In this retrospective study, we aim to investigate the demographic and clinical features of patients with nontuberculous mycobacteria (NTM) lung disease in our hospital and the trends and diversity of NTM species isolated in the period of 2009-2018.

Inclusion Criteria:

• Patients older than 18 years old.
• patients with one or more respiratory isolates (namely, sputum, tracheal aspirates, bronchial washing, bronchial aspirates, bronchial trap and bronchoalveolar lavage) of mycobacteria collected in the Prince of Wales Hospital in the period of 2009-2018.

Exclusion Criteria:

• none

The Clinical Data Analysis and Reporting System (CDARS) will be queried to identify patients from whom one or more respiratory isolates (namely, sputum, tracheal aspirates, bronchial washing, bronchial aspirates, bronchial trap and bronchoalveolar lavage) of mycobacteria collected in the Prince of Wales Hospital in the period of 2009-2018. Specimen and clinical information is linked through the Clinical Management System (CMS). The clinical history from the CMS will be reviewed to assess the comorbid conditions and baseline demographic information.

Laboratory reported use of DNA probes for identification of Mycobacterium avium complex (MAC), M. avium, Mycobacterium intracellulare, Mycobacterium kansasii, and Mycobacterium gordonae, high-performance liquid chromatography and biochemical will be used to identify rapid growers. For trend analysis, no changes in methods for species identification during the study periods will be reported.