Nontuberculous Mycobacterial Pulmonary Disease

Nontuberculous mycobacteria (NTM) generally refer to > 180 species of mycobacteria other than Mycobacterium tuberculosis complex, M. leprae and M. ulcerans. Initially these organisms were recognized as causes of TB-like illnesses, with cavitary upper lobe radiological changes. Disease was seen predominantly in people with underlying risk factors, such as structural lung disease or forms of immunosuppression, however the proportion of patients with no identifiable risk factors has risen significantly. This NTM-PD often affects middle aged to elderly people, predominantly female, and may be a manifestation of a complex genetic disorder, determined by interactions among multiple genes with various environmental exposures. Not all patients who have NTM in their sputum will have infection, and not all with infection will have disease requiring immediate treatment. Criteria have been developed to aid in the assessment process. The decision to initiate treatment is complex, and requires an individualized analysis of the benefits and potential toxicities. For patients with disease, combination therapy for 12–24 months is generally required and follow up should be lifelong.