| Abstract: |
| The possibility of coexistence of several strains for an infectious disease
can be a major concern for policy makers in taking informed decisions to alleviate its effect on the population. For instance, the emergence of different strains of the Coronavirus disease (COVID-19) has generated significant concerns due to its attendant waves after waves of infected populations across the world. So a compelling question is whether some of these mutated strains could become locally adapted to coexist. In this talk, we study some reaction-diffusion systems for infectious diseases and investigate how the dynamics is impacted by the movement of populations and spatial heterogeneity of the environment. General conditions for the existence, uniqueness and stability of the coexistence steady states are established. Our analysis revealed two mechanisms for the coexistence of strains: (i) when the ratio of the transmission probability of two strains falls into some intermediate ranges; (ii) when the diffusion rate of two strains falls into proper
ranges. Interestingly, when there is no coexistence of strains, it is possible for the ``weak strain to be dominant for some intermediate range of diffusion rates, in strong contrast to small and large diffusion cases where the ``weak strain always go extinct. |
|