Asymmetry in the presence of migration stabilizes multistrain disease outbreaks

TL;DR

This study demonstrates that migration between different populations can stabilize disease dynamics, delaying outbreaks and reducing infections in multistrain disease models, with implications for controlling epidemics.

Contribution

It reveals that migration stabilizes multistrain disease outbreaks by delaying bifurcations, a novel insight supported by generic bifurcation analysis and numerical simulations.

Findings

Migration stabilizes endemic steady states.

Migration delays the onset of large outbreaks.

Migration reduces total infection numbers.

Abstract

We study the effect of migration between coupled populations, or patches, on the stability properties of multistrain disease dynamics. The epidemic model used in this work displays a Hopf bifurcation to oscillations in a single well mixed population. It is shown numerically that migration between two non-identical patches stabilizes the endemic steady state, delaying the onset of large amplitude outbreaks and reducing the total number of infections. This result is motivated by analyzing generic Hopf bifurcations with different frequencies and with diffusive coupling between them. Stabilization of the steady state is again seen, indicating that our observation in the full multistrain model is based on qualitative characteristics of the dynamics rather than on details of the disease model.