Reproduction number and sensitivity analysis of cassava mosaic disease spread for policy design

Abstract

We develop a mathematical model for the dynamics of Cassava Mosaic Disease (CMD), which is driven by both planting of infected cuttings and whitefly transmission. We use the model to analyze the dynamics of a CMD outbreak and to identify the most cost-effective policy for controlling it. The model uses the reproduction number R0 as a threshold, calculated using the Next-Generation Method. A locally-Asymptotically-stable disease-free equilibrium is established when R0 < 1, proved by the Routh-Hurwitz criterion. The globally-Asymptotically-stable disease-free and endemicequilibrium points are obtained using Lyapunov s method and LaSalle s invariance principle. Our results indicate that the disease-free equilibrium point is globally-Asymptotically-stable when R0 1, while the endemic-equilibrium point is globally-Asymptotically-stable when R0 > 1. Our sensitivity analysis shows that R0 is most sensitive to the density of whitefly. Numerical simulations confirmed the effectiveness of whitefly control for limiting an outbreak while minimizing costs.