Research

 

My research program aims to understand the spread and control of infectious diseases within and between animal species. To achieve this aim, I test hypotheses regarding infectious disease dynamics by using real-world data in models. My professional training has equipped me with a rare combination of skills: I conduct both field-based data collection and theoretical modeling. I direct fieldwork both domestically and abroad to collect data relevant to the transmission of various animal diseases. This work involves counting and trapping wild animals, determining rates of contact between individuals, and collecting blood, tissue, or feces to test for the presence of pathogens. I then analyze the empirical data and develop custom-made models to understand past and predict future disease dynamics­—in an effort to guide and prioritize future monitoring and control strategies. Mathematical models are critical tools in the fight against infectious diseases because they allow us to conduct virtual experiments that would otherwise be unethical or unachievable in the real world.

 

My current research on animal health focuses on the following broad aims:

Aim 1: Discover how diseases that infect multiple animal species are maintained and persist in ecosystems.  Understanding infectious disease ecology in systems that include multiple animal species has direct applications to the health of humans, domestic animals, and wildlife of conservation concern. However, little is known about the mechanisms that allow diseases to persist in these complex systems. For example, canine distemper virus (CDV) and rabies kill wild and domestic carnivores, but we often do not know which carnivore species to target for disease control. I am leading new research with the urban coyote research project (http://urbancoyoteresearch.com) focusing on the dynamics of coyote pathogens in and around Chicago.  Since the start of the research project in 2000, we have over 450 blood samples from coyotes. My PhD student, Katie Worsley-Tonks is discovering the role of coyotes in maintaining pathogens that can infect domestic animals (e.g. CDV, Sarcoptic mange) as well as pathogens that infect humans (e.g. Toxoplasma and Lyme).

 

Aim 2: Discover how fragmented landscapes and management interventions interact to influence disease spread.  Landscape structure determines how much movement and migration occurs between wildlife populations, which in turn affects the spread of infectious diseases. For example, the endangered Florida panther faces a plethora of extinction risks. One key risk is habitat fragmentation, because it potentially amplifies other extinction risks, including disease.  I am the co-Principal Investigator on National Science Foundation grant to determine the effectiveness of disease interventions in panthers living in fragmented habitats (http://felidae.colostate.edu/). This research focuses on determining the best interventions to combat Feline Leukemia Virus (FeLV); a disease that can cause devastating population declines in panthers. Nick Fountain-Jones and I are using data about the relatedness of animals, their pathogens, and landscape structure to predict transmission dynamics of diseases. Specifically, we are constructing models of disease transmission in panther and bobcat populations living in California, Colorado, and Florida to determine optimal disease control strategies.

 

Aim 3: Discover how to promote food security and reduce public health threats by controlling diseases in production animal systems. As the world’s population grows and the size of the middle class increases, so does the demand for animal protein. Livestock production will play an increasingly important role in securing global access to food and fighting hunger. With a USDA-NIFA grant, and a grant on “Development of a modeling framework for the regional spread of pathogens in swine populations,” Kim VanderWaal, Amy Kinsley, and I are tackling questions regarding the spread of bovine tuberculosis in cattle populations in Minnesota and Uruguay and porcine epidemic diarrhea virus, influenza, and foot and mouth disease in the US swine populations.  Infectious diseases not only threaten food security but also pose a problem for human health when diseases “spill over” from livestock into humans.