Irlbeck, David M, Vernon, Suzanne D, McCleary, K Kimberly et al. · BMC research notes · 2014 · DOI
Researchers investigated whether two viruses (XMRV and pMLV) were present in people with ME/CFS, as had been suggested by earlier studies. They collected blood samples from people with ME/CFS and healthy people across five different U.S. locations and used sensitive testing methods to look for these viruses. They found no meaningful difference in virus detection between the two groups, and the virus sequences they did find appeared to be contamination from lab materials rather than real infections.
This rigorous, multi-site study provides important negative evidence that resolves conflicting earlier reports claiming viral associations with ME/CFS. By using well-characterized patient samples and standardized methods, it helps clarify what is not causing ME/CFS and redirects research toward more promising investigative directions, reducing false hope from unconfirmed viral hypotheses.
This study does not prove that no viruses are involved in ME/CFS—only that XMRV and pMLV are not consistently associated with the condition. It also does not rule out other viral triggers or cofactors; it specifically addresses these two murine retroviruses. The negative finding does not establish the underlying cause of ME/CFS.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
The first block is for the primary paper and is the citation you should use in research work. The atlas-snapshot line only applies if you are specifically referring to this atlas’s reading of the paper on the date shown.
Primary citation
Irlbeck, David M, Vernon, Suzanne D, McCleary, K Kimberly, Bateman, Lucinda, Klimas, Nancy G, Lapp, Charles W, et al. (2014). No association found between the detection of either xenotropic murine leukemia virus-related virus or polytropic murine leukemia virus and chronic fatigue syndrome in a blinded, multi-site, prospective study by the establishment and use of the SolveCFS BioBank.. BMC research notes. https://doi.org/10.1186/1756-0500-7-461
BibTeX
@article{mecfsatlas-irlbeck-2014-association-found,
author = {Irlbeck, David M and Vernon, Suzanne D and McCleary, K Kimberly and Bateman, Lucinda and Klimas, Nancy G and Lapp, Charles W and Peterson, Daniel L and Brown, James R and Remlinger, Katja S and Wilfret, David A and Gerondelis, Peter},
title = {No association found between the detection of either xenotropic murine leukemia virus-related virus or polytropic murine leukemia virus and chronic fatigue syndrome in a blinded, multi-site, prospective study by the establishment and use of the SolveCFS BioBank.},
journal = {BMC research notes},
year = {2014},
doi = {10.1186/1756-0500-7-461},
note = {PubMed: 25092471},
url = {https://www.mecfsatlas.com/evidence/irlbeck-2014-association-found},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-29. https://www.mecfsatlas.com/evidence/irlbeck-2014-association-found
Contribute
Private, reviewed by a human. Not a public comment thread.