Divergent trends in pulmonary tuberculosis notification rates between teachers and students in Southwest China, 2010–2024: a joinpoint regression analysis

School-based tuberculosis (TB) control in China primarily targets students, while teachers—a potentially under-recognized group—have received limited attention. We compared long-term trends in pulmonary TB (PTB) notification rates between teachers and students in Chengdu, Southwest China, from 2010 to 2024, to inform school TB prevention strategies. Annual PTB notification data for the general population, teachers, and students were retrospectively collected. Joinpoint regression was performed using the NCI Joinpoint Regression Program (v6.1.0) with data-driven model selection (maximum 2 joinpoints, permutation tests/Bayesian Information Criterion). A parallelism test was used to compare trends. Sensitivity analyses excluded the COVID-19 period (2020–2022). The general-population PTB notification rate declined from 61.78 to 35.63 per 100,000 (-42.3%). Teachers showed 0 joinpoints (APC = -2.19%, 95% CI -5.04% to 0.75%, P = 0.130); students showed 2 joinpoints (2017, 2021), with APCs of -7.11% (2010–2017), -1.41% (2017–2021), and − 17.32% (2021–2024). The parallelism test rejected the null hypothesis of parallel trends ( P = 0.005). In 2024, the teacher rate was 2.77 times the student rate (16.00 vs. 5.78/100,000). After excluding 2020–2022, both groups showed 0 joinpoints (teacher APC = -3.53%, student APC = -7.22%), and parallelism was not rejected ( P = 0.206). Student PTB notification rates in Chengdu declined significantly, while teacher rates showed a non-significant slow decline. Teacher rates remained persistently higher than student rates, with the gap narrowing to a minimum in the mid-2010s, widening thereafter, and slightly narrowing recently. Teachers may represent an under-recognized group in school-based TB control. Enhanced screening and health management for teachers are recommended.