Jason, Leonard A, Furst, Jacob, Worth, Rebecca et al. · Frontiers in medicine · 2026 · DOI
This study followed college students over 7 years to see what happened to those who developed ME/CFS after infectious mononucleosis caused by Epstein-Barr virus (EBV). Researchers found that people who had severe ME/CFS 6 months after their infection were very likely to still have ME/CFS 7 years later, while those with milder symptoms often recovered. This suggests that how sick someone is early on may predict whether ME/CFS will persist long-term.
This study provides critical long-term outcome data for ME/CFS patients dealing with post-viral illness, showing that severe presentations tend to be persistent conditions rather than temporary complications. Understanding these trajectories helps both patients and clinicians set realistic expectations and may inform prognosis and treatment planning for those experiencing ME/CFS after infectious mononucleosis.
This study does not prove that EBV infection causes ME/CFS in all patients, as it focuses only on cases where IM preceded ME/CFS diagnosis. It does not establish whether early severity predicts poor outcomes due to biological mechanisms or other factors, nor does it apply necessarily to ME/CFS cases triggered by other infections or with unclear onset triggers.
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
Jason, Leonard A, Furst, Jacob, Worth, Rebecca, & Katz, Ben Z (2026). Outcomes of ME/CFS following infectious mononucleosis: seven-year follow-up of a prospective study.. Frontiers in medicine. https://doi.org/10.3389/fmed.2026.1676628
BibTeX
@article{mecfsatlas-jason-2026-outcomes-cfs,
author = {Jason, Leonard A and Furst, Jacob and Worth, Rebecca and Katz, Ben Z},
title = {Outcomes of ME/CFS following infectious mononucleosis: seven-year follow-up of a prospective study.},
journal = {Frontiers in medicine},
year = {2026},
doi = {10.3389/fmed.2026.1676628},
note = {PubMed: 41836950},
url = {https://www.mecfsatlas.com/evidence/jason-2026-outcomes-cfs},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-28. https://www.mecfsatlas.com/evidence/jason-2026-outcomes-cfs
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