Characteristics and risk factors of drug-resistant tuberculosis in Sichuan, China: An observational study

This study aimed to determine the epidemiological characteristics of drug-resistant tuberculosis (DR-TB) and investigate the risk factors associated with multidrug-resistant tuberculosis (MDR-TB) in Sichuan, China.

The study involved 5180 clinical isolates collected from Sichuan since 2013, with non-tuberculous mycobacteria excluded. Drug susceptibility testing was conducted using four first-line anti-TB drugs, fluoroquinolones, and second-line injectable agents. Multivariable logistic regression analysis was used to assess risk factors for MDR-TB based on patients' treatment history, age, sex, ethnicity, health facility, living environment and human immunodeficiency virus (HIV) status.

Among the 5180 participants, resistance was highest for isoniazid (23.59%), followed by rifampin (18.42%), streptomycin (18.42%) and ethambutol (2.47%). The prevalence of MDR-TB was 774 (14.94%) among all cases, with 575 (14.20%) in newly diagnosed tuberculosis (TB) patients and 199 (17.60%) in previously treated patients. Additionally, 17 (0.33%) patients were diagnosed with MDR-TB. Furthermore, urban living was identified as a protective factor against MDR-TB (odds ratio [OR] 0.80, 95% confidence interval [CI] 0.68-0.94, p = 0.004). Notably, individuals younger than 60 were more likely to develop MDR-TB, especially those aged 32-45 (OR 2.22, 95% CI 1.74-2.83, p < 0.001). In addition, HIV-positive status was identified as a risk factor for MDR-TB (OR 2.06, 95% CI 1.21-3.49, p = 0.008).

The study demonstrated that the prevalence of DR-TB among the study subjects exceeded the national level. Patients living in rural areas, those with a history of TB treatment, HIV-positive individuals, and younger patients were more likely to develop MDR-TB.