The Enterovirus Theory of Disease Etiology in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Critical Review.
O'Neal, Adam J, Hanson, Maureen R · Frontiers in medicine · 2021 · DOI
Quick Summary
This review examined whether enteroviruses—common viruses that cause colds, stomach infections, and other illnesses—might be responsible for ME/CFS. While some studies found these viruses more often in ME/CFS patients than in healthy people, the evidence has been mixed and hard to interpret. The authors argue that past research methods weren't good enough to definitively answer the question, and they call for better studies using modern technology to investigate this possibility further.
Why It Matters
Understanding whether enteroviruses cause or contribute to ME/CFS is crucial for developing targeted treatments and explaining disease mechanisms. If enteroviral persistence is confirmed with better methods, it could open pathways to antiviral interventions and provide patients with concrete biological explanations for their symptoms. This review highlights the urgent need for well-designed studies that could finally resolve a decades-long scientific debate.
Observed Findings
Increased prevalence of enteroviral detection in ME/CFS patient cohorts compared to healthy control groups across multiple studies
Enteroviral persistence in secondary infection sites (central nervous system, muscle, cardiac tissue) is biologically plausible and documented in other conditions
Historical ME/CFS outbreaks showed epidemiological and clinical features consistent with enteroviral spread
Past studies used inconsistent sample types, detection methods, and quality standards, limiting comparability
Older molecular techniques had insufficient sensitivity to reliably detect persistent or low-level chronic infections
Inferred Conclusions
Evidence suggests one or more enterovirus groups may have caused documented ME/CFS outbreaks, particularly in epidemiological clusters
Current chronic enteroviral infection in ME/CFS patients cannot be excluded due to methodological inadequacies in prior research
Modern molecular methods and standardized study protocols are essential for definitively answering the enterovirus-ME/CFS question
If chronic enteroviral infection is present in ME/CFS, it could contribute significantly to morbidity and prevent recovery
Remaining Questions
What is the true prevalence of persistent enteroviral infection in current ME/CFS populations when studied with optimized modern molecular methods?
What This Study Does Not Prove
This review does not prove that enteroviruses cause ME/CFS—it identifies that past evidence is suggestive but methodologically insufficient. The review cannot establish causation from correlation, nor does it demonstrate that antiviral treatments would be effective. It also does not rule out other potential etiologies or rule in enteroviral infection as the sole cause of disease.