Which two endemic fungi have a high prevalence in the Americas and cause significant lung disease?

• A. Histoplasma capsulatum and Blastomyces dermatitidis
• B. Aspergillus fumigatus and Histoplasma capsulatum
• C. Histoplasma capsulatum and Coccidioides spp.
• D. Coccidioides spp. and Paracoccidioides brasiliensis

Answer: (C)

Endemic fungal infections tied to geography often present as lung diseases after inhaling environmental spores. Histoplasma capsulatum is widespread across the Americas, especially in the Ohio and Mississippi River valleys, but found in many regions as well; inhalation of microconidia causes histoplasmosis, with a spectrum from mild respiratory illness to pneumonia and, in some cases, disseminated disease. Coccidioides species are also strongly endemic to the Americas, most notably in the southwestern United States and parts of Mexico and Central America; inhaled arthroconidia lead to coccidioidomycosis, commonly presenting as fever and pneumonia and can, in a subset of patients, progress or disseminate. Together, these two fungi represent classic endemic causes of significant lung disease across large areas of the Americas. While other endemic fungi exist, such as Blastomyces and Paracoccidioides, their geographic patterns and typical clinical presentations are less broadly representative of “high prevalence in the Americas” with prominent pulmonary disease compared to histoplasma and coccidioides.