Tuberculosis screening among children and adolescents in China: insights from a mathematical model

Background: Tuberculosis (TB) continues to be prevalent in China also among children and adolescents in China. We built a dynamic mathematical model for TB transmission in China, and applied it to compare the epidemic trends 2021–2030 under a range of screening interventions focusing on children and adolescents. Methods: We developed a dynamic mathematical model with a flexible structure. The model can be applied either stochastically or deterministically, and can encompass arbitrary age structure and resistance levels. In the present version, we used the deterministic version excluding resistance but including age structure with six groups: 0–5, 6–11, 12–14, 15–17, 18–64, and 65 years and above. We parameterized the model by literature data and fitting it to case and death estimates provided by the World Health Organization. We compared the new TB cases and TB-related deaths in each age group over the period 2021–2030 in 10 scenarios that involved intensified screening of particular age groups of children, adolescents, or young adults, or decreased or increased diagnostic accuracy of the screening. Results: Screening the entire age class of 18-year-old persons would prevent 517,000 TB cases and 14,600 TB-related deaths between years 2021 and 2030, corresponding to 6.6% and 5.5% decrease from the standard of care projection, respectively. Annual screening of children aged 6–11 and, to a lesser extent, 0–5 years, also reduced TB incidence and mortality, particularly among children of the respective ages but also in other age groups. In contrast, intensified screening of adolescents did not have a major impact. Screening with a simpler and less accurate method resulted in worsened outcomes, which could not be offset by more intensive screening. More accurate screening and better sensitivity to detect latent TB could prevent 2.3 million TB cases and 68,500 TB deaths in the coming 10 years. Conclusion: Routine screening in schools can efficiently reduce the burden of TB in China. Screening should be intensified particularly among children in primary school age.