Comparative yield of blood culture for fungi and mycobacteria, liver biopsy, and bone marrow biopsy in the diagnosis of fever of undetermined origin in human immunodeficiency virus-infected patients.

The diagnostic yield of mycobacterial blood cultures, bone marrow biopsy, and liver biopsy for determining the cause of unexplained fever was compared prospectively in eight men and four women with serologic evidence of human immunodeficiency virus infection and fever of undetermined origin. Mycobacterial infection was found in 8 of the 12 patients (Mycobacterium tuberculosis in 3 and Mycobacterium avium in 5). Mycobacteria were isolated from the blood of 6 of these 8 patients. The mean interval from blood culture inoculation to growth was 28 days. Acid-fast organisms or granulomas were seen in four bone marrow and six liver specimens. Liver biopsy revealed acid-fast bacilli in a higher percentage of cases (75%) than did bone marrow biopsy (25%). Mycobacterial blood culture is a relatively slow method that occasionally fails to diagnose mycobacterial infection. In febrile patients infected with human immunodeficiency virus, liver biopsy is the most rapid method of diagnosing mycobacterial infection.