So it is, again, we are driven to report evidence-based absence of evidence for a very contentious virus: the murine retrovirus known as XMRV. From a preprint online publication in Journal of Virology:
Absence of XMRV and other MLV-related viruses in patients with Chronic Fatigue Syndrome
J. Virol., published ahead of print on 4 May 2011 doi: doi:10.1128/JVI.00693-11
Clifford H. Shin, Lucinda Bateman, Robert Schlaberg, Ashley M. Bunker, Christopher J. Leonard, Ronald W. Hughen, Alan R. Light, Kathleen C. Light, and Ila R. Singh
“Chronic fatigue syndrome (CFS) is a multi-system disorder characterized by prolonged and severe fatigue that is not relieved by rest. Attempts to treat CFS have been largely ineffective primarily because the etiology of the disorder is unknown. Recently CFS has been associated with xenotropic murine leukemia virus-related virus (XMRV) as well as other murine leukemia virus (MLV)-related viruses, though not all studies have found these associations. We collected blood samples from 100 CFS patients and 200 self-reported healthy volunteers from the same geographical area. We analyzed these in a blinded manner using molecular, serological and viral replication assays. We also analyzed samples from patients in the original study that reported XMRV in CFS. We did not find XMRV or related MLVs, either as viral sequences or infectious virus, nor did we find antibodies to these viruses in any of the patient samples, including those from the original study. We show that at least some of the discrepancy with previous studies is due to the presence of trace amounts of mouse DNA in the Taq polymerase enzymes used in these previous studies. Our findings do not support an association between CFS and MLV- related viruses including XMRV and off-label use of antiretrovirals for the treatment of CFS does not seem justified at present.”
I would have said “enough said, then!” Except that this will not be the end. Oh, no….