Patterns and trends of primary drug-resistant tuberculosis in Chongqing, China, from 2012 to 2020

Primary drug-resistant tuberculosis (DR-TB) contributes significantly to the global TB epidemic, particularly in countries with high TB burdens. This study aimed to investigate the characteristics of primary DR-TB prevalence in Chongqing, China, from 2012 to 2020. A total of 4546 newly diagnosed and 2769 relapse TB patients admitted to the hospital from 2012 to 2020 were included. Categorical variables were compared using Pearson chi-square test or Fisher exact test, as appropriate. Logistic regression analysis was performed to determine factors associated with primary DR-TB. The rate of primary DR-TB was 24.5%, whereas that of acquired DR-TB was 67.8%. Among newly diagnosed TB cases, the percentage of DR-TB (from 48.9 to 44.2%), mono-resistant TB (from 11.8 to 9.7%), multidrug-resistant TB (MDR-TB; from 25.3 to 6.9%), and pre-extensive drug-resistant TB (from 13.7 to 5.8%) showed a decreasing trend from 2012 to 2020. Age from 15 to 64 years was a risk factor for the development of primary DR-TB (15–44 yearsadjusted odds ratio = 2.227, 95% confidence interval1.053–4.710; 45–64 yearsadjusted odds ratio = 2.223, 95% confidence interval1.048–4.717). The rates of primary DR-TB (P = .041) and MDR-TB (P = .007) were significantly higher in the age group of 15 to 64 years than in the age groups of ≤14 years and ≥65 years. Noticeably, rising trends of primary DR-TB (from 0 to 27.3%) and MDR-TB (from 0 to 9.1%) in the population of ≤14 years were observed from 2012 to 2020. Although the rate of primary DR-TB showed a downward trend, a rising drug-resistance rate among some particular subgroups was still observed. Further control of primary DR-TB should focus more on TB patients aged 15 to 64 years.