Iwakami, Etsuko, Arashima, Yasutomo, Kato, Kimitoshi et al. · Internal medicine (Tokyo, Japan) · 2005 · DOI
Researchers tested whether a specific bacterium called Coxiella burnetii might be causing ME/CFS by treating infected patients with antibiotics. While the antibiotics successfully cleared the infection in all patients tested, symptoms like fever, headache, and fatigue did not improve in the ME/CFS group—though they did improve significantly in patients who had post-Q fever fatigue syndrome (a related condition). This suggests that even though some ME/CFS patients carry this bacterium, it may not be the main cause of their illness.
This study directly investigates a plausible infectious trigger for ME/CFS by testing therapeutic response, which could help clarify disease mechanisms. The finding that antibiotic treatment successfully eradicated a known pathogen yet failed to improve ME/CFS symptoms challenges the hypothesis that C. burnetii is a primary driver of ME/CFS, helping researchers focus investigation on other potential causes and maintaining pathobiological distinctions between ME/CFS and post-infectious fatigue syndromes.
This study does not prove that C. burnetii plays no role in any ME/CFS cases—it only suggests low direct involvement in the studied population. The small sample size (4 CFS patients) limits generalizability, and the observation that some ME/CFS patients carry the infection without symptom improvement does not rule out indirect mechanisms or involvement in a subgroup. Correlation between infection clearance and lack of symptom improvement does not establish causality in the opposite direction.
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
Iwakami, Etsuko, Arashima, Yasutomo, Kato, Kimitoshi, Komiya, Tomoyoshi, Matsukawa, Yoshihiro, Ikeda, Tadao, et al. (2005). Treatment of chronic fatigue syndrome with antibiotics: pilot study assessing the involvement of Coxiella burnetii infection.. Internal medicine (Tokyo, Japan). https://doi.org/10.2169/internalmedicine.44.1258
BibTeX
@article{mecfsatlas-iwakami-2005-treatment-chronic,
author = {Iwakami, Etsuko and Arashima, Yasutomo and Kato, Kimitoshi and Komiya, Tomoyoshi and Matsukawa, Yoshihiro and Ikeda, Tadao and Arakawa, Yasuyuki and Oshida, Shigemi},
title = {Treatment of chronic fatigue syndrome with antibiotics: pilot study assessing the involvement of Coxiella burnetii infection.},
journal = {Internal medicine (Tokyo, Japan)},
year = {2005},
doi = {10.2169/internalmedicine.44.1258},
note = {PubMed: 16415546},
url = {https://www.mecfsatlas.com/evidence/iwakami-2005-treatment-chronic},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-29. https://www.mecfsatlas.com/evidence/iwakami-2005-treatment-chronic
Contribute
Private, reviewed by a human. Not a public comment thread.