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Published on: May 2, 2018
A point-source outbreak of Coccidioidomycosis among a highway construction crew
1a School of Public Health, University of California , Berkeley , California.
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.
Insights
A highway construction crew in Kern County, CA, experienced a coccidioidomycosis outbreak due to inhaling Coccidioides immitis spores from disturbed soil. This point-source outbreak highlights the need for dust control and respiratory protection in endemic areas.
Area of Science:
- Mycology
- Infectious Diseases
- Occupational Health
Background:
- Coccidioidomycosis, caused by Coccidioides immitis spores, is endemic in specific regions of California.
- Disturbance of endemic soil, common in construction, can aerosolize infectious spores.
- Inhalation of these spores leads to respiratory infection in susceptible individuals.
Purpose of the Study:
- To report a cluster of coccidioidomycosis cases in a highway construction crew.
- To identify the source and circumstances of the outbreak.
- To emphasize the importance of preventive measures in occupational settings.
Main Methods:
- Case investigation of a cluster of seven coccidioidomycosis cases.
- Epidemiological analysis of exposure timing and location.
- Review of environmental factors at the construction site.
Main Results:
- Seven cases of coccidioidomycosis occurred within a highway construction crew in Kern County, CA.
- Exposure likely resulted from inhaling soil dust during seven work days in June/July 2008.
- Illness onset occurred 2-3 weeks post-exposure, consistent with a point-source outbreak.
Conclusions:
- Occupational exposure to Coccidioides immitis during construction poses a significant risk in endemic areas.
- Lack of awareness and inadequate dust control measures contributed to the outbreak.
- Implementation of engineering controls, administrative procedures, and respiratory protection is crucial for prevention.
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