Impact of public health and social measures on hand-foot-mouth disease transmission and prediction of upcoming season after relaxation of COVID-19 control measures

Abstract Background School based-measures such as school closure and school holidays have been considered a viable intervention during the hand-foot-mouth disease (HFMD) epidemic. However, the impact of public health and social measures (PHSMs) on HFMD transmission and the consequences of the HFMD epidemic after relaxing the PHSMs remains unclear. Methods Korean national surveillance data on HFMD from 2014 to 2019 was used to estimate the temporal changes in HFMD transmissibility (instantaneous reproductive number, \({R}_{t}\)). Furthermore, we used a simulation based stochastic transmission model to predict the future burden of HFMDs after relaxation of COVID-19 PHSMs, assuming all the Korean population was susceptible to HFMD in 2023, the stochastic transmission model simulated the number of HFMD cases in South Korea. Results We found that school holidays and 2015 PHSMs reduced the \({R}_{t}\) by 2–7% and 13%, respectively. Model projections indicated that the peak magnitude for season 2023, after relaxation of COVID-19 PHSMs in late 2022, could be 2·5–8·5 fold larger than that of the HFMD seasons during the pre-pandemic. Conclusions PHSMs likely have a larger impact on HFMD transmission than school-based measures alone (i.e. school holidays). Furthermore, complete relaxation of COVID-19 PHSMs could significantly increase the HFMD infection burden for the upcoming HFMD season. Preventive measures targeting preschoolers could be considered as potential options for reducing the future burden of HFMD.