Surveillance for tuberculosis drug resistance in Hangzhou, Zhejiang

Objective To investigate the prevalence of drug resistant tuberculosis (TB) in Hangzhou, Zhejiang provincec, and provide evidence for the revision of local TB control strategy. Methods Sputum samples were collected from all smear-positive TB patients registered in 2011 in Hangzhou and traditional biochemical reaction was done to identify the isolated strains. The strains' drug susceptibilities to Isoniazid, Rifampicin, Ethambutol, Streptomycin, Ofloxacin and Kanamycin were detected with modified Lowenstein-Jensen Culture Medium recommended by WHO. Results A total of 1845 smear-positive TB patients were registered in 2011, 1394 were culture positive, and 1184 were identified as Mycobacterium tuberculosis infections and had drug test results. Of the 1184 patients, 31.33% were resistant to at least one first-line drug, 11.57% were multi drug resistant (MDR), 0.90% were extensively drug resistant (XDR). Of the MDR patients, 29.93% were resistant to Ofloxacin, 3.65% were resistant to Kanamycin. The drug resistant rates to Isoniazid, Streptomycin, Rifampicin and Ethambutol were 19.51%, 17.15%, 16.98%, and 5.07%, respectively. The drug resistant rate in re-treated cases was significantly higher than that in new cases. Conclusion The prevalence of drug resistant TB was high in Hangzhou, It is necessary to improve the chemotherapy for drug resistant cases and strengthen the management of new cases and re-treated cases to reduce the incidence of MDR-TB or XDR-TB.