DISSERTATION RESEARCH: Influences of host variation on pathogen prevalence and disease dynamics in free-living communities

Indiana University, Bloomington IN

Investigators

Abstract

Vector-borne and zoonotic diseases (e.g. Lyme Disease, West Nile virus) have become an increased public health and wildlife management concern in the US and globally. Recent research in disease ecology has greatly improved our understanding of the behavior and dynamics of parasites and pathogens. While evidence shows some hosts become infected or transmit pathogens more than others, most theoretical models describing disease dynamics have ignored differences among individuals. Sources of individual variability such as sex, age, pathogen co-infection status, previous infection, and immune function influence how hosts become infected. Integrating population- and individual-level approaches can better describe how pathogens are affected by the small-scale environment of the host and the larger-scale community of hosts, vectors, and pathogens, leading to better assessment of disease risk and pathogen prevalence. This research addresses the following questions: 1) How does variation among individual hosts affect parasite load and probability of infection? 2) How does variation in the probability of host infection determine pathogen prevalence at the population and community level? To address these questions, ticks and small mammal hosts will be repeatedly sampled across the season of peak tick activity, and the co-infection status of hosts and ticks, as well as the host immune response, will be evaluated. Next-generation, high throughput sequencing will be used to analyze tick and host microbial co-infection patterns. A combination of a general, functional immune assay and detailed measurement of host cytokine profiles will be used to inform how the immune system interacts with vectors and vector-borne infection. This project investigates many levels of diversity, from bacterial to vector, host, and environment, using techniques from multiple fields of biological science. The results of this research project may lead to better on the ground assessment of human risk for vector-borne disease. The interdisciplinary nature of this research provides many opportunities for undergraduate research projects, from animal behavior to vector and pathogen genetics, making this project exciting to a broad diversity of students. Educational literature on tick-borne disease and minimizing risk will be designed for local DNR, parks and recreation groups.