title: Transmission or Within-Host Dynamics Driving Pulses of Zoonotic Viruses in Reservoir-Host Populations.
abstract: Progress in combatting zoonoses that emerge from wildlife is often constrained by limited knowledge of the biology of pathogens within reservoir hosts. We focus on the host-pathogen dynamics of four emerging viruses associated with bats: Hendra, Nipah, Ebola, and Marburg viruses. Spillover of bat infections to humans and domestic animals often coincides with pulses of viral excretion within bat populations, but the mechanisms driving such pulses are unclear. Three hypotheses dominate current research on these emerging bat infections. First, pulses of viral excretion could reflect seasonal epidemic cycles driven by natural variations in population densities and contact rates among hosts. If lifelong immunity follows recovery, viruses may disappear locally but persist globally through migration; in either case, new outbreaks occur once births replenish the susceptible pool. Second, epidemic cycles could be the result of waning immunity within bats, allowing local circulation of viruses through oscillating herd immunity. Third, pulses could be generated by episodic shedding from persistently infected bats through a combination of physiological and ecological factors. The three scenarios can yield similar patterns in epidemiological surveys, but strategies to predict or manage spillover risk resulting from each scenario will be different. We outline an agenda for research on viruses emerging from bats that would allow for differentiation among the scenarios and inform development of evidence-based interventions to limit threats to human and animal health. These concepts and methods are applicable to a wide range of pathogens that affect humans, domestic animals, and wildlife.
authors.affiliation: Montana State University, Department of Microbiology and Immunology, Bozeman, Montana, United States of America.|Center for Infectious Disease Dynamics, Pennsylvania State University, State College, Pennsylvania, United States of America.
authors.forename: Raina K
authors.initials: RK
authors.lastname: Plowright
authors.affiliation: Environmental Futures Research Institute, Griffith University, Brisbane, Queensland, Australia.
authors.forename: Alison J
authors.initials: AJ
authors.lastname: Peel
authors.affiliation: Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom.|MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom.
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Streicker
authors.affiliation: USDA/APHIS/WS National Wildlife Research Center, Fort Collins, Colorado, United States of America.
authors.forename: Amy T
authors.initials: AT
authors.lastname: Gilbert
authors.affiliation: Griffith School of Environment, Griffith University, Brisbane, Queensland, Australia.
authors.forename: Hamish
authors.initials: H
authors.lastname: McCallum
authors.affiliation: Disease Dynamics Unit, Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom.
authors.forename: James
authors.initials: J
authors.lastname: Wood
authors.affiliation: CSIRO Health and Biosecurity Business Unit, Australian Animal Health Laboratory, Geelong, Victoria, Australia.
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Baker
authors.affiliation: Disease Dynamics Unit, Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Olivier
authors.initials: O
authors.lastname: Restif
mesh_terms: D000818:Animals; D002685:Chiroptera / Q000821:virology*; D004196:Disease Outbreaks; D004197:Disease Reservoirs / Q000821:virology*; D004463:Ecology; D016563:Filoviridae; D045403:Henipavirus; D006801:Humans; D015047:Zoonoses / Q000453:epidemiology*