Why do I consider the presence of XMRV to be confirmed if there are conflicting studies?
- The testing and science used in the study was excellent. When looking for a needle in a haystack, you need the right tools or you won't find it. Not finding it doesn't mean it's not there.
- The researchers were unrelated to the WPI researchers and had no financial ties. I consider the WPI folks to be excellent and motivated by the right reasons, but independent verification and confirmation still adds a lot.
- That the healthy patients were mostly negative while CFS patients were largely positive confirms that the testing was not "too sensitive." A second form of confirmatory testing was also done to confirm positive results.
This positive study distinguished people with CFS from healthy controls, was well done, and was conducted independently of any financial interests. That it reproduced the findings seen earlier in another well-done study is very convincing. Given this, other studies that found no XMRV in anyone suggests the researchers might need new eyeglasses.
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As lawyers and debaters are fond of saying "absence of evidence is not evidence". When the quack concluded that "all tests were normal" and therefore there was nothing wrong with me, I pointed out that what he'd tested for merely proved I didn't have diabetes, anemia, or lupus. It did *not* prove that I didn't have something else he hadn't tested for. There were oodles of virii that wouldn't show up on the tests he did, and oodles more for which there wasn't a test yet.
Eventually, another doctor did a C-Reactive Protein test (which confirms infection or inflammation), which was "off the charts" -- 10x what it should be. We still didn't know *which* virus I had, but we did have evidence that there was something very wrong physically.