Seasonal migration shapes when and where animals are infected with pathogens, but physiological costs associated with migration can also cause latent infections to reactivate (“migratory relapse”). We develop a mathematical model to explore how migratory relapse influences peak infection risk and its seasonal timing. We show that relapse can amplify infection across the annual cycle and may be crucial for maintaining pathogens in migratory populations. Conversely, relapse can reduce infection by pathogens that cause high mortality during migration. Relapse can cause infection prevalence to peak outside of periods when most transmission occurs, with implications for surveillance of potentially zoonotic pathogens.
Becker Daniel J., Ketterson Ellen D. and Hall Richard J.. 2020. Reactivation of latent infections with migration shapes population-level disease dynamics. Proc. R. Soc. B. 287:20201829. http://doi.org/10.1098/rspb.2020.1829
Redwing photo provided by Richard Hall