Histoplasmosis is endemic in which region?

• A. Central and Eastern United States
• B. Pacific Northwest
• C. Northern Europe
• D. Sub-Saharan Africa

Answer: (A)

Histoplasmosis is a fungal infection whose distribution is strongly tied to a specific geographic area. The organism Histoplasma capsulatum is common in soils enriched with bird or bat guano, and it is most prevalent in the central and eastern United States, especially the Ohio and Mississippi River valleys. People typically acquire it by inhaling spores while doing outdoor activities, cleaning old buildings, spelunking, or disturbing soil in these areas. Because of this established endemic zone, central and eastern U.S. is the region most associated with histoplasmosis. The Pacific Northwest, Northern Europe, and Sub-Saharan Africa are not the classic endemic regions for this disease, though sporadic cases can occur outside the main belt.