Histoplasmosis duboisii (African histoplasmosis). An African case reported from Chile with ultrastructural study.

A case of histoplasmosis duboisii in a 30 year-old engineer is presented. The diagnosis was made with the help of light microscopy, electron microscopy and cultures. Although diagnosed in Chile, the patient probably acquired the disease in the endemic African area, more precisely in the Ivory Coast. Differential diagnosis between Histoplasma capsulatum var. capsulatum and Histoplasma capsulatum var. duboisii is based primarily on the larger in-vivo yeast form size of the latter. Electron microscopy study, the first done on the duboisii variety of Histoplasma capsulatum in human material to our knowledge, was not essential for this purpose. Differential diagnosis between Histoplasma capsulatum var. duboisii and Blastomyces dermatitidis is based on morphological tissue changes and mycologic characteristics. Once more, a case of an "exotic" or geographically restricted disease is detected far from its endemic area, thanks to easier means of transportation. Earth is a shrinking planet.