A call to action: Understanding land use-induced zoonotic spillover to protect environmental, animal, and human health

Abstract

The rapid, global spread and human health impacts of SARS-CoV-2, the agent of COVID-19 disease, demonstrates humanity’s vulnerability to zoonotic disease pandemics. Although anthropogenic land use change is known to be the major driver of zoonotic pathogen spillover from wildlife to human populations, the scientific underpinnings of land use-induced zoonotic spillover have rarely been investigated from the macro-ecology perspective. We call on colleagues to advance our knowledge of land use implications for zoonotic disease emergence. A wide range of disciplinary cosmologies, approaches, and tools are needed to identify the environmental triggers of spillover and inform the decisions needed to protect public health by reducing spillover risk as a biosecurity priority. We call for a mechanistic focus on the zoonotic pathogen “infect-shed-spill-spread” cascade and review the relevant literature, elucidating the current biases and information gaps. We also consider the opportunities for better instituting the necessary scientific collaboration, primary technical challenges, and policy and management issues that warrant particular attention.

Ecological Countermeasures for Pandemic Prevention: When Ecological Restoration is a Human Health Imperative

“…As One Health and Planetary Health collaborations become better institutionalized, opportunities will increase to advance ecological countermeasures in concept and practice. Plowright et al (2020) emphasize that studies of land use-induced zoonotic spillover as an interdisciplinary priority is justified from technical perspectives, as well as strategic pragmatism. Gaps in our knowledge of land use influences on the infect-shed-spillspread cascade need to be addressed in situ in order to inform ecological countermeasures.…”

“…Scientific understanding of land use-induced spillover is in its infancy. Plowright et al (2020) summarize information gaps for the factors driving the infectshed-spill-spread cascade. White and Razgour (2020) point out that, at least for mammals, the majority of published studies regarding anthropogenic land use change influences on zoonotic pathogen dynamics are reviews rather than primary empirical studies.…”

“…They call on scientists to expand the number of empirical studies of land useinduced spillover for comparative purposes, as well as to identify ecological countermeasure options in specific contexts. Plowright et al (2020;Supplementary Material) and Becker et al (2020) review data gaps and provide examples of inquiry needs to advance such studies. 4.…”

“…Advent of the COVID-19 pandemic (SARS-CoV-2 virus) provides impetus for further discussion and operationalization of ecological approaches to protecting human health. This realization inspired Plowright et al (2020) to call on scientists to investigate the mechanisms by which land use change drives zoonotic spillover into human populations (termed 'land useinduced spillover'), Reaser et al (2020a) to propose fostering landscape immunity (the ecological conditions that, in combination, keep pathogen populations in check and foster the immunological defenses of wild species within a particular ecosystem) as an approach to reducing spillover risk, and Reaser et al (2020b) to recommend priority actions for employing protected areas to safeguard human populations from future pandemics. Here we expand on this new body of work by focusing on 'ecological countermeasures' as a novel concept and technical approach to addressing land use-induced spillover.…”

“…For zoonotic disease outbreaks, countermeasures have largely focused on medical and veterinary interventions (Sokolow et al 2019). We define ecological countermeasures as highly targeted, landscape-based interventions to arrest one or more of the elements of land use-induced spillover, particularly the environmental stressors that: 1) trigger increased susceptibility of wildlife to pathogen infection; 2) cause these animal hosts to shed viable pathogens in sufficient quantity to spill over to (infect) other susceptible hosts, including humans; and 3) then spread through the human population ('the infect-shed-spill-spread' cascade; Plowright et al 2020; Figures 1 and 2 therein). Ideally, ecological countermeasures would be used to restore landscape immunity and/or reduce human exposure to wildlife-transmitted pathogens (Figure 1; see contextual overview in Reaser et al 2020b).…”