Nontuberculous mycobacteria, a 5-year study of respiratory tract samples

<b>Introduction:</b> The isolation of nontuberculous mycobacteria (NTM) from respiratory specimens is increasing worldwide. Multiple risk factors (RF) are involved in this fact. The principal aim of this study is to describe clinical and radiologic characteristics of patients with NTM isolations. The second aim is to determine whether these RF play any role in the isolation of more than one species of NTM in the same patient. <b>Methods:</b> Retrospective analysis of 280 patients with pulmonary NTM isolated from 2013 to 2017. Database collected from the Department of Microbiology and medical history. <b>Results:</b> Data analysis showed that 68% were men. The average age was 70 (55-85) and 66% had been smokers. <b>Symptoms:</b> cough and sputum production 46%, hemoptysis 15%. Figure 1 is a comparative table between RF in patients with 1 species of NTM isolated and those with 2 or more. Radiologic patterns on CT scan: bronchiectasis 18%, alveolar infiltrates 17%, lung nodules 15%, cavitary lesions 3%. Most frequent MNT isolated: MAI 65%, M. fortuitum complex 14%, M. gordonae 8% and M. lentiflavum 4%. Most specimens were isolated from sputum 69% followed by bronchial aspirate 21% and bronchoalveolar lavage 9%. Only 12 patients received treatment. <b>Conclusions:</b> Among the studied sample, most were men and smokers. Bronchoscopy allowed diagnosis in more than a third of cases, being MAI and M. fortuitum most frequently isolated specimens. Bronchiectasis is a RF for a second NTM reinfection.