[Studies on epidemiology of nontuberculous mycobacteriosis--on the regional difference of the incidence of pulmonary diseases due to M. kansasii and M. avium complex in Tokyo area].

On 397 patients with pulmonary disease due to nontuberculous mycobacteria (NTM) [102 due to M. kansasii (MK) and 295 due to M. avium complex (MAC)] observed at National Tokyo Chest Hospital, 191 patients with pulmonary disease (59 due to MK and 132 due to MAC) observed at Fukujuji Hospital of Antituberculosis Association and 257 patients from whose sputum MK (36) or MAC (221) were isolated in Byotai-Seiri Clinical Laboratory, the distribution of these patients by domicile in Tokyo area was analysed. The percentage of patients with MK disease among the whole patients with MK disease and MAC disease (MK ratio) in each community area was investigated. MK ratio was 30.9% in the 23 wards and 16.4% in Tama section of Tokyo in the patients observed at National Tokyo Chest Hospital. It was 37.0% in the 23 wards and 32.1% in Tama section in the patients observed at Fukujuji Hospital and was 17.7% in the 23 wards and 8.1% in Tama section in the patients observed at Byotai-Seiri Clinical Laboratory. MK ratio in Tokyo was considerably higher in the 23 wards that were densely populated industrial and commercial areas than in Tama section, a comparatively sparsely populated suburb. MK ratio in patients of Ota Hospital located in the 23 wards was higher (36.4%) than that of Tachikawa-Sogo Hospital located in Tama area (10.0%). Regional differences in MK ratio were remarkable in Tokyo area. A high MK ratio appeared to correlate with a high incidence rate of tuberculosis. From the results mentioned above, it was suggested that M.K. disease may be transmitted from person to person.