We study the dynamics of infectious diseases in reservoir hosts, the process of pathogen spillover, and infectious diseases in species of conservation concern. We work across multiple disciplines including ecology, epidemiology, immunology, microbiology, and mathematical modeling. We work in the field, in the lab and in silico.

 

Infectious Diseases in Reservoir Hosts

We study

the dynamics of infection in reservoir host species with an emphasis on diseases in bats. Bats are hosts to some of the most notorious infections that spill over from animals to humans. Understanding the dynamics of these pathogens within bat populations is key to understanding how they filter through ecological systems to spill over to domestic animals and humans. See our review on The Ecological Dynamics of Emerging Bat Virus Spillover in the Proceedings of the Royal Society B. We are pursuing a comparative approach to understand the drivers of bat infectious disease dynamics across populations and species.

We study

the dynamics of Hendra virus and what drives pulses of infection in bat populations. Hendra virus typifies the spillover process for many emerging bat viruses and is therefore an excellent model system for bat infections in less tractable systems. Hendra virus is a fatal zoonotic paramyxovirus that is transmitted from its reservoir host, Australian Pteropus bats (fruit bats), to horses and subsequently to humans. Like many of the other bat viruses, Hendra virus can be excreted in pulses from reservoir bat populations. These pulses have been linked with spillover to horses. To understand viral dynamics in bat populations we combine empirical data and modeling approaches, and collaborate with interdisciplinary teams working across a range of scales from cells to landscapes.

Pathogen Spillover

Transmission of disease

between species (spillover) is a profound issue for human, livestock and wildlife health. The conditions that enable spillover are dynamic and occur over many scales of time, space and ecological organization. We are interested in how these conditions interact to allow pathogens to cross species barriers.

Infectious Diseases and Conservation

Pneumonia in bighorn sheep

populations is a significant threat to the survival of the species. To address this problem we formed the Bighorn Sheep Disease Consortium. See a link to our publications here. We are conducting a multi-year field investigation of apparently asymptomatic chronic carriers of Mycoplasma ovipneumoniae (the agent that causes pneumonia) to explore how these carriers drive recurrent pneumonia outbreaks in lambs, and population declines. Our team works across disciplines using field, laboratory, dynamic modeling and statistical modeling approaches to understand this complex wildlife disease. See recent work by PhD student Kezia Manlove on the costs and benefits of group living with disease, our work on epidemiological approaches to understanding bighorn sheep immune responses, and spatiotemporal dynamics of pneumonia in bighorn sheep populations.

Specific questions we address in this system include:

  • Links between immunology and epidemiology (e.g. how resistance or tolerance responses affect population dynamics of infectious diseases)
  • The connectivity trade-offs: host connectivity versus disease spread and persistence
  • Mitigation of pathogen threats to advance wildlife conservation

Assessing the Energetic Effects of White-Nose Syndrome in the Context of Climate Change

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White-nose syndrome (WNS),

caused by the fungal pathogen Pseudogymnoascus destructans, is the most devastating disease currently affecting North American wild mammals. WNS infection alters the physiology and bioenergetics of bat hibernation, leading to depleted fat stores and ultimately mortality. The fungal pathogen has spread throughout eastern and central North America, and as it spreads west, it will infect new populations, species, and hibernacula. Our project is developing the science to help identify species that are susceptible to WNS and thereby species of management concern. To do so, we will use a mechanistic WNS survivorship model based on the physiologies of the host and pathogen, and interactions with the hibernacula microclimate. We are also working to combine the survivorship model with species distribution models to explore the ecology and management of WNS disease dynamics under changing climate conditions.

Our core objectives are:

  • Collect robust morphometrics, bioenergetics and hibernacula environmental data on western North American bat species representing different hibernating behaviors and geographic settings
  • Examine the transferability of the mechanistic WNS bioenergetics survivorship model (based on host, pathogen and environmental characteristics) developed for bat species affected by WNS in the East to a set of representative bat species found in the West
  • Develop approaches that integrate the mechanistic WNS survivorship model with species distribution models to evaluate the presence of WNS with plausible scenarios of non-stationary conditions (e.g. climate change) and to explore the sensitivity of the integrated model to different parameters and data availability