[Trends in drug-resistant tuberculosis in National Higashisaitama Hospital, 1994-2001]

To know the prevalence of resistance to four first-line anti-tuberculosis drugs, we reviewed the results of drug-susceptibility tests of patients with tuberculosis who were admitted to our hospital from 1994 to 2001. Among patients with no prior chemotherapy against tuberculosis, the complete resistance rate was 1.9% for INH, 0.81% for RFP, 5.1% for SM, 0.81% for EB, and 0.32% for multiple drug-resistance (MDR). The acquired resistance rate was 9.7% for INH, 11.5% for RFP, 7.3% for SM, 2.4% for EB, and 6.1% for MDR. There was no significant increase in the prevalence of drug resistance between the first half (1994-1997) and the latter half (1998-2001) of the investigation periods. Compared with the previous reports, our results indicated no increase in the prevalence of drug resistance in tuberculosis patients with no prior treatment and the decrease of prevalence in patients with prior treatment of tuberculosis. A multi-drug regimen consisted of INH, RFP, PZA and EB or SM, which is currently considered as a standard regimen of tuberculosis chemotherapy and used quite widely, does not seem to induce the increase of drug-resistant tuberculosis.