Cytomegalovirus, Epstein-Barr virus, and human herpesvirus-6 infections in patients with myalgic еncephalomyelitis/chronic fatigue syndrome. — CFSMEATLAS
Cytomegalovirus, Epstein-Barr virus, and human herpesvirus-6 infections in patients with myalgic еncephalomyelitis/chronic fatigue syndrome.
Shikova, Evelina, Reshkova, Valentina, Kumanova, Аntoniya et al. · Journal of medical virology · 2020 · DOI
Quick Summary
Researchers tested 58 ME/CFS patients and 50 healthy people for three common viruses (EBV, CMV, and HHV-6) that have been suspected of triggering ME/CFS. They found that ME/CFS patients had significantly higher rates of active EBV infection in their bloodstream compared to healthy people, though most people in both groups carried these viruses in a dormant state. This suggests that for some patients, active EBV infection may play a role in ME/CFS development.
Why It Matters
This study provides evidence that active EBV reactivation may contribute to ME/CFS pathogenesis in at least some patients, moving beyond speculation to measured biological differences. Understanding which viral infections are actually active versus dormant could guide targeted treatment approaches and help identify disease subtypes within the ME/CFS population.
Observed Findings
Active EBV DNA was detected in plasma from 24.1% of ME/CFS patients versus 4% of controls—a statistically significant difference (P=0.0027).
Active CMV and HHV-6 DNA were detected in plasma from only 3.4% and 1.7% of ME/CFS patients respectively, with no active infection in controls.
Latent viral infection rates were similar between groups: 74-84% for CMV, 81-84% for EBV, and 82-82.8% for HHV-6, indicating these viruses are common in both populations.
Virus-specific antibody levels (IgG and IgM) showed no significant differences between ME/CFS patients and controls.
Inferred Conclusions
Active EBV infection is significantly more common in ME/CFS patients than healthy controls, suggesting EBV reactivation may be an important factor in at least a subset of ME/CFS cases.
The distinction between active and latent infection is important; most people carry these viruses dormantly, but active replication may be pathologically relevant.
EBV appears to be a more significant factor than CMV or HHV-6 in ME/CFS based on this data.
Remaining Questions
Does active EBV infection directly cause ME/CFS, or is it a consequence of immune dysfunction in affected patients?
Why do only some ME/CFS patients have active EBV infection? Are there distinct ME/CFS subtypes based on viral activation status?
What This Study Does Not Prove
This study does not prove that EBV causes ME/CFS—only that active EBV infection is more common in ME/CFS patients. It does not explain whether the virus triggers the disease, results from it, or is coincidentally associated. The findings cannot be generalized beyond Bulgarian populations without further research.