To the Editor. —I enjoyed reading the recent article by Prego et al.1 Their work further justifies the use of early tissue biopsy in the evaluation of unexplained fever among patients with the acquired immunodeficiency syndrome.
Mycobacteria were identified as the predominant pathogens in this New York—based study.1 However, these results do not take into account the geographic location of the study center. In the southeastern United States, histoplasmosis is an extremely common illness among patients with acquired immunodeficiency syndrome.2 Unexplained fever and the presence of granulomas in tissue sections often lead to the diagnosis of disseminated histoplasmosis rather than mycobacterial infection; a trial of antifungal therapy is often justified in such cases.
As Prego and coworkers conclude, tissue biopsy and culture are valuable diagnostic tools. We should not forget, however, that the relative incidence of an opportunistic pathogen may vary strikingly with geographic location.