Tack, Matthias, Gruber, Rosalie, Betting, Leia et al. · Medicina (Kaunas, Lithuania) · 2026 · DOI
This study followed hospital workers who got COVID-19 to see how many developed long-lasting fatigue and ME/CFS. About 12% still had fatigue months later, and 3% met the criteria for ME/CFS. Researchers found that people with these conditions often had signs of viral reactivation, immune system changes, and blood clotting abnormalities.
This study provides concrete evidence that ME/CFS can develop after COVID-19 infection and identifies potential biological mechanisms—including viral reactivation and autoimmune activation—that might explain how post-viral infections trigger ME/CFS. Understanding these mechanisms is crucial for developing diagnostic tests and future treatments.
This study does not prove that EBV reactivation, autoantibodies, or coagulation changes cause ME/CFS, only that they are associated with it in this small cohort. The lack of a control group means we cannot determine if these findings are specific to post-COVID ME/CFS or common in other populations. The findings cannot be generalized beyond hospital employees or establish causation.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
The first block is for the primary paper and is the citation you should use in research work. The atlas-snapshot line only applies if you are specifically referring to this atlas’s reading of the paper on the date shown.
Primary citation
Tack, Matthias, Gruber, Rosalie, Betting, Leia, Herbrandt, Swetlana, Wu, Shuling, Schlößer, Barbara, et al. (2026). Assessment and Incidence Determination of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Following a SARS-CoV-2 Infection in a Prospective Cohort of Hospital Employees.. Medicina (Kaunas, Lithuania). https://doi.org/10.3390/medicina62030480
BibTeX
@article{mecfsatlas-tack-2026-assessment-incidence,
author = {Tack, Matthias and Gruber, Rosalie and Betting, Leia and Herbrandt, Swetlana and Wu, Shuling and Schlößer, Barbara and Häussermann, Peter and Maegele, Marc and Schlang, Gerlinde and Mattner, Frauke},
title = {Assessment and Incidence Determination of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Following a SARS-CoV-2 Infection in a Prospective Cohort of Hospital Employees.},
journal = {Medicina (Kaunas, Lithuania)},
year = {2026},
doi = {10.3390/medicina62030480},
note = {PubMed: 41901562},
url = {https://www.mecfsatlas.com/evidence/tack-2026-assessment-incidence},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-26. https://www.mecfsatlas.com/evidence/tack-2026-assessment-incidence
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