Abstract
A total of 487 cases with pulmonary tuberculosis who were admitted to the Attatched Sanatorium of Research Institute during the period from 1954 to 1961 undergone original treatmet by chemotherapy and observed for longer than 6 months, were subjected to the study. Strains were defined as resistant, if there is any growth of tubercle bacilli on culture media containing 10γASM, 1γ IγNH or 1γA PAS. The results obtained were the following:
1. At the beginning of treatment, 281 cases (57.7%) were bacilli positive, and among them, 270 were positive by culture. Primay drug resist ance was found in 56 cases (20.7%).
2. Positive conversion of tubercle bacilli was found in 52 cases (10.7%) after continuing negative finding for longer than 4 months. Among them, 25 (48%) were smear positive and culture negative, and remaining 27 (52%) were culture positive. Among the latter, 20 cases (74%) were resistant to at least one of SM, INH and PAS.
3. Comparing the drug resistance at the beginning of treatment and at the time of positive conversion, multiple drug resistance arid INH resistance were found more frequently among the latter. (cf. Table 9).
4. The rate of drug resistant cases among positive converted cases showed no correlation with the quantity of bacilli discharge and the presence of cavity.
5. The clinical course of positive converted cases was different by the drug susceptibility and the quantity of bacilli discharge. Nearly all of the drug susceptible cases and most of the drug resistant cases with a small quantity of bacilli discharge converted to negative again under the same regimen of chemotherapy, while most of the drug resistant cases with a large quantity of bacilli discharge converted to negative by the surgical treatment.
6. Among 243 cases without cavity through out the whole observation period, 6 (2.5%) were resistant at the time of positive conversion.
7. The above mentioned results showed that most of the cases converted to positive after continuing negative finding for certain period were drug resistant, but their clinical course, especially that of the cases with a small quan tity of bacilli discharge, was different with that of the cases showing continuous bacilli discharge.
