A point-source outbreak of Coccidioidomycosis among a highway construction crew

ABSTRACT

Coccidioidomycosis is an infection caused by inhaling spores of the soil fungus Coccidioides immitis (hereafter termed Cocci). Cocci is endemic in certain areas of California. When soil containing the fungus is disturbed, as during earth-moving activities, respirable Cocci spores can become airborne and be inhaled by persons in the vicinity. This article describes a cluster of seven Cocciodioidomycosis cases among a highway construction crew that occurred in June/July 2008 in Kern County, CA, which is among the most highly endemic regions for Cocci in California. The exposures spanned no more than seven work days, and illness developed within two to three weeks of the exposures. Given the common source of exposure (soil dust generated at the work site) and the multiple cases occurring close in time, the cluster can also be termed a “point-source outbreak.” The contractor was not informed of the infection risk and did not take adequate precautions against dust exposure. Appropriate engineering/administrative controls and respiratory protection are discussed.

KEYWORDS:

• Highway construction
• occupational Coccidioidomycosis
• soil fungus exposure

Author's Note

The description of the exposure incident is based on the trial evidence in a personal injury lawsuit brought by the affected contractor employees against the contracting agency (Case No. FCS03718, Superior Court of California, Solano County). The jury decided that the contracting agency was liable for the plaintiffs' infections, and the verdict was upheld on appeal. The author served as an expert witness on behalf of the plaintiffs.

Additional information

Notes on contributors

Mark Nicas

Author's Note

The description of the exposure incident is based on the trial evidence in a personal injury lawsuit brought by the affected contractor employees against the contracting agency (Case No. FCS03718, Superior Court of California, Solano County). The jury decided that the contracting agency was liable for the plaintiffs' infections, and the verdict was upheld on appeal. The author served as an expert witness on behalf of the plaintiffs.