Its great that they have also clarified key features of the Canadian guidelines, esp post exertional malaise, for any docs/readers who might be new to CFS/ME and why this is so important for patient selection in an ideal world.
Hello all, I'm new round here, by the way. (Although actually I've been lurking for months reading all your highly intelligent posts!)
I think the CDC would have done the "usual" tests to exclude infection and used mainstream definitions of infection to exclude patients with infection. (e.g. EBV IgM presence = active or recent EBV infection) But they might not have tested for viruses like HHV-6 (remember, viruses don't cause CFS in their view) and even if they did, a very high IgG might not be interpreted as an infection either but rather an epiphenomenon or an effect of the deranged system in CFS and thus ignored. This is the impression I get from reading CDC papers -- they often just use the blanket phrase that other diseases were ruled out rather than explicitly stating which tests were obtained in every subject to exclude illnesses.
So, short story, there are probably people in the CDC cohorts who have viremia but between low numbers due to case definition and questionable techniques, few were found with XMRV.
Yeah, I was confused by the "highly viremic" phrase as well. If Madmax is still around, I hope he/she asks the researchers to explicilty define what they mean by "highly viremic." Was it a clinical definition by symptoms or based on labs (e.g. high EBV/ HHV-6 titers)? No guessing should need to be done. Researchers would want to know and the WPI should have learned from the first Science paper that leaving definitions vague (such as the descriptions of the populations studied) causes problems. WPI, I donate money to you and while I appreciate your work, please tighten it up! I've published scientific papers and know if these issues had come up on my papers, I would be criticized for it.