Environmental variation across multiple spatial scales and temporal lags influences Hendra virus spillover

Faust, C. L. , Castellanos, A. A., Peel, A. J., Eby, P., Plowright, R. K., Han, B. A. and Bharti, N. (2023) Environmental variation across multiple spatial scales and temporal lags influences Hendra virus spillover. Journal of Applied Ecology, 60(7), pp. 1457-1467. (doi: 10.1111/1365-2664.14415)

Abstract

1. Pathogens can spill over and infect new host species by overcoming a series of ecological and biological barriers. Hendra virus (HeV) circulates in Australian flying foxes and provides a data-rich study system for identifying environmental drivers underlying spillover events. The frequency of spillover events to horses has varied interannually since the virus was first discovered in 1994. These observations suggest that HeV spillover events are driven, in part, by environmental factors, including loss of flying fox habitat and climate variability. 2. We explicitly examine the impact of environmental variation on the risk of HeV spillover at three spatial scales relevant to this system. We use a dataset of 60 spillover events and boosted regression tree methods to identify environmental features (including concurrent and lagged temperature, rainfall, vegetation indices, land cover, and climate indices) at three spatial scales (1-km, 20-km, 100-km radii) associated with horse contacts and reservoir species ecology. 3. We find that temperature, local (1-km radius) human population density, and landscape (100-km radius) forest cover and pasture are the most influential environmental features associated with HeV spillover risk. By including multiple spatial scales and temporal lags in environmental features, we can more accurately quantify risk across space and time than with models that use a single scale. For example, high quality vegetation at the local scale and within a foraging radius (20-km) in the concurrent month and previous years, combined with poorer quality vegetation at the landscape scale in the concurrent month increase risk of HeV spillover. These and other environmental associations likely influence the dynamic foraging behaviour of reservoir flying foxes and drive contacts that facilitate spillover into horse populations. 4. Synthesis and application: Current management of HeV spillover focuses on local-scale interventions – primarily through vaccination and detection of infected horses. Our study finds that HeV spillover risk is also driven by environmental changes over much larger scales and demonstrates management practices would benefit from incorporating landscape interventions alongside local interventions.

• Item Type: Articles
• Additional Information: Research was funded by the National Science Foundation (DEB-1716698, EF-2133763), a DARPA PREEMPT Program Cooperative Agreement (D18AC00031), and The Huck Institutes of the Life Sciences (Penn State University). Peel was supported by an ARC DECRA Fellowship (DE190100710).
• Keywords: Boosted regression trees, flying foxes, land cover change, landscape management, multi‐scale, Pteropus, zoonoses.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Faust, Christina
• Authors: Faust, C. L., Castellanos, A. A., Peel, A. J., Eby, P., Plowright, R. K., Han, B. A., and Bharti, N.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Journal of Applied Ecology
• Publisher: Wiley
• ISSN: 0021-8901
• ISSN (Online): 1365-2664
• Published Online: 21 April 2023
• Copyright Holders: Copyright © 2023 The Authors
• First Published: First published in Journal of Applied Ecology 60(7):1457-1467
• Publisher Policy: Reproduced under a Creative Commons License