9. Fractional SEIR Model for Modelling the Spread of COVID-19 in Namibia

In this chapter, a fractional SEIR model and its robust first-order unconditionally convergent numerical method is proposed. Initial conditions based on Namibian data as of 4 July 2020 were used to simulate two scenarios. In the first scenario, it is assumed that the proper control mechanisms for kerbing the spread of COVID-19 are in place. In the second scenario, a worst-case scenario is presented. The worst case is characterised by ineffective COVID-19 control mechanisms. Results indicate that if proper control mechanisms are followed, Namibia can contain the spread of COVID-19 in the country to a lowest level of 1, 800 positive cases by October 2020. However, if no proper control mechanisms are followed, Namibia can hit a potentially unmanageable level of over 14, 000 positive cases by October 2020. From a mathematical point of view, results indicate that the fractional SEIR model and the proposed method are appropriate for modelling the chaotic nature observed in the spread of COVID-19. Results herein are fundamentally important to policy and decision-makers in devising appropriate control and management strategies for curbing further spread of COVID-19 in Namibia.