Shefer, A, Dobbins, J G, Fukuda, K et al. · Journal of psychiatric research · 1997 · DOI
Researchers surveyed over 3,300 state office workers in California to see if there was an unusual outbreak of long-lasting fatigue or ME/CFS-like illness. They found that about 18% of workers reported fatigue lasting at least a month, but this rate was similar in buildings thought to have clusters and in a comparison building, suggesting there was no outbreak. The study identified that certain groups—including women, Hispanic workers, Native American workers, and those with lower income or education—were more likely to report fatigue.
This study is important because it uses a systematic, population-based approach to investigate alleged ME/CFS outbreaks in occupational settings—a common concern that is rarely rigorously evaluated. By identifying social determinants and demographic risk factors for fatiguing illness, it highlights that ME/CFS and fatigue-related conditions affect vulnerable populations disproportionately and that outbreak investigations must account for underlying population disparities.
This study does not prove that environmental or occupational exposures play no role in ME/CFS etiology—the case definition used was compatible with, but not equivalent to, strict CFS criteria, and the study design cannot determine causation. The finding of similar prevalence across buildings does not exclude the possibility of risk factors specific to office environments more broadly. Additionally, cross-sectional questionnaire data may not capture acute incident cases or severe cases unable to work.
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
Shefer, A, Dobbins, J G, Fukuda, K, Steele, L, Koo, D, Nisenbaum, R, et al. (1997). Fatiguing illness among employees in three large state office buildings, California, 1993: was there an outbreak?. Journal of psychiatric research. https://doi.org/10.1016/s0022-3956(96)00049-0
BibTeX
@article{mecfsatlas-shefer-1997-fatiguing-illness,
author = {Shefer, A and Dobbins, J G and Fukuda, K and Steele, L and Koo, D and Nisenbaum, R and Rutherford, G W},
title = {Fatiguing illness among employees in three large state office buildings, California, 1993: was there an outbreak?},
journal = {Journal of psychiatric research},
year = {1997},
doi = {10.1016/s0022-3956(96)00049-0},
note = {PubMed: 9201645},
url = {https://www.mecfsatlas.com/evidence/shefer-1997-fatiguing-illness},
}Atlas snapshot reference
ME/CFS Atlas. Generator v1 / Scanner v1.4 / policy v0.1. Accessed 2026-05-30. https://www.mecfsatlas.com/evidence/shefer-1997-fatiguing-illness
Contribute
Private, reviewed by a human. Not a public comment thread.