SIS Epidemic Spreading Under Multilayer Population Dispersal in Patchy Environments

In this article, we study susceptible–infected–susceptible (SIS) epidemic spreading models under population dispersal on multilayer networks. We consider a patchy environment in which each patch comprises individuals belonging to different classes. Individuals disperse to other patches on a multilayer network, in which each layer corresponds to a class. The dispersal on each layer is modeled by a continuous-time Markov chain (CTMC). At each time, individuals disperse according to their CTMC and subsequently interact with the local individuals in the patch according to an SIS model. We establish the existence of various equilibria under different parameter regimes and establish their (almost) global asymptotic stability using Lyapunov techniques. We also derive simple conditions that highlight the influence of the multilayer network on the stability of these equilibria. For this model, we study optimal intervention strategies using a convex optimization framework. Finally, we numerically illustrate the influence of the multilayer network structure and the effectiveness of the optimal intervention strategies.