Ali, Mir A, Dale, Janet K, Kozak, Christine A et al. · Virology journal · 2011 · DOI
A 2009 study claimed to find a virus called XMRV in most ME/CFS patients, raising hopes for a viral cause. This 2011 study looked for the same virus in ME/CFS patients from similar U.S. regions but found no clear evidence it was present or unique to ME/CFS patients. The small DNA signals they detected appeared to be contamination from mouse DNA rather than actual virus infection.
This study was critical for the ME/CFS field because it provided evidence against a widely publicized viral hypothesis, preventing patients from pursuing ineffective treatments targeting XMRV. The rigorous methodology helped establish that contamination, not infection, likely explained earlier positive findings, refocusing research efforts on other potential mechanisms.
This study does not prove ME/CFS has no viral cause—only that XMRV is not a distinguishing feature of the disease in these patient cohorts. The findings do not rule out other viruses or infectious agents as potential ME/CFS triggers. Geographic, temporal, or sampling differences might explain why the original 2009 study reached different conclusions.
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
Ali, Mir A, Dale, Janet K, Kozak, Christine A, Goldbach-Mansky, Raphaela, Miller, Frederick W, Straus, Stephen E, et al. (2011). Xenotropic murine leukemia virus-related virus is not associated with chronic fatigue syndrome in patients from different areas of the us in the 1990s.. Virology journal. https://doi.org/10.1186/1743-422X-8-450
BibTeX
@article{mecfsatlas-ali-2011-xenotropic-murine,
author = {Ali, Mir A and Dale, Janet K and Kozak, Christine A and Goldbach-Mansky, Raphaela and Miller, Frederick W and Straus, Stephen E and Cohen, Jeffrey I},
title = {Xenotropic murine leukemia virus-related virus is not associated with chronic fatigue syndrome in patients from different areas of the us in the 1990s.},
journal = {Virology journal},
year = {2011},
doi = {10.1186/1743-422X-8-450},
note = {PubMed: 21943244},
url = {https://www.mecfsatlas.com/evidence/ali-2011-xenotropic-murine},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-28. https://www.mecfsatlas.com/evidence/ali-2011-xenotropic-murine
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