Exploring the Distribution of Coccidioides immitis in South Central Washington State

Introduction Coccidioidomycosis, commonly referred to as Valley Fever, is caused by the soil-borne saprophytic fungus C. immitis and posadasii. These species have historically been found in the desert southwest and Mexico; however, in 2010 there were three coccidioidomycosis cases identified in central Washington. Colonization of soils by C. immitis has been confirmed at exposure sites associated with these cases1. Multiple studies have identified a relationship between environmental conditions and C. immitis growth areas2,3,4, but these relationships have not been evaluated in Washington. The Washington State Department of Health has been conducting environmental surveillance in an effort to understand the geographic distribution of C. immitis in central Washington and the associated risk to humans and animals. Here we describe our environmental surveillance efforts and present preliminary findings related to environmental conditions of C. immitis growth areas in central Washington.