Mathematical modeling, analysis and control of African cassava mosaic disease

International audience African cassava mosaic is a viral disease that affects cassava plants, a major staple food in the tropics. This disease generates significant yield losses and is hence a major threat to food security. Its vector is the white fly, which transmits the diseasewhile feeding on cassava leaves. Symptoms include leaf chlorosis, leaf deformation, and stunted plant growth. There are resistant cassava varieties, but they can still be infected. The disease can also affect other plants (mostly wild plants). We propose a new epidemiological model, based on previous works. It comprises four population groups: susceptible and resistant cassava, alternative hosts which can act as disease reservoirs, and vectors. Each group is subdivided into healthy and infected populations, leading to eight state variables. Transmission occurs through the vector population and host-specific rates are considered. We study the model and focus on the impact of several control measures: resistant/tolerant cassava plants, with different resistance levels; phytosanitation, including the use of healthy cuttings and roguing, which consists in eliminating diseased plants; vector control, including biological control based on natural enemies. We investigate synergies between these controls.