Cuende, J I, Civeira, P, Diez, N et al. · Anales de medicina interna (Madrid, Spain : 1984) · 1997
Researchers tested 20 ME/CFS patients for active herpesvirus-6 (HHV-6) infection, a virus that had been suspected as a possible cause of ME/CFS. They found that half the patients had antibodies showing past HHV-6 infection, but sensitive testing detected only small amounts of viral DNA in blood cells and no active viral replication. This suggests that while many ME/CFS patients may have been infected with HHV-6 in the past, the virus is not actively multiplying in their bodies.
For decades, researchers have investigated whether herpesviruses like HHV-6 could explain ME/CFS's symptoms and underlying biology. This study helps clarify that while HHV-6 exposure is common in ME/CFS patients, evidence of active viral replication is absent, which has important implications for whether antiviral treatments might be effective and for understanding the true role of HHV-6 in the condition.
This study does not prove that HHV-6 plays no role in ME/CFS pathology; latent or persistent low-level infection (even without active replication) could theoretically contribute to immune dysregulation. The cross-sectional design cannot establish causation or determine whether HHV-6 triggered the initial disease. The small sample size limits generalizability of the findings.
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
Cuende, J I, Civeira, P, Diez, N, & Prieto, J (1997). [High prevalence without reactivation of herpes virus 6 in subjects with chronic fatigue syndrome].. Anales de medicina interna (Madrid, Spain : 1984). https://pubmed.ncbi.nlm.nih.gov/9453750/
BibTeX
@article{mecfsatlas-cuende-1997-high-prevalence,
author = {Cuende, J I and Civeira, P and Diez, N and Prieto, J},
title = {[High prevalence without reactivation of herpes virus 6 in subjects with chronic fatigue syndrome].},
journal = {Anales de medicina interna (Madrid, Spain : 1984)},
year = {1997},
note = {PubMed: 9453750},
url = {https://www.mecfsatlas.com/evidence/cuende-1997-high-prevalence},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-30. https://www.mecfsatlas.com/evidence/cuende-1997-high-prevalence
Contribute
Private, reviewed by a human. Not a public comment thread.