[Nontuberculous Mycobacteria: Diagnostic Challenges and Individualized Therapeutic Approaches]

Non-tuberculous mycobacteria (NTM) are increasingly recognized as clinically relevant pathogens, particularly in countries with a low tuberculosis incidence. Recent data from Denmark demonstrate a continuous annual rise in NTM-related pulmonary disease (NTM-PD) of 4.6% over 3 decades, with more than half of the isolates associated with true disease. Structural lung diseases such as bronchiectasis, prior tuberculosis, and chronic pulmonary conditions are major risk factors, alongside immunodeficiencies and immunosuppressive therapies. The diagnosis of NTM-PD requires a combination of clinical symptoms, radiological findings, and the microbiological confirmation. Novel diagnostic tools, such as anti-GPL IgA serology and a CRISPR-Cas-based cfDNA assay, show promise for differentiating colonization from disease and monitoring treatment response, but the sputum culture remains essential for species identification and drug susceptibility testing. Treatment is complex and species-specific, with macrolides forming the backbone of most regimens. Refractory cases, particularly those involving Mycobacterium abscessus, pose therapeutic challenges and often require multidisciplinary management. Inhaled liposomal amikacin (ALIS) has shown benefit in refractory MAC disease. Clinical decision-making must balance efficacy, tolerability, and long-term adherence, highlighting the need for individualized treatment strategies and regular monitoring. This review outlines current evidence and practical recommendations for clinicians managing NTM-PD.