Dynamics of hand, foot and mouth disease in children under 15 years old: A case study of Malaysia using age-structured modelling approach

Abstract

Hand, foot, and mouth disease (HFMD) is a viral infection that primarily affects children. The disease is characterized by fever, sores in the mouth, and a rash on the hands, feet, and buttocks. In this case study, we analyze the dynamics of HFMD in children under 15 years old in Malaysia using an age-structured modeling approach. First we prove backward bifurcation for a baseline model which is then extended to an age-structured model. We used data on the incidence of HFMD in Malaysia from 2021 to 2022 to calibrate the model parameters and simulate the disease dynamics. Sensitivity analysis is done by Latin hypercube sampling - partial rank correlation coefficient (LHS/PRCC) method. Simulation is done and the impact of imperfect vaccine and quarantine is explored. Our results show that the dynamics of the disease is mostly driven by children under 5 years old. The model also predicts that vaccination could significantly reduce the incidence of HFMD in Malaysia. Vaccination is most effective when targeted at young children, who are at the highest risk of disease as this will lead to drastic decrease in the incidence of HFMD in all age groups. Our simulations show that quarantining of infected children until they fully recover will reduce the transmission of HFMD, but this strategy needs to be sustained for a sufficient duration to have a significant impact. The result of this paper can inform the development of policies for controlling the spread of HFMD and other infectious diseases in Malaysia and other similar settings.