Determining the effect of contaminated environment and direct transmission on the dynamics of monkeypox virus

Abstract

This study presents a deterministic mathematical model for direct and indirect transmission dynamics of Monkeypox disease. Direct transmission is through close contact with asymptomatic humans, symptomatic infectious human and infectious rodents while the indirect transmission is considered to be through contaminated environment. Four equilibrium states, that is, Monkeypox-Free equilibrium, E₀, Infected rodents only equilibrium state, E₁, Infected humans only equilibrium state, E₂, and Infected rodents and infected humans equilibrium state, E₃ is established. The global stability of the Monkeypox-Free equilibrium state is examined in terms of the reproduction ratio, R₀. The global stability of Infected rodents only equilibrium state is proved using LyapunovKasovskii-Lasalle stability theorem while a Lyapunov function is constructed by adopting Voltera-Lyapunov matrix conditions and used to prove the Infected humans only equilibrium. Latin Hypercube Sampling technique and partial rank correlation coefficient is used to perform sensitivity analysis of the influence of various human parameters on R0h and it is noted that human-to-human contact rate, environment-to-human contact rate, human virus shedding rate, virus decay rate from the environment, human recruitment rate and recovery rate of the symptomatic infectious humans were crucial parameters in the spread of Monkeypox infection in the human population. This is supported by the simulation results. Based on this, it recommended that policymakers, decision-makers and medical practitioners should pay much attention to these parameters and constitute control strategies that would increase on the recovery rate of the symptomatic humans, minimise human-to-human contact rate and human recruitment rate in order to minimize Monkeypox infections among human population.