Impact of non-pharmacological interventions on incidence of hand, foot and mouth disease during the COVID-19 pandemic: a large population-based observational study

Hand, foot, and mouth disease (HFMD) is a highly prevalent and contagious disease, particularly in children under five years old. Its transmission route resembles that of COVID-19. During the COVID-19 pandemic, non-pharmaceutical interventions (NPIs) were implemented to curb viral spread, which may have concurrently reduced HFMD incidence.

Utilizing HFMD surveillance data from the Anhui Provincial Center for Disease Control and Prevention (2015–2020) and varying levels of COVID-19 emergency measures, a Bayesian structural time series model predicted the counterfactual HFMD incidence and quantified the causal relationships with NPIs.

During the implementation of NPIs, the 915 cases observed between weeks 4 and 20 of 2020 reflected a 94.9% reduction from the expected cases number (915 vs. 17,790), avoiding approximately 16,875 cases. The relative reduction of male cases (95.2%) was similar to that of female cases (94.3%). Different age groups the number of cases decline roughly similar were 93.1%, 95.3%, 97.8%, 94.9%.

During the COVID-19 pandemic, NPIs implemented in response to COVID-19 effectively reduced HFMD incidence. NPIs should be promoted for future control of enteric infectious diseases such as HFMD.