Investigating the Expanding Geographic Range of Coccidioides

Valley fever or coccidioidomycosis is a life threatening fungal infection caused by inhalation of Coccidioides sp. arthroconidia present in soil and dust in the dessert areas of the Southwestern United States. Unlike most other human pathogenic fungi, Coccidioides can infect immunocompetent individuals and cause a broad spectrum of diseases ranging from asymptomatic infection to mild respiratory illness to severe life-threatening infections. Recent data suggest that the incidence of valley fever has risen dramatically in the last decade and the pathogen’s endemic range is expanding. The number of reported cases of coccidioidomycosis in the United States has increased more than 420% since 1998, and over 10,000 cases are typically reported each year. Furthermore, clusters of the valley fever and viable Coccidioides arthroconidia have been reported in the southcentral Washington State, well outside of the currently accepted endemic range. Although the exact causes of the increased incidence and the expanding geographic range of coccidioidomycosis are not fully understood, climate and population changes that occurred in recent decades have likely contributed to these trends. This presentation will discuss our recent findings describing ecology and distribution of valley fever.