Mycobacterium avium: a pathogen of patients with acquired immunodeficiency syndrome.

Mycobacterium avium complex has been isolated with increasing frequency from humans during the last few decades. Thirteen patients admitted to the UCLA Medical Center with the diagnosis of acquired immunodeficiency syndrome (AIDS), in addition to having Kaposi's sarcoma, Pneumocystis pneumonia, and other opportunistic infections, also had M. avium complex isolated from a variety of tissues and fluids submitted for culture. Of these patients, 10 had histologic and bacteriologic evidence of disseminated mycobacterial infection, and M. avium complex was isolated from the blood of 5. The organisms were isolated from routine bacteriologic and diphasic fungal blood culture bottles. Periodic cultures of sputum, urine, and other body fluids and tissues should be performed for mycobacterial infections in all such patients. Routine blood cultures should be kept for at least 8 weeks to check for the presence of acid-fast bacteria in general and for M. avium complex in particular from all patients with immune deficiencies.