Temporal trends in clinical and molecular epidemiology of pediatric hand, foot, and mouth disease, 2008-2024: Insights from 17 years of surveillance

<h2>Abstract</h2><h3>Objective</h3> We aimed to investigate the temporal trends in the clinical and molecular epidemiology of pediatric hand, foot, and mouth disease (HFMD) since its designation as a notifiable disease (2008). <h3>Methods</h3> We retrospectively analyzed the pediatric HFMD cases from a single-center database from 2008 to 2024 and performed a binary logistic regression model to identify risk factors for severe disease among laboratory-confirmed cases. <h3>Results</h3> 114,420 HFMD cases were reported over 17 years, including 569 severe cases (0.50%, 569/114,420) and 27 deaths (4.75%, 27/569). Following a peak in 2010, annual case numbers stabilized at approximately 10,000 from 2016, declined markedly after vaccine introduction, and dropped further during the COVID-19 pandemic, with a rebound in 2023. Before 2016, Coxsackievirus A16 (CV-A16) (30.66%) and Enterovirus 71 (EV-A71) (23.15%) were the predominant serotypes; subsequently, Coxsackievirus A6 (CV-A6) gradually emerged as the dominant circulating strain. A gradual increase in the age of affected children was observed, with a notable rise in cases among those aged ≥5 years during the post-pandemic period. Multivariable analysis revealed younger age, EV-A71 infection, and rural residence as independent risk factors for severe HFMD. <h3>Conclusions</h3> The evolving epidemiology of pediatric HFMD and the rising age of susceptibility highlight the need for continuous surveillance and early warning to guide prevention and strengthen public health response.