Prevalence and Clinical Implications of Nontuberculous Mycobacteria Isolation and Infection among Patients with Bronchiectasis in the Jerusalem Area

Background: Bronchiectasis is an obstructive chronic lung disease characterized by structural changes in large and small airways, namely permanent widening of bronchial lumen resulting in chronic inflammation and infection. Nontuberculous mycobacteria (NTM) are environmental mycobacteria that may cause human infection or colonization with over 150 species identified to date. Bronchiectasis with NTM colonization or infection is often encountered but with varying prevalence and unknown clinical or prognostic significance. Objectives: To find the prevalence of NTM among patients with bronchiectasis in the Jerusalem district. To assess whether there were clinical differences between patients with bronchiectasis who were isolated with NTM and those without. Methods: In this retrospective observational research study, we reviewed all computerized medical charts of patients over 18 years of age, who were diagnosed with bronchiectasis at Hadassah Medical Centers in Jerusalem between 2012 and 2017. We assessed the prevalence of NTM pulmonary disease. To compare patients with and without NTM, we reviewed and analyzed clinical, radiological, and microbiological data of all NTM patients and a group of controls in a 4:1 ratio. Results: Prevalence of NTM among bronchiectasis patients was 5.1%, slightly lower than previously reported in Israel. We did not find clinically or radiological significant differences in patients with NTM disease compared to controls. This result included a similar number of exacerbations, hospitalization rates, number of lobes involved, and pulmonary function tests. Conclusions: Bronchiectasis patients with isolation of Pseudomonas aeruginosa experienced more exacerbations than patients with other isolates, consistent with previous studies.