Spatial and temporal dynamics of animals and the host-density threshold in epizootiology

Abstract The concept of a host-density threshold, commonly discussed in theoretical epidemiology and epizootiology, is based on simple theoretical models and several vague definitions. We computed a more complex model on a supercomputer to study the temporal and spatial dynamics of an insect population and its microsporidian disease. Results demonstrated that the threshold is sensitive to initial prevalence of the disease, intragenerational temporal dynamics, and spatial dynamics of the host. The threshold also depends on whether pathogen persistence, an increase in prevalence, an increase in density of infected hosts, or an epidemic is being predicted. To improve epizootiological theory, models with greater realism must be studied and the concept must include general temporal and spatial scales.

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