Virulence evolution in fragmented populations

Faculty of Veterinary Medicine, Utrecht University, the Netherlands

Marieke Jesse

Marieke Jesse

Most epidemiological models focus on infection dynamics at the level of individual hosts or a population of hosts, without addressing the evolution of the infectious agent. Yet, disease evolution can significantly alter infection dynamics, at both the individual and the population level.

The evolution of the virulence of an infectious agent is often analyzed in terms of a trade-off between the agent’s needs for achieving intense transmission between hosts while keeping hosts alive to prolong such transmission. Most research has therefore concentrated on the effects of virulence on classical epidemiological parameters, such as transmission rate or the length of the infectious period. Our aim in this project is to extend understanding of virulence evolution to host populations that are fragmented in space, forming patchy structures.

This will require us to study, in addition, the effects of virulence on the spatial demography of hosts, including impacts on their residence time within patches, distance of movement between patches, and their chance of surviving such movement. We will use a stochastic model of a disease that is directly transmitted in continuous time in a host population that is patchy in space. The spread of the disease within and between patches will be modelled based on SIS-type dynamics excluding super-infection.

The connectivity structure of the patchy host population is an important topic in this research, and different options will be studied; for example, all patches can be equally connected, or there can be a maximum movement distance for hosts.

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Last edited: 24 March 2016

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