Multi-zonal transmission dynamics of pandemic COVID-19 and its stability.

At the end of 2019, the novel coronavirus (COVID-19) outbreak was identified in Wuhan city of China. Because of its profoundly infectious nature, it was converted into a pandemic in a very short period. Globally, 6,291,764 COVID-19 confirmed cases, and a total of 374,359 deaths are reported as of 1st June 2020; nevertheless, the circumstances become more and more critical over time. Controlling this global pandemic has necessitated extensive strategies putting into practice. Based on the intensity of the epidemic, the model discriminates area into three different types of zones, and this distinction is crucial to construct various effective strategies for all three types of zones separately. The threshold value of the COVID-19 based on the data from zone-wise distribution of Indian districts from 15th April to 3rd May 2020 is calculated. Furthermore, the model is modified in a multi-group model to analyse the global transmission of COVID-19. Optimal control theory is applied to the model. Five control strategies are included based on the level of intensity of COVID-19 .