Prevalence and risk factors of multi-drug resistant tuberculosis in Dalian, China

Objectives To investigate the prevalence and risk factors associated with multi-drug resistant tuberculosis (MDR-TB) in Dalian, China. Methods This was a retrospective review of data from patients attending a TB clinic in Dalian, China between 2012 and 2015. Demographic and drug susceptibility data were retrieved from TB treatment cards. Univariate logistic analysis was used to assess the association between risk factors and MDR-TB. Results Among the 3552 patients who were smear positive for Mycobacterium tuberculosis (MTB), 2918 (82.2%) had positive MTB cultures and 1106 (31.1%) had isolates that showed resistance to at least one drug. The overall prevalence of MDR-TB was 10.1% (359/3552; 131/2261 [5.8%] newly diagnosed and 228/1291 [17.7%] previously treated patients). Importantly, 75 extensively drug-resistant TB isolates were detected from 25 newly treated and 50 previously treated patients. In total, 215 (6.1%) patients were infected with a poly-resistant strain of MTB. Previously treated patients and older patients were more likely to develop MDR-TB. Conclusions The study showed a high prevalence of MDR-TB among the study population. History of previous TB treatment and older age were associated with MDR-TB.