Endemic and Other Dimorphic Mycoses in The Americas

Endemic fungi are thermally dimorphic fungi that have a limited geographic range and can cause both primary disease and opportunistic infections. The Americas are home to more genera of endemic fungi than anywhere else on earth. These include Coccidioides, Histoplasma, Blastomyces, Paracoccidioides, and Sporothrix. Endemic fungi are found across the Americas and the Caribbean, from Blastomyces gilchristi, which extends into the northeast corners of North America, to Histoplasma capsulatum, which occurs all the way down in the southern regions of South America and into the Caribbean Islands. Symptoms of endemic fungal infection, when present, mimic those of many other diseases and are often diagnosed only after initial treatment for a bacterial or viral disease has failed. Endemic fungi place a significant medical burden on the populations they affect, especially in immunocompromised individuals and in resource-limited settings. This review summarizes the ecology, geographical range, epidemiology, and disease forms of the endemic fungi found in the Americas. An emphasis is placed on new and proposed taxonomic changes, including the assignment of new species names in Histoplasma, Blastomyces, and Paracoccidioides.