A GIS Model of the Habitat of the Fungus Coccidioides Immitis in the Tucson Basin

Author: Peter Schilling Johnson
Organization: University of Arizona

Harvill Bldg, Box 2
University of Arizona
Tucson, AZ 85721
USA

Phone: 520-621-6181
Fax: 520-621-6181
peter@casa.arizona.edu

Coccidioidomycosis (valley fever) is a disease endemic to arid regions in the western hemisphere and is caused by the soil-dwelling fungus Coccidioides immitis (C. immitis).

Previous studies have considered separately temperature, moisture, salinity, and pH of the soil in influencing the habitat of fungus. However, no study has attempted to model these variables in concert with each other. This paper will endeavor to demonstrate the utility of using a geographic information system to organize and analyze the parameters deemed important in explaining the habitat preferences for C. immitis. Both logistic and stepwise regression methods will be employed in the construction of this model. Success of this model would indicate that typical modeling procedures used in describing the habitat of surface animals are also useful in describing the habitat of fungus. Also, a successful model would point to the possibility of the construction of a predictive model of valley fever based on changing environmental conditions.