Pathogenesis and epidemiology of opportunistic mycotic infections: a review

The pathogenesis, epidemiology, and ecology of pathogenic and opportunistic systemic infecting fungi are reviewed. The pathogenic fungi including the etiologic agents of histoplasmosis, blastomycosis, coccidioidomycosis, and paracoccidioidomycosis are limited geographically, can establish an infection in a normal host, and exhibit thermal dimorphism. In contrast, the opportunist fungi (Asperigillus sp., Candida sp., Cryptococcus sp., Mucor sp., and Rhizopus sp.) are widely distributed in nature, require altered host defenses for infection, and do not exhibit thermal dimorphism. Mechanisms of pathogenesis are also discussed.