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Glidden CK, Singleton AL, Chamberlin A, Tuan R, Palasio RGS, Caldeira RL, Monteiro AMV, Lwiza KMM, Liu P, Silva V, Athni TS, Sokolow SH, Mordecai EA, De Leo GA. Climate and urbanization drive changes in the habitat suitability of Schistosoma mansoni competent snails in Brazil. bioRxiv 2024:2024.01.03.574120. [PMID: 38260310 PMCID: PMC10802398 DOI: 10.1101/2024.01.03.574120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Schistosomiasis is a neglected tropical disease caused by Schistosoma parasites. Schistosoma are obligate parasites of freshwater Biomphalaria snails, so controlling snail populations is critical to reducing transmission risk. As snails are sensitive to environmental conditions, we expect their distribution is significantly impacted by global change. Here, we leveraged machine learning, remote sensing, and 30 years of snail occurrence records to map the historical and current distribution of competent Biomphalaria throughout Brazil. We identified key features influencing the distribution of suitable habitat and determined how Biomphalaria habitat has changed with climate and urbanization over the last three decades. Our models show that climate change has driven broad shifts in snail host range, whereas expansion of urban and peri-urban areas has driven localized increases in habitat suitability. Elucidating change in Biomphalaria distribution - while accounting for non-linearities that are difficult to detect from local case studies - can help inform schistosomiasis control strategies.
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2
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Faiad SM, Williams MA, Goodman M, Sokolow S, Olden JD, Mitchell K, Andriantsoa R, Gordon Jones JP, Andriamaro L, Ravoniarimbinina P, Rasamy J, Ravelomanana T, Ravelotafita S, Ravo R, Rabinowitz P, De Leo GA, Wood CL. Temperature affects predation of schistosome-competent snails by a novel invader, the marbled crayfish Procambarus virginalis. PLoS One 2023; 18:e0290615. [PMID: 37703262 PMCID: PMC10499222 DOI: 10.1371/journal.pone.0290615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 08/12/2023] [Indexed: 09/15/2023] Open
Abstract
The human burden of environmentally transmitted infectious diseases can depend strongly on ecological factors, including the presence or absence of natural enemies. The marbled crayfish (Procambarus virginalis) is a novel invasive species that can tolerate a wide range of ecological conditions and colonize diverse habitats. Marbled crayfish first appeared in Madagascar in 2005 and quickly spread across the country, overlapping with the distribution of freshwater snails that serve as the intermediate host of schistosomiasis-a parasitic disease of poverty with human prevalence ranging up to 94% in Madagascar. It has been hypothesized that the marbled crayfish may serve as a predator of schistosome-competent snails in areas where native predators cannot and yet no systematic study to date has been conducted to estimate its predation rate on snails. Here, we experimentally assessed marbled crayfish consumption of uninfected and infected schistosome-competent snails (Biomphalaria glabrata and Bulinus truncatus) across a range of temperatures, reflective of the habitat range of the marbled crayfish in Madagascar. We found that the relationship between crayfish consumption and temperature is unimodal with a peak at ~27.5°C. Per-capita consumption increased with body size and was not affected either by snail species or their infectious status. We detected a possible satiation effect, i.e., a small but significant reduction in per-capita consumption rate over the 72-hour duration of the predation experiment. Our results suggest that ecological parameters, such as temperature and crayfish weight, influence rates of consumption and, in turn, the potential impact of the marbled crayfish invasion on snail host populations.
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Affiliation(s)
- Sara M. Faiad
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, United States of America
| | - Maureen A. Williams
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, United States of America
- Department of Biology, McDaniel College, Westminster, MD, United States of America
| | - Maurice Goodman
- Hopkins Marine Station, Dept. of Oceans and of Earth System Science, Doerr School of Sustainability, Stanford University, Stanford, CA, United States of America
| | - Susanne Sokolow
- Hopkins Marine Station, Dept. of Oceans and of Earth System Science, Doerr School of Sustainability, Stanford University, Stanford, CA, United States of America
- Marine Science Institute, University of California, Santa Barbara, Santa Barbara, CA, United States of America
| | - Julian D. Olden
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, United States of America
| | - Kaitlyn Mitchell
- Hopkins Marine Station, Dept. of Oceans and of Earth System Science, Doerr School of Sustainability, Stanford University, Stanford, CA, United States of America
| | - Ranja Andriantsoa
- Réseau International Schistosomiase Environnement Aménagement et Lutte (RISEAL) Madagascar, Madagascar
| | | | - Luciano Andriamaro
- Réseau International Schistosomiase Environnement Aménagement et Lutte (RISEAL) Madagascar, Madagascar
| | | | - Jeanne Rasamy
- Réseau International Schistosomiase Environnement Aménagement et Lutte (RISEAL) Madagascar, Madagascar
- Department of Zoology and Animal Biodiversity, University of Antananarivo, Antananarivo, Madagascar
| | - Tsilavina Ravelomanana
- Réseau International Schistosomiase Environnement Aménagement et Lutte (RISEAL) Madagascar, Madagascar
- Department of Zoology and Animal Biodiversity, University of Antananarivo, Antananarivo, Madagascar
| | - Salohy Ravelotafita
- Department of Zoology and Animal Biodiversity, University of Antananarivo, Antananarivo, Madagascar
| | - Ranaivosolo Ravo
- Department of Zoology and Animal Biodiversity, University of Antananarivo, Antananarivo, Madagascar
| | - Peter Rabinowitz
- Department of Environmental/Occupational Health Sciences, Global Health, University of Washington, Seattle, WA, United States of America
- Center for One Health Research (COHR), University of Washington, Seattle, WA, United States of America
| | - Giulio A. De Leo
- Hopkins Marine Station, Dept. of Oceans and of Earth System Science, Doerr School of Sustainability, Stanford University, Stanford, CA, United States of America
- Woods Institute for the Environment, Stanford University, Stanford, CA, United States of America
| | - Chelsea L. Wood
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, United States of America
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Rohr JR, Sack A, Bakhoum S, Barrett CB, Lopez-Carr D, Chamberlin AJ, Civitello DJ, Diatta C, Doruska MJ, De Leo GA, Haggerty CJE, Jones IJ, Jouanard N, Lund AJ, Ly AT, Ndione RA, Remais JV, Riveau G, Schacht AM, Seck M, Senghor S, Sokolow SH, Wolfe C. A planetary health innovation for disease, food and water challenges in Africa. Nature 2023:10.1038/s41586-023-06313-z. [PMID: 37438520 DOI: 10.1038/s41586-023-06313-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 06/12/2023] [Indexed: 07/14/2023]
Abstract
Many communities in low- and middle-income countries globally lack sustainable, cost-effective and mutually beneficial solutions for infectious disease, food, water and poverty challenges, despite their inherent interdependence1-7. Here we provide support for the hypothesis that agricultural development and fertilizer use in West Africa increase the burden of the parasitic disease schistosomiasis by fuelling the growth of submerged aquatic vegetation that chokes out water access points and serves as habitat for freshwater snails that transmit Schistosoma parasites to more than 200 million people globally8-10. In a cluster randomized controlled trial (ClinicalTrials.gov: NCT03187366) in which we removed invasive submerged vegetation from water points at 8 of 16 villages (that is, clusters), control sites had 1.46 times higher intestinal Schistosoma infection rates in schoolchildren and lower open water access than removal sites. Vegetation removal did not have any detectable long-term adverse effects on local water quality or freshwater biodiversity. In feeding trials, the removed vegetation was as effective as traditional livestock feed but 41 to 179 times cheaper and converting the vegetation to compost provided private crop production and total (public health plus crop production benefits) benefit-to-cost ratios as high as 4.0 and 8.8, respectively. Thus, the approach yielded an economic incentive-with important public health co-benefits-to maintain cleared waterways and return nutrients captured in aquatic plants back to agriculture with promise of breaking poverty-disease traps. To facilitate targeting and scaling of the intervention, we lay the foundation for using remote sensing technology to detect snail habitats. By offering a rare, profitable, win-win approach to addressing food and water access, poverty alleviation, infectious disease control and environmental sustainability, we hope to inspire the interdisciplinary search for planetary health solutions11 to the many and formidable, co-dependent global grand challenges of the twenty-first century.
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Affiliation(s)
- Jason R Rohr
- Department of Biological Sciences, Environmental Change Initiative, Eck Institute of Global Health, University of Notre Dame, Notre Dame, IN, USA.
| | - Alexandra Sack
- Department of Biological Sciences, Environmental Change Initiative, Eck Institute of Global Health, University of Notre Dame, Notre Dame, IN, USA
| | - Sidy Bakhoum
- Department of Animal Biology, Université Cheikh Anta Diop, Dakar, Senegal
| | - Christopher B Barrett
- Charles H. Dyson School of Applied Economics and Management, Cornell University, Ithaca, NY, USA
| | - David Lopez-Carr
- Department of Geography, University of California, Santa Barbara, CA, USA
| | - Andrew J Chamberlin
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
- Woods Institute for the Environment, Stanford University, Stanford, CA, USA
| | | | - Cledor Diatta
- Centre de Recherche Biomédicale Espoir pour la Santé, Saint-Louis, Senegal
| | - Molly J Doruska
- Charles H. Dyson School of Applied Economics and Management, Cornell University, Ithaca, NY, USA
| | - Giulio A De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
| | - Christopher J E Haggerty
- Department of Biological Sciences, Environmental Change Initiative, Eck Institute of Global Health, University of Notre Dame, Notre Dame, IN, USA
| | - Isabel J Jones
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
- Woods Institute for the Environment, Stanford University, Stanford, CA, USA
| | - Nicolas Jouanard
- Centre de Recherche Biomédicale Espoir pour la Santé, Saint-Louis, Senegal
- Station d'Innovation Aquacole, Saint-Louis, Senegal
| | - Andrea J Lund
- Emmett Interdisciplinary Program in Environment and Resources, Stanford University, Stanford, CA, USA
- Department of Environmental and Occupational Health, University of Colorado School of Public Health, Anschutz Medical Campus, Aurora, CO, USA
| | - Amadou T Ly
- Centre de Recherche Biomédicale Espoir pour la Santé, Saint-Louis, Senegal
| | - Raphael A Ndione
- Centre de Recherche Biomédicale Espoir pour la Santé, Saint-Louis, Senegal
| | - Justin V Remais
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, USA
| | - Gilles Riveau
- Centre de Recherche Biomédicale Espoir pour la Santé, Saint-Louis, Senegal
- Université Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, U1019-UMR 9017-CIIL-Center for Infection and Immunité of Lille, Lille, France
| | - Anne-Marie Schacht
- Centre de Recherche Biomédicale Espoir pour la Santé, Saint-Louis, Senegal
| | - Momy Seck
- Station d'Innovation Aquacole, Saint-Louis, Senegal
| | - Simon Senghor
- Centre de Recherche Biomédicale Espoir pour la Santé, Saint-Louis, Senegal
| | - Susanne H Sokolow
- Woods Institute for the Environment, Stanford University, Stanford, CA, USA
| | - Caitlin Wolfe
- College of Public Health, University of South Florida, Tampa, FL, USA
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Haggerty CJE, Delius BK, Jouanard N, Ndao PD, De Leo GA, Lund AJ, Lopez-Carr D, Remais JV, Riveau G, Sokolow SH, Rohr JR. Pyrethroid insecticides pose greater risk than organophosphate insecticides to biocontrol agents for human schistosomiasis. Environ Pollut 2023; 319:120952. [PMID: 36586553 DOI: 10.1016/j.envpol.2022.120952] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 12/22/2022] [Accepted: 12/23/2022] [Indexed: 06/17/2023]
Abstract
Use of agrochemicals, including insecticides, is vital to food production and predicted to increase 2-5 fold by 2050. Previous studies have shown a positive association between agriculture and the human infectious disease schistosomiasis, which is problematic as this parasitic disease infects approximately 250 million people worldwide. Certain insecticides might runoff fields and be highly toxic to invertebrates, such as prawns in the genus Macrobrachium, that are biocontrol agents for snails that transmit the parasites causing schistosomiasis. We used a laboratory dose-response experiment and an observational field study to determine the relative toxicities of three pyrethroid (esfenvalerate, λ-cyhalothrin, and permethrin) and three organophosphate (chlorpyrifos, malathion, and terbufos) insecticides to Macrobrachium prawns. In the lab, pyrethroids were consistently several orders of magnitude more toxic than organophosphate insecticides, and more likely to runoff fields at lethal levels according to modeling data. At 31 water contact sites in the lower basin of the Senegal River where schistosomiasis is endemic, we found that Macrobrachium prawn survival was associated with pyrethroid but not organophosphate application rates to nearby crop fields after controlling for abiotic and prawn-level factors. Our laboratory and field results suggest that widely used pyrethroid insecticides can have strong non-target effects on Macrobrachium prawns that are biocontrol agents where 400 million people are at risk of human schistosomiasis. Understanding the ecotoxicology of high-risk insecticides may help improve human health in schistosomiasis-endemic regions undergoing agricultural expansion.
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Affiliation(s)
- Christopher J E Haggerty
- Department of Biological Sciences, Environmental Change Initiative, Eck Institute of Global Health, University of Notre Dame, Notre Dame, IN, USA
| | - Bryan K Delius
- Duquesne University, Department of Biological Sciences, Pittsburgh, PA, USA
| | - Nicolas Jouanard
- Centre de Recherche Biomédicale Espoir pour La Santé, Saint-Louis, Senegal; Station D'Innovation Aquacole, Saint-Louis, Senegal
| | - Pape D Ndao
- Station D'Innovation Aquacole, Saint-Louis, Senegal; Université Gaston Berger (UGB), Route de Ngallèle, BP 234, Saint-Louis, Senegal
| | - Giulio A De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
| | - Andrea J Lund
- Department of Environmental and Occupational Health, Colorado School of Public Health, University of Colorado, Anschutz, Aurora, CO, USA
| | - David Lopez-Carr
- Human-Environment Dynamics Lab, Department of Environmental Studies, UCSB, Santa Barbara, CA, USA
| | - Justin V Remais
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, USA
| | - Gilles Riveau
- Centre de Recherche Biomédicale Espoir pour La Santé, Saint-Louis, Senegal; University of Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, U1019-UMR 9017-CIIL, Center for Infection and Immunity of Lille, Lille, France
| | - Susanne H Sokolow
- Woods Institute for the Environment, Stanford University, Stanford, CA, USA
| | - Jason R Rohr
- Department of Biological Sciences, Environmental Change Initiative, Eck Institute of Global Health, University of Notre Dame, Notre Dame, IN, USA; Marine Science Institute, University of California, Santa Barbara, CA, USA.
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5
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Pourtois JD, Tallam K, Jones I, Hyde E, Chamberlin AJ, Evans MV, Ihantamalala FA, Cordier LF, Razafinjato BR, Rakotonanahary RJL, Tsirinomen'ny Aina A, Soloniaina P, Raholiarimanana SH, Razafinjato C, Bonds MH, De Leo GA, Sokolow SH, Garchitorena A. Climatic, land-use and socio-economic factors can predict malaria dynamics at fine spatial scales relevant to local health actors: Evidence from rural Madagascar. PLOS Glob Public Health 2023; 3:e0001607. [PMID: 36963091 PMCID: PMC10021226 DOI: 10.1371/journal.pgph.0001607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 01/23/2023] [Indexed: 02/24/2023]
Abstract
While much progress has been achieved over the last decades, malaria surveillance and control remain a challenge in countries with limited health care access and resources. High-resolution predictions of malaria incidence using routine surveillance data could represent a powerful tool to health practitioners by targeting malaria control activities where and when they are most needed. Here, we investigate the predictors of spatio-temporal malaria dynamics in rural Madagascar, estimated from facility-based passive surveillance data. Specifically, this study integrates climate, land-use, and representative household survey data to explain and predict malaria dynamics at a high spatial resolution (i.e., by Fokontany, a cluster of villages) relevant to health care practitioners. Combining generalized linear mixed models (GLMM) and path analyses, we found that socio-economic, land use and climatic variables are all important predictors of monthly malaria incidence at fine spatial scales, via both direct and indirect effects. In addition, out-of-sample predictions from our model were able to identify 58% of the Fokontany in the top quintile for malaria incidence and account for 77% of the variation in the Fokontany incidence rank. These results suggest that it is possible to build a predictive framework using environmental and social predictors that can be complementary to standard surveillance systems and help inform control strategies by field actors at local scales.
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Affiliation(s)
- Julie D Pourtois
- Biology Department, Stanford University, Stanford, CA, United States of America
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, United States of America
| | - Krti Tallam
- Biology Department, Stanford University, Stanford, CA, United States of America
| | - Isabel Jones
- Biology Department, Stanford University, Stanford, CA, United States of America
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, United States of America
| | - Elizabeth Hyde
- School of Medicine, Stanford University, Stanford, CA, United States of America
| | - Andrew J Chamberlin
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, United States of America
| | - Michelle V Evans
- MIVEGEC, Université de Montpellier, CNRS, IRD, Montpellier, France
| | - Felana A Ihantamalala
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, MA, United States of America
- NGO Pivot, Ifanadiana, Madagascar
| | | | | | - Rado J L Rakotonanahary
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, MA, United States of America
- NGO Pivot, Ifanadiana, Madagascar
| | | | | | | | - Celestin Razafinjato
- Programme National de Lutte contre le Paludisme, Ministère de la Santé Publique, Antananarivo, Madagascar
| | - Matthew H Bonds
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, MA, United States of America
- NGO Pivot, Ifanadiana, Madagascar
| | - Giulio A De Leo
- Biology Department, Stanford University, Stanford, CA, United States of America
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, United States of America
| | - Susanne H Sokolow
- Woods Institute for the Environment, Stanford University, Stanford, CA, United States of America
- Marine Science Institute and Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA, United States of America
| | - Andres Garchitorena
- MIVEGEC, Université de Montpellier, CNRS, IRD, Montpellier, France
- NGO Pivot, Ifanadiana, Madagascar
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6
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Sokolow SH, Nova N, Jones IJ, Wood CL, Lafferty KD, Garchitorena A, Hopkins SR, Lund AJ, MacDonald AJ, LeBoa C, Peel AJ, Mordecai EA, Howard ME, Buck JC, Lopez-Carr D, Barry M, Bonds MH, De Leo GA. Ecological and socioeconomic factors associated with the human burden of environmentally mediated pathogens: a global analysis. Lancet Planet Health 2022; 6:e870-e879. [PMID: 36370725 PMCID: PMC9669458 DOI: 10.1016/s2542-5196(22)00248-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 08/22/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND Billions of people living in poverty are at risk of environmentally mediated infectious diseases-that is, pathogens with environmental reservoirs that affect disease persistence and control and where environmental control of pathogens can reduce human risk. The complex ecology of these diseases creates a global health problem not easily solved with medical treatment alone. METHODS We quantified the current global disease burden caused by environmentally mediated infectious diseases and used a structural equation model to explore environmental and socioeconomic factors associated with the human burden of environmentally mediated pathogens across all countries. FINDINGS We found that around 80% (455 of 560) of WHO-tracked pathogen species known to infect humans are environmentally mediated, causing about 40% (129 488 of 359 341 disability-adjusted life years) of contemporary infectious disease burden (global loss of 130 million years of healthy life annually). The majority of this environmentally mediated disease burden occurs in tropical countries, and the poorest countries carry the highest burdens across all latitudes. We found weak associations between disease burden and biodiversity or agricultural land use at the global scale. In contrast, the proportion of people with rural poor livelihoods in a country was a strong proximate indicator of environmentally mediated infectious disease burden. Political stability and wealth were associated with improved sanitation, better health care, and lower proportions of rural poverty, indirectly resulting in lower burdens of environmentally mediated infections. Rarely, environmentally mediated pathogens can evolve into global pandemics (eg, HIV, COVID-19) affecting even the wealthiest communities. INTERPRETATION The high and uneven burden of environmentally mediated infections highlights the need for innovative social and ecological interventions to complement biomedical advances in the pursuit of global health and sustainability goals. FUNDING Bill & Melinda Gates Foundation, National Institutes of Health, National Science Foundation, Alfred P. Sloan Foundation, National Institute for Mathematical and Biological Synthesis, Stanford University, and the US Defense Advanced Research Projects Agency.
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Affiliation(s)
- Susanne H Sokolow
- Woods Institute for the Environment, Stanford University, Stanford, CA, USA; Marine Science Institute, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Nicole Nova
- Department of Biology, Stanford University, Stanford, CA, USA; High Meadows Environmental Institute, Princeton University, Princeton, NJ, USA.
| | - Isabel J Jones
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
| | - Chelsea L Wood
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, USA
| | - Kevin D Lafferty
- US Geological Survey, Western Ecological Research Center, c/o Marine Science Institute, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Andres Garchitorena
- MIVEGEC, Université Montpellier, Centre National de la Recherche Scientifique, Institut de Recherche pour le Développement, Montpellier, France; PIVOT, Division of Global Health Equity, Brigham and Women's Hospital, Boston, MA, USA
| | | | - Andrea J Lund
- Emmett Interdisciplinary Program in Environment and Resources (E-IPER), Stanford University, Stanford, CA, USA
| | - Andrew J MacDonald
- Department of Biology, Stanford University, Stanford, CA, USA; Earth Research Institute, University of California Santa Barbara, Santa Barbara, CA, USA
| | | | - Alison J Peel
- Centre for Planetary Health and Food Security, Griffith University, Nathan, QLD, Australia
| | - Erin A Mordecai
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Meghan E Howard
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Julia C Buck
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC, USA
| | - David Lopez-Carr
- Department of Geography, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Michele Barry
- Woods Institute for the Environment, Stanford University, Stanford, CA, USA; Center for Innovation in Global Health, Stanford University, Stanford, CA, USA
| | - Matthew H Bonds
- PIVOT, Division of Global Health Equity, Brigham and Women's Hospital, Boston, MA, USA; Department of Global Health and Social Medicine, Harvard Medical School, Boston, MA
| | - Giulio A De Leo
- Woods Institute for the Environment, Stanford University, Stanford, CA, USA; Department of Biology, Stanford University, Stanford, CA, USA; Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
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7
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Hopkins SR, Lafferty KD, Wood CL, Olson SH, Buck JC, De Leo GA, Fiorella KJ, Fornberg JL, Garchitorena A, Jones IJ, Kuris AM, Kwong LH, LeBoa C, Leon AE, Lund AJ, MacDonald AJ, Metz DCG, Nova N, Peel AJ, Remais JV, Stewart Merrill TE, Wilson M, Bonds MH, Dobson AP, Lopez Carr D, Howard ME, Mandle L, Sokolow SH. Evidence gaps and diversity among potential win-win solutions for conservation and human infectious disease control. Lancet Planet Health 2022; 6:e694-e705. [PMID: 35932789 PMCID: PMC9364143 DOI: 10.1016/s2542-5196(22)00148-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/21/2022] [Accepted: 06/14/2022] [Indexed: 06/08/2023]
Abstract
As sustainable development practitioners have worked to "ensure healthy lives and promote well-being for all" and "conserve life on land and below water", what progress has been made with win-win interventions that reduce human infectious disease burdens while advancing conservation goals? Using a systematic literature review, we identified 46 proposed solutions, which we then investigated individually using targeted literature reviews. The proposed solutions addressed diverse conservation threats and human infectious diseases, and thus, the proposed interventions varied in scale, costs, and impacts. Some potential solutions had medium-quality to high-quality evidence for previous success in achieving proposed impacts in one or both sectors. However, there were notable evidence gaps within and among solutions, highlighting opportunities for further research and adaptive implementation. Stakeholders seeking win-win interventions can explore this Review and an online database to find and tailor a relevant solution or brainstorm new solutions.
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Affiliation(s)
- Skylar R Hopkins
- Department of Applied Ecology, North Carolina State University, Raleigh, NC, USA; National Center for Ecological Analysis and Synthesis, Santa Barbara, CA, USA.
| | - Kevin D Lafferty
- Western Ecological Research Center, US Geological Survey at Marine Science Institute, University of California, Santa Barbara, CA, USA
| | - Chelsea L Wood
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, USA
| | - Sarah H Olson
- Wildlife Conservation Society, Health Program, Bronx, NY, USA
| | - Julia C Buck
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC, USA
| | - Giulio A De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
| | - Kathryn J Fiorella
- Department of Population Medicine and Diagnostic Sciences and Master of Public Health Program, Cornell University, Ithaca, NY, USA
| | - Johanna L Fornberg
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, USA
| | - Andres Garchitorena
- MIVEGEC, Université Montpellier, Centre National de la Recherche Scientifique, Institut de Recherche pour le Développement, Montpellier, France; NGO PIVOT, Ranomafana, Madagascar
| | - Isabel J Jones
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
| | - Armand M Kuris
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, USA
| | - Laura H Kwong
- Woods Institute for the Environment, Stanford University, Stanford, CA, USA
| | | | - Ariel E Leon
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA; US Geological Survey, National Wildlife Health Center, Madison, WI, USA
| | - Andrea J Lund
- Department of Environmental and Occupational Health, University of Colorado School of Public Health, Aurora, CO, USA
| | - Andrew J MacDonald
- Bren School of Environmental Science and Management, University of California, Santa Barbara, CA, USA
| | - Daniel C G Metz
- Scripps Institution of Oceanography, University of California, San Diego, CA, USA
| | - Nicole Nova
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Alison J Peel
- Centre for Planetary Health and Food Security, Griffith University, Nathan, QLD, Australia
| | - Justin V Remais
- Division of Environmental Health Sciences, University of California, Berkeley, CA, USA
| | | | - Maya Wilson
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA
| | - Matthew H Bonds
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, MA, USA
| | - Andrew P Dobson
- Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - David Lopez Carr
- Department of Geography, University of California, Santa Barbara, CA, USA
| | - Meghan E Howard
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Lisa Mandle
- Woods Institute for the Environment, Stanford University, Stanford, CA, USA
| | - Susanne H Sokolow
- Woods Institute for the Environment, Stanford University, Stanford, CA, USA
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8
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Hopkins SR, Jones IJ, Buck JC, LeBoa C, Kwong LH, Jacobsen K, Rickards C, Lund AJ, Nova N, MacDonald AJ, Lambert-Peck M, De Leo GA, Sokolow SH. Environmental Persistence of the World's Most Burdensome Infectious and Parasitic Diseases. Front Public Health 2022; 10:892366. [PMID: 35875032 PMCID: PMC9305703 DOI: 10.3389/fpubh.2022.892366] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 05/30/2022] [Indexed: 11/13/2022] Open
Abstract
Humans live in complex socio-ecological systems where we interact with parasites and pathogens that spend time in abiotic and biotic environmental reservoirs (e.g., water, air, soil, other vertebrate hosts, vectors, intermediate hosts). Through a synthesis of published literature, we reviewed the life cycles and environmental persistence of 150 parasites and pathogens tracked by the World Health Organization's Global Burden of Disease study. We used those data to derive the time spent in each component of a pathogen's life cycle, including total time spent in humans versus all environmental stages. We found that nearly all infectious organisms were “environmentally mediated” to some degree, meaning that they spend time in reservoirs and can be transmitted from those reservoirs to human hosts. Correspondingly, many infectious diseases were primarily controlled through environmental interventions (e.g., vector control, water sanitation), whereas few (14%) were primarily controlled by integrated methods (i.e., combining medical and environmental interventions). Data on critical life history attributes for most of the 150 parasites and pathogens were difficult to find and often uncertain, potentially hampering efforts to predict disease dynamics and model interactions between life cycle time scales and infection control strategies. We hope that this synthetic review and associated database serve as a resource for understanding both common patterns among parasites and pathogens and important variability and uncertainty regarding particular infectious diseases. These insights can be used to improve systems-based approaches for controlling environmentally mediated diseases of humans in an era where the environment is rapidly changing.
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Affiliation(s)
- Skylar R. Hopkins
- National Center for Ecological Analysis and Synthesis, Santa Barbara, CA, United States
- Department of Applied Ecology, North Carolina State University, Raleigh, NC, United States
- *Correspondence: Skylar R. Hopkins
| | - Isabel J. Jones
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, United States
| | - Julia C. Buck
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC, United States
| | - Christopher LeBoa
- Department of Epidemiology, Stanford University, Stanford, CA, United States
| | - Laura H. Kwong
- Stanford Woods Institute for the Environment, Stanford University, Stanford, CA, United States
| | - Kim Jacobsen
- School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| | - Chloe Rickards
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA, United States
| | - Andrea J. Lund
- Emmett Interdisciplinary Program in Environment and Resources, Stanford University, Stanford, CA, United States
| | - Nicole Nova
- Department of Biology, Stanford University, Stanford, CA, United States
| | - Andrew J. MacDonald
- Department of Biology, Stanford University, Stanford, CA, United States
- Earth Research Institute, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Miles Lambert-Peck
- United Nations University for the Advanced Study of Sustainability, Tokyo, Japan
| | - Giulio A. De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, United States
| | - Susanne H. Sokolow
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, United States
- Marine Science Institute, University of California, Santa Barbara, Santa Barbara, CA, United States
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9
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Glidden CK, Nova N, Kain MP, Lagerstrom KM, Skinner EB, Mandle L, Sokolow SH, Plowright RK, Dirzo R, De Leo GA, Mordecai EA. Human-mediated impacts on biodiversity and the consequences for zoonotic disease spillover. Curr Biol 2021; 31:R1342-R1361. [PMID: 34637744 DOI: 10.1016/j.cub.2021.08.070] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Human-mediated changes to natural ecosystems have consequences for both ecosystem and human health. Historically, efforts to preserve or restore 'biodiversity' can seem to be in opposition to human interests. However, the integration of biodiversity conservation and public health has gained significant traction in recent years, and new efforts to identify solutions that benefit both environmental and human health are ongoing. At the forefront of these efforts is an attempt to clarify ways in which biodiversity conservation can help reduce the risk of zoonotic spillover of pathogens from wild animals, sparking epidemics and pandemics in humans and livestock. However, our understanding of the mechanisms by which biodiversity change influences the spillover process is incomplete, limiting the application of integrated strategies aimed at achieving positive outcomes for both conservation and disease management. Here, we review the literature, considering a broad scope of biodiversity dimensions, to identify cases where zoonotic pathogen spillover is mechanistically linked to changes in biodiversity. By reframing the discussion around biodiversity and disease using mechanistic evidence - while encompassing multiple aspects of biodiversity including functional diversity, landscape diversity, phenological diversity, and interaction diversity - we work toward general principles that can guide future research and more effectively integrate the related goals of biodiversity conservation and spillover prevention. We conclude by summarizing how these principles could be used to integrate the goal of spillover prevention into ongoing biodiversity conservation initiatives.
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Affiliation(s)
| | - Nicole Nova
- Department of Biology, Stanford University, Stanford, CA 94305, USA.
| | - Morgan P Kain
- Department of Biology, Stanford University, Stanford, CA 94305, USA; Natural Capital Project, Stanford University, Stanford, CA 94305, USA
| | | | - Eloise B Skinner
- Department of Biology, Stanford University, Stanford, CA 94305, USA; Centre for Planetary Health and Food Security, Griffith University, Gold Coast, QLD 4222, Australia
| | - Lisa Mandle
- Department of Biology, Stanford University, Stanford, CA 94305, USA; Natural Capital Project, Stanford University, Stanford, CA 94305, USA; Woods Institute for the Environment, Stanford University, Stanford, CA 94305, USA
| | - Susanne H Sokolow
- Woods Institute for the Environment, Stanford University, Stanford, CA 94305, USA; Marine Science Institute, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Raina K Plowright
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT 59717, USA
| | - Rodolfo Dirzo
- Department of Biology, Stanford University, Stanford, CA 94305, USA; Woods Institute for the Environment, Stanford University, Stanford, CA 94305, USA
| | - Giulio A De Leo
- Department of Biology, Stanford University, Stanford, CA 94305, USA; Woods Institute for the Environment, Stanford University, Stanford, CA 94305, USA; Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - Erin A Mordecai
- Department of Biology, Stanford University, Stanford, CA 94305, USA
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10
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Lund AJ, Sokolow SH, Jones IJ, Wood CL, Ali S, Chamberlin A, Sy AB, Sam MM, Jouanard N, Schacht AM, Senghor S, Fall A, Ndione R, Riveau G, De Leo GA, López-Carr D. Exposure, hazard, and vulnerability all contribute to Schistosoma haematobium re-infection in northern Senegal. PLoS Negl Trop Dis 2021; 15:e0009806. [PMID: 34610025 PMCID: PMC8525765 DOI: 10.1371/journal.pntd.0009806] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 10/19/2021] [Accepted: 09/10/2021] [Indexed: 11/19/2022] Open
Abstract
Background Infectious disease risk is driven by three interrelated components: exposure, hazard, and vulnerability. For schistosomiasis, exposure occurs through contact with water, which is often tied to daily activities. Water contact, however, does not imply risk unless the environmental hazard of snails and parasites is also present in the water. By increasing reliance on hazardous activities and environments, socio-economic vulnerability can hinder reductions in exposure to a hazard. We aimed to quantify the contributions of exposure, hazard, and vulnerability to the presence and intensity of Schistosoma haematobium re-infection. Methodology/Principal findings In 13 villages along the Senegal River, we collected parasitological data from 821 school-aged children, survey data from 411 households where those children resided, and ecological data from all 24 village water access sites. We fit mixed-effects logistic and negative binomial regressions with indices of exposure, hazard, and vulnerability as explanatory variables of Schistosoma haematobium presence and intensity, respectively, controlling for demographic variables. Using multi-model inference to calculate the relative importance of each component of risk, we found that hazard (Ʃwi = 0.95) was the most important component of S. haematobium presence, followed by vulnerability (Ʃwi = 0.91). Exposure (Ʃwi = 1.00) was the most important component of S. haematobium intensity, followed by hazard (Ʃwi = 0.77). Model averaging quantified associations between each infection outcome and indices of exposure, hazard, and vulnerability, revealing a positive association between hazard and infection presence (OR = 1.49, 95% CI 1.12, 1.97), and a positive association between exposure and infection intensity (RR 2.59–3.86, depending on the category; all 95% CIs above 1) Conclusions/Significance Our findings underscore the linkages between social (exposure and vulnerability) and environmental (hazard) processes in the acquisition and accumulation of S. haematobium infection. This approach highlights the importance of implementing both social and environmental interventions to complement mass drug administration. While the impacts of natural hazards tend to be described in terms of social determinants such as exposure and vulnerability, the risk for infectious disease is often expressed in terms of environmental determinants without fully considering the socio-ecological processes that put people in contact with infective agents of disease. In the case of schistosomiasis, risk is determined by human interactions with freshwater environments where schistosome parasites circulate between people and aquatic snails. In this study, we quantified the relative contributions of exposure, hazard, and vulnerability to schistosome re-infection among schoolchildren in an endemic region of northern Senegal. We find that hazard and vulnerability influence whether a child becomes infected, while exposure and hazard influence the burden of worms once infection is acquired. Increasing numbers of worms is known to be positively associated with increasing severity of disease. Our findings underscore the importance of evaluating social and environmental determinants of disease simultaneously; omitting measures of exposure, hazard or vulnerability may limit our understanding of risk.
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Affiliation(s)
- Andrea J. Lund
- Emmett Interdisciplinary Program in Environment and Resources, Stanford University, Stanford, California, United States of America
- * E-mail:
| | - Susanne H. Sokolow
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
- Woods Institute for the Environment, Stanford University, Stanford, California, United States of America
| | - Isabel J. Jones
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
| | - Chelsea L. Wood
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington, United States of America
| | - Sofia Ali
- Stanford University, Stanford, California, United States of America
| | - Andrew Chamberlin
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
| | - Alioune Badara Sy
- Centre de Recherche Biomédicale–Espoir Pour La Sante, Saint Louis, Sénégal
| | - M. Moustapha Sam
- Centre de Recherche Biomédicale–Espoir Pour La Sante, Saint Louis, Sénégal
| | - Nicolas Jouanard
- Centre de Recherche Biomédicale–Espoir Pour La Sante, Saint Louis, Sénégal
- Station d’Innovation Aquacole, Saint Louis, Sénégal
| | - Anne-Marie Schacht
- Centre de Recherche Biomédicale–Espoir Pour La Sante, Saint Louis, Sénégal
- University of Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, Center for Infection and Immunity of Lille, Lille, France
| | - Simon Senghor
- Centre de Recherche Biomédicale–Espoir Pour La Sante, Saint Louis, Sénégal
| | - Assane Fall
- Centre de Recherche Biomédicale–Espoir Pour La Sante, Saint Louis, Sénégal
| | - Raphael Ndione
- Centre de Recherche Biomédicale–Espoir Pour La Sante, Saint Louis, Sénégal
| | - Gilles Riveau
- Centre de Recherche Biomédicale–Espoir Pour La Sante, Saint Louis, Sénégal
- University of Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, Center for Infection and Immunity of Lille, Lille, France
| | - Giulio A. De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
- Woods Institute for the Environment, Stanford University, Stanford, California, United States of America
| | - David López-Carr
- Department of Geography, University of California, Santa Barbara, CA, United States of America
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11
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Tallam K, Liu ZYC, Chamberlin AJ, Jones IJ, Shome P, Riveau G, Ndione RA, Bandagny L, Jouanard N, Eck PV, Ngo T, Sokolow SH, De Leo GA. Identification of Snails and Schistosoma of Medical Importance via Convolutional Neural Networks: A Proof-of-Concept Application for Human Schistosomiasis. Front Public Health 2021; 9:642895. [PMID: 34336754 PMCID: PMC8319642 DOI: 10.3389/fpubh.2021.642895] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 06/08/2021] [Indexed: 11/21/2022] Open
Abstract
In recent decades, computer vision has proven remarkably effective in addressing diverse issues in public health, from determining the diagnosis, prognosis, and treatment of diseases in humans to predicting infectious disease outbreaks. Here, we investigate whether convolutional neural networks (CNNs) can also demonstrate effectiveness in classifying the environmental stages of parasites of public health importance and their invertebrate hosts. We used schistosomiasis as a reference model. Schistosomiasis is a debilitating parasitic disease transmitted to humans via snail intermediate hosts. The parasite affects more than 200 million people in tropical and subtropical regions. We trained our CNN, a feed-forward neural network, on a limited dataset of 5,500 images of snails and 5,100 images of cercariae obtained from schistosomiasis transmission sites in the Senegal River Basin, a region in western Africa that is hyper-endemic for the disease. The image set included both images of two snail genera that are relevant to schistosomiasis transmission – that is, Bulinus spp. and Biomphalaria pfeifferi – as well as snail images that are non-component hosts for human schistosomiasis. Cercariae shed from Bi. pfeifferi and Bulinus spp. snails were classified into 11 categories, of which only two, S. haematobium and S. mansoni, are major etiological agents of human schistosomiasis. The algorithms, trained on 80% of the snail and parasite dataset, achieved 99% and 91% accuracy for snail and parasite classification, respectively, when used on the hold-out validation dataset – a performance comparable to that of experienced parasitologists. The promising results of this proof-of-concept study suggests that this CNN model, and potentially similar replicable models, have the potential to support the classification of snails and parasite of medical importance. In remote field settings where machine learning algorithms can be deployed on cost-effective and widely used mobile devices, such as smartphones, these models can be a valuable complement to laboratory identification by trained technicians. Future efforts must be dedicated to increasing dataset sizes for model training and validation, as well as testing these algorithms in diverse transmission settings and geographies.
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Affiliation(s)
- Krti Tallam
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, United States
| | - Zac Yung-Chun Liu
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, United States
| | - Andrew J Chamberlin
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, United States
| | - Isabel J Jones
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, United States
| | - Pretom Shome
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, United States
| | - Gilles Riveau
- Centre de Recherche Biomédicale Espoir pour la Santé, Saint-Louis, Senegal.,Univ Lille, Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), Centre Hospitalier Universitaire (CHU) Lille, Institut Pasteur de Lille, U1019-Unité Mixte de Recherche (UMR) 9017-CIIL-Center for Infection and Immunity of Lille, Lille, France
| | - Raphael A Ndione
- Centre de Recherche Biomédicale Espoir pour la Santé, Saint-Louis, Senegal
| | - Lydie Bandagny
- Centre de Recherche Biomédicale Espoir pour la Santé, Saint-Louis, Senegal
| | - Nicolas Jouanard
- Centre de Recherche Biomédicale Espoir pour la Santé, Saint-Louis, Senegal.,Station d'Innovation Aquacole (SIA), à Université Gaston Berger, Saint-Louis, Senegal
| | - Paul Van Eck
- International Business Machines Corporation (IBM) Silicon Valley Lab, San Jose, CA, United States
| | - Ton Ngo
- International Business Machines Corporation (IBM) Silicon Valley Lab, San Jose, CA, United States
| | - Susanne H Sokolow
- International Business Machines Corporation (IBM) Silicon Valley Lab, San Jose, CA, United States.,Department of Ecology Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Giulio A De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, United States.,Woods Institute for the Environment, Stanford University, Pacific Grove, CA, United States
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12
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Pourtois JD, Kratochvil MJ, Chen Q, Haddock NL, Burgener EB, De Leo GA, Bollyky PL. Filamentous Bacteriophages and the Competitive Interaction between Pseudomonas aeruginosa Strains under Antibiotic Treatment: a Modeling Study. mSystems 2021; 6:e0019321. [PMID: 34156288 PMCID: PMC8269214 DOI: 10.1128/msystems.00193-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 05/24/2021] [Indexed: 01/22/2023] Open
Abstract
Pseudomonas aeruginosa (Pa) is a major bacterial pathogen responsible for chronic lung infections in cystic fibrosis patients. Recent work has implicated Pf bacteriophages, nonlytic filamentous viruses produced by Pa, in the chronicity and severity of Pa infections. Pf phages act as structural elements in Pa biofilms and sequester aerosolized antibiotics, thereby contributing to antibiotic tolerance. Consistent with a selective advantage in this setting, the prevalence of Pf-positive (Pf+) bacteria increases over time in these patients. However, the production of Pf phages comes at a metabolic cost to bacteria, such that Pf+ strains grow more slowly than Pf-negative (Pf-) strains in vitro. Here, we use a mathematical model to investigate how these competing pressures might influence the relative abundance of Pf+ versus Pf- strains in different settings. Our model suggests that Pf+ strains of Pa cannot outcompete Pf- strains if the benefits of phage production falls onto both Pf+ and Pf- strains for a majority of parameter combinations. Further, phage production leads to a net positive gain in fitness only at antibiotic concentrations slightly above the MIC (i.e., concentrations for which the benefits of antibiotic sequestration outweigh the metabolic cost of phage production) but which are not lethal for Pf+ strains. As a result, our model suggests that frequent administration of intermediate doses of antibiotics with low decay rates and high killing rates favors Pf+ over Pf- strains. These models inform our understanding of the ecology of Pf phages and suggest potential treatment strategies for Pf+ Pa infections. IMPORTANCE Filamentous phages are a frontier in bacterial pathogenesis, but the impact of these phages on bacterial fitness is unclear. In particular, Pf phages produced by Pa promote antibiotic tolerance but are metabolically expensive to produce, suggesting that competing pressures may influence the prevalence of Pf+ versus Pf- strains of Pa in different settings. Our results identify conditions likely to favor Pf+ strains and thus antibiotic tolerance. This study contributes to a better understanding of the unique ecology of filamentous phages in both environmental and clinical settings and may facilitate improved treatment strategies for combating antibiotic tolerance.
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Affiliation(s)
- Julie D. Pourtois
- Department of Biology, Stanford University, Stanford, California, USA
- Hopkins Marine Station, Stanford University, Pacific Grove, California, USA
| | - Michael J. Kratochvil
- Department of Materials Science and Engineering, Stanford University, Stanford, California, USA
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Qingquan Chen
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Naomi L. Haddock
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Elizabeth B. Burgener
- Center for Excellence in Pulmonary Biology, Department of Pediatrics, Stanford University, Stanford, California, USA
| | - Giulio A. De Leo
- Department of Biology, Stanford University, Stanford, California, USA
- Hopkins Marine Station, Stanford University, Pacific Grove, California, USA
| | - Paul L. Bollyky
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
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13
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Athni TS, Shocket MS, Couper LI, Nova N, Caldwell IR, Caldwell JM, Childress JN, Childs ML, De Leo GA, Kirk DG, MacDonald AJ, Olivarius K, Pickel DG, Roberts SO, Winokur OC, Young HS, Cheng J, Grant EA, Kurzner PM, Kyaw S, Lin BJ, López RC, Massihpour DS, Olsen EC, Roache M, Ruiz A, Schultz EA, Shafat M, Spencer RL, Bharti N, Mordecai EA. The influence of vector-borne disease on human history: socio-ecological mechanisms. Ecol Lett 2021; 24:829-846. [PMID: 33501751 PMCID: PMC7969392 DOI: 10.1111/ele.13675] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/08/2020] [Accepted: 12/09/2020] [Indexed: 01/14/2023]
Abstract
Vector-borne diseases (VBDs) are embedded within complex socio-ecological systems. While research has traditionally focused on the direct effects of VBDs on human morbidity and mortality, it is increasingly clear that their impacts are much more pervasive. VBDs are dynamically linked to feedbacks between environmental conditions, vector ecology, disease burden, and societal responses that drive transmission. As a result, VBDs have had profound influence on human history. Mechanisms include: (1) killing or debilitating large numbers of people, with demographic and population-level impacts; (2) differentially affecting populations based on prior history of disease exposure, immunity, and resistance; (3) being weaponised to promote or justify hierarchies of power, colonialism, racism, classism and sexism; (4) catalysing changes in ideas, institutions, infrastructure, technologies and social practices in efforts to control disease outbreaks; and (5) changing human relationships with the land and environment. We use historical and archaeological evidence interpreted through an ecological lens to illustrate how VBDs have shaped society and culture, focusing on case studies from four pertinent VBDs: plague, malaria, yellow fever and trypanosomiasis. By comparing across diseases, time periods and geographies, we highlight the enormous scope and variety of mechanisms by which VBDs have influenced human history.
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Affiliation(s)
- Tejas S. Athni
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Marta S. Shocket
- Department of Biology, Stanford University, Stanford, CA, USA
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, USA
| | - Lisa I. Couper
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Nicole Nova
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Iain R. Caldwell
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia
| | - Jamie M. Caldwell
- Department of Biology, Stanford University, Stanford, CA, USA
- Department of Biology, University of Hawaii at Manoa, Honolulu, HI, USA
| | - Jasmine N. Childress
- Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Marissa L. Childs
- Emmett Interdisciplinary Program in Environment and Resources, Stanford University, Stanford, CA, USA
| | - Giulio A. De Leo
- Hopkins Marine Station of Stanford University, Pacific Grove, CA, USA
- Woods Institute for the Environment, Stanford University, Stanford, CA, USA
| | - Devin G. Kirk
- Department of Biology, Stanford University, Stanford, CA, USA
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Andrew J. MacDonald
- Bren School of Environmental Science and Management, University of California, Santa Barbara, CA, USA
- Earth Research Institute, University of California, Santa Barbara, CA, USA
| | | | - David G. Pickel
- Department of Classics, Stanford University, Stanford, CA, USA
| | | | - Olivia C. Winokur
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Hillary S. Young
- Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Julian Cheng
- Department of Biology, Stanford University, Stanford, CA, USA
| | | | | | - Saw Kyaw
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Bradford J. Lin
- Department of Biology, Stanford University, Stanford, CA, USA
| | | | | | - Erica C. Olsen
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Maggie Roache
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Angie Ruiz
- Department of Biology, Stanford University, Stanford, CA, USA
| | | | - Muskan Shafat
- Department of Biology, Stanford University, Stanford, CA, USA
| | | | - Nita Bharti
- Department of Biology, Center for Infectious Disease Dynamics, Penn State University, University Park, PA, USA
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14
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Lund AJ, Rehkopf DH, Sokolow SH, Sam MM, Jouanard N, Schacht AM, Senghor S, Fall A, Riveau G, De Leo GA, Lopez-Carr D. Land use impacts on parasitic infection: a cross-sectional epidemiological study on the role of irrigated agriculture in schistosome infection in a dammed landscape. Infect Dis Poverty 2021; 10:35. [PMID: 33745442 PMCID: PMC7983278 DOI: 10.1186/s40249-021-00816-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 03/05/2021] [Indexed: 01/20/2023] Open
Abstract
Background Water resources development promotes agricultural expansion and food security. But are these benefits offset by increased infectious disease risk? Dam construction on the Senegal River in 1986 was followed by agricultural expansion and increased transmission of human schistosomes. Yet the mechanisms linking these two processes at the individual and household levels remain unclear. We investigated the association between household land use and schistosome infection in children. Methods We analyzed cross-sectional household survey data (n = 655) collected in 16 rural villages in August 2016 across demographic, socio-economic and land use dimensions, which were matched to Schistosoma haematobium (n = 1232) and S. mansoni (n = 1222) infection data collected from school-aged children. Mixed effects regression determined the relationship between irrigated area and schistosome infection presence and intensity. Results Controlling for socio-economic and demographic risk factors, irrigated area cultivated by a household was associated with an increase in the presence of S. haematobium infection (odds ratio [OR] = 1.14; 95% confidence interval [95% CI]: 1.03–1.28) but not S. mansoni infection (OR = 1.02; 95% CI: 0.93–1.11). Associations between infection intensity and irrigated area were positive but imprecise (S. haematobium: rate ratio [RR] = 1.05; 95% CI: 0.98–1.13, S. mansoni: RR = 1.09; 95% CI: 0.89–1.32). Conclusions Household engagement in irrigated agriculture increases individual risk of S. haematobium but not S. mansoni infection. Increased contact with irrigated landscapes likely drives exposure, with greater impacts on households relying on agricultural livelihoods.![]() Supplementary Information The online version contains supplementary material available at 10.1186/s40249-021-00816-5.
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Affiliation(s)
- Andrea J Lund
- Emmett Interdisciplinary Program in Environment and Resources, Stanford University, 473 Via Ortega Suite 226, Stanford, CA, USA.
| | - David H Rehkopf
- Department of Epidemiology and Population Health, Stanford University School of Medicine, Stanford University, 1701 Page Mill Road Room 229, Palo Alto, CA, USA
| | - Susanne H Sokolow
- Woods Institute for the Environment, Stanford University, 473 Via Ortega, Stanford, CA, USA.,Hopkins Marine Station, Stanford University, 120 Ocean View Blvd, Pacific Grove, CA, USA
| | - M Moustapha Sam
- Centre de Recherche Biomédicale-Espoir Pour La Sante, 263 Route de la Corniche, BP 226, Saint-Louis, Sénégal
| | - Nicolas Jouanard
- Station d'Innovation Aquacole, UGB Cote Cite SAED, BP 524, Saint-Louis, Sénégal.,Center for Infection and Immunology of Lille, Institut Pasteur de Lille, 1 Rue du Professeur Calmette, 59800, Lille, France
| | - Anne-Marie Schacht
- Centre de Recherche Biomédicale-Espoir Pour La Sante, 263 Route de la Corniche, BP 226, Saint-Louis, Sénégal.,Center for Infection and Immunology of Lille, Institut Pasteur de Lille, 1 Rue du Professeur Calmette, 59800, Lille, France
| | - Simon Senghor
- Centre de Recherche Biomédicale-Espoir Pour La Sante, 263 Route de la Corniche, BP 226, Saint-Louis, Sénégal
| | - Assane Fall
- Centre de Recherche Biomédicale-Espoir Pour La Sante, 263 Route de la Corniche, BP 226, Saint-Louis, Sénégal
| | - Gilles Riveau
- Centre de Recherche Biomédicale-Espoir Pour La Sante, 263 Route de la Corniche, BP 226, Saint-Louis, Sénégal.,Center for Infection and Immunology of Lille, Institut Pasteur de Lille, 1 Rue du Professeur Calmette, 59800, Lille, France
| | - Giulio A De Leo
- Hopkins Marine Station, Stanford University, 120 Ocean View Blvd, Pacific Grove, CA, USA
| | - David Lopez-Carr
- Department of Geography, University of California, 4836 Ellison Hall, Santa Barbara, CA, USA
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15
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Chamberlin AJ, Jones IJ, Lund AJ, Jouanard N, Riveau G, Ndione R, Sokolow SH, Wood CL, Lafferty KD, De Leo GA. Visualization of schistosomiasis snail habitats using light unmanned aerial vehicles. Geospat Health 2021; 15. [PMID: 33461284 DOI: 10.4081/gh.2020.818] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 02/13/2020] [Indexed: 06/12/2023]
Abstract
Schistosomiasis, or "snail fever", is a parasitic disease affecting over 200 million people worldwide. People become infected when exposed to water containing particular species of freshwater snails. Habitats for such snails can be mapped using lightweight, inexpensive and field-deployable consumer-grade Unmanned Aerial Vehicles (UAVs), also known as drones. Drones can obtain imagery in remote areas with poor satellite imagery. An unexpected outcome of using drones is public engagement. Whereas sampling snails exposes field technicians to infection risk and might disturb locals who are also using the water site, drones are novel and fun to watch, attracting crowds that can be educated about the infection risk.
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Affiliation(s)
| | - Isabel J Jones
- Hopkins Marine Station, Stanford University, Pacific Grove, CA.
| | - Andrea J Lund
- Emmett Interdisciplinary Program in Environment and Resources, Stanford University, Stanford, CA.
| | - Nicolas Jouanard
- Biomedical Research Center EPLS, Saint Louis; Station d'Innovation Aquacole, Saint Louis.
| | | | | | | | - Chelsea L Wood
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA.
| | - Kevin D Lafferty
- Western Ecological Research Center, United States Geological Survey; Marine Science Institute, University of California, Santa Barbara, CA.
| | - Giulio A De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA.
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16
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White TD, Ong T, Ferretti F, Block BA, McCauley DJ, Micheli F, De Leo GA. Tracking the response of industrial fishing fleets to large marine protected areas in the Pacific Ocean. Conserv Biol 2020; 34:1571-1578. [PMID: 33031635 DOI: 10.1111/cobi.13584] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 07/03/2020] [Accepted: 07/03/2020] [Indexed: 06/11/2023]
Abstract
Large marine protected areas (MPAs) of unprecedented size have recently been established across the global oceans, yet their ability to meet conservation objectives is debated. Key areas of debate include uncertainty over nations' abilities to enforce fishing bans across vast, remote regions and the intensity of human impacts before and after MPA implementation. We used a recently developed vessel tracking data set (produced using Automatic Identification System detections) to quantify the response of industrial fishing fleets to 5 of the largest MPAs established in the Pacific Ocean since 2013. After their implementation, all 5 MPAs successfully kept industrial fishing effort exceptionally low. Detected fishing effort was already low in 4 of the 5 large MPAs prior to MPA implementation, particularly relative to nearby regions that did not receive formal protection. Our results suggest that these large MPAs may present major conservation opportunities in relatively intact ecosystems with low immediate impact to industrial fisheries, but the large MPAs we considered often did not significantly reduce fishing effort because baseline fishing was typically low. It is yet to be determined how large MPAs may shape global ocean conservation in the future if the footprint of human influence continues to expand. Continued improvement in understanding of how large MPAs interact with industrial fisheries is a crucial step toward defining their role in global ocean management.
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Affiliation(s)
- Timothy D White
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, U.S.A
| | - Tiffany Ong
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, U.S.A
| | - Francesco Ferretti
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, U.S.A
- Virginia Polytechnic Institute and State University, Blacksburg, VA, U.S.A
| | - Barbara A Block
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, U.S.A
| | - Douglas J McCauley
- Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA, U.S.A
- Marine Science Institute, University of California Santa Barbara, Santa Barbara, CA, U.S.A
| | - Fiorenza Micheli
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, U.S.A
- Stanford Center for Ocean Solutions, Pacific Grove, CA, U.S.A
| | - Giulio A De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, U.S.A
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17
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Jones IJ, MacDonald AJ, Hopkins SR, Lund AJ, Liu ZYC, Fawzi NI, Purba MP, Fankhauser K, Chamberlin AJ, Nirmala M, Blundell AG, Emerson A, Jennings J, Gaffikin L, Barry M, Lopez-Carr D, Webb K, De Leo GA, Sokolow SH. Improving rural health care reduces illegal logging and conserves carbon in a tropical forest. Proc Natl Acad Sci U S A 2020; 117:28515-28524. [PMID: 33106399 PMCID: PMC7668090 DOI: 10.1073/pnas.2009240117] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Tropical forest loss currently exceeds forest gain, leading to a net greenhouse gas emission that exacerbates global climate change. This has sparked scientific debate on how to achieve natural climate solutions. Central to this debate is whether sustainably managing forests and protected areas will deliver global climate mitigation benefits, while ensuring local peoples' health and well-being. Here, we evaluate the 10-y impact of a human-centered solution to achieve natural climate mitigation through reductions in illegal logging in rural Borneo: an intervention aimed at expanding health care access and use for communities living near a national park, with clinic discounts offsetting costs historically met through illegal logging. Conservation, education, and alternative livelihood programs were also offered. We hypothesized that this would lead to improved health and well-being, while also alleviating illegal logging activity within the protected forest. We estimated that 27.4 km2 of deforestation was averted in the national park over a decade (∼70% reduction in deforestation compared to a synthetic control, permuted P = 0.038). Concurrently, the intervention provided health care access to more than 28,400 unique patients, with clinic usage and patient visitation frequency highest in communities participating in the intervention. Finally, we observed a dose-response in forest change rate to intervention engagement (person-contacts with intervention activities) across communities bordering the park: The greatest logging reductions were adjacent to the most highly engaged villages. Results suggest that this community-derived solution simultaneously improved health care access for local and indigenous communities and sustainably conserved carbon stocks in a protected tropical forest.
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Affiliation(s)
- Isabel J Jones
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA 93950;
| | - Andrew J MacDonald
- Department of Biology, Stanford University, Stanford, CA 94305
- Earth Research Institute, University of California, Santa Barbara, CA 93106
- Bren School of Environmental Science and Management, University of California, Santa Barbara, CA 93106
| | - Skylar R Hopkins
- National Center for Ecological Analysis and Synthesis, Santa Barbara, CA 93101
- Department of Applied Ecology, North Carolina State University, Raleigh, NC 27607
| | - Andrea J Lund
- Emmett Interdisciplinary Program in Environment and Resources, Stanford University, Stanford, CA 94305
| | - Zac Yung-Chun Liu
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA 93950
| | | | | | - Katie Fankhauser
- Oregon Health and Science University, School of Public Health, Portland, OR 97239
| | - Andrew J Chamberlin
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA 93950
| | - Monica Nirmala
- Alam Sehat Lestari, Sukadana, West Kalimantan 78852, Indonesia
| | | | | | | | - Lynne Gaffikin
- Department of Obstetrics and Gynecology, Stanford University, Stanford, CA 94305
- Center for Innovation in Global Health, Stanford University, Stanford, CA 94305
| | - Michele Barry
- Center for Innovation in Global Health, Stanford University, Stanford, CA 94305
| | - David Lopez-Carr
- Department of Geography, University of California, Santa Barbara, CA 93117
| | | | - Giulio A De Leo
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA 93950
- Woods Institute for the Environment, Stanford University, Stanford, CA 94305
| | - Susanne H Sokolow
- Center for Innovation in Global Health, Stanford University, Stanford, CA 94305;
- Woods Institute for the Environment, Stanford University, Stanford, CA 94305
- Marine Science Institute, University of California, Santa Barbara, CA 93106
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18
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Castonguay FM, Sokolow SH, De Leo GA, Sanchirico JN. Cost-effectiveness of combining drug and environmental treatments for environmentally transmitted diseases. Proc Biol Sci 2020; 287:20200966. [PMID: 32842925 PMCID: PMC7482273 DOI: 10.1098/rspb.2020.0966] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 08/03/2020] [Indexed: 01/13/2023] Open
Abstract
Control of neglected tropical diseases (NTDs) via mass drug administration (MDA) has increased considerably over the past decade, but strategies focused exclusively on human treatment show limited efficacy. This paper investigated trade-offs between drug and environmental treatments in the fight against NTDs by using schistosomiasis as a case study. We use optimal control techniques where the planner's objective is to treat the disease over a time horizon at the lowest possible total cost, where the total costs include treatment, transportation and damages (reduction in human health). We show that combining environmental treatments and drug treatments reduces the dependency on MDAs and that this reduction increases when the planners take a longer-run perspective on the fight to reduce NTDs. Our results suggest that NTDs with environmental reservoirs require moving away from a reliance solely on MDA to integrated treatment involving investment in both drug and environmental controls.
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Affiliation(s)
- François M. Castonguay
- Department of Agricultural and Resource Economics, University of California, Davis, Davis, CA 95616, USA
| | - Susanne H. Sokolow
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
- Woods Institute for the Environment, Stanford University, Stanford, CA 94305, USA
- Marine Science Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Giulio A. De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
- Woods Institute for the Environment, Stanford University, Stanford, CA 94305, USA
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - James N. Sanchirico
- Department of Environmental Science and Policy, University of California, Davis, Davis, CA 95616, USA
- Resources for the Future, Washington, DC 20036, USA
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19
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Haggerty CJE, Bakhoum S, Civitello DJ, De Leo GA, Jouanard N, Ndione RA, Remais JV, Riveau G, Senghor S, Sokolow SH, Sow S, Wolfe C, Wood CL, Jones I, Chamberlin AJ, Rohr JR. Aquatic macrophytes and macroinvertebrate predators affect densities of snail hosts and local production of schistosome cercariae that cause human schistosomiasis. PLoS Negl Trop Dis 2020; 14:e0008417. [PMID: 32628666 PMCID: PMC7365472 DOI: 10.1371/journal.pntd.0008417] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/16/2020] [Accepted: 05/22/2020] [Indexed: 12/22/2022] Open
Abstract
Background Schistosomiasis is responsible for the second highest burden of disease among neglected tropical diseases globally, with over 90 percent of cases occurring in African regions where drugs to treat the disease are only sporadically available. Additionally, human re-infection after treatment can be a problem where there are high numbers of infected snails in the environment. Recent experiments indicate that aquatic factors, including plants, nutrients, or predators, can influence snail abundance and parasite production within infected snails, both components of human risk. This study investigated how snail host abundance and release of cercariae (the free swimming stage infective to humans) varies at water access sites in an endemic region in Senegal, a setting where human schistosomiasis prevalence is among the highest globally. Methods/Principal findings We collected snail intermediate hosts at 15 random points stratified by three habitat types at 36 water access sites, and counted cercarial production by each snail after transfer to the laboratory on the same day. We found that aquatic vegetation was positively associated with per-capita cercarial release by snails, probably because macrophytes harbor periphyton resources that snails feed upon, and well-fed snails tend to produce more parasites. In contrast, the abundance of aquatic macroinvertebrate snail predators was negatively associated with per-capita cercarial release by snails, probably because of several potential sublethal effects on snails or snail infection, despite a positive association between snail predators and total snail numbers at a site, possibly due to shared habitat usage or prey tracking by the predators. Thus, complex bottom-up and top-down ecological effects in this region plausibly influence the snail shedding rate and thus, total local density of schistosome cercariae. Conclusions/Significance Our study suggests that aquatic macrophytes and snail predators can influence per-capita cercarial production and total abundance of snails. Thus, snail control efforts might benefit by targeting specific snail habitats where parasite production is greatest. In conclusion, a better understanding of top-down and bottom-up ecological factors that regulate densities of cercarial release by snails, rather than solely snail densities or snail infection prevalence, might facilitate improved schistosomiasis control. Over 800 million people are at risk of schistosomiasis and environmental factors that regulate densities of cercariae parasites that infect humans remain poorly understood. We sampled a spatially extensive area at 36 water-access points in northern Senegal, and quantified densities of snail intermediate hosts, snail predators, and aquatic vegetation in each sample, as well as cercariae released from snails after they were brought to the laboratory. We found that the quantity of submerged aquatic vegetation, particularly Ceratophyllum spp., was positively associated with schistosome cercariae released per infected snail, and total potential cercariae released by the collected snails per water access site. In contrast, the abundance of aquatic predators near infected snails (in the same sweep) was negatively associated with the per-capita cercarial release by infected snails, but positively associated with total snail abundance per site. Additionally, snail densities and potential cercarial densities (estimated as the sum of cercariae released by all collected, infected snails at a site) were only weakly correlated, suggesting that snail densities alone might not accurately reflect total potential of those snails to emit schistosome cercariae. Overall, a better understanding of aquatic factors that can influence the production of schistosome cercariae under field conditions, rather than snail host abundance alone, might facilitate improvements in schistosomiasis monitoring and control.
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Affiliation(s)
- Christopher J. E. Haggerty
- Department of Biological Sciences, Environmental Change Initiative, Eck Institute of Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
- Department of Integrative Biology, University of South Florida, Tampa, Florida, United States of America
- * E-mail:
| | | | - David J. Civitello
- Department of Biology, Emory University, Atlanta, Georgia, United States of America
| | - Giulio A. De Leo
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
| | - Nicolas Jouanard
- Station d'Innovation Aquacole, Saint-Louis, Senegal
- Centre de Recherche Biomédicale Espoir pour la Santé, Saint-Louis, Senegal
| | - Raphael A. Ndione
- Centre de Recherche Biomédicale Espoir pour la Santé, Saint-Louis, Senegal
| | - Justin V. Remais
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California, United States of America
| | - Gilles Riveau
- Centre de Recherche Biomédicale Espoir pour la Santé, Saint-Louis, Senegal
- Institut Pasteur de Lille—CIIL, France
| | - Simon Senghor
- Centre de Recherche Biomédicale Espoir pour la Santé, Saint-Louis, Senegal
| | - Susanne H. Sokolow
- Woods Institute for the Environment, Stanford University, Stanford, California, United States of America
| | - Souleymane Sow
- Centre de Recherche Biomédicale Espoir pour la Santé, Saint-Louis, Senegal
| | - Caitlin Wolfe
- College of Public Health, University of South Florida, Tampa, Florida, United States of America
| | - Chelsea L. Wood
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington, United States of America
| | - Isabel Jones
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
| | - Andrew J. Chamberlin
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
| | - Jason R. Rohr
- Department of Biological Sciences, Environmental Change Initiative, Eck Institute of Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
- Department of Integrative Biology, University of South Florida, Tampa, Florida, United States of America
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20
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Hoover CM, Sokolow SH, Kemp J, Sanchirico JN, Lund AJ, Jones IJ, Higginson T, Riveau G, Savaya A, Coyle S, Wood CL, Micheli F, Casagrandi R, Mari L, Gatto M, Rinaldo A, Perez-Saez J, Rohr JR, Sagi A, Remais JV, De Leo GA. Modelled effects of prawn aquaculture on poverty alleviation and schistosomiasis control. Nat Sustain 2020; 2:611-620. [PMID: 33313425 PMCID: PMC7731924 DOI: 10.1038/s41893-019-0301-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 04/26/2019] [Indexed: 05/23/2023]
Abstract
Recent evidence suggests that snail predators may aid efforts to control the human parasitic disease schistosomiasis by eating aquatic snail species that serve as intermediate hosts of the parasite. Potential synergies between schistosomiasis control and aquaculture of giant prawns are evaluated using an integrated bio-economic-epidemiologic model. Combinations of stocking density and aquaculture cycle length that maximize cumulative, discounted profit are identified for two prawn species in sub-Saharan Africa: the endemic, non-domesticated Macrobrachium vollenhovenii, and the non-native, domesticated Macrobrachium rosenbergii. At profit maximizing densities, both M. rosenbergii and M. vollenhovenii may substantially reduce intermediate host snail populations and aid schistosomiasis control efforts. Control strategies drawing on both prawn aquaculture to reduce intermediate host snail populations and mass drug administration to treat infected individuals are found to be superior to either strategy alone. Integrated aquaculture-based interventions can be a win-win strategy in terms of health and sustainable development in schistosomiasis endemic regions of the world.
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Affiliation(s)
- Christopher M. Hoover
- Division of Environmental Health Sciences, University of California, Berkeley School of Public Health, Berkeley, CA 94720 USA
| | - Susanne H. Sokolow
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950 USA
- Woods Institute for the Environment and Center for Innovation in Global Health, Stanford University, Stanford, CA 94305 USA
| | - Jonas Kemp
- Program in Human Biology, Stanford University, Stanford, CA 94305 USA
| | - James N. Sanchirico
- Department of Environmental Science and Policy, University of California, Davis, Davis, CA 95616 USA
| | - Andrea J. Lund
- Emmett Interdisciplinary Program in Environment and Resources, School of Earth, Energy and Environmental Sciences, Stanford University, Stanford, CA 94305 USA
| | - Isabel J. Jones
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950 USA
| | - Tyler Higginson
- Middlebury Institute of International Studies at Monterey, Monterey, CA 93940 USA
| | - Gilles Riveau
- Biomedical Research Center EPLS, Saint Louis, Senegal
| | - Amit Savaya
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Shawn Coyle
- Kentucky State University, Aquaculture Division, Aquaculture Research Center, Frankfort, KY 40601 USA
| | - Chelsea L. Wood
- University of Washington, School of Aquatic and Fishery Sciences, Seattle, WA 98195 USA
| | - Fiorenza Micheli
- Hopkins Marine Station and Center for Ocean Solutions, Stanford University, Pacific Grove, CA 93950 USA
| | - Renato Casagrandi
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
| | - Lorenzo Mari
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
| | - Marino Gatto
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
| | - Andrea Rinaldo
- Laboratory of Ecohydrology, School of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Switzerland
| | - Javier Perez-Saez
- Laboratory of Ecohydrology, School of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Switzerland
| | - Jason R. Rohr
- Department of Biological Sciences, Eck Institute of Global Health, Environmental Change Initiative University of Notre Damea, Notre Dame, IN, 46556 USA
- Department of Integrative Biology, University of South Florida, Tampa, FL, 33620 USA
| | - Amir Sagi
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Justin V. Remais
- Division of Environmental Health Sciences, University of California, Berkeley School of Public Health, Berkeley, CA 94720 USA
| | - Giulio A. De Leo
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950 USA
- Woods Institute for the Environment and Center for Innovation in Global Health, Stanford University, Stanford, CA 94305 USA
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21
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Buck JC, De Leo GA, Sokolow SH. Concomitant Immunity and Worm Senescence May Drive Schistosomiasis Epidemiological Patterns: An Eco-Evolutionary Perspective. Front Immunol 2020; 11:160. [PMID: 32161583 PMCID: PMC7053360 DOI: 10.3389/fimmu.2020.00160] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 01/21/2020] [Indexed: 11/13/2022] Open
Abstract
In areas where human schistosomiasis is endemic, infection prevalence and egg output are known to rise rapidly through childhood, reach a peak at 8-15 years of age, and decline thereafter. A similar peak ("overshoot") followed by return to equilibrium infection levels sometimes occurs a year or less after mass drug administration. These patterns are usually assumed to be due to acquired immunity, which is induced by exposure, directed by the host's immune system, and develops slowly over the lifetime of the host. Other explanations that have been advanced previously include differential exposure of hosts, differential mortality of hosts, and progressive pathology. Here we review these explanations and offer a novel (but not mutually exclusive) explanation, namely that adult worms protect the host against larval stages for their own benefit ("concomitant immunity") and that worm fecundity declines with worm age ("reproductive senescence"). This explanation approaches schistosomiasis from an eco-evolutionary perspective, as concomitant immunity maximizes the fitness of adult worms by reducing intraspecific competition within the host. If correct, our hypothesis could have profound implications for treatment and control of human schistosomiasis. Specifically, if immunity is worm-directed, then treatment of long-standing infections comprised of old senescent worms could enable infection with new, highly fecund worms. Furthermore, our hypothesis suggests revisiting research on therapeutics that mimic the concomitant immunity-modulating activity of adult worms, while minimizing pathological consequences of their eggs. We emphasize the value of an eco-evolutionary perspective on host-parasite interactions.
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Affiliation(s)
- Julia C. Buck
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC, United States
| | - Giulio A. De Leo
- Department of Biology, Stanford University, Hopkins Marine Station, Pacific Grove, CA, United States
- Woods Institute for the Environment, Stanford University, Stanford, CA, United States
| | - Susanne H. Sokolow
- Department of Biology, Stanford University, Hopkins Marine Station, Pacific Grove, CA, United States
- Woods Institute for the Environment, Stanford University, Stanford, CA, United States
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22
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Maier T, Wheeler NJ, Namigai EKO, Tycko J, Grewelle RE, Woldeamanuel Y, Klohe K, Perez-Saez J, Sokolow SH, De Leo GA, Yoshino TP, Zamanian M, Reinhard-Rupp J. Gene drives for schistosomiasis transmission control. PLoS Negl Trop Dis 2019; 13:e0007833. [PMID: 31856157 PMCID: PMC6922350 DOI: 10.1371/journal.pntd.0007833] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Schistosomiasis is one of the most important and widespread neglected tropical diseases (NTD), with over 200 million people infected in more than 70 countries; the disease has nearly 800 million people at risk in endemic areas. Although mass drug administration is a cost-effective approach to reduce occurrence, extent, and severity of the disease, it does not provide protection to subsequent reinfection. Interventions that target the parasites’ intermediate snail hosts are a crucial part of the integrated strategy required to move toward disease elimination. The recent revolution in gene drive technology naturally leads to questions about whether gene drives could be used to efficiently spread schistosome resistance traits in a population of snails and whether gene drives have the potential to contribute to reduced disease transmission in the long run. Responsible implementation of gene drives will require solutions to complex challenges spanning multiple disciplines, from biology to policy. This Review Article presents collected perspectives from practitioners of global health, genome engineering, epidemiology, and snail/schistosome biology and outlines strategies for responsible gene drive technology development, impact measurements of gene drives for schistosomiasis control, and gene drive governance. Success in this arena is a function of many factors, including gene-editing specificity and efficiency, the level of resistance conferred by the gene drive, how fast gene drives may spread in a metapopulation over a complex landscape, ecological sustainability, social equity, and, ultimately, the reduction of infection prevalence in humans. With combined efforts from across the broad global health community, gene drives for schistosomiasis control could fortify our defenses against this devastating disease in the future.
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Affiliation(s)
- Theresa Maier
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom
| | - Nicolas James Wheeler
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Global Health Institute of Merck (KGaA), Eysins, Switzerland
| | | | - Josh Tycko
- Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Richard Ernest Grewelle
- Hopkins Marine Station, School of Humanities and Sciences, Stanford University, Pacific Grove, California, United States of America
| | - Yimtubezinash Woldeamanuel
- Department of Microbiology, Immunology & Parasitology, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | | | - Javier Perez-Saez
- Laboratory of Ecohydrology, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Susanne H. Sokolow
- Woods Institute for the Environment, Stanford University, Stanford, California, United States of America
- Marine Science Institute, University of California, Santa Barbara, California, United States of America
| | - Giulio A. De Leo
- Hopkins Marine Station, School of Humanities and Sciences, Stanford University, Pacific Grove, California, United States of America
| | - Timothy P. Yoshino
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Mostafa Zamanian
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
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23
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Wood CL, Sokolow SH, Jones IJ, Chamberlin AJ, Lafferty KD, Kuris AM, Jocque M, Hopkins S, Adams G, Buck JC, Lund AJ, Garcia-Vedrenne AE, Fiorenza E, Rohr JR, Allan F, Webster B, Rabone M, Webster JP, Bandagny L, Ndione R, Senghor S, Schacht AM, Jouanard N, Riveau G, De Leo GA. Precision mapping of snail habitat provides a powerful indicator of human schistosomiasis transmission. Proc Natl Acad Sci U S A 2019; 116:23182-23191. [PMID: 31659025 PMCID: PMC6859407 DOI: 10.1073/pnas.1903698116] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Recently, the World Health Organization recognized that efforts to interrupt schistosomiasis transmission through mass drug administration have been ineffective in some regions; one of their new recommended strategies for global schistosomiasis control emphasizes targeting the freshwater snails that transmit schistosome parasites. We sought to identify robust indicators that would enable precision targeting of these snails. At the site of the world's largest recorded schistosomiasis epidemic-the Lower Senegal River Basin in Senegal-intensive sampling revealed positive relationships between intermediate host snails (abundance, density, and prevalence) and human urogenital schistosomiasis reinfection (prevalence and intensity in schoolchildren after drug administration). However, we also found that snail distributions were so patchy in space and time that obtaining useful data required effort that exceeds what is feasible in standard monitoring and control campaigns. Instead, we identified several environmental proxies that were more effective than snail variables for predicting human infection: the area covered by suitable snail habitat (i.e., floating, nonemergent vegetation), the percent cover by suitable snail habitat, and size of the water contact area. Unlike snail surveys, which require hundreds of person-hours per site to conduct, habitat coverage and site area can be quickly estimated with drone or satellite imagery. This, in turn, makes possible large-scale, high-resolution estimation of human urogenital schistosomiasis risk to support targeting of both mass drug administration and snail control efforts.
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Affiliation(s)
- Chelsea L Wood
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA 98195;
| | - Susanne H Sokolow
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950
| | - Isabel J Jones
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950
| | | | - Kevin D Lafferty
- Western Ecological Research Center, United States Geological Survey, Santa Barbara, CA 93106
- Marine Science Institute, University of California, Santa Barbara, CA 93106
| | - Armand M Kuris
- Marine Science Institute, University of California, Santa Barbara, CA 93106
| | - Merlijn Jocque
- Aquatic and Terrestrial Ecology, Royal Belgian Institute of Natural Sciences, 1000 Brussels, Belgium
| | - Skylar Hopkins
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24060
| | - Grant Adams
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA 98195
| | - Julia C Buck
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC 28403
| | - Andrea J Lund
- Emmett Interdisciplinary Program in Environment and Resources, Stanford University, Stanford, CA 94305
| | - Ana E Garcia-Vedrenne
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095
| | - Evan Fiorenza
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA 98195
| | - Jason R Rohr
- Department of Biological Sciences, Environmental Change Initiative, Eck Institute of Global Health, University of Notre Dame, Notre Dame, IN 46556
| | - Fiona Allan
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London SW7 5BD, United Kingdom
- London Centre for Neglected Tropical Disease Research, Imperial College London School of Public Health, London W2 1PG, United Kingdom
| | - Bonnie Webster
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London SW7 5BD, United Kingdom
- London Centre for Neglected Tropical Disease Research, Imperial College London School of Public Health, London W2 1PG, United Kingdom
| | - Muriel Rabone
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London SW7 5BD, United Kingdom
- London Centre for Neglected Tropical Disease Research, Imperial College London School of Public Health, London W2 1PG, United Kingdom
| | - Joanne P Webster
- London Centre for Neglected Tropical Disease Research, Imperial College London School of Public Health, London W2 1PG, United Kingdom
- Centre for Emerging, Endemic, and Exotic Diseases, Department of Pathology and Population Sciences, Royal Veterinary College, University of London, London NW1 0TU, United Kingdom
| | - Lydie Bandagny
- Biomedical Research Center Espoir Pour La Santé, BP 226 Saint-Louis, Senegal
| | - Raphaël Ndione
- Biomedical Research Center Espoir Pour La Santé, BP 226 Saint-Louis, Senegal
| | - Simon Senghor
- Biomedical Research Center Espoir Pour La Santé, BP 226 Saint-Louis, Senegal
| | - Anne-Marie Schacht
- Biomedical Research Center Espoir Pour La Santé, BP 226 Saint-Louis, Senegal
| | - Nicolas Jouanard
- Biomedical Research Center Espoir Pour La Santé, BP 226 Saint-Louis, Senegal
- Station d'Innovation Aquacole, BP 524 Saint-Louis, Senegal
| | - Gilles Riveau
- Biomedical Research Center Espoir Pour La Santé, BP 226 Saint-Louis, Senegal
| | - Giulio A De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950
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24
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Castro MC, Baeza A, Codeço CT, Cucunubá ZM, Dal’Asta AP, De Leo GA, Dobson AP, Carrasco-Escobar G, Lana RM, Lowe R, Monteiro AMV, Pascual M, Santos-Vega M. Development, environmental degradation, and disease spread in the Brazilian Amazon. PLoS Biol 2019; 17:e3000526. [PMID: 31730640 PMCID: PMC6881077 DOI: 10.1371/journal.pbio.3000526] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 11/27/2019] [Indexed: 12/03/2022] Open
Abstract
The Amazon is Brazil's greatest natural resource and invaluable to the rest of the world as a buffer against climate change. The recent election of Brazil's president brought disputes over development plans for the region back into the spotlight. Historically, the development model for the Amazon has focused on exploitation of natural resources, resulting in environmental degradation, particularly deforestation. Although considerable attention has focused on the long-term global cost of "losing the Amazon," too little attention has focused on the emergence and reemergence of vector-borne diseases that directly impact the local population, with spillover effects to other neighboring areas. We discuss the impact of Amazon development models on human health, with a focus on vector-borne disease risk. We outline policy actions that could mitigate these negative impacts while creating opportunities for environmentally sensitive economic activities.
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Affiliation(s)
- Marcia C. Castro
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Andres Baeza
- Center for Global Discovery and Conservation Science (GDCS), Arizona State University, Tempe, Arizona, United States of America
| | | | - Zulma M. Cucunubá
- MRC Centre for Global Infectious Disease Analysis (MRC GIDA), Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Ana Paula Dal’Asta
- Instituto Nacional de Pesquisas Espaciais, São José dos Campos, São Paulo, Brazil
| | - Giulio A. De Leo
- Woods Institute for the Environment and Hopkins Marine Station of Stanford University, Pacific Grove, California, United States of America
| | - Andrew P. Dobson
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Gabriel Carrasco-Escobar
- Institute of Tropical Medicine “Alexander von Humboldt,” Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Raquel Martins Lana
- Programa de Computação Científica, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Rachel Lowe
- Centre on Climate Change and Planetary Health & Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Barcelona Institute for Global Health, Barcelona, Spain
| | | | - Mercedes Pascual
- Department of Ecology and Evolution, University of Chicago, Chicago, Illinois, United States of America
| | - Mauricio Santos-Vega
- Departamento de Ingeniería Biomédica, Grupo de Investigación en Biología Matemática y Computacional BIOMAC, Universidad de los Andes, Bogotá, Colombia
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25
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Lund AJ, Sam MM, Sy AB, Sow OW, Ali S, Sokolow SH, Bereknyei Merrell S, Bruce J, Jouanard N, Senghor S, Riveau G, Lopez-Carr D, De Leo GA. Unavoidable Risks: Local Perspectives on Water Contact Behavior and Implications for Schistosomiasis Control in an Agricultural Region of Northern Senegal. Am J Trop Med Hyg 2019; 101:837-847. [PMID: 31452497 PMCID: PMC6779182 DOI: 10.4269/ajtmh.19-0099] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 06/24/2019] [Indexed: 12/31/2022] Open
Abstract
Human schistosomiasis is a snail-borne parasitic disease affecting more than 200 million people worldwide. Direct contact with snail-infested freshwater is the primary route of exposure. Water management infrastructure, including dams and irrigation schemes, expands snail habitat, increasing the risk across the landscape. The Diama Dam, built on the lower basin of the Senegal River to prevent saltwater intrusion and promote year-round agriculture in the drought-prone Sahel, is a paradigmatic case. Since dam completion in 1986, the rural population-whose livelihoods rely mostly on agriculture-has suffered high rates of schistosome infection. The region remains one of the most hyperendemic regions in the world. Because of the convergence between livelihoods and environmental conditions favorable to transmission, schistosomiasis is considered an illustrative case of a disease-driven poverty trap (DDPT). The literature to date on the topic, however, remains largely theoretical. With qualitative data generated from 12 focus groups in four villages, we conducted team-based theme analysis to investigate how perception of schistosomiasis risk and reported preventive behaviors may suggest the presence of a DDPT. Our analysis reveals three key findings: 1) rural villagers understand schistosomiasis risk (i.e., where and when infections occur), 2) accordingly, they adopt some preventive behaviors, but ultimately, 3) exposure persists, because of circumstances characteristic of rural livelihoods. These findings highlight the capacity of local populations to participate actively in schistosomiasis control programs and the limitations of widespread drug treatment campaigns. Interventions that target the environmental reservoir of disease may provide opportunities to reduce exposure while maintaining resource-dependent livelihoods.
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Affiliation(s)
- Andrea J. Lund
- Emmett Interdisciplinary Program in Environment and Resources, Stanford University, Stanford, California
| | | | - Alioune Badara Sy
- Centre de Recherche Biomédicale – Espoir Pour la Santé, Saint Louis, Sénégal
| | | | - Sofia Ali
- Stanford University, Stanford, California
| | | | - Sylvia Bereknyei Merrell
- Department of Surgery, Stanford Surgery Policy Improvement Research & Education Center (S-SPIRE), School of Medicine, Stanford University, Stanford, California
| | - Janine Bruce
- Pediatric Advocacy Program, Department of Pediatrics, School of Medicine, Stanford University, Stanford, California
| | - Nicolas Jouanard
- Centre de Recherche Biomédicale – Espoir Pour la Santé, Saint Louis, Sénégal
- Station d’Innovation Aquacole, Saint Louis, Senegal
| | - Simon Senghor
- Centre de Recherche Biomédicale – Espoir Pour la Santé, Saint Louis, Sénégal
| | - Gilles Riveau
- Centre de Recherche Biomédicale – Espoir Pour la Santé, Saint Louis, Sénégal
| | - David Lopez-Carr
- Department of Geography, University of California, Santa Barbara, Santa Barbara, California
| | - Giulio A. De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, California
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26
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Sokolow SH, Nova N, Pepin KM, Peel AJ, Pulliam JRC, Manlove K, Cross PC, Becker DJ, Plowright RK, McCallum H, De Leo GA. Ecological interventions to prevent and manage zoonotic pathogen spillover. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180342. [PMID: 31401951 PMCID: PMC6711299 DOI: 10.1098/rstb.2018.0342] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Spillover of a pathogen from a wildlife reservoir into a human or livestock host requires the pathogen to overcome a hierarchical series of barriers. Interventions aimed at one or more of these barriers may be able to prevent the occurrence of spillover. Here, we demonstrate how interventions that target the ecological context in which spillover occurs (i.e. ecological interventions) can complement conventional approaches like vaccination, treatment, disinfection and chemical control. Accelerating spillover owing to environmental change requires effective, affordable, durable and scalable solutions that fully harness the complex processes involved in cross-species pathogen spillover. This article is part of the theme issue ‘Dynamic and integrative approaches to understanding pathogen spillover’.
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Affiliation(s)
- Susanne H Sokolow
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA.,Woods Institute for the Environment, Stanford University, Stanford, CA 94305, USA.,Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
| | - Nicole Nova
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Kim M Pepin
- National Wildlife Research Center, USDA-APHIS, Fort Collins, CO 80521, USA
| | - Alison J Peel
- Environmental Futures Research Institute, Griffith University, Nathan, Queensland 4111, Australia
| | - Juliet R C Pulliam
- South African DST-NRF Centre of Excellence in Epidemiological Modelling and Analysis (SACEMA), Stellenbosch University, Stellenbosch 7600, South Africa
| | - Kezia Manlove
- Department of Wildland Resources and Ecology Center, Utah State University, Logan, UT 84321, USA
| | - Paul C Cross
- US Geological Survey, Northern Rocky Mountain Science Center, Bozeman, MT 59715, USA
| | - Daniel J Becker
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA.,Department of Biology, Indiana University, Bloomington, IN 47403, USA
| | - Raina K Plowright
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA
| | - Hamish McCallum
- Environmental Futures Research Institute, Griffith University, Nathan, Queensland 4111, Australia
| | - Giulio A De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA.,Woods Institute for the Environment, Stanford University, Stanford, CA 94305, USA.,Department of Biology, Stanford University, Stanford, CA 94305, USA
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27
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Aalto EA, Micheli F, Boch CA, Espinoza Montes JA, Woodson CB, De Leo GA. Catastrophic Mortality, Allee Effects, and Marine Protected Areas. Am Nat 2019; 193:391-408. [DOI: 10.1086/701781] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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28
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Arostegui MC, Wood CL, Jones IJ, Chamberlin AJ, Jouanard N, Faye DS, Kuris AM, Riveau G, De Leo GA, Sokolow SH. Potential Biological Control of Schistosomiasis by Fishes in the Lower Senegal River Basin. Am J Trop Med Hyg 2019; 100:117-126. [PMID: 30479247 PMCID: PMC6335894 DOI: 10.4269/ajtmh.18-0469] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Accepted: 09/26/2018] [Indexed: 12/19/2022] Open
Abstract
More than 200 million people in sub-Saharan Africa are infected with schistosome parasites. Transmission of schistosomiasis occurs when people come into contact with larval schistosomes emitted from freshwater snails in the aquatic environment. Thus, controlling snails through augmenting or restoring their natural enemies, such as native predators and competitors, could offer sustainable control for this human disease. Fishes may reduce schistosomiasis transmission directly, by preying on snails or parasites, or indirectly, by competing with snails for food or by reducing availability of macrophyte habitat (i.e., aquatic plants) where snails feed and reproduce. To identify fishes that might serve as native biological control agents for schistosomiasis in the lower Senegal River basin-one of the highest transmission areas for human schistosomiasis globally-we surveyed the freshwater fish that inhabit shallow, nearshore habitats and conducted multivariate analyses with quantitative diet data for each of the fish species encountered. Ten of the 16 fish species we encountered exhibited diets that may result in direct (predation) and/or indirect (food competition and habitat removal) control of snails. Fish abundance was low, suggesting limited effects on schistosomiasis transmission by the contemporary fish community in the lower Senegal River basin in the wild. Here, we highlight some native species-such as tilapia, West African lungfish, and freshwater prawns-that could be aquacultured for local-scale biological control of schistosomiasis transmission.
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Affiliation(s)
- Martin C. Arostegui
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington
| | - Chelsea L. Wood
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington
| | - Isabel J. Jones
- Hopkins Marine Station of Stanford University, Pacific Grove, California
| | | | - Nicolas Jouanard
- Biomedical Research Center Espoir Pour La Santé, Saint-Louis, Sénégal
| | | | - Armand M. Kuris
- Department of Ecology, Evolution and Marine Biology, and Marine Science Institute, University of California, Santa Barbara, California
| | - Gilles Riveau
- Biomedical Research Center Espoir Pour La Santé, Saint-Louis, Sénégal
| | - Giulio A. De Leo
- Hopkins Marine Station of Stanford University, Pacific Grove, California
| | - Susanne H. Sokolow
- Hopkins Marine Station of Stanford University, Pacific Grove, California
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29
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Arakala A, Hoover CM, Marshall JM, Sokolow SH, De Leo GA, Rohr JR, Remais JV, Gambhir M. Estimating the elimination feasibility in the 'end game' of control efforts for parasites subjected to regular mass drug administration: Methods and their application to schistosomiasis. PLoS Negl Trop Dis 2018; 12:e0006794. [PMID: 30418968 PMCID: PMC6258430 DOI: 10.1371/journal.pntd.0006794] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 11/26/2018] [Accepted: 08/27/2018] [Indexed: 11/18/2022] Open
Abstract
Progress towards controlling and eliminating parasitic worms, including schistosomiasis, onchocerciasis, and lymphatic filariasis, is advancing rapidly as national governments, multinational NGOs, and pharmaceutical companies launch collaborative chemotherapeutic control campaigns. Critical questions remain regarding the potential for achieving elimination of these infections, and analytical methods can help to quickly estimate progress towards-and the probability of achieving-elimination over specific timeframes. Here, we propose the effective reproduction number, Reff, as a proxy of elimination potential for sexually reproducing worms that are subject to poor mating success at very low abundance (positive density dependence, or Allee effects). Reff is the number of parasites produced by a single reproductive parasite at a given stage in the transmission cycle, over the parasite's lifetime-it is the generalized form of the more familiar basic reproduction number, R0, which only applies at the beginning of an epidemic-and it can be estimated in a 'model-free' manner by an estimator ('ε'). We introduce ε, demonstrate its estimation using simulated data, and discuss how it may be used in planning and evaluation of ongoing elimination efforts for a range of parasitic diseases.
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Affiliation(s)
- Arathi Arakala
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia
| | - Christopher M. Hoover
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California, United States of America
| | - John M. Marshall
- Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California, United States of America
| | - Susanne H. Sokolow
- Department of Biology—Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
| | - Giulio A. De Leo
- Department of Biology—Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
| | - Jason R. Rohr
- Department of Integrative Biology, University of Southern Florida, Tampa, Florida, United States of America
| | - Justin V. Remais
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California, United States of America
| | - Manoj Gambhir
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia
- Health Modelling and Analytics, IBM Research Australia, Melbourne, Australia
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30
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Halstead NT, Hoover CM, Arakala A, Civitello DJ, De Leo GA, Gambhir M, Johnson SA, Jouanard N, Loerns KA, McMahon TA, Ndione RA, Nguyen K, Raffel TR, Remais JV, Riveau G, Sokolow SH, Rohr JR. Agrochemicals increase risk of human schistosomiasis by supporting higher densities of intermediate hosts. Nat Commun 2018; 9:837. [PMID: 29483531 PMCID: PMC5826950 DOI: 10.1038/s41467-018-03189-w] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Accepted: 01/26/2018] [Indexed: 11/09/2022] Open
Abstract
Schistosomiasis is a snail-borne parasitic disease that ranks among the most important water-based diseases of humans in developing countries. Increased prevalence and spread of human schistosomiasis to non-endemic areas has been consistently linked with water resource management related to agricultural expansion. However, the role of agrochemical pollution in human schistosome transmission remains unexplored, despite strong evidence of agrochemicals increasing snail-borne diseases of wildlife and a projected 2- to 5-fold increase in global agrochemical use by 2050. Using a field mesocosm experiment, we show that environmentally relevant concentrations of fertilizer, a herbicide, and an insecticide, individually and as mixtures, increase densities of schistosome-infected snails by increasing the algae snails eat and decreasing densities of snail predators. Epidemiological models indicate that these agrochemical effects can increase transmission of schistosomes. Identifying agricultural practices or agrochemicals that minimize disease risk will be critical to meeting growing food demands while improving human wellbeing.
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Affiliation(s)
- Neal T Halstead
- Department of Integrative Biology, University of South Florida, Tampa, FL, 33620, USA.
- Wildlands Conservation, Inc., 15310 Amberly Drive, Suite 250, Tampa, FL, 33647, USA.
| | - Christopher M Hoover
- Division of Environmental Health Sciences, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Arathi Arakala
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, 3800,, Australia
- Department of Mathematical Sciences, RMIT University, GPO Box 2476, Melbourne, 3001, Australia
| | | | - Giulio A De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, 93950, USA
- Stanford Woods Institute for the Environment, Stanford University, Stanford, CA, 94305, USA
| | - Manoj Gambhir
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, 3800,, Australia
- IBM Research Australia, Global Services Australia Pvt. Ltd., 60 City Road, Southbank, 3006, Australia
| | - Steve A Johnson
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL, 32611, USA
| | - Nicolas Jouanard
- Centre de Recherche Biomédicale Espoir pour la Santé, BP 226, Saint-Louis, Senegal
| | - Kristin A Loerns
- Department of Integrative Biology, University of South Florida, Tampa, FL, 33620, USA
| | - Taegan A McMahon
- Department of Biology, University of Tampa, Tampa, FL, 33606, USA
| | - Raphael A Ndione
- Centre de Recherche Biomédicale Espoir pour la Santé, BP 226, Saint-Louis, Senegal
| | - Karena Nguyen
- Department of Integrative Biology, University of South Florida, Tampa, FL, 33620, USA
| | - Thomas R Raffel
- Department of Biological Sciences, Oakland University, Rochester, MI, 48309, USA
| | - Justin V Remais
- Division of Environmental Health Sciences, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Gilles Riveau
- Centre de Recherche Biomédicale Espoir pour la Santé, BP 226, Saint-Louis, Senegal
- CIIL - Institut Pasteur de Lille, 1 Rue du Professeur Calmette, 59019, Lille, France
| | - Susanne H Sokolow
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, 93950, USA
- Stanford Woods Institute for the Environment, Stanford University, Stanford, CA, 94305, USA
| | - Jason R Rohr
- Department of Integrative Biology, University of South Florida, Tampa, FL, 33620, USA
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31
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Sokolow SH, Jones IJ, Jocque M, La D, Cords O, Knight A, Lund A, Wood CL, Lafferty KD, Hoover CM, Collender PA, Remais JV, Lopez-Carr D, Fisk J, Kuris AM, De Leo GA. Nearly 400 million people are at higher risk of schistosomiasis because dams block the migration of snail-eating river prawns. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0127. [PMID: 28438916 PMCID: PMC5413875 DOI: 10.1098/rstb.2016.0127] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2016] [Indexed: 11/21/2022] Open
Abstract
Dams have long been associated with elevated burdens of human schistosomiasis, but how dams increase disease is not always clear, in part because dams have many ecological and socio-economic effects. A recent hypothesis argues that dams block reproduction of the migratory river prawns that eat the snail hosts of schistosomiasis. In the Senegal River Basin, there is evidence that prawn populations declined and schistosomiasis increased after completion of the Diama Dam. Restoring prawns to a water-access site upstream of the dam reduced snail density and reinfection rates in people. However, whether a similar cascade of effects (from dams to prawns to snails to human schistosomiasis) occurs elsewhere is unknown. Here, we examine large dams worldwide and identify where their catchments intersect with endemic schistosomiasis and the historical habitat ranges of large, migratory Macrobrachium spp. prawns. River prawn habitats are widespread, and we estimate that 277–385 million people live within schistosomiasis-endemic regions where river prawns are or were present (out of the 800 million people who are at risk of schistosomiasis). Using a published repository of schistosomiasis studies in sub-Saharan Africa, we compared infection before and after the construction of 14 large dams for people living in: (i) upstream catchments within historical habitats of native prawns, (ii) comparable undammed watersheds, and (iii) dammed catchments beyond the historical reach of migratory prawns. Damming was followed by greater increases in schistosomiasis within prawn habitats than outside prawn habitats. We estimate that one third to one half of the global population-at-risk of schistosomiasis could benefit from restoration of native prawns. Because dams block prawn migrations, our results suggest that prawn extirpation contributes to the sharp increase of schistosomiasis after damming, and points to prawn restoration as an ecological solution for reducing human disease. This article is part of the themed issue ‘Conservation, biodiversity and infectious disease: scientific evidence and policy implications’.
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Affiliation(s)
- Susanne H Sokolow
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA .,Marine Science Institute, and Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93106, USA
| | - Isabel J Jones
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - Merlijn Jocque
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - Diana La
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - Olivia Cords
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - Anika Knight
- Department of Biology, Medaille College, Buffalo, NY 14214, USA.,Department of Veterinary Technology, Medaille College, Buffalo, NY 14214, USA
| | - Andrea Lund
- Emmett Interdisciplinary Program in Environmental Resources, School of Earth, Energy, and Environmental Sciences, Stanford University, Stanford, CA 94305, USA
| | - Chelsea L Wood
- Department of Ecology and Evolutionary Biology and Michigan Society of Fellows, University of Michigan, Ann Arbor, MI 48109, USA.,School of Aquatic and Fishery Science, University of Washington, Seattle, WA 98195, USA
| | - Kevin D Lafferty
- Marine Science Institute, and Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93106, USA.,Western Ecological Research Center, U.S. Geological Survey, Santa Barbara, CA 93106, USA
| | - Christopher M Hoover
- Division of Environmental Health Sciences, School of Public Health, University of California Berkeley, Berkeley, CA 94720, USA
| | - Phillip A Collender
- Division of Environmental Health Sciences, School of Public Health, University of California Berkeley, Berkeley, CA 94720, USA
| | - Justin V Remais
- Division of Environmental Health Sciences, School of Public Health, University of California Berkeley, Berkeley, CA 94720, USA
| | - David Lopez-Carr
- Department of Geography, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Jonathan Fisk
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - Armand M Kuris
- Marine Science Institute, and Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA 93106, USA
| | - Giulio A De Leo
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
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Sokolow SH, Wood CL, Jones IJ, Lafferty KD, Kuris AM, Hsieh MH, De Leo GA. To Reduce the Global Burden of Human Schistosomiasis, Use 'Old Fashioned' Snail Control. Trends Parasitol 2018; 34:23-40. [PMID: 29126819 PMCID: PMC5819334 DOI: 10.1016/j.pt.2017.10.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 09/30/2017] [Accepted: 10/16/2017] [Indexed: 12/27/2022]
Abstract
Control strategies to reduce human schistosomiasis have evolved from 'snail picking' campaigns, a century ago, to modern wide-scale human treatment campaigns, or preventive chemotherapy. Unfortunately, despite the rise in preventive chemotherapy campaigns, just as many people suffer from schistosomiasis today as they did 50 years ago. Snail control can complement preventive chemotherapy by reducing the risk of transmission from snails to humans. Here, we present ideas for modernizing and scaling up snail control, including spatiotemporal targeting, environmental diagnostics, better molluscicides, new technologies (e.g., gene drive), and 'outside the box' strategies such as natural enemies, traps, and repellants. We conclude that, to achieve the World Health Assembly's stated goal to eliminate schistosomiasis, it is time to give snail control another look.
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Affiliation(s)
- Susanne H Sokolow
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA; Marine Science Institute, University of California, Santa Barbara, CA 93106, USA.
| | - Chelsea L Wood
- School of Aquatic and Fishery Sciences, University of Washington, Box 355020, Seattle, WA 98195-5020, USA
| | - Isabel J Jones
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - Kevin D Lafferty
- U.S. Geological Survey, Western Ecological Research Center, c/o Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
| | - Armand M Kuris
- Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
| | - Michael H Hsieh
- Children's National Health System, Washington DC, 20010, USA; The George Washington University, Washington DC, 20037, USA; Biomedical Research Institute, Rockville, MD 20850, USA
| | - Giulio A De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
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Ciddio M, Mari L, Sokolow SH, De Leo GA, Casagrandi R, Gatto M. The spatial spread of schistosomiasis: A multidimensional network model applied to Saint-Louis region, Senegal. Adv Water Resour 2017; 108:406-415. [PMID: 29056816 PMCID: PMC5637889 DOI: 10.1016/j.advwatres.2016.10.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 09/13/2016] [Accepted: 10/10/2016] [Indexed: 05/06/2023]
Abstract
Schistosomiasis is a parasitic, water-related disease that is prevalent in tropical and subtropical areas of the world, causing severe and chronic consequences especially among children. Here we study the spatial spread of this disease within a network of connected villages in the endemic region of the Lower Basin of the Senegal River, in Senegal. The analysis is performed by means of a spatially explicit metapopulation model that couples local-scale eco-epidemiological dynamics with spatial mechanisms related to human mobility (estimated from anonymized mobile phone records), snail dispersal and hydrological transport of schistosome larvae along the main water bodies of the region. Results show that the model produces epidemiological patterns consistent with field observations, and point out the key role of spatial connectivity on the spread of the disease. These findings underline the importance of considering different transport pathways in order to elaborate disease control strategies that can be effective within a network of connected populations.
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Affiliation(s)
- Manuela Ciddio
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
| | - Lorenzo Mari
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
| | - Susanne H. Sokolow
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, United States
- Marine Science Institute, University of California, Santa Barbara, CA 93106, United States
| | - Giulio A. De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, United States
| | - Renato Casagrandi
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
| | - Marino Gatto
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
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Mari L, Ciddio M, Casagrandi R, Perez-Saez J, Bertuzzo E, Rinaldo A, Sokolow SH, De Leo GA, Gatto M. Heterogeneity in schistosomiasis transmission dynamics. J Theor Biol 2017; 432:87-99. [PMID: 28823529 PMCID: PMC5595357 DOI: 10.1016/j.jtbi.2017.08.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 06/30/2017] [Accepted: 08/15/2017] [Indexed: 01/30/2023]
Abstract
Transmission dynamics of schistosomiasis presents multiple heterogeneity sources. A comprehensive framework for heterogeneous disease transmission is proposed. Heterogeneous multigroup communities can be more prone to parasite transmission. Presence of multiple water sources can hinder parasite transmission. Spatial and temporal heterogeneities can have nontrivial implications for endemicity.
Simple models of disease propagation often disregard the effects of transmission heterogeneity on the ecological and epidemiological dynamics associated with host-parasite interactions. However, for some diseases like schistosomiasis, a widespread parasitic infection caused by Schistosoma worms, accounting for heterogeneity is crucial to both characterize long-term dynamics and evaluate opportunities for disease control. Elaborating on the classic Macdonald model for macroparasite transmission, we analyze families of models including explicit descriptions of heterogeneity related to differential transmission risk within a community, water contact patterns, the distribution of the snail host population, human mobility, and the seasonal fluctuations of the environment. Through simple numerical examples, we show that heterogeneous multigroup communities may be more prone to schistosomiasis than homogeneous ones, that the availability of multiple water sources can hinder parasite transmission, and that both spatial and temporal heterogeneities may have nontrivial implications for disease endemicity. Finally, we discuss the implications of heterogeneity for disease control. Although focused on schistosomiasis, results from this study may apply as well to other parasitic infections with complex transmission cycles, such as cysticercosis, dracunculiasis and fasciolosis.
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Affiliation(s)
- Lorenzo Mari
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy.
| | - Manuela Ciddio
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
| | - Renato Casagrandi
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
| | - Javier Perez-Saez
- Laboratory of Ecohydrology, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Enrico Bertuzzo
- Dipartimento di Scienze Ambientali, Informatica e Statistica, Università Ca' Foscari Venezia, 30170 Venezia Mestre, Italy
| | - Andrea Rinaldo
- Laboratory of Ecohydrology, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland; Dipartimento ICEA, Università di Padova, 35131 Padova, Italy
| | - Susanne H Sokolow
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA; Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
| | - Giulio A De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - Marino Gatto
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy
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Swartz SJ, De Leo GA, Wood CL, Sokolow SH. Infection with schistosome parasites in snails leads to increased predation by prawns: implications for human schistosomiasis control. ACTA ACUST UNITED AC 2017; 218:3962-7. [PMID: 26677260 DOI: 10.1242/jeb.129221] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Schistosomiasis - a parasitic disease that affects over 200 million people across the globe - is primarily transmitted between human definitive hosts and snail intermediate hosts. To reduce schistosomiasis transmission, some have advocated disrupting the schistosome life cycle through biological control of snails, achieved by boosting the abundance of snails' natural predators. But little is known about the effect of parasitic infection on predator-prey interactions, especially in the case of schistosomiasis. Here, we present the results of laboratory experiments performed on Bulinus truncatus and Biomphalaria glabrata snails to investigate: (i) rates of predation on schistosome-infected versus uninfected snails by a sympatric native river prawn, Macrobrachium vollenhovenii, and (ii) differences in snail behavior (including movement, refuge-seeking and anti-predator behavior) between infected and uninfected snails. In predation trials, prawns showed a preference for consuming snails infected with schistosome larvae. In behavioral trials, infected snails moved less quickly and less often than uninfected snails, and were less likely to avoid predation by exiting the water or hiding under substrate. Although the mechanism by which the parasite alters snail behavior remains unknown, these results provide insight into the effects of parasitic infection on predator-prey dynamics and suggest that boosting natural rates of predation on snails may be a useful strategy for reducing transmission in schistosomiasis hotspots.
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Affiliation(s)
- Scott J Swartz
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Giulio A De Leo
- Department of Biology, Stanford University, Stanford, CA 94305, USA Hopkins Marine Station of Stanford University, Pacific Grove, CA 93950, USA
| | - Chelsea L Wood
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA Michigan Society of Fellows, University of Michigan, Ann Arbor, MI 48109, USA
| | - Susanne H Sokolow
- Hopkins Marine Station of Stanford University, Pacific Grove, CA 93950, USA Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
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Rossi G, De Leo GA, Pongolini S, Natalini S, Zarenghi L, Ricchi M, Bolzoni L. The Potential Role of Direct and Indirect Contacts on Infection Spread in Dairy Farm Networks. PLoS Comput Biol 2017; 13:e1005301. [PMID: 28125610 PMCID: PMC5268397 DOI: 10.1371/journal.pcbi.1005301] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 12/12/2016] [Indexed: 11/19/2022] Open
Abstract
Animals' exchanges are considered the most effective route of between-farm infectious disease transmission. However, despite being often overlooked, the infection spread due to contaminated equipment, vehicles, or personnel proved to be important for several livestock epidemics. This study investigated the role of indirect contacts in a potential infection spread in the dairy farm network of the Province of Parma (Northern Italy). We built between-farm contact networks using data on cattle exchange (direct contacts), and on-farm visits by veterinarians (indirect contacts). We compared the features of the contact structures by using measures on static and temporal networks. We assessed the disease spreading potential of the direct and indirect network structures in the farm system by using data on the infection state of farms by paratuberculosis. Direct and indirect networks showed non-trivial differences with respect to connectivity, contact distribution, and super-spreaders identification. Furthermore, our analyses on paratuberculosis data suggested that the contributions of direct and indirect contacts on diseases spread are apparent at different spatial scales. Our results highlighted the potential role of indirect contacts in between-farm disease spread and underlined the need for a deeper understanding of these contacts to develop better strategies for prevention of livestock epidemics.
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Affiliation(s)
- Gianluigi Rossi
- Dipartimento di Bioscienze, Università degli studi di Parma, Parco Area delle Scienze, Parma, Italy
- Risk Analysis Unit, Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia Romagna, Via dei Mercati, Parma, Italy
| | - Giulio A. De Leo
- Dipartimento di Bioscienze, Università degli studi di Parma, Parco Area delle Scienze, Parma, Italy
- Stanford University, Hopkins Marine Station, Pacific Grove, CA, United States of America
| | - Stefano Pongolini
- Risk Analysis Unit, Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia Romagna, Via dei Mercati, Parma, Italy
| | - Silvano Natalini
- Servizio Veterinario e Igiene Alimenti, Assessorato Politiche per la Salute Regione Emilia-Romagna, Viale Aldo Moro, Bologna, Italy
| | - Luca Zarenghi
- Servizio Igiene degli Allevamenti e Produzioni Zootecniche, AUSL di Parma, Via Vasari, Parma, Italy
| | - Matteo Ricchi
- National Reference Centre for Paratuberculosis, Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Strada Faggiola 1, loc. Gariga—Podenzano (PC), Italy
| | - Luca Bolzoni
- Risk Analysis Unit, Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia Romagna, Via dei Mercati, Parma, Italy
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Abstract
Marine reserves (MRs) are used worldwide as a means of conserving biodiversity and protecting depleted populations. Despite major investments in MRs, their environmental and social benefits have proven difficult to demonstrate and are still debated. Clear expectations of the possible outcomes of MR establishment are needed to guide and strengthen empirical assessments. Previous models show that reserve establishment in overcapitalized, quota-based fisheries can reduce both catch and population abundance, thereby negating fisheries and even conservation benefits. By using a stage-structured, spatially explicit stochastic model, we show that catches under quota-based fisheries that include a network of MRs can exceed maximum sustainable yield (MSY) under conventional quota management if reserves provide protection to old, large spawners that disproportionally contribute to recruitment outside the reserves. Modelling results predict that the net fishery benefit of MRs is lost when gains in fecundity of old, large individuals are small, is highest in the case of sedentary adults with high larval dispersal, and decreases with adult mobility. We also show that environmental variability may mask fishery benefits of reserve implementation and that MRs may buffer against collapse when sustainable catch quotas are exceeded owing to stock overestimation or systematic overfishing.
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Affiliation(s)
- Giulio A De Leo
- Stanford University, Hopkins Marine Station and Woods Institute for the Environment, Pacific Grove, CA 93950, USA
| | - Fiorenza Micheli
- Stanford University, Hopkins Marine Station and Woods Institute for the Environment, Pacific Grove, CA 93950, USA
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Sokolow SH, Wood CL, Jones IJ, Swartz SJ, Lopez M, Hsieh MH, Lafferty KD, Kuris AM, Rickards C, De Leo GA. Global Assessment of Schistosomiasis Control Over the Past Century Shows Targeting the Snail Intermediate Host Works Best. PLoS Negl Trop Dis 2016; 10:e0004794. [PMID: 27441556 PMCID: PMC4956325 DOI: 10.1371/journal.pntd.0004794] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 05/31/2016] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Despite control efforts, human schistosomiasis remains prevalent throughout Africa, Asia, and South America. The global schistosomiasis burden has changed little since the new anthelmintic drug, praziquantel, promised widespread control. METHODOLOGY We evaluated large-scale schistosomiasis control attempts over the past century and across the globe by identifying factors that predict control program success: snail control (e.g., molluscicides or biological control), mass drug administrations (MDA) with praziquantel, or a combined strategy using both. For data, we compiled historical information on control tactics and their quantitative outcomes for all 83 countries and territories in which: (i) schistosomiasis was allegedly endemic during the 20th century, and (ii) schistosomiasis remains endemic, or (iii) schistosomiasis has been "eliminated," or is "no longer endemic," or transmission has been interrupted. PRINCIPAL FINDINGS Widespread snail control reduced prevalence by 92 ± 5% (N = 19) vs. 37 ± 7% (N = 29) for programs using little or no snail control. In addition, ecological, economic, and political factors contributed to schistosomiasis elimination. For instance, snail control was most common and widespread in wealthier countries and when control began earlier in the 20th century. CONCLUSIONS/SIGNIFICANCE Snail control has been the most effective way to reduce schistosomiasis prevalence. Despite evidence that snail control leads to long-term disease reduction and elimination, most current schistosomiasis control efforts emphasize MDA using praziquantel over snail control. Combining drug-based control programs with affordable snail control seems the best strategy for eliminating schistosomiasis.
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Affiliation(s)
- Susanne H. Sokolow
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
- Marine Science Institute, and Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, California, United States of America
- * E-mail:
| | - Chelsea L. Wood
- Michigan Society of Fellows, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Isabel J. Jones
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
| | - Scott J. Swartz
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
| | - Melina Lopez
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
| | - Michael H. Hsieh
- Children's National Health System, Washington, D.C., United States of America
- The George Washington University, Washington, D.C., United States of America
- Biomedical Research Institute, Rockville, Maryland, United States of America
| | - Kevin D. Lafferty
- Marine Science Institute, and Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, California, United States of America
- Western Ecological Research Center, U.S. Geological Survey, Santa Barbara, California, United States of America
| | - Armand M. Kuris
- Marine Science Institute, and Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Chloe Rickards
- Department of Bioengineering, Stanford University, Stanford, California, United States of America
| | - Giulio A. De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
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Perez-Saez J, Mari L, Bertuzzo E, Casagrandi R, Sokolow SH, De Leo GA, Mande T, Ceperley N, Froehlich JM, Sou M, Karambiri H, Yacouba H, Maiga A, Gatto M, Rinaldo A. A Theoretical Analysis of the Geography of Schistosomiasis in Burkina Faso Highlights the Roles of Human Mobility and Water Resources Development in Disease Transmission. PLoS Negl Trop Dis 2015; 9:e0004127. [PMID: 26513655 PMCID: PMC4625963 DOI: 10.1371/journal.pntd.0004127] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 09/08/2015] [Indexed: 12/28/2022] Open
Abstract
We study the geography of schistosomiasis across Burkina Faso by means of a spatially explicit model of water-based disease dynamics. The model quantitatively addresses the geographic stratification of disease burden in a novel framework by explicitly accounting for drivers and controls of the disease, including spatial information on the distributions of population and infrastructure, jointly with a general description of human mobility and climatic/ecological drivers. Spatial patterns of disease are analysed by the extraction and the mapping of suitable eigenvectors of the Jacobian matrix subsuming the stability of the disease-free equilibrium. The relevance of the work lies in the novel mapping of disease burden, a byproduct of the parametrization induced by regional upscaling, by model-guided field validations and in the predictive scenarios allowed by exploiting the range of possible parameters and processes. Human mobility is found to be a primary control at regional scales both for pathogen invasion success and the overall distribution of disease burden. The effects of water resources development highlighted by systematic reviews are accounted for by the average distances of human settlements from water bodies that are habitats for the parasite’s intermediate host. Our results confirm the empirical findings about the role of water resources development on disease spread into regions previously nearly disease-free also by inspection of empirical prevalence patterns. We conclude that while the model still needs refinements based on field and epidemiological evidence, the proposed framework provides a powerful tool for large-scale public health planning and schistosomiasis management. Dynamical models of schistosomiasis infections, even spatially explicit ones, have so far only addressed spatial scales encompassing at best a few villages and the disease transmission impacts of related short-range human mobility. Here, we build from existing models of disease dynamics and spread, including a proxy of the ecology of the intermediate host of the parasite, and from generalized reproduction numbers of SIR-type systems developed for epidemics of waterborne disease, to set up large-scale projections of spatial patterns of the disease at whole country level. We ground our study in Burkina Faso in sub-Saharan Africa, and its model of social and economic development including the infrastructure built to exploit water resources, especially irrigation schemes, which have been empirically linked to enhanced disease burden. We make extensive use of remotely sensed and field data, and capitalize on ecohydrological insight. We suggest that reliable nationwide patterns of disease burden can be projected in relation to the key roles of human mobility and water resources development subsuming exposure, and claim that the case at hand provides an insightful example towards the integration of development and environmental thinking not confined to ad-hoc indicators of human development.
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Affiliation(s)
- Javier Perez-Saez
- Laboratory of Ecohydrology, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Lorenzo Mari
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano, Italy
| | - Enrico Bertuzzo
- Laboratory of Ecohydrology, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Renato Casagrandi
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano, Italy
| | - Susanne H. Sokolow
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
- Marine Science Institute, University of California Santa Barbara, California, United States of America
| | - Giulio A. De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
- Woods Institute for the Environment, Stanford University, California, United States of America
| | - Theophile Mande
- Laboratory of Ecohydrology, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Natalie Ceperley
- Laboratory of Ecohydrology, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Jean-Marc Froehlich
- Laboratory of Ecohydrology, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Mariam Sou
- Institute International d’Ingénierie de l’Eau et de l’Environment, Ouagadougou, Burkina Faso
| | - Harouna Karambiri
- Institute International d’Ingénierie de l’Eau et de l’Environment, Ouagadougou, Burkina Faso
| | - Hamma Yacouba
- Institute International d’Ingénierie de l’Eau et de l’Environment, Ouagadougou, Burkina Faso
| | - Amadou Maiga
- Institute International d’Ingénierie de l’Eau et de l’Environment, Ouagadougou, Burkina Faso
| | - Marino Gatto
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano, Italy
| | - Andrea Rinaldo
- Laboratory of Ecohydrology, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Dipartimento ICEA, Università di Padova, Padova, Italy
- * E-mail:
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40
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Bevacqua D, Melià P, Gatto M, De Leo GA. A global viability assessment of the European eel. Glob Chang Biol 2015; 21:3323-3335. [PMID: 25965113 DOI: 10.1111/gcb.12972] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 03/19/2015] [Accepted: 03/23/2015] [Indexed: 06/04/2023]
Abstract
The global European eel (Anguilla anguilla) stock is critically endangered according to the IUCN, and the European Commission has urged the development of conservation plans aimed to ensure its viability. However, the complex life cycle of this panmictic species, which reproduces in the open ocean but spends most of its prereproductive life in continental waters (thus embracing a huge geographic range and a variety of habitat types), makes it difficult to assess the long-term effectiveness of conservation measures. The interplay between local and global stressors raises intriguing cross-scale conservation challenges that require a comprehensive modelling approach to be addressed. We developed a full life cycle model of the global European eel stock, encompassing both the oceanic and the continental phases of eel's life, and explicitly allowing for spatial heterogeneity in vital rates, availability of suitable habitat and settlement potential via a metapopulation approach. We calibrated the model against a long-term time series of global European eel catches and used it to hindcast the dynamics of the stock in the past and project it over the 21st century under different management scenarios. Although our analysis relies on a number of inevitable simplifying assumptions and on data that may not embrace the whole range of variation in population dynamics at the small spatiotemporal scale, our hindcast is consistent with the general pattern of decline of the stock over recent decades. The results of our projections suggest that (i) habitat loss played a major role in the European eel decline; (ii) the viability of the global stock is at risk if appropriate protection measures are not implemented; (iii) the recovery of spawner escapement requires that fishing mortality is significantly reduced; and (iv) the recovery of recruitment might not be feasible if reproductive output is not enhanced.
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Affiliation(s)
- Daniele Bevacqua
- Dipartimento di Bioscienze, Università degli Studi di Parma, viale Usberti 11/A, 43100, Parma, Italy
- INRA, UR1115 PSH, 84914, Avignon, France
| | - Paco Melià
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, via Ponzio 34/5, 20133, Milano, Italy
- Consorzio Interuniversitario per le Scienze del Mare, Piazzale Flaminio 9, 00196, Roma, Italy
| | - Marino Gatto
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, via Ponzio 34/5, 20133, Milano, Italy
- Consorzio Interuniversitario per le Scienze del Mare, Piazzale Flaminio 9, 00196, Roma, Italy
| | - Giulio A De Leo
- Dipartimento di Bioscienze, Università degli Studi di Parma, viale Usberti 11/A, 43100, Parma, Italy
- Hopkins Marine Station, Stanford University, 120 Oceanview blvd, 93950, Pacific Grove, CA, USA
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Rossi G, De Leo GA, Pongolini S, Natalini S, Vincenzi S, Bolzoni L. Epidemiological modelling for the assessment of bovine tuberculosis surveillance in the dairy farm network in Emilia-Romagna (Italy). Epidemics 2015; 11:62-70. [PMID: 25979283 DOI: 10.1016/j.epidem.2015.02.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 02/11/2015] [Accepted: 02/25/2015] [Indexed: 10/23/2022] Open
Abstract
Assessing the performance of a surveillance system for infectious diseases of domestic animals is a challenging task for health authorities. Therefore, it is important to assess what strategy is the most effective in identifying the onset of an epidemic and in minimizing the number of infected farms. The aim of the present work was to evaluate the performance of the bovine tuberculosis (bTB) surveillance system in the network of dairy farms in the Emilia-Romagna (ER) Region, Italy. A bTB-free Region since 2007, ER implements an integrated surveillance strategy based on three components, namely routine on-farm tuberculin skin-testing performed every 3 years, tuberculin skin-testing of cattle exchanged between farms, and post-mortem inspection at slaughterhouses. We assessed the effectiveness of surveillance by means of a stochastic network model of both within-farm and between-farm bTB dynamics calibrated on data available for ER dairy farms. Epidemic dynamics were simulated for five scenarios: the current ER surveillance system, a no surveillance scenario that we used as the benchmark to characterize epidemic dynamics, three additional scenarios in which one of the surveillance components was removed at a time so as to outline its significance in detecting the infection. For each scenario we ran Monte Carlo simulations of bTB epidemics following the random introduction of an infected individual in the network. System performances were assessed through the comparative analysis of a number of statistics, including the time required for epidemic detection and the total number of infected farms during the epidemic. Our analysis showed that slaughterhouse inspection is the most effective surveillance component in reducing the time for disease detection, while routine surveillance in reducing the number of multi-farms epidemics. On the other hand, testing exchanged cattle improved the performance of the surveillance system only marginally.
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Affiliation(s)
- Gianluigi Rossi
- Dipartimento di Bioscienze, Università di Parma, Parco Area delle Scienze 11/A, I-43124 Parma, Italy.
| | - Giulio A De Leo
- Stanford University, Hopkins Marine Station, Pacific Grove, CA 93950, USA
| | - Stefano Pongolini
- Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna, Via dei Mercati, 13/A, Parma I-43122, Italy
| | - Silvano Natalini
- Servizio Veterinario e Igiene Alimenti Assessorato Politiche per la Salute Regione Emilia-Romagna, Viale Aldo Moro 21, Bologna I-40127, Italy
| | - Simone Vincenzi
- Center for Stock Assessment Research, Department of Applied Mathematics and Statistics, University of California, Santa Cruz, CA 95064, USA; Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Via Ponzio 34/5, I-20133 Milan, Italy
| | - Luca Bolzoni
- Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna, Via dei Mercati, 13/A, Parma I-43122, Italy; Department of Biodiversity and Molecular Ecology, Research and Innovation Centre - Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy
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Bolzoni L, Tessoni V, Groppi M, De Leo GA. React or wait: which optimal culling strategy to control infectious diseases in wildlife. J Math Biol 2013; 69:1001-25. [PMID: 24057080 DOI: 10.1007/s00285-013-0726-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 08/23/2013] [Indexed: 11/26/2022]
Abstract
We applied optimal control theory to an SI epidemic model to identify optimal culling strategies for diseases management in wildlife. We focused on different forms of the objective function, including linear control, quadratic control, and control with limited amount of resources. Moreover, we identified optimal solutions under different assumptions on disease-free host dynamics, namely: self-regulating logistic growth, Malthusian growth, and the case of negligible demography. We showed that the correct characterization of the disease-free host growth is crucial for defining optimal disease control strategies. By analytical investigations of the model with negligible demography, we demonstrated that the optimal strategy for the linear control can be either to cull at the maximum rate at the very beginning of the epidemic (reactive culling) when the culling cost is low, or never to cull, when culling cost is high. On the other hand, in the cases of quadratic control or limited resources, we demonstrated that the optimal strategy is always reactive. Numerical analyses for hosts with logistic growth showed that, in the case of linear control, the optimal strategy is always reactive when culling cost is low. In contrast, if the culling cost is high, the optimal strategy is to delay control, i.e. not to cull at the onset of the epidemic. Finally, we showed that for diseases with the same basic reproduction number delayed control can be optimal for acute infections, i.e. characterized by high disease-induced mortality and fast dynamics, while reactive control can be optimal for chronic ones.
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Affiliation(s)
- Luca Bolzoni
- Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Via dei Mercati 13, 43100 , Parma, Italy,
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Pujolar JM, Schiavina M, Di Franco A, Melià P, Guidetti P, Gatto M, De Leo GA, Zane L. Understanding the effectiveness of marine protected areas using genetic connectivity patterns and Lagrangian simulations. DIVERS DISTRIB 2013. [DOI: 10.1111/ddi.12114] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Affiliation(s)
- José Martin Pujolar
- Dipartimento di Biologia; Università di Padova; I-35131 Padova Italy
- Department of Bioscience; Aarhus University; DK-8000 Aarhus Denmark
| | - Marcello Schiavina
- Dipartimento di Elettronica e Informazione; Politecnico di Milano; I-20133 Milano Italy
- Dipartimento di Scienze Ambientali; Università degli Studi di Parma; I-43100 Parma Italy
| | - Antonio Di Franco
- Laboratory of Conservation and Management of Marine and Coastal Resources; DiSTeBA; University of Salento; 73100 Lecce Italy
- Université de Nice Sophia-Antipolis; Faculté des Sciences; EA 4228 ECOMERS; F-06108 Nice cedex 2 France
| | - Paco Melià
- Dipartimento di Elettronica e Informazione; Politecnico di Milano; I-20133 Milano Italy
| | - Paolo Guidetti
- Laboratory of Conservation and Management of Marine and Coastal Resources; DiSTeBA; University of Salento; 73100 Lecce Italy
- Université de Nice Sophia-Antipolis; Faculté des Sciences; EA 4228 ECOMERS; F-06108 Nice cedex 2 France
| | - Marino Gatto
- Dipartimento di Elettronica e Informazione; Politecnico di Milano; I-20133 Milano Italy
| | - Giulio A. De Leo
- Dipartimento di Scienze Ambientali; Università degli Studi di Parma; I-43100 Parma Italy
- Hopkins Marine Station; Stanford University; 93950 Pacific Grove CA USA
| | - Lorenzo Zane
- Dipartimento di Biologia; Università di Padova; I-35131 Padova Italy
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Cordioli M, Ranzi A, De Leo GA, Lauriola P. A review of exposure assessment methods in epidemiological studies on incinerators. J Environ Public Health 2013; 2013:129470. [PMID: 23840228 PMCID: PMC3694556 DOI: 10.1155/2013/129470] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 05/23/2013] [Indexed: 11/18/2022]
Abstract
Incineration is a common technology for waste disposal, and there is public concern for the health impact deriving from incinerators. Poor exposure assessment has been claimed as one of the main causes of inconsistency in the epidemiological literature. We reviewed 41 studies on incinerators published between 1984 and January 2013 and classified them on the basis of exposure assessment approach. Moreover, we performed a simulation study to explore how the different exposure metrics may influence the exposure levels used in epidemiological studies. 19 studies used linear distance as a measure of exposure to incinerators, 11 studies atmospheric dispersion models, and the remaining 11 studies a qualitative variable such as presence/absence of the source. All reviewed studies utilized residence as a proxy for population exposure, although residence location was evaluated with different precision (e.g., municipality, census block, or exact address). Only one study reconstructed temporal variability in exposure. Our simulation study showed a notable degree of exposure misclassification caused by the use of distance compared to dispersion modelling. We suggest that future studies (i) make full use of pollution dispersion models; (ii) localize population on a fine-scale; and (iii) explicitly account for the presence of potential environmental and socioeconomic confounding.
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Affiliation(s)
- Michele Cordioli
- Department of Bio-Sciences, University of Parma, Parco Area delle Scienze 11/a, 43124 Parma, Italy.
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Abstract
The removal of individuals from an infected population (culling) is a common strategy used to eradicate wildlife diseases. The manipulation of host density can impose strong selective pressures on pathogen virulence by changing the ecological conditions, thus affecting the effectiveness of eradication programs. We present an analysis of the effect of virulence evolution on culling by extending a susceptible-infected model to the case of competing strains with superinfection. To assess both short- and long-term effects, we first carried out the analysis on an ecological timescale, with a two-strain competition model; then we explore the dynamics of a continuum of pathogenic strains on evolutionary timescales using a quantitative genetics approach (when infection and evolutionary processes occur on comparable timescales) and a game-theoretic approach (when evolutionary processes occur on a slower scale). We demonstrate that the competition among pathogenic variants in the presence of superinfection affects outcome of culling campaigns, since increased host mortality may select for less virulent strains able to establish in sparser populations. This can lead to the counterintuitive result that disease abundance and prevalence may even increase with culling, thus making the eradication of infections considerably less likely. This is particularly relevant in the case of zoonoses where higher prevalence and abundance of pathogens in wild reservoirs may increase the risk of spillover in livestock and humans.
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Affiliation(s)
- Luca Bolzoni
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre-Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy.
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Cordioli M, Vincenzi S, De Leo GA. Effects of heat recovery for district heating on waste incineration health impact: a simulation study in Northern Italy. Sci Total Environ 2013; 444:369-380. [PMID: 23280295 DOI: 10.1016/j.scitotenv.2012.11.079] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Revised: 10/30/2012] [Accepted: 11/25/2012] [Indexed: 06/01/2023]
Abstract
The construction of waste incinerators in populated areas always causes substantial public concern. Since the heat from waste combustion can be recovered to power district heating networks and allows for the switch-off of domestic boilers in urbanized areas, predictive models for health assessment should also take into account the potential benefits of abating an important source of diffuse emission. In this work, we simulated the dispersion of atmospheric pollutants from a waste incinerator under construction in Parma (Italy) into different environmental compartments and estimated the potential health effect of both criteria- (PM(10)) and micro-pollutants (PCDD/F, PAH, Cd, Hg). We analyzed two emission scenarios, one considering only the new incinerator, and the other accounting for the potential decrease in pollutant concentrations due to the activation of a district heating network. We estimated the effect of uncertainty in parameter estimation on health risk through Monte Carlo simulations. In addition, we analyzed the robustness of health risk to alternative assumptions on: a) the geographical origins of the potentially contaminated food, and b) the dietary habits of the exposed population. Our analysis showed that under the specific set of assumptions and emission scenarios explored in the present work: (i) the proposed waste incinerator plant appears to cause negligible harm to the resident population; (ii) despite the net increase in PM(10) mass balance, ground-level concentration of fine particulate matter may be curbed by the activation of an extensive district heating system powered through waste combustion heat recovery and the concurrent switch-off of domestic/industrial heating boilers. In addition, our study showed that the health risk caused by waste incineration emissions is sensitive to assumptions about the typical diet of the resident population, and the geographical origins of food production.
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Affiliation(s)
- Michele Cordioli
- Department of Environmental Sciences, University of Parma, Parco Area delle Scienze 33/A, I-43100 Parma, Italy.
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Quadroni S, Galassi S, Capoccioni F, Ciccotti E, Grandi G, De Leo GA, Bettinetti R. Contamination, parasitism and condition of Anguilla anguilla in three Italian stocks. Ecotoxicology 2013; 22:94-108. [PMID: 23076840 DOI: 10.1007/s10646-012-1006-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/02/2012] [Indexed: 06/01/2023]
Abstract
In conjunction with habitat loss and overfishing, pollution and parasitism are believed to be relevant causes of collapse of Anguilla, as these can affect eel swimming ability and the development of gonads and embryos. The present study investigated Persistent Organic Pollutant (POP) concentrations, infection levels of Anguillicoloides crassus, lipid content and gonad abnormalities in eels sampled in 2007-2008 in three Italian water bodies (Caprolace Lake, Lesina Lagoon and Tevere River) that vary in salinity, trophic condition, contamination level and fishing pressure. Our analysis revealed that low-to-moderate levels of contamination and parasitism were not associated with gonad abnormalities in Caprolace Lake and Lesina Lagoon. On the contrary, POP concentrations and abundances of swim bladder nematodes were remarkably high in eels from the heavily urbanized Tevere River and were associated with significant gonad and swim bladder alterations. Contamination and infestation levels were so high to potentially impair spawner successful migration and reproduction. POP concentrations in Tevere eels also exceeded levels considered safe for food consumption. Though marginally contaminated, eels from the oligotrophic Caprolace Lake were in critical health condition: their lipid reserve was so low as to be considered insufficient to sustain the energetic costs of the transoceanic migration. Lesina eel stock was the only one displaying relatively good quality but here spawner abundance is likely limited by overfishing. Our results suggest that multiple stressors may potentially affect eel reproductive success. More definitive studies are needed to assess whether health effects caused by these multiple stressors are additive, compensatory or synergistic.
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Affiliation(s)
- Silvia Quadroni
- Department of Theoretical and Applied Sciences (Environmental Section), University of Insubria, Via Dunant 3, 21100, Varese, Italy.
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Di Franco A, Coppini G, Pujolar JM, De Leo GA, Gatto M, Lyubartsev V, Melià P, Zane L, Guidetti P. Assessing dispersal patterns of fish propagules from an effective mediterranean marine protected area. PLoS One 2012; 7:e52108. [PMID: 23284887 PMCID: PMC3527352 DOI: 10.1371/journal.pone.0052108] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Accepted: 11/12/2012] [Indexed: 11/18/2022] Open
Abstract
Successfully enforced marine protected areas (MPAs) have been widely demonstrated to allow, within their boundaries, the recovery of exploited species and beyond their boundaries, the spillover of juvenile and adult fish. Little evidence is available about the so-called ‘recruitment subsidy’, the augmented production of propagules (i.e. eggs and larvae) due to the increased abundance of large-sized spawners hosted within effective MPAs. Once emitted, propagules can be locally retained and/or exported elsewhere. Patterns of propagule retention and/or export from MPAs have been little investigated, especially in the Mediterranean. This study investigated the potential for propagule production and retention/export from a Mediterranean MPA (Torre Guaceto, SW Adriatic Sea) using the white sea bream, Diplodus sargus sargus, as a model species. A multidisciplinary approach was used combining 1) spatial distribution patterns of individuals (post-settlers and adults) assessed through visual census within Torre Guaceto MPA and in northern and southern unprotected areas, 2) Lagrangian simulations of dispersal based on an oceanographic model of the region and data on early life-history traits of the species (spawning date, pelagic larval duration) and 3) a preliminary genetic study using microsatellite loci. Results show that the MPA hosts higher densities of larger-sized spawners than outside areas, potentially guaranteeing higher propagule production. Model simulations and field observation suggest that larval retention within and long-distance dispersal across MPA boundaries allow the replenishment of the MPA and of exploited populations up to 100 km down-current (southward) from the MPA. This pattern partially agrees with the high genetic homogeneity found in the entire study area (no differences in genetic composition and diversity indices), suggesting a high gene flow. By contributing to a better understanding of propagule dispersal patterns, these findings provide crucial information for the design of MPAs and MPA networks effective to replenish fish stocks and enhance fisheries in unprotected areas.
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Affiliation(s)
- Antonio Di Franco
- Laboratory of Conservation and Management of Marine and Coastal Resources, Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, University of Salento-Consorzio Nazionale Interuniversitario per le Scienze del Mare, Lecce, Italy.
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Micheli F, Saenz-Arroyo A, Greenley A, Vazquez L, Espinoza Montes JA, Rossetto M, De Leo GA. Evidence that marine reserves enhance resilience to climatic impacts. PLoS One 2012; 7:e40832. [PMID: 22855690 PMCID: PMC3408031 DOI: 10.1371/journal.pone.0040832] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 06/15/2012] [Indexed: 11/18/2022] Open
Abstract
Establishment of marine protected areas, including fully protected marine
reserves, is one of the few management tools available for local communities to
combat the deleterious effect of large scale environmental impacts, including
global climate change, on ocean ecosystems. Despite the common hope that
reserves play this role, empirical evidence of the effectiveness of local
protection against global problems is lacking. Here we show that marine reserves
increase the resilience of marine populations to a mass mortality event possibly
caused by climate-driven hypoxia. Despite high and widespread adult mortality of
benthic invertebrates in Baja California, Mexico, that affected populations both
within and outside marine reserves, juvenile replenishment of the species that
supports local economies, the pink abalone Haliotis corrugata,
remained stable within reserves because of large body size and high egg
production of the protected adults. Thus, local protection provided resilience
through greater resistance and faster recovery of protected populations.
Moreover, this benefit extended to adjacent unprotected areas through larval
spillover across the edges of the reserves. While climate change mitigation is
being debated, coastal communities have few tools to slow down negative impacts
of global environmental shifts. These results show that marine protected areas
can provide such protection.
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Affiliation(s)
- Fiorenza Micheli
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America.
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50
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Bevacqua D, Capoccioni F, Melià P, Vincenzi S, Pujolar JM, De Leo GA, Ciccotti E. Fishery-induced selection for slow somatic growth in European eel. PLoS One 2012; 7:e37622. [PMID: 22666373 PMCID: PMC3358250 DOI: 10.1371/journal.pone.0037622] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Accepted: 04/22/2012] [Indexed: 11/30/2022] Open
Abstract
Both theoretical and experimental studies have shown that fishing mortality can induce adaptive responses in body growth rates of fishes in the opposite direction of natural selection. We compared body growth rates in European eel (Anguilla anguilla) from three Mediterranean stocks subject to different fishing pressure. Results are consistent with the hypotheses that i) fast-growing individuals are more likely to survive until sexual maturity than slow-growing ones under natural conditions (no fishing) and ii) fishing can select for slow-growing individuals by removing fast-growing ones. Although the possibility of human-induced evolution seems remote for a panmictic species like such as the European eel, further research is desirable to assess the implications of the intensive exploitation on this critically endangered fish.
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Affiliation(s)
- Daniele Bevacqua
- Dipartimento di Scienze Ambientali, Università degli Studi di Parma, Parma, Italy
- INRA, UR1115 PSH, Avignon, France
| | | | - Paco Melià
- Dipartimento di Elettronica e Informazione, Politecnico di Milano, Milano, Italy
| | - Simone Vincenzi
- Centre for Stock Assessment Research, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - José M. Pujolar
- Dipartimento di Biologia, Università degli Studi di Padova, Padova, Italy
| | - Giulio A. De Leo
- Dipartimento di Scienze Ambientali, Università degli Studi di Parma, Parma, Italy
- Hopkins Marine Station, Stanford University, Stanford, California, United States of America
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