[Studies on the nontuberculous lung mycobacteriosis in Japan. (Report of the study in the year 1987 and 1988 of the Mycobacteriosis Research Group of the Japanese National Chest Hospitals)--pulmonary infection caused by Mycobacterium kansasii has begun to appear in all over Japan including north Japan Hokkaido].

Unlabelled: In this study, the Mycobacteriosis Research Group of the Japanese National Chest Hospitals (MRG) presents the reports of study years 1987 and 1988. As reported previously**, pulmonary infection caused by Mycobacterium kansasii occurred principally in South-West Japan (prefectures South-West of Tokyo) and did not appear in North Japan. However, this disease appeared in 1987 and 1988 in Hokkaido (Sapporo Hospital). Accordingly, we may say the disease occurs all over Japan. This is a noteworthy finding newly recognized in the study years. The prevalence rate of nontuberculous lung mycobacteriosis was determined as 2.92 or 2.78 in 1987 and as 2.02 or 1.91 in 1988 per 100,000 population per year. The estimated rates based on the ratio of nontuberculous lung mycobacteriosis against active lung tuberculosis and based on the ratio of nontuberculous lung mycobacteriosis against culture-positive lung tuberculosis well agreed with each other.

Comment: In this country, chest physicians customarily report their cases of nontuberculous mycobacteriosis including lung tuberculosis, because the payment of treatment for patients with tuberculosis is free. Because of this custom, tuberculosis statistics surely contain cases of nontuberculous mycobacteriosis. Caution about this has been paid in calculating the prevalence rate. From the study year 1987, the MRG chairman moved from Michio Tsukamura, The National Chubu Hospital, to Nobuhiko Kita, The National Kinki Chuo Hospital.