Role of wildlife in the ecology of multihost pathogens

点击翻译按钮获取中文摘要

The ability of pathogens to infect multiple hosts, particularly wildlife, is an important risk factor for disease emergence in humans and livestock. Understanding the dynamics of infectious agents in multihost communities is essential for reducing disease threats to humans, yet we often lack even basic information about the role of wildlife in the ecology of multihost pathogens. The overall goal of my research program is to build a mechanistic understanding of multi-host pathogen systems in order to generate a scientific basis for disease preparedness and prevention strategies aimed at controlling infectious diseases affecting humans and livestock. *** This research proposal is focused on two host-pathogen systems: 1) Campylobacter, an important cause of bacterial enteritis in humans in Canada, at the wildlife-livestock interface, and 2) Borrelia burgdorferi, the causative agent of Lyme disease, in wildlife hosts and vectors. Although livestock are the primary reservoir of Campylobacter, this pathogen is also found at very high prevalence in a variety of wildlife species. However, the role of wildlife in the epidemiology of Campylobacter on farms remains unclear because there is conflicting evidence as to whether wildlife carry livestock strains of Campylobacter. My first objective is to a) determine the role of wildlife in the maintenance of Campylobacter on farms, and b) characterize the environmental and demographic factors affecting Campylobacter occurrence in wildlife. *** The ecology of the Lyme disease system is complex, due in part to the fact that the ticks are capable of feeding on almost any vertebrate host, but host species vary greatly in their ability to manage tick loads through grooming and in their competency as hosts (i.e., their ability to become infected with and transmit B. burgdorferi). For this reason, host biodiversity is thought to be critical in determining the spread of Lyme disease and Lyme disease risk to humans. My second objective is to a) compare the relative roles of birds, mammals, and reptiles as hosts for subadult ticks and as potential reservoirs of B. burgdorferi and b) assess the impact of wildlife host diversity on disease risk to humans. *** My proposed research combines field studies of hosts, molecular characterization of pathogens, and statistical modelling in order to better understand how pathogens are maintained in wildlife populations and to establish transmission dynamics in two important multihost pathogen systems. *** ******