Abstract: Objective To explore the situation of sputum culture conversion, and to evaluate the risk factors of sputum culture conversion for patients with multidrug-resistant TB.  Methods In Xuzhou, Nantong and Zhenjiang, tuberculosis culture and strains identification were carried out on the sputum smear-positive patients, and then drug susceptibility test(DST) was carried out with proportion method. Standardized treatment regimen and individualized regimen were given to MDR-TB patients registered from 1 January 2009 to 30 June 2012. Surveillane and DOTS were implemented to each patient during the treatment. Bacteriologic, treatment outcome and risk factors of sputum culture conversion were evaluated. Three hundred and seventy-six MDR-TB patients had been analyzed, including 278 male, and 98 female. The average age was (49.33±15.36) years old. Data was analyzed using SPSS 13.0, Chi-squared test and logistic regression were used for univariate and multivariate statistics. P value less than 0.05 was considered statistically significant.  Results 58.78% (221/376), 61.97% (233/376) and 61.17% (230/376) patients got culture conversion at 2, 4 and 6 months’ treatment, which had no significant differences between them (χ²=0.807, P>0.05). The treatment success rates of patients got culture conversion at 2, 4 and 6 months were 69.68% (154/221), 71.24% (166/233) and 73.48% (169/230) respectively, which were all higher than patients with culture positive results or without culture results (χ²=60.804，82.619，101.047, P<0.01). The treatment success rate of patients with positive culture at 2 months’ treatment was 31.33% (26/83), and was higher than that at 6 months’ (16.36%, 9/55)(χ²=3.912, P<0.05). In a multivariate analysis, previous TB treatment (P<0.01, OR=0.205; 95%CI: 0.070－0.598), resistance to second line drugs (P<0.05, OR=2.609; 95%CI: 1.097－6.206) and resistance to kanamycin (P<0.05, OR=10.008; 95%CI: 1.101－90.974) had statistically significant negative association with culture conversion at 2 months.  Conclusion About 60% MDR-TB patients get culture conversion at 2 months’ treatment. Previous TB treatment, resistance to second line drugs and resistance to kanamycin are associated with culture conversion at 2 months.

Key words: Tuberculosis, pulmonary/drug therapy, Drug resistance, multiple, bacterial, Treatment outcome, Retrospective study