Expanding epidemiology of blastomycosis: Clinical features and investigation of 2 cases in Colorado

On the basis of case reports of blastomycosis, Blastomyces dermatitidis is widely accepted to be endemic in the central United States in and around th e Ohio and Mississippi River Valleys, Blastomycosis also occurs in parts of Canada and in the southeastern United States. However, there has been no l arge-scale skin testing, and the environmental range of B. dermatitidis may have been underestimated. We describe 2 immunocompetent patients with blas tomycosis acquired while working in the Front Range region of the Rocky Mou ntains. The patients were coworkers engaged in a prairie dog relocation pro ject. In the course of this work, they bad extensive contact with contamina ted soil. Significantly above-average rainfall before the exposure may have contributed to favorable conditions for sporulation of the fungus.