Sex- and age-specific transmission pathways of mumps: a mechanistic SEPIAR modeling study in Chengdu, China (2008–2019)

INTRODUCTION: Despite widespread mumps vaccination, recurrent outbreaks persist globally, underscoring the need to clarify sex- and age-specific transmission mechanisms. OBJECTIVES: This study characterizes mumps epidemiology in Chengdu (2008-2019) and quantifies sex- and age-specific transmission pathways using a mechanistic modeling framework. METHODS: ) across 64 transmission pathways. RESULTS: : 1.18 to males 5-9; 0.75 to males 0-4; 0.55 within the same group). Sensitivity and empirical uncertainty analyses confirmed the robustness of these transmission patterns. CONCLUSIONS: Sex and age may play an important role in shaping mumps transmission dynamics in Chengdu. The SEPIAR model may offer a useful framework for characterizing transmission pathways and identifying groups that could contribute disproportionately to spread. Interventions such as targeted vaccination during seasonal peaks, considering booster doses for females aged 10-14, enhancing surveillance in high‑incidence districts, and improving reporting capacity in rural areas could help reduce transmission and may support more effective and sustained mumps control in large urban settings.