Abstract: Objective  To analyze the resistance characteristics of different registration classification smear positive TB patients (especially MDR-TB) and to understand the risk factors in order to provide reliable references for development of drug-resistant TB control strategy. Methods  Two sputum samples were collected from each smear positive patient in 3 categories-new, re-treatment (relapse, transfer in and others) and treatment failure (failure of new patient, retreatment patient and new patients who remain smear positive after 3 months of treatment) for sputum culture by proportional method, six kinds of anti-TB drugs (INH, RFP, EMB, S, Km, Ofx) were tested for susceptibility. Between December 2006 and March 2012, a total of 2110 cases of smear positive TB patients were sputum cultured, in which 1947 cases (92.3%) were culture positive; through drug susceptibility test (DST) and bacterial typing, 1800 cases of Mtb (92.4%) were identified eventually.  Results  Among the 1800 Mtb cases, a total of 794 cases (44.1%，794/1800) were identified as drug-resistant TB, out of which, 244 cases (13.6%,244/1800) were single-drug-resistant (SDR) TB, 155 cases (8.6%,155/1800) were poly-drug-resistant (PDR) TB, 395 cases (21.9%,395/1800) were MDR-TB, the detection rate of MDR-TB is significantly higher than SDR-TB and PDR-TB (χ²=43.4, χ²=123.6，P＜0.01).The detection rate of SDR for new, re-treatment and treatment failure TB patients was 11.9%(57/480), 14.4%(159/1107)and 13.1%(28/213) respectively, the difference is not statistically significant (χ²=0.33, P=0.85); the detection rate of PDR for new, re-treatment and treatment failure TB patients was 5.4%(26/480), 9.8%(109/1107) and 9.4%(20/213) respectively, the difference is not statistically significant between retreatment and treatment failure cases (χ²=0.04, P=0.84). however, they are higher than that of new TB cases (χ²=8.53, P=0.01); the detection rate of MDR for new, re-treatment and treatment failure TB patients was 14.4%(69/480)，22.5%(249/1107) and 36.2%(77/213)respectively, the detection rate of treatment failure TB patients is higher than that of new and re-treatment TB patients (χ²=17.92, χ²=42.07, P＜0.01). Conclusion  The detection rate of drug resistant TB is high among smear positive TB patients in Wuhan. The diversity and complexity of drug resistant spectrum poses a threat to TB control in China.

Key words: Tuberculosis, Pulmonary/drug therapy, Drug resistance, bacterial, Wuhan city