Histoplasmosis: Epidemiology, Diagnosis, and Clinical Manifestations

Purpose of Review This review highlights the epidemiology, diagnosis, and clinical manifestations of histoplasmosis. Recent Findings There is an increasing awareness of histoplasmosis in Central and South America in patients with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), and deaths from histoplasmosis in this region may outnumber deaths from tuberculosis. Diagnosis in this region is hampered by lack of rapid diagnostic tests. Growth of H. capsulatum in culture is definitive, but takes weeks. In areas in which antigen testing is available, this has become an important rapid diagnostic tool, and methods combining antigen and antibody testing appear to improve diagnostic accuracy for acute pulmonary and central nervous system histoplasmosis. Pulmonary histoplasmosis, although usually self-limited, rarely can lead to life-threatening complications. Uncommon, but serious and sometimes fatal complications of disseminated histoplasmosis include Addison's disease, meningitis, culture-negative endocarditis, and hemophagocytic lymphohistiocytosis. The use of antigen testing has improved our ability to diagnose histoplasmosis, but these tests are not universally available. Complications of both pulmonary and disseminated histoplasmosis remain challenging.