Interrelational changes in the epidemiology and clinical features of nontuberculous mycobacterial pulmonary disease and tuberculosis in a referral hospital in Japan

Background and objectives The incidence of nontuberculous mycobacterial pulmonary disease (NTM-PD) is increasing, while that of tuberculosis (TB) is decreasing in many industrialized countries, including Japan. However, the long-term evaluation of clinico-epidemiological features of NTM-PD in relation to TB are limited. We aimed to clarify the long-term changes in the epidemiology and clinical features of NTM-PD in relation to those of TB at a nationally-designated TB center in Japan. Methods We reviewed all mycobacterial examination records at Fukujuji Hospital between 2006 and 2016. Cases of NTM-PD were defined according to the 2007 American Thoracic Society/Infectious Disease Society of America microbiologic criteria. The current characteristics of Mycobacterium avium complex pulmonary disease (MAC-PD) were compared with those in the 1980s and circa 2000. Results We identified a total of 3,546 pulmonary TB cases and 2,155 NTM-PD cases. While the annual number of incident pulmonary TB cases remained stable over the study period (P = 0.59), that of NTM-PD cases increased significantly from 165 to 278 (P Conclusions The annual number of incident NTM-PD cases increased markedly. In contrast to patients with TB, the mean age of new NTM-PD patients did not increase in the last 10 years. Among MAC-PD patients, the proportions accounted for by the NB form increased significantly in both sexes.