Mass school testing for Mycobacterium tuberculosis infection and disease in an adolescent population: A prospective...

ObjectivesAdolescents remain underprioritized in tuberculosis (TB) control, with limited evidence guiding screening and preventive strategies. Leveraging a mass school-based screening program in eastern China, we evaluated the prognostic value of tuberculin skin test (TST) induration size for predicting progression to active TB disease among adolescents within a prospective cohort framework.Methods:From 2018 to 2021, TST-based screening was conducted among newly enrolled students across 68 high schools in Jiangsu Province, China. All students were screened at baseline and followed through record linkage. Binary logistic and Cox proportional hazards regression models identified factors associated with Mycobacterium tuberculosis (Mtb) infection and disease progression.ResultsAmong 198,276 students, TST positivity at 5 mm, 10 mm, and 15 mm cutoffs was 11%, 6%, and 2% respectively. Adjusted hazard ratios (95% CI) for indurations of 5-9 mm, 10-14 mm, and ≥15 mm versus <5 mm were 1.27 (0.46-3.50), 6.65 (3.85-11.49), and 10.02 (5.23-19.20). However, sensitivity to detect incident TB at each cutoff remained low (<40%). Compared with students recruited in 2018-2019, TST positivity was lower among those recruited in 2020 (aRR = 0.73; 95% CI, 0.59-0.89) and 2021 (aRR = 0.68; 95% CI, 0.53-0.86), as was TB progression among students recruited in 2021 (aHR = 0.35; 95% CI, 0.16-0.76).ConclusionIn this large school-based prospective cohort, larger TST indurations were associated with subsequent TB, but overall sensitivity and positive predictive value of TST screening were low. School-entry TST screening alone cannot identify most at-risk adolescents, and more targeted strategies are needed to detect and protect them.