It does make you think doesnt it, if they have found nothing you would expect them to be shouting that from the roof tops by now wouldnt they ? Because of the high infection figures in the science paper both cfs and healthy population, the implications must be frightening to them, for so many reasons.
I don't think the CDC really likes to confirm discoveries, they like to be the ones to make them. And it is possible that long-standing inter-agency rivalry could mean that they especially wouldn't want to confirm a discovery made, in part, by the NCI.
You know, I once held the CDC in very high regard. Their whole behavior toward "CFS" has been very disillusioning. <sigh> These people are not our friends.