Tuberculosis infection and related factors among 15–17 years old teenagers in Eastern China

Tuberculosis infection (TBI) is a great barrier to tuberculosis control. Previous large-scale study had revealed that the TBI rate was between 13% and 20% for the general population in China. However, there is no large sample size study to evaluate the prevalence of TBI among teenagers. Therefore, it is important to investigate the strength of TBI and explore associated factors among senior high middle school freshmen with a large sample size in eastern China. A total of 30011 students, of senior high middle school in Taizhou city, China aged between 15-17 years old, were asked for health examination and TBI testing using ESAT6-CFP10 (C-TST) assay. Both univariate and multivariate logistic regression analyses were employed to evaluate potential risk factors for TBI. The study included 22,109 teenagers aged 15-17 years from 65 senior middle schools, and the TBI rate was 0.76% (95%CI, 0.65% -0.88%). The multivariate analysis showed that non-Han ethnicity (OR=4.21, 95%CI: 1.49-11.87, P=0.01), BCG scar (OR=0.52, 95%CI: 0.30-0.91, P=0.02), and family history of tuberculosis (OR=7.75, 95%CI: 2.44-24.57, P<0.01) were significantly associated with TBI in senior high middle school freshmen. Our results indicated the prevalence of TBI among teenage students was low. BCG vaccination was associated with a lower risk of TBI. In contrast, family history of tuberculosis and non-Han ethnicity were associated with increased risk of TBI for students in the eastern area of China. Targeting risk groups for TBI testing would benefit the implementation of preventive measures.