Atypical mycobacterial infection

Alternative names:

mycobacteria other than tuberculosis; nontuberculous atypical mycobacterial disease

Definition:

An infection caused by a species of Mycobacterium, other than tuberculosis, that is often resistant to antituberculous drugs.

Causes, incidence, and risk factors:

Atypical mycobacterial infection can cause infections such as abscesses, septic arthritis and osteomyelitis (bone infection). It can infect the lungs, the lymph glands, or skin and soft tissues.

Several species of Mycobacterium cause different infections. Mycobacterium avium intracellulare frequently affects AIDS patients. Mycobacterium marinum and M. ulcerans cause skin infections. M. marinum is responsible for swimming pool granuloma. M. avium-intracellulare and M. kansasii cause lung disease.

Atypical mycobacterial infections occur in approximately 3 out of 10,000 people annually but the incidence is increasing as the AIDS population grows. Populations at risk include individuals with pre-existing lung disease and immunocompromised (immunosuppressed) persons.