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How should environmental stress affect the population dynamics of disease?

January 1, 2003

We modelled how stress affects the population dynamics of infectious disease. We were specifically concerned with stress that increased susceptibility of uninfected hosts when exposed to infection. If such stresses also reduced resources, fecundity and/or survivorship, there was a reduction in the host carrying capacity. This lowered the contact between infected and uninfected hosts, thereby decreasing transmission. In addition, stress that increased parasite mortality decreased disease. The opposing effects of stress on disease dynamics made it difficult to predict the response of disease to environmental stress. We found analytical solutions with negative, positive, convex and concave associations between disease and stress. Numerical simulations with randomly generated parameter values suggested that the impact of host-specific diseases generally declined with stress while the impact of non-specific (or open) diseases increased with stress. These results help clarify predictions about the interaction between environmental stress and disease in natural populations.

Citation Information

Publication Year 2003
Title How should environmental stress affect the population dynamics of disease?
DOI 10.1046/j.1461-0248.2003.00480.x
Authors Kevin D. Lafferty, Robert D. Holt
Publication Type Article
Publication Subtype Journal Article
Series Title Ecology Letters
Series Number
Index ID 1008180
Record Source USGS Publications Warehouse
USGS Organization Western Ecological Research Center