Diagnosis and treatment of lung infection with nontuberculous mycobacteria

Purpose of review Pulmonary infections caused by nontuberculous mycobacteria (NTM) are diagnosed with increasing frequency, in part due to growing at-risk populations but also as a result of improved awareness and diagnostic facilities. This review summarizes recent literature regarding epidemiological, clinical, diagnostic and therapeutic aspects of NTM lung infections. Recent findings The number of species known to cause NTM infections has increased due to the extended use of molecular techniques. The number of recognized risk factors, including newly discovered inherited immunological disorders and novel types of immunomodulating drugs such as antagonists of tumor necrosis factor-alpha is also growing. Revised diagnostic criteria for NTM lung infection are available but the decision whether to treat a patient remains a matter of careful individual evaluation taking into account the NTM species, extent of disease, general condition and underlying disorders. No major breakthrough has been made with regard to treatment. Antibiotic treatment of NTM infection is complicated by the necessary long duration and the adverse toxicity profile of many of the potentially effective drugs while there is an uncertain correlation between in-vitro susceptibility and in-vivo effectiveness except for two drug-NTM species combinations. The role for novel antibiotics in the treatment of NTM infection is still uncertain. Summary Much remains unknown regarding treatment of NTM lung infections. In order to provide optimal care, the recommendations provided in the 2007 American Thoracic Society/Infectious Diseases Society of America statement should be taken as a starting point and there should be a low threshold to seek expert consultation.