[A study on drug resistance of newly admitted pulmonary tuberculosis patients. Part 1. Prevalence of drug resistance according to the sensitivity test at local laboratories, and its trend over 25 years in Japan. Tuberculosis Research Committee, (Ryoken)].

As a part of the epidemiological surveillance for the resistance to anti-tuberculosis drugs in pulmonary tuberculosis patients, successive surveys of the prevalence of resistance to tuberculosis drugs were conducted by Tuberculosis Research Committee "Ryoken". The prevalence of drug resistance according to the sensitivity test at local laboratories was reported as follows from the results of the ninth survey conducted in 1982. 1. In 1957, the percentage of the patients without history of previous chemotherapy among the newly admitted patients to hospital was only 17.8%, but it increased in each survey reaching 64.2% in 1982. 2. According to the results of sensitivity tests at local institutions, the prevalence of initial resistance to at least one of SM, INH and/or PAS was 13.6%, and that to each of the drug was 8.8%, 4.2% and 5.1%, respectively. 3. Prevalence of acquired resistance to at least one of SM, INH and/or PAS among newly admitted patients with history of previous treatment was 54.0% in 1957, and it increased in each survey reaching 65.4% in 1963. Since then, it decreased gradually, and became 40.1% in 1982. Decrease in the prevalence of acquired resistance was statistically confirmed.