Evaluation of viral infection as an etiology of ME/CFS: a systematic review and meta-analysis.
Hwang, Jae-Hyun, Lee, Jin-Seok, Oh, Hyeon-Muk et al. · Journal of translational medicine · 2023 · DOI
Quick Summary
Researchers analyzed 64 studies involving nearly 5,000 ME/CFS patients to see if viral infections might cause or trigger the illness. They found that certain viruses—particularly Borna disease virus, human herpesvirus-7, parvovirus B19, enterovirus, and Coxsackie B virus—appeared more frequently in ME/CFS patients compared to healthy people and those with other diseases. While these associations are promising leads, finding a virus more often in patients doesn't prove it causes ME/CFS.
Why It Matters
ME/CFS lacks a confirmed biological cause, leaving patients without clear diagnostic tests or targeted treatments. This comprehensive analysis suggests specific viruses warrant investigation as potential triggers, particularly relevant given post-COVID conditions resembling ME/CFS. Identifying viral associations could guide future diagnostic development and mechanistic research into ME/CFS pathogenesis.
Observed Findings
Borna disease virus showed the strongest association with ME/CFS (odds ratio ≥3.47 compared to healthy and diseased controls).
Human herpesvirus-7, parvovirus B19, enterovirus, and Coxsackie B virus all demonstrated odds ratios greater than 2.0.
Meta-analysis included 18 different viral species evaluated across the 64 studies.
Control groups comprised both healthy subjects and individuals with 10 other diseases, including multiple sclerosis and fibromyalgia.
The quality and methodology of viral detection varied significantly across included studies.
Inferred Conclusions
Multiple viral species show statistical association with ME/CFS, with Borna disease virus demonstrating a moderate-strength association warranting priority investigation.
Viral infection may play a role in ME/CFS etiopathogenesis, though the mechanism (trigger, persistent infection, or other) remains unclear.
Future studies should standardize viral detection methods and assess whether viral infections precede ME/CFS onset.
Remaining Questions
Does infection with these viruses actually cause ME/CFS, or are they merely more common in patients due to immune dysfunction?
Can standardized, validated viral detection methods confirm these associations and determine which viruses are most important?
What This Study Does Not Prove
This study demonstrates association, not causation—finding a virus more often in ME/CFS patients does not prove it causes the disease. The findings do not establish whether viral infections trigger ME/CFS, persist as a pathogenic agent, or represent a secondary consequence of immune dysfunction. Additionally, different studies used different viral detection methods, which may affect the reliability of comparisons across viruses.