Changing Epidemiology of Nontuberculous Mycobacterial Lung Diseases in a Tertiary Referral Hospital in Korea between 2001 and 2015.

This study investigated the changes in the major etiologic organisms and clinical phenotypes of nontuberculous mycobacterial lung disease (NTM-LD) over a recent 15-year period in Korea. The increase of number of patients with NTM-LD was primarily due to an increase of Mycobacterium avium complex (MAC) lung disease (LD). Among MAC cases, the proportion of M. avium increased compared with M. intracellulare, whereas the incidence of M. abscessus complex and M. kansasii LD remained relatively stable. The proportion of cases of the nodular bronchiectatic form increased compared with the fibrocavitary form of NTM-LD.