Age- and sex-related characteristics of the increasing trend of nontuberculous mycobacteria pulmonary disease in a tertiary hospital in South Korea from 2006 to 2016

Background/Aims: The incidence rate of nontuberculous mycobacterial pulmonary disease (NTM-PD) is increasing worldwide. However, data regarding the age- and sex-specific epidemiology of NTM-PD are limited. This study aimed to investigate the long-term epidemiologic trends of NTM-PD within the recent 11-year period in a tertiary referral hospital in Korea. Methods: We retrospectively reviewed the medical records of the patients diagnosed with NTM-PD between January 2006 and December 2016 at Severance Hospital, South Korea. Results: There were 1,017 incident cases with NTM-PD during the study period. The mean age was 62.7 years, and 41.2% were men. Women were younger than men (59.9 years vs. 66.7 years, p < 0.001) and a higher proportion of women had bronchiectasis (88.6% vs. 77.1%, p < 0.004 The incidence rates of NTM-PD annually increased by 14% (95% confidence interval, 10% to 19%) from 1.2 in 2006 to 4.8 in 2016 (per 100,000 patients-year). The peak incidence rate was in the 50s for women and in the 70s for men, except for those aged >= 80 years. Mycobacterium avi-um complex was the most common causative species of NTM-PD (63.6%). Conclusions: The incidence rate of NTM-PD in a tertiary referral hospital in South Korea continued to increase from 2006 to 2016. Furthermore, there were age- and sex-related differences in the clinical characteristics, which might contribute to understanding the nature of the disease and inherited and acquired host factors.