Relating coccidioidomycosis (valley fever) incidence to soil moisture conditions

• Type of Material: Article
• Authors: E.J. Coopersmith, USDA-ARS-Hydrology and Remote Sensing Laboratory; Jesse Bell, Emory University; K. Benedict, Centers for Disease Control and Prevention; J. Shriber, Emory University; O. McCotter, Centers for Disease Control and Prevention; M.H. Cosh, USDA-ARS-Hydrology and Remote Sensing Laboratory
• Language: English
• Date: 2017-04-17
• Publisher: American Geophysical Union (AGU)
• Publication Version: Final Published Version
• Copyright Statement: Copyright 2017. The Authors.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1002/2016GH000033
• Title of Journal or Parent Work: GeoHealth
• ISSN: 2471-1403
• Volume: 1
• Start Page: 51
• End Page: 63
• Grant/Funding Information: This work was also supported by NOAA through the Cooperative Institute for Climate and Satellites-North Carolina under Cooperative Agreement NA14NES432003.; This work was supported by the NASA Terrestrial Hydrology Program (NNH10ZDA001N-THP) and USDA Agricultural Research Service (ARS 58-8042-5-077). USDA is an equal opportunity provider and employer.
• Research Categories: Biology, Virology; Health Sciences, Public Health; Health Sciences, Immunology

Abstract

Coccidioidomycosis (also called Valley fever) is caused by a soilborne fungus, Coccidioides spp., in arid regions of the southwestern United States. Though some who develop infections from this fungus remain asymptomatic, others develop respiratory disease as a consequence. Less commonly, severe illness and death can occur when the infection spreads to other regions of the body. Previous analyses have attempted to connect the incidence of coccidioidomycosis to broadly available climatic measurements, such as precipitation or temperature. However, with the limited availability of long-term, in situ soil moisture data sets, it has not been feasible to perform a direct analysis of the relationships between soil moisture levels and coccidioidomycosis incidence on a larger temporal and spatial scale. Utilizing in situ soil moisture gauges throughout the southwest from the U.S. Climate Reference Network and a model with which to extend those estimates, this work connects periods of higher and lower soil moisture in Arizona and California between 2002 and 2014 to the reported incidence of coccidioidomycosis. The results indicate that in both states, coccidioidomycosis incidence is related to soil moisture levels from previous summers and falls. Stated differently, a higher number of coccidioidomycosis cases are likely to be reported if previous bands of months have been atypically wet or dry, depending on the location.