E2 ModeratePreliminaryPEM ?ObservationalPeer-reviewedMachine draft
Shadow Burden of Undiagnosed Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) on Society: Retrospective and Prospective-In Light of COVID-19.
Araja, Diana, Berkis, Uldis, Lunga, Asja et al. · Journal of clinical medicine · 2021 · DOI
Quick Summary
This study examined how many people in Latvia may have ME/CFS symptoms but have never received a diagnosis, and investigated whether COVID-19 might cause similar long-term problems. Researchers compared symptom reports from diagnosed ME/CFS patients with undiagnosed people experiencing similar symptoms, and also tracked people who had recovered from COVID-19. The research found that undiagnosed patients face a significant financial burden on the healthcare system and themselves, and that COVID-19 can trigger ME/CFS-like symptoms in some people.
Why It Matters
This study highlights the substantial 'hidden' population of undiagnosed ME/CFS patients who face significant healthcare costs and disability without recognition or appropriate treatment. Given the emerging risk of post-viral ME/CFS following COVID-19, these findings underscore the urgent need for improved diagnostic pathways and disease awareness, particularly as post-pandemic cases may substantially increase the societal burden of ME/CFS.
Observed Findings
- Undiagnosed patients with longstanding symptoms reported self-rated severity similar to diagnosed ME/CFS patients, suggesting substantial unmet diagnostic need.
- Direct medical costs for undiagnosed ME/CFS patients in Latvia exceeded EUR 15 million annually, with projected 15% increase from COVID-19 consequences.
- Former COVID-19 patients showed significantly lower severity of fatigue and functional impairment compared to ME/CFS and undiagnosed patient groups at 6 months post-infection.
- Psychological distress (anxiety) and episodic fatigue were significantly more prominent in post-COVID patients than in established ME/CFS populations.
- Estimated number of undiagnosed ME/CFS patients in Latvia is approximately 5 times higher than the number of formally diagnosed patients.
Inferred Conclusions
- ME/CFS creates substantial 'shadow burden' on society through undiagnosed cases with high direct medical costs and disability, even before accounting for post-COVID complications.
- COVID-19 can induce ME/CFS-relevant symptoms, suggesting the need for extended monitoring and preventive strategies to prevent progression to chronic post-viral conditions.
- Improved diagnostic approaches and earlier recognition of ME/CFS could significantly reduce individual and societal burden going forward.
- ME/CFS patients do not appear to be at higher risk for severe COVID-19, but COVID-19 survivors require screening for ME/CFS-relevant complications.
What This Study Does Not Prove
This study does not prove causation between COVID-19 and ME/CFS development—it identifies symptom overlap at a single timepoint (6 months post-infection). The study cannot establish why undiagnosed patients remain undiagnosed (healthcare access, clinician awareness, patient factors) or predict the actual percentage of COVID-19 patients who will develop true ME/CFS. The financial estimates are based on Latvia's healthcare system and may not generalize to other countries.
Tags
Symptom:Cognitive DysfunctionFatigue
Phenotype:Infection-TriggeredLong COVID Overlap
Method Flag:Weak Case DefinitionExploratory OnlyMixed Cohort
Metadata
- DOI
- 10.3390/jcm10143017
- PMID
- 34300183
- Review status
- Machine draft
- Evidence level
- Single-study or moderate support from human research
- Last updated
- 8 April 2026