ORIGINAL RESEARCH article
Front. Med.
Sec. Infectious Diseases: Pathogenesis and Therapy
Outcomes of ME/CFS Following Infectious Mononucleosis: Seven-year Follow-up of a Prospective Study
Leonard A. Jason 1
Jacob Furst 1
Rebecca Worth 1
Ben Katz 2
1. DePaul University, Chicago, United States
2. Ann & Robert H Lurie Children's Hospital of Chicago, Chicago, United States
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Abstract
Background: Many individuals with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) report experiencing an infectious illness prior to disease onset. Approximately 30% of cases are linked to Epstein–Barr virus (EBV) infection resulting in Infectious Mononucleosis (IM). Methods: We examined the progression of ME/CFS following IM among a cohort of college students who were recruited before they developed the infection. This sample represented a socioeconomically and ethnically diverse population of young adults who were monitored over a 7-year period. Assessments of health status, psychological functioning, and blood biomarkers were conducted at four time points: (1) baseline, when participants were healthy and at least six weeks from IM onset; (2) within six weeks of IM diagnosis; (3) six months post-IM, when participants had either recovered or met criteria for ME/CFS; and (4) the 7-year follow-up. Results: At follow-up, 81% of participants who had initially presented with severe ME/CFS continued to fulfill diagnostic criteria. In contrast, only about one-third of those with moderate or lingering symptoms at six months still had ME/CFS seven years later. Conclusions: These findings indicate that ME/CFS following IM tends to persist over the long term, particularly among those whose illness was more severe at onset.
Summary
Keywords
chronic fatigue syndrome, Epstein Barr virus, Infectious Mononucleosis, Myalgic encephalomyelitis, Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome
Received
30 July 2025
Accepted
21 January 2026
Copyright
© 2026 Jason, Furst, Worth and Katz. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Leonard A. Jason
Disclaimer
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