Drug-resistant Mycobacterium tuberculosis in Japan: a nationwide survey, 2002.

Objective: To determine the prevalence of anti-tuberculosis drug resistance in Japan.

Methods: A total of 3122 Mycobacterium tuberculosis strains were collected from different patients admitted to 99 participating hospitals between June and November 2002. The proportion method was employed to perform drug susceptibility testing for four first-line anti-tuberculosis drugs, isoniazid (INH), rifampicin (RMP), streptomycin (SM) and ethambutol (EMB).

Results: Resistance in new cases was observed to be as follows: 2.8% to INH, 1.0% to RMP, 7.0% to SM and 0.9% to EMB. Resistance in previously treated cases was 18.9% to INH, 11.0% to RMP, 14.4% to SM and 8.4% to EMB. There was a significant difference in the prevalence of resistance in new and previously treated cases for each of the drugs. The prevalence of drug resistance was shown to have decreased since the 1997 survey, except in the case of EMB.

Conclusions: This study showed a clear decrease in the prevalence of initial and acquired drug resistance to major anti-tuberculosis drugs in Japan between 1997 and 2002, except for multidrug resistance. Further effort is needed to provide high-quality DOTS in Japan.