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Open-File Report 00-348

Operational Guidelines (version 1.0) for Geological Fieldwork in Areas Endemic for Coccidioidomycosis (Valley Fever)

By Frederick S. Fisher, Mark W. Bultman, and Demosthenes Pappagianis

Thumbnail of and link to report PDF (200 kB)Abstract

Coccidioidomycosis (Valley Fever) is a disease caused by the inhalation of the arthroconidia (spores) of Coccidioides immitis, a fungus that lives in the soils of southwestern United States. Although large numbers of people are exposed to the arthroconidia and are consequently infected, very few individuals contract the more serious forms of the disease. Earth scientists working in field areas where Coccidioides immitis is endemic have an increased risk of becoming infected. Because field operations often disturb the upper surface of the ground, they may inhale large numbers of arthroconidia. This also increases their risk of developing more severe forms of the disease. Any other occupations or activities that create dusty conditions in endemic areas also have increased risk of infection. Risk management strategies can lower the incidence of infection and also reduce the numbers of arthroconidia inhaled thereby decreasing the chances of developing more serious disease. Dust control, by utilizing dust masks, and dust prevention, by limiting ground disturbing activities, are the primary weapons against infection. However, infection risk can also be lowered by conducting fields studies in the winter months; avoiding sites favorable for Coccidioides immitis growth; seeking prompt medical treatment if flu-like or respiratory illness occur during, or within a few weeks following, fieldwork; getting a coccidioidin skin test to determine susceptibility to the disease; and by educating all members of the field party about the possibilities and consequences of infection.

First posted September 14, 2000

For additional information, contact:
Geology, Minerals, Energy, and Geophysics Science Center
U.S. Geological Survey
345 Middlefield Road, MS 901
Menlo Park, CA 94025-3591

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Suggested citation:

Fisher, Frederick S., Bultman, Mark W., and Pappagianis, Demosthenes, 2000, Operational Guidelines (version 1.0) for Geological Fieldwork in Areas Endemic for Coccidioidomycosis (Valley Fever): U.S. Geological Survey Open-File Report 00-348, 16 pp.,




Endemic areas

Character of the Disease

Habitat of C. immitis

Risk Management Strategies


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