COVID-۱۹ Dynamics in Africa Under the Influence of Asymptomatic Cases and Re-infection

Since December ۲۰۱۹ that the coronavirus pandemic (COVID-۱۹) has hit the world, with over ۱۳ million cases recorded, only a little above ۴.۶۷ percent of the cases have been recorded in the continent of Africa. The percentage of cases in Africa rose significantly from ۲ percent in the month of May ۲۰۲۰ to above ۴.۶۷ percent by the end of July ۱۵, ۲۰۲۰. This rapid increase in the percentage indicates a need to study the transmission, control strategy, and dynamics of COVID-۱۹ in Africa. In this study, a nonlinear mathematical model to investigate the impact of asymptomatic cases on the transmission dynamics of COVID-۱۹ in Africa is proposed. The model is analyzed, the reproduction number is obtained, the local and the global asymptotic stability of the equilibria were established. We investigate the existence of backward bifurcation and we present the numerical simulations to verify our theoretical results. The study shows that the reproduction number is a decreasing function of detection rate and as the rate of re-infection increases, both the asymptomatic and symptomatic cases rise significantly. The results also indicate that repeated and increase testing to detect people living with the disease will be very effective in containing and reducing the burden of COVID-۱۹ in Africa.

کلیدواژه ها:

Coronavirus ، COVID-۱۹ ، Reproduction Number ، re-infections ، asymptomatic case detection