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. 2021 Feb 19;16(2):e0247263.
doi: 10.1371/journal.pone.0247263. eCollection 2021.

Using soil survey data to model potential Coccidioides soil habitat and inform Valley fever epidemiology

Robert R Dobos  1 , Kaitlin Benedict  2 , Brendan R Jackson  2 , Orion Z McCotter  2
Affiliations

Using soil survey data to model potential Coccidioides soil habitat and inform Valley fever epidemiology

Robert R Dobos et al. PLoS One. .

Abstract

Coccidioidomycosis, also known as Valley fever, is a disease that can result in substantial illness and death. It is most common in the southwestern United States and areas of Latin America with arid climates, though reports increasingly suggest its range is wider than previously recognized. The natural habitat of the causative organisms, Coccidioides spp., have been associated with certain soil properties and climatic conditions. Current understanding of its geographic range is primarily defined by skin test studies and outbreak locations. We developed a fuzzy system model to predict suitable soil habitats for Coccidioides across the western United States based on parameters (electrical conductivity, organic matter content, pH, water holding capacity, temperature, and precipitation) from sites where soil sampling has confirmed the presence of Coccidioides. The model identified high coccidioidomycosis incidence areas as having high suitability and identified pockets of elevated suitability corresponding with outbreak locations outside the traditional range. By providing high-resolution estimates of Coccidioides suitability, including areas without public health surveillance for coccidioidomycosis, this model may be able to aid public health and clinical provider decision making. Awareness of possible Coccidioides soil habitats could help mitigate risk during soil-disturbing activities and help providers improve coccidioidomycosis diagnosis and treatment.

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Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Predicted Coccidioides habitat suitability index for the western United States.
Fig 2
Fig 2. Predicted Coccidioides habitat suitability index for Arizona.
Fig 3
Fig 3. Predicted Coccidioides habitat suitability index for Maricopa County, Arizona, which has the highest incidence of coccidioidomycosis in the state.
Fig 4
Fig 4. Predicted Coccidioides habitat suitability index for Kern County, California, which has the highest incidence of coccidioidomycosis in the state.
Fig 5
Fig 5. Predicted Coccidioides habitat suitability index for Texas.
Fig 6
Fig 6. Predicted Coccidioides habitat suitability index for south-central Washington.
Fig 7
Fig 7. Predicted Coccidioides habitat suitability index for Dinosaur National Monument, Utah.
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Grants and funding

The author(s) received no specific funding for this work.