Proportions and Risk Factors of Developing Multidrug Resistance Among Patients with Tuberculosis in China: A Population-Based Case-Control Study.

ABSTRACT

AIMS: Limited studies have been conducted to explore risk factors of developing multidrug-resistant tuberculosis (MDR-TB) in China. This study aimed to find the proportions and risk factors of developing MDR-TB in China among new patients and previously treated tuberculosis (TB) patients. METHODS: A population-based case-control study was conducted from March 2010 to December 2013 in five cities in China. Proportions and risk factors of developing MDR-TB were calculated and analyzed separately for new patients and previously treated patients. RESULTS: The proportion of MDR-TB was 3.9% among new patients and 25.3% among previously treated patients in our study population. The proportion of extensively drug resistant TB was 0.1% among new patients and 1.4% among previously treated patients in our study population. Multivariate analysis found that being registered as migrants (odds ratio [OR] = 6.08; 95% confidence interval [CI] 1.75-21.09), having more than three affected lung fields (OR = 2.18; 95% CI 1.20-2.94), having more than 8 months of initial treatment (OR = 2.15; 95% CI 1.09-4.28), having more than three prior episodes of anti-TB treatment (OR = 3.10; 95% CI 1.48-6.48), and experiencing failure or continued worsening from the last treatment (OR = 3.82; 95% CI 1.86-7.85) were associated with developing MDR-TB in previously treated patients with TB. Univariate analysis showed that less than 30 years of living in the same location (p = 0.034) was a risk factor for new patients with MDR-TB. CONCLUSION: The surveillance of multidrug resistance among patients with previously treated TB who also possess these risk factors and the management of patients with MDR-TB should be reinforced.