Non-tuberculous mycobacterial lung disease

Non-tuberculous mycobacterial lung disease is a chronic and often underrecognized infection caused by environmental mycobacteria that colonize susceptible airways. These organisms are widely present in soil, water, and household environments, but only a fraction of exposed individuals develop clinically significant illness. The condition occurs most frequently in people with preexisting airway abnormalities such as bronchiectasis, chronic obstructive pulmonary disease, or cystic fibrosis, as well as in older adults without obvious risk factors. Symptoms can be subtle, including fatigue, chronic cough, or low-grade fever, and are easily mistaken for tuberculosis or recurrent bacterial infections, leading to delays in diagnosis. High-resolution imaging and repeated positive cultures are essential to establish clinical relevance rather than incidental colonization.

Treatment is particularly demanding, as non-tuberculous mycobacterial lung disease requires lengthy multidrug regimens, often combining macrolides with companion agents such as rifamycins and ethambutol. Therapy may extend beyond a year, and patients must be closely monitored for drug toxicity, resistance development, and adherence difficulties. In some cases, surgical resection offers benefit for localized disease, while airway clearance and nutritional optimization improve long-term outcomes. Ongoing investigations into host immune response, bacterial persistence, and novel drug targets are reshaping management strategies. Advances in rapid molecular diagnostics and new antimicrobials provide hope for earlier intervention and improved success rates. Non-tuberculous mycobacterial lung disease remains a growing challenge worldwide, and multidisciplinary care—uniting pulmonologists, microbiologists, infectious disease specialists, and patient education—offers the most effective path toward reducing disease burden and enhancing survival.