[Nontuberculous mycobacteriosis mortality in Japan]

The aim of this research was to clarify epidemiological characteristics of nontuberculous mycobacteriosis deaths in Japan. We analyzed the frequency of deaths due to nontuberculous mycobacteriosis (NTM) and regional differences using the Vital Statistics of Japan, published by the Ministry of Health, Labour and Welfare. The crude death rate was calculated using the Population Census of Japan published every 5 years (Ministry of Internal Affairs and Communications). In addition, changes in the proportions of death cases due to NTM disease among total autopsies were calculated using the Annual of the Pathological Autopsy in Japan (The Japanese Society of Pathology).

NTM disease deaths appeared for the first time in 1970, with a marked increase by 2007, when there were 912 certified deaths. The increase was more marked after the mid-1990s. The number of women's deaths exceeded 300 in 1999 and reached 570 in 2007, while that of men exceeded 300 in 2001 and remained at nearly the same level until 2007. The death rate increased in all eight regions of Japan. The highest single-year regional death rate was 212 in Kanto in 2005. However, correcting by population size, the crude death rate was higher in the western regions of Japan than in the eastern ones. The proportion of NTM among total autopsies also showed an increase from 0.066% in 1993 to 0.304% in 2007. Included in the report is a comparison of trends of NTM deaths with those of major respiratory diseases including tuberculosis, emphysema, bronchial asthma and airway cancers.