The diagnosis and management of disease caused by M. avium complex, M. kansasii, and other mycobacteria.

Because mycobacteria other than Mycobacterium tuberculosis are common in the environment and yet are infrequent causes of disease in humans, their isolation from a clinical specimen must be carefully evaluated before concluding that disease exists. It is often necessary to accumulate and weigh a cascade of various clinical factors before a diagnosis can be made. Mycobacterium avium complex has emerged as an increasingly important pathogen, particularly in patients with the acquired immunodeficiency syndrome. Even after the diagnosis of disease has been established, its management must be carefully individualized because highly effective treatment regimens are not available except for Mycobacterium kansasii. A scheme to categorize patients with M. avium complex according to the nature of their disease, together with subsequent management strategies, is presented.