Extrapulmonary Mycobacterium avium complex infections in immunocompetent patients

Abstract

The Mycobacterium avium complex (MAC) includes ubiquitous bacteria that typically cause infection in immunocompromised patients. This paper reviews the presentation, diagnosis, pathogenesis, and treatment of extrapulmonary MAC infections in immunocompetent patients by compiling information from case reports identified by a PubMed search. Mycobacterium avium complex infections in immunocompetent patients can present primarily with extrapulmonary symptoms, and this makes the diagnosis of MAC infection in these patients more difficult. The American Thoracic Society has not established criteria for the diagnosis of extrapulmonary MAC infections; testing for MAC should be based on clinical suspicion or after the exclusion of all other causative agents. Methods of testing should include molecular and biochemical tests, since these tests provide more definitive identification than routine cultures. Extrapulmonary presentations usually respond well to macrolide based multi-drug regimens started as soon as a MAC infection is identified. 

Key words: Mycobacterium avium, infection, diagnosis, treatment