Approach to the diagnosis and treatment of non-tuberculous mycobacterial disease

Abstract

Non-tuberculous mycobacteria (NTM) is a collective name given to a group of more than 190 species of Mycobacterium. The clinical presentation for most NTM infections is non-specific, often resulting in delayed diagnosis. Further complicating matters is that NTM organisms can be difficult to isolate. Medications used to treat NTM infection can be difficult for patients to tolerate, and prolonged courses of anti-mycobacterial therapy are often required for adequate suppression or eradication. Herein, we review different NTM syndromes, appropriate diagnostic tests, and treatment regimens.

Keywords: ADR, adverse drug reactions; AFB, acid fast bacilli; AST, antimicrobial-susceptibility testing; ATS, American Thoracic Society; BCG, Bacille Calmette-Guerin; CLSI, Clinical and Laboratory Standards Institute; COPD, chronic obstructive pulmonary disease; ECG, electrocardiogram; EMB, ethambutol; Erm, erythromycin ribosomal methylase; FDA, Food and Drug Administration; HIV, human immunodeficiency virus; HRCT, high resolution computed tomography; IDSA, Infectious Disease Society of America; INF-γ, interferon- γ; INH, isoniazid; MAC, Mycobacterium avium complex; MALDI-TOF, matrix-assisted laser desorption ionization time-of-flight mass spectrometry; MGIT, mycobacteria growth indicator tube; MIC, minimum inhibitory concentrations; Mycobacterium abscessus; Mycobacterium avium; NTM, non-tuberculous mycobacteria; Non-tuberculous mycobacteria; PCR, polymerase chain reaction; PFT, pulmonary function test; TB, tuberculosis; TDM, therapeutic drug monitoring.

Fig. 1

Radiographic images of patients with fibro-cavitary MAC. A. Chest roentgenogram demonstrating a left apical thin walled cavity with surrounding pleural reaction. The background lung architecture has increased reticular markings consistent with scarring. B. Chest computed tomography, axial section, demonstrating a thick-walled cavitary lesion in the left upper lobe.

Fig. 2

High resolution chest computed tomography of nodular bronchiectasis affecting the lingula. Lingula and right middle lobe are thought to be more often involved in nodular bronchiectatic NTM.