Investigation of an outbreak of “Humidifier fever” in a print shop

Authors

  • Margaret Mamolen MD,

    Corresponding author
    1. Division of Field Epidemiology, Epidemiology Program Office, Centers for Disease Control, Atlanta, GA
    2. Epidemiology Division, Vermont Department of Health (VDH), Burlington, VT
    • 311 North Street, Burlington, VT 05401
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  • Daniel M. Lewis PhD,

    1. Immunology Section, Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Morgantown, WV
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  • Michael A. Blanchet,

    1. Division of Occupational and Radiological Health, VDH, Vermont Occupational Safety and Health Administration, Montpelier, VT
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  • Frederick J. Satink,

    1. Division of Occupational and Radiological Health, VDH, Vermont Occupational Safety and Health Administration, Montpelier, VT
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  • Richard L. Vogt MD

    1. Epidemiology Division, Vermont Department of Health (VDH), Burlington, VT
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Abstract

An outbreak of “humidifier fever” affected 16 (57%) of 28 workers in a print shop. The most common symptoms were myalgia, chills or subjective fever, and cough. Illness began 5–13 hours after entering the workplace, and lasted 2–24 hours. A humidifier in use the day of the outbreak was found to be contaminated with fungi, amebae, and Gram-negative bacteria. The risk of illness was highest for those who had been on the job 3 months before the outbreak, a time when the humidifier was in constant use. Serologic studies of print shop workers showed positive reactions to extracts of organisms isolated from the humidifier, but could neither distinguish ill from well workers, nor identify causative organisms. The presence of endotoxin-producing bacteria and the clinical syndrome are consistent with an organic dust toxic syndrome. Previous exposure appeared to be the major risk factor for illness. © 1993 Wiley-Liss, Inc.

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