Name two endemic mycoses of the Americas and their geographic distribution.

• A. Histoplasma capsulatum (Mississippi/Ohio River valleys; parts of Central/South America) and Coccidioides spp. (southwestern United States, parts of Mexico and Central America)
• B. Histoplasma capsulatum (Mississippi River valleys) and Coccidioides spp. (Southeast United States)
• C. Histoplasma capsulatum (Europe) and Coccidioides spp. (Australia)
• D. Histoplasma capsulatum (Mississippi/Ohio River valleys; parts of Central/South America) and Coccidioides spp. (Southwestern United States)

Answer: (D)

Endemic mycoses in the Americas come from fungi with distinct, geography-loving patterns: Histoplasma capsulatum causes histoplasmosis and is classicly tied to soils in the Mississippi and Ohio River valleys, with distribution extending into parts of Central and South America. Coccidioides species cause coccidioidomycosis and are most strongly associated with arid regions of the southwestern United States, with additional foci in parts of Mexico and Central America. The combination described in this option matches these well-known endemic zones: Histoplasma in the Mississippi/Ohio valleys and nearby Central/South American areas, and Coccidioides in the Southwestern United States. The other choices place these fungi in regions that aren’t their characteristic endemic areas, or mix in locations outside the Americas, which makes them less accurate.