Role of the microbiology laboratory in the diagnosis of opportunistic infections in persons infected with human immunodeficiency virus.

Patients with defects in the immune system caused by infection with human immunodeficiency virus are predisposed to a variety of opportunistic infections, many of which can be diagnosed by conventional or special microbiological procedures. This article reviews the laboratory diagnosis of bloodstream, lower respiratory tract, gastrointestinal tract, and central nervous system infections in persons infected with human immunodeficiency virus. Laboratories serving health care facilities in which a large number of patients with human immunodeficiency virus infection are cared for should consider enhancing the detection of the specific pathogens affecting these patients by the use of special procedures, including blood culture methods for mycobacteria and fungi, examination of induced sputum for Pneumocystis carinii, and modified acid-fast stains on feces to identify Cryptosporidium and Isospora belli.