My daughter and I were recently diagnosed with Lyme disease. I have been struggling with the question of how Lyme relates to CFS, and whether we really have CFS at all. I came across this on the Columbia University Medical Center website: I found this interesting because it comes from a Lyme doctor. The only comments I had heard about Lyme and XMRV prior to this were from Dr. Mikovitz. I believe she indicated at some point that 30% of Lyme patients they tested were positive for XMRV, and that treating both the Lyme and XMRV might be necessary. For now, we will proceed with Lyme treatment, and follow the developments on XMRV carefully. The quote is here: http://vesta.cumc.columbia.edu/lymedisease/news/user/featNews.php?sel=newsFeat The website is a good source of Lyme information.