Differences in Histoplasmosis in Patients with Acquired Immunodeficiency Syndrome in the United States and Brazil

Demographic and clinical parameters among patients with acquired immunodeficiency syndrome and histoplasmosis in Brazil and United States were compared. The Brazilian isolates were typed by restriction-fragment length polymorphism analysis and were DNA fingerprinted by random amplification of polymorphic DNA (RAPD)-polymerase chain reaction (PCR). Skin lesions occurred in 66% of Brazilian case patients, compared with 1%-7% of US case patients. Of 21 treated case patients, 4 (19%) died, a rate similar to that of the US case patients (5%-13%). By nuclear gene typing, the Brazilian isolates were equally divided between South American classes 5 and 6, and RAPD-PCR showed 18 distinct genetic fingerprints in 20 isolates. Skin lesions are more common in infection with class 5 or 6 organisms than with class 2 Histoplasma capsulatum. The role of genetic differences in the organism as a cause for the clinical differences requires investigation.