% with active virus.
Plus, now, their tests are not reliable as a commercial, FDA test. I am not dogging them, evidently there is a different level of precision with commercial, FDA approved test compared to research tests.
Isn't it interesting that 4% of healthy people showed active virus. Peterson said he thinks there is another factor, likely another virus, that contributes to people developing CFS, oops, I mean XAND.