Opinion | Published:

Pathways to zoonotic spillover

Nature Reviews Microbiology volume 15, pages 502510 (2017) | Download Citation

Abstract

Zoonotic spillover, which is the transmission of a pathogen from a vertebrate animal to a human, presents a global public health burden but is a poorly understood phenomenon. Zoonotic spillover requires several factors to align, including the ecological, epidemiological and behavioural determinants of pathogen exposure, and the within-human factors that affect susceptibility to infection. In this Opinion article, we propose a synthetic framework for animal-to-human transmission that integrates the relevant mechanisms. This framework reveals that all zoonotic pathogens must overcome a hierarchical series of barriers to cause spillover infections in humans. Understanding how these barriers are functionally and quantitatively linked, and how they interact in space and time, will substantially improve our ability to predict or prevent spillover events. This work provides a foundation for transdisciplinary investigation of spillover and synthetic theory on zoonotic transmission.

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Acknowledgements

The authors thank J. Wood and E. Fleishman for helpful comments and conversations. R.K.P. and H.M. are supported by the Commonwealth of Australia, the State of New South Wales and the State of Queensland under the National Hendra Virus Research Program, awarded through the Rural Industries Research and Development Corporation. R.K.P. is supported by the US National Institutes of General Medical Sciences IDeA Program (grants P20GM103474 and P30GM110732), P. Thye, the Morris Animal Foundation, Montana University System Research Initiative (grant 51040-MUSRI2015-03), a Defense Advanced Research Projects Agency (DARPA) Young Faculty Award and the US Department of Defense Strategic Environmental Research and Development Program (SERDP; grant RC-2633). J.O.L.-S. is supported by the US National Science Foundation (NSF; grants OCE-1335657 and DEB-1557022) and the US Department of Defense SERDP (grant RC-2635). J.O.L.-S., A.L.G. and P.J.H. are supported by the RAPIDD program of the Science & Technology Directorate of the Department of Homeland Security, the Fogarty International Center (part of the US National Institutes of Health), and by IDEAS (Infectious Disease Evolution Across Scales), which is a Research Coordination Network (DEB-1354890) funded by the US National Science Foundation.

Author information

Affiliations

  1. Department of Microbiology and Immunology, Montana State University, Bozeman, Montana 59717, USA.

    • Raina K. Plowright
  2. Colin R. Parrish is at the Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA.

    • Colin R. Parrish
  3. Griffith School of Environment, Griffith University, Brisbane, Queensland 4111, Australia.

    • Hamish McCallum
  4. Peter J. Hudson is at the Center for Infectious Disease Dynamics, Pennsylvania State University, State College, Pennsylvania 16802, USA.

    • Peter J. Hudson
  5. Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut 06520–8034, USA.

    • Albert I. Ko
  6. Department of Ecology & Evolutionary Biology, Princeton University, Princeton, New Jersey 08544, USA.

    • Andrea L. Graham
  7. Department of Ecology & Evolutionary Biology, University of California, Los Angeles, Los Angeles, California 90095-7239, USA; and at Fogarty International Center, National Institutes of Health, Bethesda, Maryland 20892–2220, USA.

    • James O. Lloyd-Smith

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Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Raina K. Plowright.

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    Supplementary information S1 (box)

    A mathematical representation of spillover

Image files

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    Supplementary information S2 (movie)

    Spatiotemporal dynamics of spillover. Gaps in barriers to spillover may be highly dynamic in time and space meaning that the alignment of gaps in all barriers may be rare and brief.

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https://doi.org/10.1038/nrmicro.2017.45

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