Predisposing and Precipitating Factors in Epstein-Barr Virus-Caused Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.
Jason, Leonard A, Katz, Ben Z · Microorganisms · 2025 · DOI
Quick Summary
This study followed college students before and after they got infectious mononucleosis (IM) caused by Epstein-Barr virus to understand why some people develop ME/CFS afterward while others recover. Researchers collected health information and blood samples from students at three time points: before they got sick, shortly after their IM diagnosis, and six months later. By studying these young people over time, the researchers identified certain factors present before and during the infection that seemed to predict who would develop ME/CFS rather than recover.
Why It Matters
Understanding which factors predict ME/CFS development after IM could help clinicians identify high-risk patients early and guide preventive interventions. This rare prospective study design—collecting data before the triggering illness—provides stronger evidence than retrospective studies and offers insights applicable to other post-viral syndromes like Long COVID.
Observed Findings
Approximately 11-13% of people developed ME/CFS within 6 months after IM, with rates declining to 7-9% at one year follow-up.
Pre-illness baseline factors (Stage 1) predicted who would develop ME/CFS following IM infection.
Factors present at the time of IM diagnosis (Stage 2) also predicted non-recovery and ME/CFS development.
The study included an ethnically and sociodemographically diverse cohort of young adults.
Inferred Conclusions
Both pre-existing biological or psychological vulnerability factors and acute-phase illness characteristics contribute to ME/CFS development after IM.
Prospective study designs with pre-illness baseline data are essential for identifying true risk factors in post-viral syndromes.
The mechanisms underlying ME/CFS following IM may involve multiple interactive factors rather than single causative elements.
Remaining Questions
Which specific baseline biological or psychological factors most strongly predict ME/CFS development, and what are their mechanisms?
Why do most people (87-89%) recover from IM while a minority develop ME/CFS, and are these risk factors modifiable?
Do the predictive factors identified in IM-triggered ME/CFS apply similarly to other post-viral syndromes like Long COVID?
What This Study Does Not Prove
This study does not prove causation between the identified risk factors and ME/CFS development; it identifies correlations. The findings cannot establish which factors are directly responsible for ME/CFS pathophysiology versus which are markers of underlying vulnerability. Results from college students may not apply to children, older adults, or other populations.
Tags
Symptom:Fatigue
Biomarker:Blood Biomarker
Phenotype:Infection-TriggeredPediatric
Method Flag:PEM Not DefinedWeak Case DefinitionExploratory Only