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Zimmer C, Jimeno B, Martin LB. HPA flexibility and FKBP5: promising physiological targets for conservation. Philos Trans R Soc Lond B Biol Sci 2024; 379:20220512. [PMID: 38310934 PMCID: PMC10838639 DOI: 10.1098/rstb.2022.0512] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 10/22/2023] [Indexed: 02/06/2024] Open
Abstract
Hypothalamic-pituitary-adrenal axis (HPA) flexibility is an emerging concept recognizing that individuals that will cope best with stressors will probably be those using their hormones in the most adaptive way. The HPA flexibility concept considers glucocorticoids as molecules that convey information about the environment from the brain to the body so that the organismal phenotype comes to complement prevailing conditions. In this context, FKBP5 protein appears to set the extent to which circulating glucocorticoid concentrations can vary within and across stressors. Thus, FKBP5 expression, and the HPA flexibility it causes, seem to represent an individual's ability to regulate its hormones to orchestrate organismal responses to stressors. As FKBP5 expression can also be easily measured in blood, it could be a worthy target of conservation-oriented research attention. We first review the known and likely roles of HPA flexibility and FKBP5 in wildlife. We then describe putative genetic, environmental and epigenetic causes of variation in HPA flexibility and FKBP5 expression among and within individuals. Finally, we hypothesize how HPA flexibility and FKBP5 expression should affect organismal fitness and hence population viability in response to human-induced rapid environmental changes, particularly urbanization. This article is part of the theme issue 'Endocrine responses to environmental variation: conceptual approaches and recent developments'.
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Affiliation(s)
- Cédric Zimmer
- Laboratoire d'Ethologie Expérimentale et Comparée, LEEC, Université Sorbonne Paris Nord, UR 4443, 93430 Villetaneuse, France
| | - Blanca Jimeno
- Instituto Pirenaico de Ecologia (IPE), CSIC, Avenida Nuestra Señora de la Victoria, 16, 22700 Jaca, Spain
| | - Lynn B. Martin
- Center for Global Health and Infectious Disease Research and Center for Genomics, University of South Florida, Tampa, FL 33612, USA
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2
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Gilbertson MLJ, Hart SN, VanderWaal K, Onorato D, Cunningham M, VandeWoude S, Craft ME. Seasonal changes in network connectivity and consequences for pathogen transmission in a solitary carnivore. Sci Rep 2023; 13:17802. [PMID: 37853051 PMCID: PMC10584909 DOI: 10.1038/s41598-023-44815-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 10/12/2023] [Indexed: 10/20/2023] Open
Abstract
Seasonal variation in habitat use and animal behavior can alter host contact patterns with potential consequences for pathogen transmission dynamics. The endangered Florida panther (Puma concolor coryi) has experienced significant pathogen-induced mortality and continues to be at risk of future epidemics. Prior research has found increased panther movement in Florida's dry versus wet seasons, which may affect panther population connectivity and seasonally increase potential pathogen transmission. Our objective was to determine if Florida panthers are more spatially connected in dry seasons relative to wet seasons, and test if identified connectivity differences resulted in divergent predicted epidemic dynamics. We leveraged extensive panther telemetry data to construct seasonal panther home range overlap networks over an 11 year period. We tested for differences in network connectivity, and used observed network characteristics to simulate transmission of a broad range of pathogens through dry and wet season networks. We found that panthers were more spatially connected in dry seasons than wet seasons. Further, these differences resulted in a trend toward larger and longer pathogen outbreaks when epidemics were initiated in the dry season. Our results demonstrate that seasonal variation in behavioral patterns-even among largely solitary species-can have substantial impacts on epidemic dynamics.
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Affiliation(s)
- Marie L J Gilbertson
- Department of Veterinary Population Medicine, University of Minnesota, St Paul, MN, 55108, USA.
- Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, 53706, USA.
| | - S Niamh Hart
- Department of Veterinary Population Medicine, University of Minnesota, St Paul, MN, 55108, USA
| | - Kimberly VanderWaal
- Department of Veterinary Population Medicine, University of Minnesota, St Paul, MN, 55108, USA
| | - Dave Onorato
- Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, Naples, FL, 34114, USA
| | - Mark Cunningham
- Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, Gainesville, FL, 32601, USA
| | - Sue VandeWoude
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Meggan E Craft
- Department of Veterinary Population Medicine, University of Minnesota, St Paul, MN, 55108, USA
- Department of Ecology, Evolution and Behavior, University of Minnesota, St Paul, MN, 55108, USA
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3
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Dantzer B, Mabry KE, Bernhardt JR, Cox RM, Francis CD, Ghalambor CK, Hoke KL, Jha S, Ketterson E, Levis NA, McCain KM, Patricelli GL, Paull SH, Pinter-Wollman N, Safran RJ, Schwartz TS, Throop HL, Zaman L, Martin LB. Understanding Organisms Using Ecological Observatory Networks. Integr Org Biol 2023; 5:obad036. [PMID: 37867910 PMCID: PMC10586040 DOI: 10.1093/iob/obad036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 06/07/2023] [Accepted: 09/21/2023] [Indexed: 10/24/2023] Open
Abstract
Human activities are rapidly changing ecosystems around the world. These changes have widespread implications for the preservation of biodiversity, agricultural productivity, prevalence of zoonotic diseases, and sociopolitical conflict. To understand and improve the predictive capacity for these and other biological phenomena, some scientists are now relying on observatory networks, which are often composed of systems of sensors, teams of field researchers, and databases of abiotic and biotic measurements across multiple temporal and spatial scales. One well-known example is NEON, the US-based National Ecological Observatory Network. Although NEON and similar networks have informed studies of population, community, and ecosystem ecology for years, they have been minimally used by organismal biologists. NEON provides organismal biologists, in particular those interested in NEON's focal taxa, with an unprecedented opportunity to study phenomena such as range expansions, disease epidemics, invasive species colonization, macrophysiology, and other biological processes that fundamentally involve organismal variation. Here, we use NEON as an exemplar of the promise of observatory networks for understanding the causes and consequences of morphological, behavioral, molecular, and physiological variation among individual organisms.
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Affiliation(s)
- B Dantzer
- Department of Psychology, University of Michigan, Ann Arbor, MI 48109,USA
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109,USA
| | - K E Mabry
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109,USA
- Department of Biology, New Mexico State University, Las Cruces, NM 88003,USA
| | - J R Bernhardt
- Department of Biology, New Mexico State University, Las Cruces, NM 88003,USA
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - R M Cox
- Department of Biology, University of Virginia, Charlottesville, VA 22940,USA
- Department of Biological Sciences, California Polytechnic State University, San Luis Obispo, CA 93407,USA
| | - C D Francis
- Department of Biological Sciences, California Polytechnic State University, San Luis Obispo, CA 93407,USA
- Department of Biology, Centre for Biodiversity Dynamics (CBD), Norwegian University of Science and Technology (NTNU), N‐7491 Trondheim, Norway
| | - C K Ghalambor
- Department of Biology, Centre for Biodiversity Dynamics (CBD), Norwegian University of Science and Technology (NTNU), N‐7491 Trondheim, Norway
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - K L Hoke
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - S Jha
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712,USA
| | - E Ketterson
- Department of Biology, Indiana University, 1001 E. Third Street, Bloomington, IN 47405,USA
| | - N A Levis
- Department of Biology, Indiana University, 1001 E. Third Street, Bloomington, IN 47405,USA
| | - K M McCain
- Global Health and Infectious Disease Research Center, College of Public Health, University of South Florida, Tampa, FL 33612,USA
| | - G L Patricelli
- Department of Evolution and Ecology, University of California, Davis, CA 95616,USA
| | - S H Paull
- Battelle, National Ecological Observatory Network, 1685 38th Street, Boulder, CO 80301, USA
| | - N Pinter-Wollman
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA 90095, USA
| | - R J Safran
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder 80309,USA
| | - T S Schwartz
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - H L Throop
- School of Earth and Space Exploration and School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - L Zaman
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109,USA
- Center for the Study of Complex Systems, University of Michigan, Ann Arbor, MI 48109, USA
| | - L B Martin
- Global Health and Infectious Disease Research Center and Center for Genomics, College of Public Health, University of South Florida, Tampa, FL 33612,USA
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4
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Koller KK, Kernbach ME, Reese D, Unnasch TR, Martin LB. House Sparrows Vary Seasonally in Their Ability to Transmit West Nile Virus. Physiol Biochem Zool 2023; 96:332-341. [PMID: 37713719 DOI: 10.1086/725888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/17/2023]
Abstract
AbstractSeasonality in infectious disease prevalence is predominantly attributed to changes in exogenous risk factors. For vectored pathogens, high abundance, activity, and/or diversity of vectors can exacerbate disease risk for hosts. Conversely, many host defenses, particularly immune responses, are seasonally variable. Seasonality in host defenses has been attributed, in part, to the proximate (i.e., metabolic) and ultimate (i.e., reproductive fitness) costs of defense. In this study, our goal was to discern whether any seasonality is observable in how a common avian host, the house sparrow (Passer domesticus), copes with a common zoonotic arbovirus, the West Nile virus (WNV), when hosts are studied under controlled conditions. We hypothesized that if host biorhythms play a role in vector-borne disease seasonality, birds would be most vulnerable to WNV when breeding and/or molting (i.e., when other costly physiological activities are underway) and thus most transmissive of WNV at these times of year (unless birds died from infection). Overall, the results only partly supported our hypothesis. Birds were most transmissive of WNV in fall (after their molt is complete and when WNV is most prevalent in the environment), but WNV resistance, WNV tolerance, and WNV-dependent mortality did not vary among seasons. These results collectively imply that natural arboviral cycles could be partially underpinned by endogenous physiological changes in hosts. However, other disease systems warrant study, as this result could be specific to the nonnative and highly commensal nature of the house sparrow or a consequence of the relative recency of the arrival of WNV to the United States.
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Assis VR, Robert J, Titon SCM. Introduction to the special issue Amphibian immunity: stress, disease and ecoimmunology. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220117. [PMID: 37305915 PMCID: PMC10258669 DOI: 10.1098/rstb.2022.0117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 05/02/2023] [Indexed: 06/13/2023] Open
Abstract
Amphibian populations have been declining worldwide, with global climate changes and infectious diseases being among the primary causes of this scenario. Infectious diseases are among the primary drivers of amphibian declines, including ranavirosis and chytridiomycosis, which have gained more attention lately. While some amphibian populations are led to extinction, others are disease-resistant. Although the host's immune system plays a major role in disease resistance, little is known about the immune mechanisms underlying amphibian disease resistance and host-pathogen interactions. As ectotherms, amphibians are directly subjected to changes in temperature and rainfall, which modulate stress-related physiology, including immunity and pathogen physiology associated with diseases. In this sense, the contexts of stress, disease and ecoimmunology are essential for a better understanding of amphibian immunity. This issue brings details about the ontogeny of the amphibian immune system, including crucial aspects of innate and adaptive immunity and how ontogeny can influence amphibian disease resistance. In addition, the papers in the issue demonstrate an integrated view of the amphibian immune system associated with the influence of stress on immune-endocrine interactions. The collective body of research presented herein can provide valuable insights into the mechanisms underlying disease outcomes in natural populations, particularly in the context of changing environmental conditions. These findings may ultimately enhance our ability to forecast effective conservation strategies for amphibian populations. This article is part of the theme issue 'Amphibian immunity: stress, disease and ecoimmunology'.
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Affiliation(s)
- Vania Regina Assis
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, 05508-900 São Paulo, Brazil
- College of Public Health, University of South Florida, Tampa, FL 33612-9415, USA
| | - Jacques Robert
- Department of Microbiology and Immunology, University of Rochester, Rochester, NY 14642, USA
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6
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Halliday FW, Czyżewski S, Laine AL. Intraspecific trait variation and changing life-history strategies explain host community disease risk along a temperature gradient. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220019. [PMID: 36744568 PMCID: PMC9900715 DOI: 10.1098/rstb.2022.0019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 01/02/2023] [Indexed: 02/07/2023] Open
Abstract
Predicting how climate change will affect disease risk is complicated by the fact that changing environmental conditions can affect disease through direct and indirect effects. Species with fast-paced life-history strategies often amplify disease, and changing climate can modify life-history composition of communities thereby altering disease risk. However, individuals within a species can also respond to changing conditions with intraspecific trait variation. To test the effect of temperature, as well as inter- and intraspecifc trait variation on community disease risk, we measured foliar disease and specific leaf area (SLA; a proxy for life-history strategy) on more than 2500 host (plant) individuals in 199 communities across a 1101 m elevational gradient in southeastern Switzerland. There was no direct effect of increasing temperature on disease. Instead, increasing temperature favoured species with higher SLA, fast-paced life-history strategies. This effect was balanced by intraspecific variation in SLA: on average, host individuals expressed lower SLA with increasing temperature, and this effect was stronger among species adapted to warmer temperatures and lower latitudes. These results demonstrate how impacts of changing temperature on disease may depend on how temperature combines and interacts with host community structure while indicating that evolutionary constraints can determine how these effects are manifested under global change. This article is part of the theme issue 'Infectious disease ecology and evolution in a changing world'.
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Affiliation(s)
- Fletcher W. Halliday
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, 8057 Zurich, Switzerland
| | - Szymon Czyżewski
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, 8057 Zurich, Switzerland
| | - Anna-Liisa Laine
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, 8057 Zurich, Switzerland
- Research Centre for Ecological Change, Organismal & Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, PO Box 65, Helsinki FI-00014, Finland
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7
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Ruden RM, Adelman JS. Modulating disease phenotype in a songbird: A role for inflammation in disease tolerance? JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2023; 339:83-91. [PMID: 36127806 DOI: 10.1002/jez.2655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 08/02/2022] [Accepted: 08/26/2022] [Indexed: 12/15/2022]
Abstract
Individual animals vary greatly in their responses to infection, either killing off the invading pathogen (resistance) or minimizing the per-pathogen costs of infection on host fitness (tolerance). Though we understand little about the physiological drivers of tolerance in wild animals, phenotypically, it manifests as milder clinical signs of disease. Here, we use a well-described disease system, finch mycoplasmosis, to evaluate the role of inflammation in disease tolerance. House finches (Haemorhous mexicanus) infected with the bacterial pathogen Mycoplasma gallisepticum (MG) develop conjunctival pathology that satisfies the cardinal signs of inflammation. We report on a captive trial performed in 2016 and replicated in 2018 that tested whether chemotherapeutics, specifically nonsteroidal anti-inflammatory drugs (NSAIDs), can reduce lesion severity, thus pushing individuals toward more tolerant phenotypes. Though birds treated with NSAIDs in the first trial developed milder pathology per unit pathogen load, we found no effect of treatment in the second trial, perhaps due to natural variation in baseline tolerance within the source population across years. Second-trial control birds developed markedly milder pathology than first-year controls, suggesting that the effect of trial swamped the effect of treatment in this study. Moving forward, using birds from a population in which the disease is absent or only recently emerged-and so tolerance has not yet been selected for-may better elucidate the role of pro-inflammatory mediators in disease tolerance.
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Affiliation(s)
- Rachel M Ruden
- Department of Natural Resource Ecology and Management, Iowa State University, Ames, Iowa, USA.,Iowa Department of Natural Resources, Ames, Iowa, USA
| | - James S Adelman
- Department of Natural Resource Ecology and Management, Iowa State University, Ames, Iowa, USA.,Department of Biological Sciences, University of Memphis, Memphis, Tennessee, USA
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8
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Cecilia H, Vriens R, Wichgers Schreur PJ, de Wit MM, Métras R, Ezanno P, ten Bosch QA. Heterogeneity of Rift Valley fever virus transmission potential across livestock hosts, quantified through a model-based analysis of host viral load and vector infection. PLoS Comput Biol 2022; 18:e1010314. [PMID: 35867712 PMCID: PMC9348665 DOI: 10.1371/journal.pcbi.1010314] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 08/03/2022] [Accepted: 06/16/2022] [Indexed: 01/17/2023] Open
Abstract
Quantifying the variation of pathogens’ life history traits in multiple host systems is crucial to understand their transmission dynamics. It is particularly important for arthropod-borne viruses (arboviruses), which are prone to infecting several species of vertebrate hosts. Here, we focus on how host-pathogen interactions determine the ability of host species to transmit a virus to susceptible vectors upon a potentially infectious contact. Rift Valley fever (RVF) is a viral, vector-borne, zoonotic disease, chosen as a case study. The relative contributions of livestock species to RVFV transmission has not been previously quantified. To estimate their potential to transmit the virus over the course of their infection, we 1) fitted a within-host model to viral RNA and infectious virus measures, obtained daily from infected lambs, calves, and young goats, 2) estimated the relationship between vertebrate host infectious titers and probability to infect mosquitoes, and 3) estimated the net infectiousness of each host species over the duration of their infectious periods, taking into account different survival outcomes for lambs. Our results indicate that the efficiency of viral replication, along with the lifespan of infectious particles, could be sources of heterogeneity between hosts. Given available data on RVFV competent vectors, we found that, for similar infectious titers, infection rates in the Aedes genus were on average higher than in the Culex genus. Consequently, for Aedes-mediated infections, we estimated the net infectiousness of lambs to be 2.93 (median) and 3.65 times higher than that of calves and goats, respectively. In lambs, we estimated the overall infectiousness to be 1.93 times higher in individuals which eventually died from the infection than in those recovering. Beyond infectiousness, the relative contributions of host species to transmission depend on local ecological factors, including relative abundances and vector host-feeding preferences. Quantifying these contributions will ultimately help design efficient, targeted, surveillance and vaccination strategies. Viruses spread by mosquitoes present a major threat to animal and public health worldwide. When these pathogenic viruses can infect multiple species, controlling their spread becomes difficult. Rift Valley fever virus (RVFV) is such a virus. It spreads predominantly among ruminant livestock but can also spill over and cause severe disease in humans. Understanding which of these ruminant species are most important for the transmission of RVFV can help for effective control. One piece of this puzzle is to assess how effective infected animals are at transmitting RVFV to mosquitoes. To answer this question, we combine mathematical models with observations from experimental infections in cattle, sheep, and goats, and model changes in viremia over time within individuals. We then quantify the relationship between hosts’ viremia and the probability to infect mosquitoes. In combining these two analyses, we estimate the overall transmission potential of sheep, when in contact with mosquitoes, to be 3 to 5 times higher than that of goats and cattle. Further, sheep that experience a lethal infection have an even larger overall transmission potential. Once applied at the level of populations, with setting-specific herd composition and exposure to mosquitoes, these results will help unravel species’ role in RVF outbreaks.
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Affiliation(s)
- Hélène Cecilia
- INRAE, Oniris, BIOEPAR, Nantes, France
- * E-mail: (HC); (QAtB)
| | - Roosmarie Vriens
- Quantitative Veterinary Epidemiology, Wageningen University and Research, Wageningen, The Netherlands
| | | | - Mariken M. de Wit
- Quantitative Veterinary Epidemiology, Wageningen University and Research, Wageningen, The Netherlands
| | - Raphaëlle Métras
- Sorbonne Université, INSERM, Institut Pierre Louis d’Epidémiologie et de Santé Publique (IPLESP), Paris, France
| | | | - Quirine A. ten Bosch
- Quantitative Veterinary Epidemiology, Wageningen University and Research, Wageningen, The Netherlands
- * E-mail: (HC); (QAtB)
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9
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Sedda L, McCann RS, Kabaghe AN, Gowelo S, Mburu MM, Tizifa TA, Chipeta MG, van den Berg H, Takken W, van Vugt M, Phiri KS, Cain R, Tangena JAA, Jones CM. Hotspots and super-spreaders: Modelling fine-scale malaria parasite transmission using mosquito flight behaviour. PLoS Pathog 2022; 18:e1010622. [PMID: 35793345 PMCID: PMC9292116 DOI: 10.1371/journal.ppat.1010622] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 07/18/2022] [Accepted: 05/27/2022] [Indexed: 11/19/2022] Open
Abstract
Malaria hotspots have been the focus of public health managers for several years due to the potential elimination gains that can be obtained from targeting them. The identification of hotspots must be accompanied by the description of the overall network of stable and unstable hotspots of malaria, especially in medium and low transmission settings where malaria elimination is targeted. Targeting hotspots with malaria control interventions has, so far, not produced expected benefits. In this work we have employed a mechanistic-stochastic algorithm to identify clusters of super-spreader houses and their related stable hotspots by accounting for mosquito flight capabilities and the spatial configuration of malaria infections at the house level. Our results show that the number of super-spreading houses and hotspots is dependent on the spatial configuration of the villages. In addition, super-spreaders are also associated to house characteristics such as livestock and family composition. We found that most of the transmission is associated with winds between 6pm and 10pm although later hours are also important. Mixed mosquito flight (downwind and upwind both with random components) were the most likely movements causing the spread of malaria in two out of the three study areas. Finally, our algorithm (named MALSWOTS) provided an estimate of the speed of malaria infection progression from house to house which was around 200-400 meters per day, a figure coherent with mark-release-recapture studies of Anopheles dispersion. Cross validation using an out-of-sample procedure showed accurate identification of hotspots. Our findings provide a significant contribution towards the identification and development of optimal tools for efficient and effective spatio-temporal targeted malaria interventions over potential hotspot areas.
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Affiliation(s)
- Luigi Sedda
- Lancaster Ecology and Epidemiology Group, Lancaster Medical School, Lancaster University, United Kingdom
| | - Robert S. McCann
- Laboratory of Entomology, Wageningen University & Research, Wageningen, The Netherlands
- School of Global and Public Health, Kamuzu University of Health Sciences, Blantyre, Malawi
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Alinune N. Kabaghe
- School of Global and Public Health, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Steven Gowelo
- Laboratory of Entomology, Wageningen University & Research, Wageningen, The Netherlands
- School of Global and Public Health, Kamuzu University of Health Sciences, Blantyre, Malawi
- MAC Communicable Diseases Action Centre, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Monicah M. Mburu
- Laboratory of Entomology, Wageningen University & Research, Wageningen, The Netherlands
- School of Global and Public Health, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Tinashe A. Tizifa
- School of Global and Public Health, Kamuzu University of Health Sciences, Blantyre, Malawi
- Center for Tropical Medicine and Travel Medicine, University of Amsterdam, The Netherlands
| | - Michael G. Chipeta
- School of Global and Public Health, Kamuzu University of Health Sciences, Blantyre, Malawi
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Henk van den Berg
- Laboratory of Entomology, Wageningen University & Research, Wageningen, The Netherlands
| | - Willem Takken
- Laboratory of Entomology, Wageningen University & Research, Wageningen, The Netherlands
| | - Michèle van Vugt
- Center for Tropical Medicine and Travel Medicine, University of Amsterdam, The Netherlands
| | - Kamija S. Phiri
- School of Global and Public Health, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Russell Cain
- Lancaster Ecology and Epidemiology Group, Lancaster Medical School, Lancaster University, United Kingdom
| | - Julie-Anne A. Tangena
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Christopher M. Jones
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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10
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Affiliation(s)
- Amy R. Sweeny
- Institute of Evolutionary Biology University of Edinburgh Edinburgh Scotland
| | - Gregory F. Albery
- Department of Biology Georgetown University Washington DC USA
- Wissenschaftskolleg zu Berlin Berlin Germany
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11
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Ruiz-Aravena M, McKee C, Gamble A, Lunn T, Morris A, Snedden CE, Yinda CK, Port JR, Buchholz DW, Yeo YY, Faust C, Jax E, Dee L, Jones DN, Kessler MK, Falvo C, Crowley D, Bharti N, Brook CE, Aguilar HC, Peel AJ, Restif O, Schountz T, Parrish CR, Gurley ES, Lloyd-Smith JO, Hudson PJ, Munster VJ, Plowright RK. Ecology, evolution and spillover of coronaviruses from bats. Nat Rev Microbiol 2022; 20:299-314. [PMID: 34799704 PMCID: PMC8603903 DOI: 10.1038/s41579-021-00652-2] [Citation(s) in RCA: 92] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2021] [Indexed: 12/24/2022]
Abstract
In the past two decades, three coronaviruses with ancestral origins in bats have emerged and caused widespread outbreaks in humans, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since the first SARS epidemic in 2002-2003, the appreciation of bats as key hosts of zoonotic coronaviruses has advanced rapidly. More than 4,000 coronavirus sequences from 14 bat families have been identified, yet the true diversity of bat coronaviruses is probably much greater. Given that bats are the likely evolutionary source for several human coronaviruses, including strains that cause mild upper respiratory tract disease, their role in historic and future pandemics requires ongoing investigation. We review and integrate information on bat-coronavirus interactions at the molecular, tissue, host and population levels. We identify critical gaps in knowledge of bat coronaviruses, which relate to spillover and pandemic risk, including the pathways to zoonotic spillover, the infection dynamics within bat reservoir hosts, the role of prior adaptation in intermediate hosts for zoonotic transmission and the viral genotypes or traits that predict zoonotic capacity and pandemic potential. Filling these knowledge gaps may help prevent the next pandemic.
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Affiliation(s)
- Manuel Ruiz-Aravena
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Clifton McKee
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Amandine Gamble
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Tamika Lunn
- Centre for Planetary Health and Food Security, Griffith University, Nathan, QLD, Australia
| | - Aaron Morris
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Celine E Snedden
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Claude Kwe Yinda
- National Institute of Allergy and Infectious Diseases, Hamilton, MT, USA
| | - Julia R Port
- National Institute of Allergy and Infectious Diseases, Hamilton, MT, USA
| | - David W Buchholz
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Yao Yu Yeo
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Christina Faust
- Department of Biology, Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA, USA
| | - Elinor Jax
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Lauren Dee
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Devin N Jones
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Maureen K Kessler
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
- Department of Ecology, Montana State University, Bozeman, MT, USA
| | - Caylee Falvo
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Daniel Crowley
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Nita Bharti
- Department of Biology, Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA, USA
| | - Cara E Brook
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA
| | - Hector C Aguilar
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Alison J Peel
- Centre for Planetary Health and Food Security, Griffith University, Nathan, QLD, Australia
| | - Olivier Restif
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Tony Schountz
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Colin R Parrish
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Emily S Gurley
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - James O Lloyd-Smith
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Peter J Hudson
- Department of Biology, Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA, USA
| | - Vincent J Munster
- National Institute of Allergy and Infectious Diseases, Hamilton, MT, USA
| | - Raina K Plowright
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA.
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12
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CHARACTERIZING TUBERCULOSIS PROGRESSION IN WILD MEERKATS (SURICATA SURICATTA) FROM FECAL SAMPLES AND CLINICAL SIGNS. J Wildl Dis 2022; 58:309-321. [PMID: 35255146 DOI: 10.7589/jwd-d-21-00063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 11/03/2021] [Indexed: 11/20/2022]
Abstract
Tuberculosis (TB) is an increasing threat to wildlife, yet tracking its spread is challenging because infections often appear to be asymptomatic, and diagnostic tools such as blood tests can be invasive and resource intensive. Our understanding of TB biology in wildlife is therefore limited to a small number of well-studied species. Testing of fecal samples using PCR is a noninvasive method that has been used to detect Mycobacterium bovis shedding amongst badgers, yet its utility more broadly for TB monitoring in wildlife is unclear. We combined observation data of clinical signs with PCR testing of 388 fecal samples to characterize longitudinal dynamics of TB progression in 66 wild meerkats (Suricata suricatta) socially exposed to Mycobacterium suricattae between 2000 and 2018. Our specific objectives were 1) to test whether meerkat fecal samples can be used to monitor TB; 2) to characterize TB progression between three infection states (PCR-negative exposed, PCR-positive asymptomatic, and PCR positive with clinical signs); and 3) estimate individual heterogeneity in TB susceptibility, defined here as the time between TB exposure and detection, and survival after TB detection. We found that the TB detection probability once meerkats developed clinical signs was 13% (95% confidence interval 3-46%). Nevertheless, with an adapted test protocol of 10 PCR replicates per sample we detected hidden TB infections in 59% of meerkats before the onset of clinical signs. Meerkats became PCR positive approximately 14 mo after initial exposure, developed clinical signs approximately 1 yr after becoming PCR positive, and died within 5 mo of developing clinical signs. Individual variation in disease progression was high, with meerkats developing clinical signs from immediately after exposure to 3.4 yr later. Overall, our study generates novel insights into wildlife TB progression, and may help guide adapted management strategies for TB-susceptible wildlife populations.
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13
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Tardy O, Vincenot CE, Bouchard C, Ogden NH, Leighton PA. Context-dependent host dispersal and habitat fragmentation determine heterogeneity in infected tick burdens: an agent-based modelling study. ROYAL SOCIETY OPEN SCIENCE 2022. [PMID: 35360357 DOI: 10.5061/dryad.nzs7h44rx] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
As the incidence of tick-borne diseases has sharply increased over the past decade, with serious consequences for human and animal health, there is a need to identify ecological drivers contributing to heterogeneity in tick-borne disease risk. In particular, the relative importance of animal host dispersal behaviour in its three context-dependent phases of emigration, transfer and settlement is relatively unexplored. We built a spatially explicit agent-based model to investigate how the host dispersal process, in concert with the tick and host demographic processes, habitat fragmentation and the pathogen transmission process, affects infected tick distributions among hosts. A sensitivity analysis explored the impacts of different input parameters on infected tick burdens on hosts and infected tick distributions among hosts. Our simulations indicate that ecological predictors of infected tick burdens differed among the post-egg life stages of ticks, with tick attachment and detachment, tick questing activity and pathogen transmission dynamics identified as key processes, in a coherent way. We also found that the type of host settlement strategy and the proportion of habitat suitable for hosts determined super-spreading of infected ticks. We developed a theoretical mechanistic framework that can serve as a first step towards applied studies of on-the-ground public health intervention strategies.
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Affiliation(s)
- Olivia Tardy
- Research Group on Epidemiology of Zoonoses and Public Health, Faculty of Veterinary Medicine, Université de Montréal, 3200 rue Sicotte, Saint-Hyacinthe, Quebec, Canada J2S 2M2
| | - Christian E Vincenot
- Department of Social Informatics, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501, Japan
| | - Catherine Bouchard
- Research Group on Epidemiology of Zoonoses and Public Health, Faculty of Veterinary Medicine, Université de Montréal, 3200 rue Sicotte, Saint-Hyacinthe, Quebec, Canada J2S 2M2
- Public Health Risk Sciences Division, National Microbiology Laboratory, Public Health Agency of Canada, 3200 rue Sicotte, Saint-Hyacinthe, Quebec, Canada J2S 2M2
| | - Nicholas H Ogden
- Research Group on Epidemiology of Zoonoses and Public Health, Faculty of Veterinary Medicine, Université de Montréal, 3200 rue Sicotte, Saint-Hyacinthe, Quebec, Canada J2S 2M2
- Public Health Risk Sciences Division, National Microbiology Laboratory, Public Health Agency of Canada, 3200 rue Sicotte, Saint-Hyacinthe, Quebec, Canada J2S 2M2
| | - Patrick A Leighton
- Research Group on Epidemiology of Zoonoses and Public Health, Faculty of Veterinary Medicine, Université de Montréal, 3200 rue Sicotte, Saint-Hyacinthe, Quebec, Canada J2S 2M2
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14
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Tardy O, Vincenot CE, Bouchard C, Ogden NH, Leighton PA. Context-dependent host dispersal and habitat fragmentation determine heterogeneity in infected tick burdens: an agent-based modelling study. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220245. [PMID: 35360357 PMCID: PMC8965412 DOI: 10.1098/rsos.220245] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 02/28/2022] [Indexed: 05/09/2023]
Abstract
As the incidence of tick-borne diseases has sharply increased over the past decade, with serious consequences for human and animal health, there is a need to identify ecological drivers contributing to heterogeneity in tick-borne disease risk. In particular, the relative importance of animal host dispersal behaviour in its three context-dependent phases of emigration, transfer and settlement is relatively unexplored. We built a spatially explicit agent-based model to investigate how the host dispersal process, in concert with the tick and host demographic processes, habitat fragmentation and the pathogen transmission process, affects infected tick distributions among hosts. A sensitivity analysis explored the impacts of different input parameters on infected tick burdens on hosts and infected tick distributions among hosts. Our simulations indicate that ecological predictors of infected tick burdens differed among the post-egg life stages of ticks, with tick attachment and detachment, tick questing activity and pathogen transmission dynamics identified as key processes, in a coherent way. We also found that the type of host settlement strategy and the proportion of habitat suitable for hosts determined super-spreading of infected ticks. We developed a theoretical mechanistic framework that can serve as a first step towards applied studies of on-the-ground public health intervention strategies.
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Affiliation(s)
- Olivia Tardy
- Research Group on Epidemiology of Zoonoses and Public Health, Faculty of Veterinary Medicine, Université de Montréal, 3200 rue Sicotte, Saint-Hyacinthe, Quebec, Canada J2S 2M2
| | - Christian E. Vincenot
- Department of Social Informatics, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501, Japan
| | - Catherine Bouchard
- Research Group on Epidemiology of Zoonoses and Public Health, Faculty of Veterinary Medicine, Université de Montréal, 3200 rue Sicotte, Saint-Hyacinthe, Quebec, Canada J2S 2M2
- Public Health Risk Sciences Division, National Microbiology Laboratory, Public Health Agency of Canada, 3200 rue Sicotte, Saint-Hyacinthe, Quebec, Canada J2S 2M2
| | - Nicholas H. Ogden
- Research Group on Epidemiology of Zoonoses and Public Health, Faculty of Veterinary Medicine, Université de Montréal, 3200 rue Sicotte, Saint-Hyacinthe, Quebec, Canada J2S 2M2
- Public Health Risk Sciences Division, National Microbiology Laboratory, Public Health Agency of Canada, 3200 rue Sicotte, Saint-Hyacinthe, Quebec, Canada J2S 2M2
| | - Patrick A. Leighton
- Research Group on Epidemiology of Zoonoses and Public Health, Faculty of Veterinary Medicine, Université de Montréal, 3200 rue Sicotte, Saint-Hyacinthe, Quebec, Canada J2S 2M2
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15
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Piot N, Smagghe G. Critical View on the Importance of Host Defense Strategies on Virus Distribution of Bee Viruses: What Can We Learn from SARS-CoV-2 Variants? Viruses 2022; 14:503. [PMID: 35336909 PMCID: PMC8951442 DOI: 10.3390/v14030503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 02/22/2022] [Accepted: 02/26/2022] [Indexed: 02/05/2023] Open
Abstract
Bees, both wild and domesticated ones, are hosts to a plethora of viruses, with most of them infecting a wide range of bee species and genera. Although viral discovery and research on bee viruses date back over 50 years, the last decade is marked by a surge of new studies, new virus discoveries, and reports on viral transmission in and between bee species. This steep increase in research on bee viruses was mainly initiated by the global reports on honeybee colony losses and the worldwide wild bee decline, where viruses are regarded as one of the main drivers. While the knowledge gained on bee viruses has significantly progressed in a short amount of time, we believe that integration of host defense strategies and their effect on viral dynamics in the multi-host viral landscape are important aspects that are currently still missing. With the large epidemiological dataset generated over the last two years on the SARS-CoV-2 pandemic, the role of these defense mechanisms in shaping viral dynamics has become eminent. Integration of these dynamics in a multi-host system would not only greatly aid the understanding of viral dynamics as a driver of wild bee decline, but we believe bee pollinators and their viruses provide an ideal system to study the multi-host viruses and their epidemiology.
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Affiliation(s)
- Niels Piot
- Laboratory of Agrozoology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Guy Smagghe
- Laboratory of Agrozoology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
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16
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Ortega N, Roznik EA, Surbaugh KL, Cano N, Price W, Campbell T, Rohr JR. Parasite spillover to native hosts from more tolerant, supershedding invasive hosts: Implications for management. J Appl Ecol 2021. [DOI: 10.1111/1365-2664.13906] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nicole Ortega
- Department of Biology University of Tampa Tampa FL USA
| | - Elizabeth A. Roznik
- North Carolina Zoo Asheboro NC USA
- Department of Integrative Biology University of South Florida Tampa FL USA
| | - Kerri L. Surbaugh
- Department of Integrative Biology University of South Florida Tampa FL USA
| | - Natalia Cano
- Department of Integrative Biology University of South Florida Tampa FL USA
| | - Wayne Price
- Department of Biology University of Tampa Tampa FL USA
| | - Todd Campbell
- Department of Biology University of Tampa Tampa FL USA
| | - Jason R. Rohr
- Department of Biological Sciences University of Notre DameNotre Dame IN USA
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17
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Ruden RM, Adelman JS. Disease tolerance alters host competence in a wild songbird. Biol Lett 2021; 17:20210362. [PMID: 34699737 PMCID: PMC8548076 DOI: 10.1098/rsbl.2021.0362] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 10/04/2021] [Indexed: 11/12/2022] Open
Abstract
Individuals can express a range of disease phenotypes during infection, with important implications for epidemics. Tolerance, in particular, is a host response that minimizes the per-pathogen fitness costs of infection. Because tolerant hosts show milder clinical signs and higher survival, despite similar pathogen burdens, their potential for prolonged pathogen shedding may facilitate the spread of pathogens. To test this, we simulated outbreaks of mycoplasmal conjunctivitis in house finches, asking how the speed of transmission varied with tissue-specific and behavioural components of tolerance, milder conjunctivitis and anorexia for a given pathogen load, respectively. Because tissue-specific tolerance hinders pathogen deposition onto bird feeders, important transmission hubs, we predicted it would slow transmission. Because behavioural tolerance should increase interactions with bird feeders, we predicted it would speed transmission. Our findings supported these predictions, suggesting that variation in tolerance could help identify individuals most likely to transmit pathogens.
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Affiliation(s)
- Rachel M. Ruden
- Department of Natural Resource Ecology and Management, Iowa State University, Ames, IA, USA
- Iowa Department of Natural Resources, Des Moines, IA, USA
| | - James S. Adelman
- Department of Natural Resource Ecology and Management, Iowa State University, Ames, IA, USA
- Department of Biological Sciences, University of Memphis, Memphis, TN, USA
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18
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Seal S, Dharmarajan G, Khan I. Evolution of pathogen tolerance and emerging infections: A missing experimental paradigm. eLife 2021; 10:e68874. [PMID: 34544548 PMCID: PMC8455132 DOI: 10.7554/elife.68874] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 08/23/2021] [Indexed: 12/11/2022] Open
Abstract
Researchers worldwide are repeatedly warning us against future zoonotic diseases resulting from humankind's insurgence into natural ecosystems. The same zoonotic pathogens that cause severe infections in a human host frequently fail to produce any disease outcome in their natural hosts. What precise features of the immune system enable natural reservoirs to carry these pathogens so efficiently? To understand these effects, we highlight the importance of tracing the evolutionary basis of pathogen tolerance in reservoir hosts, while drawing implications from their diverse physiological and life-history traits, and ecological contexts of host-pathogen interactions. Long-term co-evolution might allow reservoir hosts to modulate immunity and evolve tolerance to zoonotic pathogens, increasing their circulation and infectious period. Such processes can also create a genetically diverse pathogen pool by allowing more mutations and genetic exchanges between circulating strains, thereby harboring rare alive-on-arrival variants with extended infectivity to new hosts (i.e., spillover). Finally, we end by underscoring the indispensability of a large multidisciplinary empirical framework to explore the proposed link between evolved tolerance, pathogen prevalence, and spillover in the wild.
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Affiliation(s)
| | - Guha Dharmarajan
- Savannah River Ecology Laboratory, University of GeorgiaAikenUnited States
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19
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Corti P, Collado B, Salgado M, Moraga CA, Radic-Schilling S, Tejeda C, Ruiz-Aravena M. Dynamic of Mycobacterium avium subspecies paratuberculosis infection in a domestic-wildlife interface: Domestic sheep and guanaco as reservoir community. Transbound Emerg Dis 2021; 69:e161-e174. [PMID: 34347393 DOI: 10.1111/tbed.14277] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 08/02/2021] [Indexed: 12/20/2022]
Abstract
Natural herbivore populations have experienced uninterrupted pressures from direct and evident domestic-wildlife interactions and competition, to indirect or less obvious ones such as pathogen transmission. Thus, pathogen spillover between wild and domestic animals is a constant concern because the domestic-wildlife interface represents the ecological frontier in which pathogen transmission takes place in both directions. In Patagonian steppe communities, extensive sheep ranching and guanaco (Lama guanicoe) populations coexist, and guanaco have shown to be infected by pathogens such as Mycobacterium avium subspecies paratuberculosis (MAP) likely transmitted from livestock. MAP causes chronic enteritis and affects mostly domestic ruminants. We evaluated MAP prevalence and pathogen shedding in both species' faeces collected in non-shared and shared sites according to presence/absence of sheep and guanaco along a year, in four different seasons (autumn, winter, and spring 2018, and summer 2019). Our results indicate that MAP circulates in both sheep and guanaco populations with self-sustained transmission; however, both species differ in their levels of competence. We detected higher pathogen shedding in sites occupied by sheep, suggesting that sheep populations may be the main source of infection for susceptible animals due to their large numbers which drive MAP dynamics.
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Affiliation(s)
- Paulo Corti
- Laboratorio de Manejo y Conservación de Vida Silvestre, Instituto de Ciencia Animal y Programa de Investigación Aplicada en Fauna Silvestre, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Bernardita Collado
- Instituto de Medicina Preventiva Veterinaria, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile.,Escuela de Graduados, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Miguel Salgado
- Instituto de Medicina Preventiva Veterinaria, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Claudio A Moraga
- School of Natural Resources and the Environment, University of Florida, Gainesville, Florida, USA.,Departamento de Ciencias Agropecuarias y Acuícolas, Facultad de Ciencias, Universidad de Magallanes, Punta Arenas, Chile
| | - Sergio Radic-Schilling
- Departamento de Ciencias Agropecuarias y Acuícolas, Facultad de Ciencias, Universidad de Magallanes, Punta Arenas, Chile
| | - Carlos Tejeda
- Instituto de Medicina Preventiva Veterinaria, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile.,Escuela de Graduados, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Manuel Ruiz-Aravena
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, USA
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20
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Tadiri CP, Fussmann GF, Scott ME. Parasite spread in experimental metapopulations: resistance, tolerance and host competence. OIKOS 2021. [DOI: 10.1111/oik.07837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
| | | | - Marilyn E. Scott
- Inst. of Parasitology, McGill Univ. Ste. Anne‐de‐Bellevue QC Canada
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21
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Plowright RK, Hudson PJ. From Protein to Pandemic: The Transdisciplinary Approach Needed to Prevent Spillover and the Next Pandemic. Viruses 2021; 13:1298. [PMID: 34372504 PMCID: PMC8310336 DOI: 10.3390/v13071298] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 06/23/2021] [Accepted: 06/25/2021] [Indexed: 01/10/2023] Open
Abstract
Pandemics are a consequence of a series of processes that span scales from viral biology at 10-9 m to global transmission at 106 m. The pathogen passes from one host species to another through a sequence of events that starts with an infected reservoir host and entails interspecific contact, innate immune responses, receptor protein structure within the potential host, and the global spread of the novel pathogen through the naive host population. Each event presents a potential barrier to the onward passage of the virus and should be characterized with an integrated transdisciplinary approach. Epidemic control is based on the prevention of exposure, infection, and disease. However, the ultimate pandemic prevention is prevention of the spillover event itself. Here, we focus on the potential for preventing the spillover of henipaviruses, a group of viruses derived from bats that frequently cross species barriers, incur high human mortality, and are transmitted among humans via stuttering chains. We outline the transdisciplinary approach needed to prevent the spillover process and, therefore, future pandemics.
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Affiliation(s)
- Raina K. Plowright
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA
| | - Peter J. Hudson
- Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, State College, PA 16802, USA;
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22
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Gameiro J, Veiga J, Valera F, Palmeirim JM, Catry I. Influence of colony traits on ectoparasite infestation in birds breeding in mixed-species colonies. Parasitology 2021; 148:904-912. [PMID: 33729107 PMCID: PMC11010175 DOI: 10.1017/s0031182021000470] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 03/11/2021] [Accepted: 03/11/2021] [Indexed: 01/22/2023]
Abstract
Coloniality in birds is often associated with an increase in parasite burden, but whether the co-occurrence of several host species influences the prevalence and abundance of ectoparasites and their relationship with colony size or density remains poorly known. Here, we studied mixed-species breeding colonies formed after the provision of artificial breeding structures for restoring the lesser kestrel (Falco naumanni) population in Portugal, to investigate the influence of colony traits on ectoparasite infestation. We sampled four groups of ectoparasites (carnid flies, haematophagous mites, louse flies and chewing lice) in four hosts: lesser kestrels, European rollers (Coracias garrulus), feral pigeons (Columba livia) and spotless starlings (Sturnus unicolor). Each host species had a distinct infracommunity of ectoparasites, regardless of colony traits such as size, density or host richness. The abundance of the most common ectoparasite, Carnus hemapterus, was influenced by colony composition – number of nests of each host species – rather than by colony size or density, with its abundance being diluted with increasing numbers of less suitable hosts such as starlings. The increased contact between multiple species of hosts in breeding colonies may complexify host–parasite interactions and challenge our current knowledge on the ecological relationships between host sociality and parasitism.
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Affiliation(s)
- João Gameiro
- cE3c – Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Jesús Veiga
- Departmento de Ecología Funcional y Evolutiva, Estación Experimental de Zonas Áridas (EEZA-CSIC), Almería, Spain
| | - Francisco Valera
- Departmento de Ecología Funcional y Evolutiva, Estación Experimental de Zonas Áridas (EEZA-CSIC), Almería, Spain
| | - Jorge M. Palmeirim
- cE3c – Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Inês Catry
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Laboratório Associado, Universidade do Porto, Vairão, Portugal
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Laboratório Associado, Instituto Superior de Agronomia, Universidade de Lisboa, Lisboa, Portugal
- School of Environmental Sciences, University of East Anglia, Norwhich, UK
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23
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Garrido M, Halle S, Flatau R, Cohen C, Navarro-Castilla Á, Barja I, Hawlena H. The dilution effect behind the scenes: testing the underlying assumptions of its mechanisms through quantifying the long-term dynamics and effects of a pathogen in multiple host species. Proc Biol Sci 2021; 288:20210773. [PMID: 34102894 PMCID: PMC8187991 DOI: 10.1098/rspb.2021.0773] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/12/2021] [Indexed: 01/01/2023] Open
Abstract
Disentangling the mechanisms that mediate the relationships between species diversity and disease risk has both theoretical and applied implications. We employed a model system of rodents and their Mycoplasma pathogens, in which an extreme negative diversity-disease relationship was demonstrated, to test the assumptions underlying three mechanisms that may explain this field pattern. Through quantifying the long-term dynamics and effects of the pathogen in its three host species, we estimated the between-host differences in pathogen spreading and transmission potentials, and host recovery potential and vulnerability to infection. The results suggest that one of the hosts is a pathogen amplifier and the other two hosts function as diluters. Considering the similarity in infection success and intensity among hosts, and the failure to detect any pathogen-induced damage, we could not validate the assumption underlying the hypotheses that diluters reduce the overall transmission or increase the mortality of infected hosts in the system. Instead, the results demonstrate that diluters clear the infection faster than amplifiers, supporting the possibility that the addition of diluters to the community may reduce the overall number of infected hosts through this mechanism. This study highlights the contribution of experimental studies that simultaneously explore different aspects of host-pathogen interactions in multiple hosts, in diversity-disease research.
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Affiliation(s)
- Mario Garrido
- Jacob Blaustein Center for Scientific Cooperation, Ben-Gurion University of the Negev, 849900 Midreshet Ben-Gurion, Israel
| | - Snir Halle
- Mitrani Department of Desert Ecology, Swiss Institute for Dryland Environmental and Energy Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 849900 Midreshet Ben-Gurion, Israel
| | - Ron Flatau
- Mitrani Department of Desert Ecology, Swiss Institute for Dryland Environmental and Energy Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 849900 Midreshet Ben-Gurion, Israel
| | - Carmit Cohen
- Mitrani Department of Desert Ecology, Swiss Institute for Dryland Environmental and Energy Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 849900 Midreshet Ben-Gurion, Israel
| | - Álvaro Navarro-Castilla
- Etho-Physiology Group. Unit of Zoology. Department of Biology. Faculty of Sciences, the Autonomous University of Madrid, Spain
| | - Isabel Barja
- Etho-Physiology Group. Unit of Zoology. Department of Biology. Faculty of Sciences, the Autonomous University of Madrid, Spain
- Center for Research on Biodiversity and Global Change (CIBC-UAM), the Autonomous University of Madrid, Spain
| | - Hadas Hawlena
- Mitrani Department of Desert Ecology, Swiss Institute for Dryland Environmental and Energy Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 849900 Midreshet Ben-Gurion, Israel
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Halliday FW, Jalo M, Laine AL. The effect of host community functional traits on plant disease risk varies along an elevational gradient. eLife 2021; 10:67340. [PMID: 33983120 PMCID: PMC8208817 DOI: 10.7554/elife.67340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 05/10/2021] [Indexed: 01/17/2023] Open
Abstract
Quantifying the relative impact of environmental conditions and host community structure on disease is one of the greatest challenges of the 21st century, as both climate and biodiversity are changing at unprecedented rates. Both increasing temperature and shifting host communities toward more fast-paced life-history strategies are predicted to increase disease, yet their independent and interactive effects on disease in natural communities remain unknown. Here, we address this challenge by surveying foliar disease symptoms in 220, 0.5 m-diameter herbaceous plant communities along a 1100-m elevational gradient. We find that increasing temperature associated with lower elevation can increase disease by (1) relaxing constraints on parasite growth and reproduction, (2) determining which host species are present in a given location, and (3) strengthening the positive effect of host community pace-of-life on disease. These results provide the first field evidence, under natural conditions, that environmental gradients can alter how host community structure affects disease. Climate change is causing shifts in the ecology and biodiversity of different world regions at unprecedented rates. Global warming is also linked with changes in the risk for certain infectious diseases in humans, but also in animals and plants. There are several possible mechanisms for this. For one thing, changing weather patterns may affect how pathogens grow and reproduce. For another, the distribution ranges of animal and plant hosts of certain disease-causing pathogens are changing because of global warming. This means that the distributions of pathogens are also changing, and so is the severity of the diseases that they cause. Increasing temperatures may also influence the physiological traits that make host species suitable for pathogens. This is because the traits that allow species to survive or adapt to changes in their environment may also make them better at hosting and transmitting the pathogens that cause disease. For example, in plant communities, rising temperatures could favor species with faster growth rates, quicker reproduction and high dispersal, and these traits are often associated with more efficient spread of disease. Despite a lot of research into the effects of climate, it remains unclear how temperature, pathogen growth and reproduction, and host species’ traits and distributions combine and interact to alter infectious disease risk, especially in wild plant communities. To investigate this, Halliday, Jalo and Laine studied an area in southeast Switzerland where natural temperature and biodiversity change gradually through the region. The aim was to explore how relationships between plant biodiversity, pathogens and disease risk change with temperature, and to understand whether environmental or biological factors influence infectious disease risk more. Halliday, Jalo and Laine measured the levels of fungal diseases found in the leaves of plant communities spanning 1,100 meters of elevation, showing that higher temperatures increase disease risk both directly and indirectly. Directly, higher temperatures increased pathogen growth and reproduction, and indirectly, they influenced which plants were present and therefore able to act as disease hosts. The results also indicated that temperature can affect how the traits of plants drive the transmission rates of fungal pathogens. Important predictors of disease risk were traits relating to the growth rate of host plants, which tended to increase in areas with low elevation where the surface of the soil was warm. This study represents the first analysis, in wild plants, of how changing temperatures, the traits of shifting host species, and resident parasite populations interact to impact infectious disease risk. The insights Halliday, Jalo and Laine provided could aid in predicting how global climate change will influence infectious disease risk.
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Affiliation(s)
- Fletcher W Halliday
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Zurich, Switzerland
| | - Mikko Jalo
- Faculty of Biological and Environmental sciences, University of Helsinki, Helsinki, Finland
| | - Anna-Liisa Laine
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Zurich, Switzerland.,Faculty of Biological and Environmental sciences, University of Helsinki, Helsinki, Finland
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25
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Managed bumble bees acquire parasites from their foraging environment: A case study on parasite spillback. J Invertebr Pathol 2021; 182:107583. [PMID: 33781766 DOI: 10.1016/j.jip.2021.107583] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 03/22/2021] [Accepted: 03/22/2021] [Indexed: 11/21/2022]
Abstract
The use of commercially reared bumble bees in agricultural environments has been recognized as a potential threat to wild pollinators due to competition, genetic contamination, and most notably, disease transmission. Higher parasite prevalence near greenhouses where managed bumble bees are used has been linked to parasite spillover from managed to wild bees. However, pathogen transmission is not unidirectional, and can also flow from wild to managed bees. These newly infected managed bees can subsequently re-infect (other) wild bees, in a process known as spillback, which is an alternative explanation for the increased parasite prevalence near greenhouses. Reducing parasite prevalence in managed bees is key to controlling host-parasite dynamics in cases of spillover; in spillback, producing managed bees that are resilient to infection is important. Here we establish that the managed bumble bee Bombus terrestris can acquire parasites from their foraging environment, which is the major infection route for Apicystis spp. and Crithidia spp., but not for Nosema spp.. Managed B. terrestris were found to have a higher prevalence of Crithdia and a higher load of Apicystis than local wild conspecifics, showing that for these parasites, spillback is a possible risk scenario.
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26
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Friesen OC, Detwiler JT. Parasite-Modified Chemical Communication: Implications for Aquatic Community Dynamics. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.634754] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Chemical communication within an aquatic environment creates an intricate signaling web that provides species with information about their surroundings. Signaling molecules, like oxylipins, mediate a multitude of interactions between free-living members of a community including non-consumptive effects by predators. Parasites are another source of signaling molecules in aquatic communities and contribute directly by synthesizing them or indirectly by manipulating host chemical cues. If chemical cues of infected hosts are altered, then non-consumptive interactions between other members of the community may also be affected. Different cues from infected hosts may alter behaviors in other individuals related to foraging, competition, and defense priming. Here, we discuss how parasites could modify host chemical cues, which may have far reaching consequences for other community members and the ecosystem. We discuss how the modification of signaling molecules by parasites may also represent a mechanism for parasite-modified behavior within some systems and provide a mechanism for non-consumptive effects of parasites. Further, we propose a host-parasite system that could be used to investigate some key, unanswered questions regarding the relationship between chemical cues, parasite-modified behavior, and non-consumptive effects. We explain how trematode-gastropod systems can be used to test whether there are alterations in the diversity and amounts of signaling molecules available, and if habitat use, immune function, and behavior of other individuals and species are affected. Finally, we argue that changes to pathway crosstalk by parasites within communities may have broad ecological implications.
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27
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Stewart Merrill TE, Hall SR, Cáceres CE. Parasite exposure and host susceptibility jointly drive the emergence of epidemics. Ecology 2020; 102:e03245. [PMID: 33190226 DOI: 10.1002/ecy.3245] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 08/18/2020] [Accepted: 09/18/2020] [Indexed: 12/20/2022]
Abstract
Parasite transmission is thought to depend on both parasite exposure and host susceptibility to infection; however, the relative contribution of these two factors to epidemics remains unclear. We used interactions between an aquatic host and its fungal parasite to evaluate how parasite exposure and host susceptibility interact to drive epidemics. In six lakes, we tracked the following factors from pre-epidemic to epidemic emergence: (1) parasite exposure (measured observationally as fungal spores attacking wild-caught hosts), (2) host susceptibility (measured experimentally as the number of fungal spores required to produce terminal infection), (3) host susceptibility traits (barrier resistance and internal clearance, both quantified with experimental assays), and (4) parasite prevalence (measured observationally from wild-caught hosts). Tracking these factors over 6 months and in almost 7,000 wild-caught hosts provided key information on the drivers of epidemics. We found that epidemics depended critically on the interaction of exposure and susceptibility; epidemics only emerged when a host population's level of exposure exceeded its individuals' capacity for recovery. Additionally, we found that host internal clearance traits (the hemocyte response) were critical in regulating epidemics. Our study provides an empirical demonstration of how parasite exposure and host susceptibility interact to inhibit or drive disease in natural systems and demonstrates that epidemics can be delayed by asynchronicity in the two processes. Finally, our results highlight how individual host traits can scale up to influence broad epidemiological patterns.
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Affiliation(s)
- Tara E Stewart Merrill
- Program in Ecology, Evolution, and Conservation Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, 61801, USA
| | - Spencer R Hall
- Department of Biology, Indiana University, Bloomington, Indiana, 47405, USA
| | - Carla E Cáceres
- Department of Evolution, Ecology, and Behavior, University of Illinois at Urbana-Champaign, Urbana, Illinois, 61801, USA
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28
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Isaïa J, Rivero A, Glaizot O, Christe P, Pigeault R. Last-come, best served? Mosquito biting order and Plasmodium transmission. Proc Biol Sci 2020; 287:20202615. [PMID: 33234076 PMCID: PMC7739503 DOI: 10.1098/rspb.2020.2615] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
A pervasive characteristic of parasite infections is their tendency to be overdispersed. Understanding the mechanisms underlying this overdispersed distribution is of key importance as it may impact the transmission dynamics of the pathogen. Although multiple factors ranging from environmental stochasticity to inter-individual heterogeneity may explain parasite overdispersion, parasite infection is also overdispersed in an inbred host population maintained under laboratory conditions, suggesting that other mechanisms are at play. Here, we show that the aggregated distribution of malaria parasites within mosquito vectors is partially explained by a temporal heterogeneity in parasite infectivity triggered by the bites of mosquitoes. Parasite transmission tripled between the mosquito's first and last blood feed in a period of only 3 h. Surprisingly, the increase in transmission is not associated with an increase in parasite investment in production of the transmissible stage. Overall, we highlight that Plasmodium is capable of responding to the bites of mosquitoes to increase its own transmission at a much faster pace than initially thought and that this is partly responsible for overdispersed distribution of infection. We discuss the underlying mechanisms as well as the broader implications of this plastic response for the epidemiology of malaria.
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Affiliation(s)
- J Isaïa
- Department of Ecology and Evolution, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - A Rivero
- MIVEGEC (UMR CNRS 5290), Montpellier, France.,CREES (Centre de Recherche en Ecologie et Evolution de la Santé), Montpellier, France
| | - O Glaizot
- Department of Ecology and Evolution, University of Lausanne, CH-1015 Lausanne, Switzerland.,Musée Cantonal de Zoologie, Lausanne, Switzerland
| | - P Christe
- Department of Ecology and Evolution, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - R Pigeault
- Department of Ecology and Evolution, University of Lausanne, CH-1015 Lausanne, Switzerland
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29
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Halliday FW, Rohr JR, Laine A. Biodiversity loss underlies the dilution effect of biodiversity. Ecol Lett 2020; 23:1611-1622. [PMID: 32808427 PMCID: PMC7693066 DOI: 10.1111/ele.13590] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 06/14/2020] [Accepted: 07/16/2020] [Indexed: 01/16/2023]
Abstract
The dilution effect predicts increasing biodiversity to reduce the risk of infection, but the generality of this effect remains unresolved. Because biodiversity loss generates predictable changes in host community competence, we hypothesised that biodiversity loss might drive the dilution effect. We tested this hypothesis by reanalysing four previously published meta-analyses that came to contradictory conclusions regarding generality of the dilution effect. In the context of biodiversity loss, our analyses revealed a unifying pattern: dilution effects were inconsistently observed for natural biodiversity gradients, but were commonly observed for biodiversity gradients generated by disturbances causing losses of biodiversity. Incorporating biodiversity loss into tests of generality of the dilution effect further indicated that scale-dependency may strengthen the dilution effect only when biodiversity gradients are driven by biodiversity loss. Together, these results help to resolve one of the most contentious issues in disease ecology: the generality of the dilution effect.
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Affiliation(s)
- Fletcher W. Halliday
- Department of Evolutionary Biology and Environmental StudiesUniversity of ZurichZurich8057Switzerland
| | - Jason R. Rohr
- Department of Biological SciencesEck Institute of Global HealthEnvironmental Change InitiativeUniversity of Notre DameNotre DameINUSA
| | - Anna‐Liisa Laine
- Department of Evolutionary Biology and Environmental StudiesUniversity of ZurichZurich8057Switzerland
- Organismal & Evolutionary Biology Research ProgramUniversity of HelsinkiPO Box 65HelsinkiFI‐00014Finland
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30
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Welsh ME, Cronin JP, Mitchell CE. Trait-based variation in host contribution to pathogen transmission across species and resource supplies. Ecology 2020; 101:e03164. [PMID: 33460129 DOI: 10.1002/ecy.3164] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 04/24/2020] [Accepted: 06/18/2020] [Indexed: 01/26/2023]
Abstract
Two key knowledge gaps currently limit the development of more predictive and general models of pathogen transmission: (1) the physiological basis of heterogeneity in host contribution to pathogen transmission (reservoir potential) remains poorly understood and (2) a general means of integrating the ecological dynamics of host communities has yet to emerge. If the traits responsible for differences in reservoir potential also modulate host community dynamics, these traits could be used to predict pathogen transmission as host communities change. In two greenhouse experiments, across 23 host species and two levels of resource supply, the reservoir potential of plant hosts increased significantly along the Leaf Economics Spectrum, a global axis of plant physiological trait covariation that features prominently in models of plant community ecology. This indicates that the traits of the Leaf Economics Spectrum underlie broad differences in reservoir potential across host species and resource supplies. Therefore, host traits could be used to integrate epidemiological models of pathogen transmission with ecological models of host community change.
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Affiliation(s)
- Miranda E Welsh
- Thompson Writing Program, Duke University, Durham, North Carolina, 27708, USA.,Environment, Ecology and Energy Program, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599, USA
| | - James Patrick Cronin
- U.S. Geological Survey, Wetland and Aquatic Research Center, 700 Cajundome Boulevard, Lafayette, Louisiana, 70506, USA
| | - Charles E Mitchell
- Environment, Ecology and Energy Program, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599, USA.,Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599, USA
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31
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Martens JM, Stokes HS, Berg ML, Walder K, Raidal SR, Magrath MJL, Bennett ATD. Beak and feather disease virus (BFDV) prevalence, load and excretion in seven species of wild caught common Australian parrots. PLoS One 2020; 15:e0235406. [PMID: 32609774 PMCID: PMC7329075 DOI: 10.1371/journal.pone.0235406] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 06/15/2020] [Indexed: 12/14/2022] Open
Abstract
Pathogens pose a major risk to wild host populations, especially in the face of ongoing biodiversity declines. Beak and feather disease virus (BFDV) can affect most if not all members of one of the largest and most threatened bird orders world-wide, the Psittaciformes. Signs of disease can be severe and mortality rates high. Its broad host range makes it a risk to threatened species in particular, because infection can occur via spill-over from abundant hosts. Despite these risks, surveillance of BFDV in locally abundant wild host species has been lacking. We used qPCR and haemagglutination assays to investigate BFDV prevalence, load and shedding in seven abundant host species in the wild in south-east Australia: Crimson Rosellas (Platycercus elegans), Eastern Rosellas (Platycercus eximius), Galahs (Eolophus roseicapillus), Sulphur-crested Cockatoos (Cacatua galerita), Blue-winged Parrots (Neophema chrysostoma), Rainbow Lorikeets (Trichoglossus moluccanus) and Red-rumped Parrots (Psephotus haematonotus). We found BFDV infection in clinically normal birds in six of the seven species sampled. We focused our analysis on the four most commonly caught species, namely Crimson Rosellas (BFDV prevalence in blood samples: 41.8%), Sulphur-crested Cockatoos (20.0%), Blue-winged Parrots (11.8%) and Galahs (8.8%). Species, but not sex, was a significant predictor for BFDV prevalence and load. 56.1% of BFDV positive individuals were excreting BFDV antigen into their feathers, indicative of active viral replication with shedding. Being BFDV positive in blood samples predicted shedding in Crimson Rosellas. Our study confirms that BFDV is endemic in our study region, and can inform targeted disease management by providing comparative data on interspecies variation in virus prevalence, load and shedding.
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Affiliation(s)
- Johanne M. Martens
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, Victoria, Australia
- * E-mail:
| | - Helena S. Stokes
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, Victoria, Australia
| | - Mathew L. Berg
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, Victoria, Australia
| | - Ken Walder
- Centre for Molecular and Medical Research, School of Medicine, Deakin University, Waurn Ponds, Victoria, Australia
| | - Shane R. Raidal
- School of Animal and Veterinary Sciences, Faculty of Science, Charles Sturt University, Wagga Wagga, Australia
| | | | - Andy T. D. Bennett
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, Victoria, Australia
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32
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Cator LJ, Johnson LR, Mordecai EA, Moustaid FE, Smallwood TRC, LaDeau SL, Johansson MA, Hudson PJ, Boots M, Thomas MB, Power AG, Pawar S. The Role of Vector Trait Variation in Vector-Borne Disease Dynamics. Front Ecol Evol 2020; 8:189. [PMID: 32775339 PMCID: PMC7409824 DOI: 10.3389/fevo.2020.00189] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Many important endemic and emerging diseases are transmitted by vectors that are biting arthropods. The functional traits of vectors can affect pathogen transmission rates directly and also through their effect on vector population dynamics. Increasing empirical evidence shows that vector traits vary significantly across individuals, populations, and environmental conditions, and at time scales relevant to disease transmission dynamics. Here, we review empirical evidence for variation in vector traits and how this trait variation is currently incorporated into mathematical models of vector-borne disease transmission. We argue that mechanistically incorporating trait variation into these models, by explicitly capturing its effects on vector fitness and abundance, can improve the reliability of their predictions in a changing world. We provide a conceptual framework for incorporating trait variation into vector-borne disease transmission models, and highlight key empirical and theoretical challenges. This framework provides a means to conceptualize how traits can be incorporated in vector borne disease systems, and identifies key areas in which trait variation can be explored. Determining when and to what extent it is important to incorporate trait variation into vector borne disease models remains an important, outstanding question.
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Affiliation(s)
- Lauren J. Cator
- Department of Life Sciences, Imperial College London, Ascot, United Kingdom
| | - Leah R. Johnson
- Department of Statistics, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Erin A. Mordecai
- Department of Biology, Stanford University, Stanford, CA, United States
| | - Fadoua El Moustaid
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
- BresMed America Inc, Las Vegas, NV, United States
| | | | - Shannon L. LaDeau
- The Cary Institute of Ecosystem Studies, Millbrook, NY, United States
| | | | - Peter J. Hudson
- Center for Infectious Disease Dynamics and Department of Biology, Pennsylvania State University, University Park, PA, United States
| | - Michael Boots
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, United States
| | - Matthew B. Thomas
- Department of Entomology, Pennsylvania State University, University Park, PA, United States
| | - Alison G. Power
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, United States
| | - Samraat Pawar
- Department of Life Sciences, Imperial College London, Ascot, United Kingdom
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33
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Towards a mechanistic understanding of competence: a missing link in diversity-disease research. Parasitology 2020; 147:1159-1170. [PMID: 32517830 DOI: 10.1017/s0031182020000943] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Biodiversity loss may increase the risk of infectious disease in a phenomenon known as the dilution effect. Circumstances that increase the likelihood of disease dilution are: (i) when hosts vary in their competence, and (ii) when communities disassemble predictably, such that the least competent hosts are the most likely to go extinct. Despite the central role of competence in diversity-disease theory, we lack a clear understanding of the factors underlying competence, as well as the drivers and extent of its variation. Our perspective piece encourages a mechanistic understanding of competence and a deeper consideration of its role in diversity-disease relationships. We outline current evidence, emerging questions and future directions regarding the basis of competence, its definition and measurement, the roots of its variation and its role in the community ecology of infectious disease.
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34
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Henschen AE, Adelman JS. What Does Tolerance Mean for Animal Disease Dynamics When Pathology Enhances Transmission? Integr Comp Biol 2020; 59:1220-1230. [PMID: 31141137 DOI: 10.1093/icb/icz065] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Host competence, or how well an individual transmits pathogens, varies substantially within and among animal populations. As this variation can alter the course of epidemics and epizootics, revealing its underlying causes will help predict and control the spread of disease. One host trait that could drive heterogeneity in competence is host tolerance, which minimizes fitness losses during infection without decreasing pathogen load. In many cases, tolerance should increase competence by extending infectious periods and enabling behaviors that facilitate contact among hosts. However, we argue that the links between tolerance and competence are more varied. Specifically, the different physiological and behavioral mechanisms by which hosts achieve tolerance should have a range of effects on competence, enhancing the ability to transmit pathogens in some circumstances and impeding it in others. Because tissue-based pathology (damage) that reduces host fitness is often critical for pathogen transmission, we focus on two mechanisms that can underlie tolerance at the tissue level: damage-avoidance and damage-repair. As damage-avoidance reduces transmission-enhancing pathology, this mechanism is likely to decrease host competence and pathogen transmission. In contrast, damage-repair does not prevent transmission-relevant pathology from occurring. Rather, damage-repair provides new, healthy tissues that pathogens can exploit, likely extending the infectious period and increasing host competence. We explore these concepts through graphical models and present three disease systems in which damage-avoidance and damage-repair alter host competence in the predicted directions. Finally, we suggest that by incorporating these links, future theoretical studies could provide new insights into infectious disease dynamics and host-pathogen coevolution.
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Affiliation(s)
- Amberleigh E Henschen
- Department of Natural Resource Ecology and Management, Iowa State University, 339 Science Hall II, 2310 Pammel Drive, Ames, IA 50011, USA
| | - James S Adelman
- Department of Natural Resource Ecology and Management, Iowa State University, 339 Science Hall II, 2310 Pammel Drive, Ames, IA 50011, USA
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35
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Becker DJ, Downs CJ, Martin LB. Multi-Scale Drivers of Immunological Variation and Consequences for Infectious Disease Dynamics. Integr Comp Biol 2020; 59:1129-1137. [PMID: 31559436 DOI: 10.1093/icb/icz138] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The immune system is the primary barrier to parasite infection, replication, and transmission following exposure, and variation in immunity can accordingly manifest in heterogeneity in traits that govern population-level infectious disease dynamics. While much work in ecoimmunology has focused on individual-level determinants of host immune defense (e.g., reproductive status and body condition), an ongoing challenge remains to understand the broader evolutionary and ecological contexts of this variation (e.g., phylogenetic relatedness and landscape heterogeneity) and to connect these differences into epidemiological frameworks. Ultimately, such efforts could illuminate general principles about the drivers of host defense and improve predictions and control of infectious disease. Here, we highlight recent work that synthesizes the complex drivers of immunological variation across biological scales of organization and scales these within-host differences to population-level infection outcomes. Such studies note the limitations involved in making species-level comparisons of immune phenotypes, stress the importance of spatial scale for immunology research, showcase several statistical tools for translating within-host data into epidemiological parameters, and provide theoretical frameworks for linking within- and between-host scales of infection processes. Building from these studies, we highlight several promising avenues for continued work, including the application of machine learning tools and phylogenetically controlled meta-analyses to immunology data and quantifying the joint spatial and temporal dependencies in immune defense using range expansions as model systems. We also emphasize the use of organismal traits (e.g., host tolerance, competence, and resistance) as a way to interlink various scales of analysis. Such continued collaboration and disciplinary cross-talk among ecoimmunology, disease ecology, and mathematical modeling will facilitate an improved understanding of the multi-scale drivers and consequences of variation in host defense.
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Affiliation(s)
- Daniel J Becker
- Department of Biology, Indiana University, Bloomington, IN 47405, USA.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA 30602, USA
| | - Cynthia J Downs
- Department of Biology, Hamilton College, Clinton, NY 13323, USA
| | - Lynn B Martin
- Department of Global and Planetary Health, University of South Florida, Tampa, FL 33620, USA
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36
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Cooke SJ, Madliger CL, Cramp RL, Beardall J, Burness G, Chown SL, Clark TD, Dantzer B, de la Barrera E, Fangue NA, Franklin CE, Fuller A, Hawkes LA, Hultine KR, Hunt KE, Love OP, MacMillan HA, Mandelman JW, Mark FC, Martin LB, Newman AEM, Nicotra AB, Robinson SA, Ropert-Coudert Y, Rummer JL, Seebacher F, Todgham AE. Reframing conservation physiology to be more inclusive, integrative, relevant and forward-looking: reflections and a horizon scan. CONSERVATION PHYSIOLOGY 2020; 8:coaa016. [PMID: 32274063 PMCID: PMC7125050 DOI: 10.1093/conphys/coaa016] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 01/27/2020] [Accepted: 02/10/2020] [Indexed: 05/21/2023]
Abstract
Applying physiological tools, knowledge and concepts to understand conservation problems (i.e. conservation physiology) has become commonplace and confers an ability to understand mechanistic processes, develop predictive models and identify cause-and-effect relationships. Conservation physiology is making contributions to conservation solutions; the number of 'success stories' is growing, but there remain unexplored opportunities for which conservation physiology shows immense promise and has the potential to contribute to major advances in protecting and restoring biodiversity. Here, we consider how conservation physiology has evolved with a focus on reframing the discipline to be more inclusive and integrative. Using a 'horizon scan', we further explore ways in which conservation physiology can be more relevant to pressing conservation issues of today (e.g. addressing the Sustainable Development Goals; delivering science to support the UN Decade on Ecosystem Restoration), as well as more forward-looking to inform emerging issues and policies for tomorrow. Our horizon scan provides evidence that, as the discipline of conservation physiology continues to mature, it provides a wealth of opportunities to promote integration, inclusivity and forward-thinking goals that contribute to achieving conservation gains. To advance environmental management and ecosystem restoration, we need to ensure that the underlying science (such as that generated by conservation physiology) is relevant with accompanying messaging that is straightforward and accessible to end users.
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Affiliation(s)
- Steven J Cooke
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental and Interdisciplinary Science, Carleton University, 1125 Colonel By Dr., Ottawa, ON, K1S 5B6, Canada
- Corresponding author: Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental and Interdisciplinary Science, Carleton University, 1125 Colonel By Dr., Ottawa, ON, K1S 5B6, Canada.
| | - Christine L Madliger
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental and Interdisciplinary Science, Carleton University, 1125 Colonel By Dr., Ottawa, ON, K1S 5B6, Canada
| | - Rebecca L Cramp
- School of Biological Sciences, The University of Queensland, Brisbane, 4072, Australia
| | - John Beardall
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Gary Burness
- Department of Biology, Trent University, 1600 West Bank Drive, Peterborough, ON, K9L 0G2, Canada
| | - Steven L Chown
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Timothy D Clark
- School of Life and Environmental Sciences, Deakin University, Geelong, Victoria 14 3216, Australia
| | - Ben Dantzer
- Department of Psychology, Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Erick de la Barrera
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro 8701, Morelia, Michoacán, 58190, Mexico
| | - Nann A Fangue
- Department of Wildlife, Fish & Conservation Biology, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Craig E Franklin
- School of Biological Sciences, The University of Queensland, Brisbane, 4072, Australia
| | - Andrea Fuller
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, 7 York Rd, Parktown, 2193, South Africa
| | - Lucy A Hawkes
- College of Life and Environmental Sciences, Hatherly Laboratories, University of Exeter, Prince of Wales Road, Exeter, EX4 4PS, UK
| | - Kevin R Hultine
- Department of Research, Conservation and Collections, Desert Botanical Garden, Phoenix, AZ 85008, USA
| | - Kathleen E Hunt
- Department of Biology, George Mason University, Fairfax, VA 22030, USA
| | - Oliver P Love
- Department of Integrative Biology, University of Windsor, 401 Sunset Avenue, Windsor, ON N9B 3P4, Canada
| | - Heath A MacMillan
- Department of Biology and Institute of Biochemistry, Carleton University, 1125 Colonel By Dr., Ottawa, ON K1S 5B6, Canada
| | - John W Mandelman
- Anderson Cabot Center for Ocean Life, New England Aquarium, 1 Central Wharf, Boston, MA 02110, USA
| | - Felix C Mark
- Department of Integrative Ecophysiology, Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Am Handelshafen 12, 27574 Bremerhaven, Germany
| | - Lynn B Martin
- Global Health and Infectious Disease Research, University of South Florida, 3720 Spectrum Boulevard, Tampa, FL 33612, USA
| | - Amy E M Newman
- Department of Integrative Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Adrienne B Nicotra
- Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - Sharon A Robinson
- School of Earth, Atmospheric and Life Sciences (SEALS) and Centre for Sustainable Ecosystem Solutions, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Yan Ropert-Coudert
- Centre d'Etudes Biologiques de Chizé, CNRS UMR 7372 - La Rochelle Université, 79360 Villiers-en-Bois, France
| | - Jodie L Rummer
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 5811, Australia
| | - Frank Seebacher
- School of Life and Environmental Sciences A08, University of Sydney, NSW 2006, Australia
| | - Anne E Todgham
- Department of Animal Science, University of California Davis, One Shields Ave. Davis, CA, 95616, USA
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Martin LB, Kernbach ME, Unnasch TR. Distinct effects of acute versus chronic corticosterone exposure on Zebra finch responses to West Nile virus. CONSERVATION PHYSIOLOGY 2019; 7:coz094. [PMID: 31824675 PMCID: PMC6894510 DOI: 10.1093/conphys/coz094] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 06/28/2019] [Accepted: 12/03/2019] [Indexed: 06/10/2023]
Abstract
Wild animals are exposed to both short- (acute) and long-term (chronic) stressors. The glucocorticoid hormones, such as corticosterone (CORT), facilitate coping with such stressors, but these hormones can have quite distinct effects contingent on the duration of their elevation. Previously, we found that experimental elevation of CORT for 2 days (via implantation) affected zebra finch (Taeniopygia guttata) responses to West Nile virus (WNV). CORT-elevated birds had higher viremia for at least 2 days longer than controls, and West Nile virus (WNV)-associated mortality occurred only in CORT-elevated birds. Here, we queried how acute elevations of CORT, via injection an hour prior to WNV exposure, would affect host responses, as short-term CORT elevations can be protective in other species. Although CORT injections and implantations elevated circulating CORT to a similar degree, the type of CORT exposure had quite distinct effects on WNV responses. CORT-implanted individuals reached higher viremia and suffered more mortality to WNV than control and CORT-injected individuals. However, CORT-implanted birds maintained body mass better during infection than the other two groups. Our results further support the possibility that chronic physiological stress affects aspects of host competence and potentially community-level WNV disease dynamics.
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Affiliation(s)
- Lynn B Martin
- Global Health and Infectious Disease Research Center, University of South Florida, Tampa, FL 33620, USA
| | - Meredith E Kernbach
- Global Health and Infectious Disease Research Center, University of South Florida, Tampa, FL 33620, USA
| | - Thomas R Unnasch
- Global Health and Infectious Disease Research Center, University of South Florida, Tampa, FL 33620, USA
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Keiser CN, Wantman T, Rebollar EA, Harris RN. Tadpole body size and behaviour alter the social acquisition of a defensive bacterial symbiont. ROYAL SOCIETY OPEN SCIENCE 2019; 6:191080. [PMID: 31598324 PMCID: PMC6774948 DOI: 10.1098/rsos.191080] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 08/01/2019] [Indexed: 05/29/2023]
Abstract
Individual differences in host phenotypes can generate heterogeneity in the acquisition and transmission of microbes. Although this has become a prominent factor of disease epidemiology, host phenotypic variation might similarly underlie the transmission of microbial symbionts that defend against pathogen infection. Here, we test whether host body size and behaviour influence the social acquisition of a skin bacterium, Janthinobacterium lividum, which in some hosts can confer protection against infection by Batrachochytrium dendrobatidis, the causative agent of the amphibian skin disease chytridiomycosis. We measured body size and boldness (time spent in an open field) of green frog tadpoles and haphazardly constructed groups of six individuals. In some groups, we exposed one individual in each group to J. lividum and, in other groups, we inoculated a patch of aquarium pebbles to J. lividum. After 24 h, we swabbed each individual to estimate the presence of J. lividum on their skin. On average, tadpoles acquired nearly four times more bacteria when housed with an exposed individual compared to those housed with a patch of inoculated substrate. When tadpoles were housed with an exposed group-mate, larger and 'bolder' individuals acquired more bacteria. These data suggest that phenotypically biased acquisition of defensive symbionts might generate biased patterns of mortality from the pathogens against which they protect.
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Affiliation(s)
- Carl N. Keiser
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Trina Wantman
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Eria A. Rebollar
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mor, Mexico
| | - Reid N. Harris
- Amphibian Survival Alliance, London SW7 2HQ, UK
- Department of Biology, James Madison University, Harrisonburg, VA 22807, USA
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39
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Glennon EE, Becker DJ, Peel AJ, Garnier R, Suu-Ire RD, Gibson L, Hayman DTS, Wood JLN, Cunningham AA, Plowright RK, Restif O. What is stirring in the reservoir? Modelling mechanisms of henipavirus circulation in fruit bat hosts. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190021. [PMID: 31401962 PMCID: PMC6711305 DOI: 10.1098/rstb.2019.0021] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Pathogen circulation among reservoir hosts is a precondition for zoonotic spillover. Unlike the acute, high morbidity infections typical in spillover hosts, infected reservoir hosts often exhibit low morbidity and mortality. Although it has been proposed that reservoir host infections may be persistent with recurrent episodes of shedding, direct evidence is often lacking. We construct a generalized SEIR (susceptible, exposed, infectious, recovered) framework encompassing 46 sub-models representing the full range of possible transitions among those four states of infection and immunity. We then use likelihood-based methods to fit these models to nine years of longitudinal data on henipavirus serology from a captive colony of Eidolon helvum bats in Ghana. We find that reinfection is necessary to explain observed dynamics; that acute infectious periods may be very short (hours to days); that immunity, if present, lasts about 1-2 years; and that recurring latent infection is likely. Although quantitative inference is sensitive to assumptions about serology, qualitative predictions are robust. Our novel approach helps clarify mechanisms of viral persistence and circulation in wild bats, including estimated ranges for key parameters such as the basic reproduction number and the duration of the infectious period. Our results inform how future field-based and experimental work could differentiate the processes of viral recurrence and reinfection in reservoir hosts. This article is part of the theme issue 'Dynamic and integrative approaches to understanding pathogen spillover'.
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Affiliation(s)
- Emma E Glennon
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, UK
| | - Daniel J Becker
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA.,Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Alison J Peel
- Environmental Futures Research Institute, Griffith University, Nathan, Queensland, QLD 4111, Australia
| | - Romain Garnier
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, UK.,Department of Biology, Georgetown University, Washington, DC 20007, USA
| | - Richard D Suu-Ire
- School of Veterinary Medicine, College of Basic and Applied Sciences, University of Ghana, Legon, Accra, Ghana
| | - Louise Gibson
- Institute of Zoology, Zoological Society of London, London NW1 4RY, UK
| | - David T S Hayman
- Molecular Epidemiology and Public Health Laboratory, Infectious Disease Research Centre, Hopkirk Research Institute, Massey University, Palmerston North, 4442, New Zealand
| | - James L N Wood
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, UK
| | | | - Raina K Plowright
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA
| | - Olivier Restif
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, UK
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