Lyme disease is caused by a bacterium that in many areas in the United States is transferred between vertebrates by ticks. Using the Lyme disease cycle as a model system, this project examines how ecological factors determine the distribution and abundance of a microparasite in nature. The first objective is to examine the effect of local vertebrate species composition on transmission dynamics. A natural host community will be manipulated through selective vaccination of the principal vertebrate host species, white-footed mice, and the effects on micoparasite dynamics will be monitored. The second objective is to look critically at how density and proportion of vectors infected differentially may affect transmission dynamics. Using a model and survey data on infection in ticks and mice, we will test which measure of infection better predicts within-season transmission dynamics in mouse populations.
Ecologists largely have ignored the ecology of microparasites despite the implications for population and community dynamics. Epidemiologists also often have ignored the importance of understanding microbe population dynamics in nature, focusing instead on vaccines and treatments. The results of this study will make contributions to both fields and advance our knowledge about these ubiquitous, diverse, and important organisms.