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Blankespoor CL, Blankespoor HD, DeJong RJ. Swimmer's itch control: Timely waterfowl brood relocation significantly reduces an avian schistosome population and human cases on recreational lakes. PLoS One 2024; 19:e0288948. [PMID: 38359003 PMCID: PMC10868848 DOI: 10.1371/journal.pone.0288948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 01/18/2024] [Indexed: 02/17/2024] Open
Abstract
Swimmer's itch (SI) is a dermatitis in humans caused by cercariae of avian and mammalian schistosomes which emerge from infected snails on a daily basis. Mitigation methods for SI have long been sought with little success. Copper sulfate application to the water to kill the snail hosts is the historically employed method, but is localized, temporary, and harmful to many aquatic species. Here, we test an alternative method to control Trichobilharzia stagnicolae, a species well-known to cause SI in northern Michigan and elsewhere in North America. Summer relocation of broods of the only known vertebrate host, common merganser (Mergus merganser), greatly reduced snail infection prevalence the following year on two large, geographically separated lakes in northern Michigan. Subsequent years of host relocation achieved and maintained snail infection prevalence at ~0.05%, more than an order of magnitude lower than pre-intervention. A Before-After-Control-Intervention (BACI) study design using multiple-year snail infection data from two intervention lakes and three control lakes demonstrates that dramatic lake-wide reduction of an avian schistosome can be achieved and is not due to natural fluctuations in the parasite populations. The relevance of reducing snail infection prevalence is demonstrated by a large seven-year data set of SI incidence in swimmers at a high-use beach, which showed a substantial reduction in SI cases in two successive years after relocation began. In addition, data from another Michigan lake where vertebrate-host based intervention occurred in the 1980's are analyzed statistically and show a remarkably similar pattern of reduction in snail infection prevalence. Together, these results demonstrate a highly effective SI mitigation strategy that avoids the use of environmentally suspect chemicals and removes incentive for lethal host removal. Biologically, the results strongly suggest that T. stagnicolae is reliant on the yearly hatch of ducklings to maintain populations at high levels on a lake and that the role of migratory hosts in the spring and fall is much less significant.
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Affiliation(s)
- Curtis L. Blankespoor
- Science Department, Jackson College, Jackson, Michigan, United States of America
- University of Michigan Biological Station, Pellston, Michigan, United States of America
- Swimmer’s Itch Solutions, LLC, Adrian, Michigan, United States of America
| | - Harvey D. Blankespoor
- University of Michigan Biological Station, Pellston, Michigan, United States of America
- Swimmer’s Itch Solutions, LLC, Adrian, Michigan, United States of America
- Department of Biology, Hope College, Holland, Michigan, United States of America
| | - Randall J. DeJong
- University of Michigan Biological Station, Pellston, Michigan, United States of America
- Swimmer’s Itch Solutions, LLC, Adrian, Michigan, United States of America
- Department of Biology, Calvin University, Grand Rapids, Michigan, United States of America
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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 : THE PREPRINT SERVER FOR BIOLOGY 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] [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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3
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Manalo DL, Bolivar JKG, Yap PR, Gomez MRR, Saldo ZP, Espino MJM, Dilig JE, Fornillos RJC, Perez SA, Baga RA, Sunico LS, Fontanilla IKC, Leonardo LR. From Perpetual Wetness to Soil Chemistry: Enumerating Environmental and Physicochemical Factors Favoring Oncomelania hupensis quadrasi Snail Presence in the Municipality of Gonzaga, Cagayan, Philippines. Trop Med Infect Dis 2023; 9:9. [PMID: 38251207 PMCID: PMC10819408 DOI: 10.3390/tropicalmed9010009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 12/02/2023] [Accepted: 12/03/2023] [Indexed: 01/23/2024] Open
Abstract
Snail control to complement mass drug administration is being promoted by the World Health Organization for schistosomiasis control. Oncomelania hupensis quadrasi, the snail intermediate host of Schistosoma japonicum in the Philippines, has a very focal distribution; thus, scrutinizing baseline data and parameters affecting this distribution is very crucial. In this study in Gonzaga, Cagayan, Philippines, snail habitats were surveyed, and the various factors affecting the existence of the snails were determined. Malacological surveys and the mapping of sites of perpetual wetness in five endemic and five neighboring non-endemic barangays were conducted. Environmental and physicochemical factors were also examined. Maps of both snail and non-snail sites were generated. Of the fifty sites surveyed, O. h. quadrasi were found in twelve sites, and two sites yielded snails that were infected with S. japonicum cercariae. Factors such as silty loam soil, proximity to a snail site, water ammonia, and soil attributes (organic matter, iron, and pH) are all significantly associated with the presence of snails. In contrast, types of habitats, temperatures, and soil aggregation have no established association with the existence of snails. Mapping snail sites and determining factors favoring snail presence are vital to eliminating snails. These approaches will significantly maximize control impact and minimize wasted efforts and resources, especially in resource-limited schistosomiasis endemic areas.
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Affiliation(s)
- Daria L. Manalo
- Department of Health, Research Institute for Tropical Medicine, 9002 Research Drive, Filinvest Corporate City, Alabang, Muntinlupa 1781, Philippines; (J.K.G.B.); (P.R.Y.); (M.R.R.G.)
- Institute of Biology, University of the Philippines Diliman, Quezon 1101, Philippines (I.K.C.F.); (L.R.L.)
| | - Jude Karlo G. Bolivar
- Department of Health, Research Institute for Tropical Medicine, 9002 Research Drive, Filinvest Corporate City, Alabang, Muntinlupa 1781, Philippines; (J.K.G.B.); (P.R.Y.); (M.R.R.G.)
- Department of Science and Technology, Science Education Institute, Taguig 1631, Philippines
| | - Paul Raymund Yap
- Department of Health, Research Institute for Tropical Medicine, 9002 Research Drive, Filinvest Corporate City, Alabang, Muntinlupa 1781, Philippines; (J.K.G.B.); (P.R.Y.); (M.R.R.G.)
- Department of Science and Technology, Science Education Institute, Taguig 1631, Philippines
| | - Ma. Ricci R. Gomez
- Department of Health, Research Institute for Tropical Medicine, 9002 Research Drive, Filinvest Corporate City, Alabang, Muntinlupa 1781, Philippines; (J.K.G.B.); (P.R.Y.); (M.R.R.G.)
| | - Zaldy P. Saldo
- Department of Health, Research Institute for Tropical Medicine, 9002 Research Drive, Filinvest Corporate City, Alabang, Muntinlupa 1781, Philippines; (J.K.G.B.); (P.R.Y.); (M.R.R.G.)
| | - Mark Joseph M. Espino
- Department of Health, Research Institute for Tropical Medicine, 9002 Research Drive, Filinvest Corporate City, Alabang, Muntinlupa 1781, Philippines; (J.K.G.B.); (P.R.Y.); (M.R.R.G.)
| | - Joselito E. Dilig
- Department of Health, Research Institute for Tropical Medicine, 9002 Research Drive, Filinvest Corporate City, Alabang, Muntinlupa 1781, Philippines; (J.K.G.B.); (P.R.Y.); (M.R.R.G.)
| | - Raffy Jay C. Fornillos
- Institute of Biology, University of the Philippines Diliman, Quezon 1101, Philippines (I.K.C.F.); (L.R.L.)
| | - Shirlyn A. Perez
- Center for Health and Development Region II, Carig Regional Center, Tuguegarao 3500, Philippines
| | - Regie A. Baga
- Center for Health and Development Region II, Carig Regional Center, Tuguegarao 3500, Philippines
| | | | - Ian Kendrich C. Fontanilla
- Institute of Biology, University of the Philippines Diliman, Quezon 1101, Philippines (I.K.C.F.); (L.R.L.)
| | - Lydia R. Leonardo
- Institute of Biology, University of the Philippines Diliman, Quezon 1101, Philippines (I.K.C.F.); (L.R.L.)
- Office of Research Coordination, University of the East, 2219 C.M. Recto Avenue, Brgy. 404, Zone 41, Sampaloc, Manila 1008, Philippines
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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] [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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5
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Schols R, Vanoverberghe I, Huyse T, Decaestecker E. Host-bacteriome transplants of the schistosome snail host Biomphalaria glabrata reflect species-specific associations. FEMS Microbiol Ecol 2023; 99:fiad101. [PMID: 37632232 PMCID: PMC10481996 DOI: 10.1093/femsec/fiad101] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 08/09/2023] [Accepted: 08/23/2023] [Indexed: 08/27/2023] Open
Abstract
Microbial symbionts can affect host phenotypes and, thereby, ecosystem functioning. The microbiome is increasingly being recognized as an important player in the tripartite interaction between parasitic flatworms, snail intermediate hosts, and the snail microbiome. In order to better understand these interactions, transplant experiments are needed, which rely on the development of a reliable and reproducible protocol to obtain microbiome-disturbed snails. Here, we report on the first successful snail bacteriome transplants, which indicate that Biomphalaria glabrata can accrue novel bacterial assemblies depending on the available environmental bacteria obtained from donor snails. Moreover, the phylogenetic relatedness of the donor host significantly affected recipients' survival probability, corroborating the phylosymbiosis pattern in freshwater snails. The transplant technique described here, complemented by field-based studies, could facilitate future research endeavors to investigate the role of specific bacteria or bacterial communities in parasitic flatworm resistance of B. glabrata and might ultimately pave the way for microbiome-mediated control of snail-borne diseases.
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Affiliation(s)
- Ruben Schols
- Department of Biology, Royal Museum for Central Africa, 3080 Tervuren, Belgium
- Laboratory of Aquatic Biology, KU Leuven, Campus Kortrijk, 8500 Kortrijk, Belgium
| | - Isabel Vanoverberghe
- Laboratory of Aquatic Biology, KU Leuven, Campus Kortrijk, 8500 Kortrijk, Belgium
| | - Tine Huyse
- Department of Biology, Royal Museum for Central Africa, 3080 Tervuren, Belgium
| | - Ellen Decaestecker
- Laboratory of Aquatic Biology, KU Leuven, Campus Kortrijk, 8500 Kortrijk, Belgium
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6
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Bu L, Lu L, Laidemitt MR, Zhang SM, Mutuku M, Mkoji G, Steinauer M, Loker ES. A genome sequence for Biomphalaria pfeifferi, the major vector snail for the human-infecting parasite Schistosoma mansoni. PLoS Negl Trop Dis 2023; 17:e0011208. [PMID: 36961841 PMCID: PMC10075465 DOI: 10.1371/journal.pntd.0011208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 04/05/2023] [Accepted: 02/27/2023] [Indexed: 03/25/2023] Open
Abstract
BACKGROUND Biomphalaria pfeifferi is the world's most widely distributed and commonly implicated vector snail species for the causative agent of human intestinal schistosomiasis, Schistosoma mansoni. In efforts to control S. mansoni transmission, chemotherapy alone has proven insufficient. New approaches to snail control offer a way forward, and possible genetic manipulations of snail vectors will require new tools. Towards this end, we here offer a diverse set of genomic resources for the important African schistosome vector, B. pfeifferi. METHODOLOGY/PRINCIPAL FINDINGS Based largely on PacBio High-Fidelity long reads, we report a genome assembly size of 772 Mb for B. pfeifferi (Kenya), smaller in size than known genomes of other planorbid schistosome vectors. In a total of 505 scaffolds (N50 = 3.2Mb), 430 were assigned to 18 large linkage groups inferred to represent the 18 known chromosomes, based on whole genome comparisons with Biomphalaria glabrata. The annotated B. pfeifferi genome reveals a divergence time of 3.01 million years with B. glabrata, a South American species believed to be similar to the progenitors of B. pfeifferi which undertook a trans-Atlantic colonization < five million years ago. CONCLUSIONS/SIGNIFICANCE The genome for this preferentially self-crossing species is less heterozygous than related species known to be preferential out-crossers; its smaller genome relative to congeners may similarly reflect its preference for selfing. Expansions of gene families with immune relevance are noted, including the FReD gene family which is far more similar in its composition to B. glabrata than to Bulinus truncatus, a vector for Schistosoma haematobium. Provision of this annotated genome will help better understand the dependencies of trematodes on snails, enable broader comparative insights regarding factors contributing to susceptibility/ resistance of snails to schistosome infections, and provide an invaluable resource with respect to identifying and manipulating snail genes as potential targets for more specific snail control programs.
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Affiliation(s)
- Lijing Bu
- Department of Biology, Center for Evolutionary and Theoretical Immunology, Parasite Division Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Lijun Lu
- Department of Biology, Center for Evolutionary and Theoretical Immunology, Parasite Division Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Martina R Laidemitt
- Department of Biology, Center for Evolutionary and Theoretical Immunology, Parasite Division Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Si-Ming Zhang
- Department of Biology, Center for Evolutionary and Theoretical Immunology, Parasite Division Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Martin Mutuku
- Center for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Gerald Mkoji
- Center for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Michelle Steinauer
- College of Osteopathic Medicine of the Pacific-Northwest, Western University of Health Sciences, Lebanon, Oregon, United States of America
| | - Eric S Loker
- Department of Biology, Center for Evolutionary and Theoretical Immunology, Parasite Division Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico, United States of America
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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. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 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] [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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Muhsin MA, Wang X, Kabole FM, Zilabumba J, Yang K. The Indispensability of Snail Control for Accelerating Schistosomiasis Elimination: Evidence from Zanzibar. Trop Med Infect Dis 2022; 7:tropicalmed7110347. [PMID: 36355889 PMCID: PMC9699613 DOI: 10.3390/tropicalmed7110347] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 10/27/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022] Open
Abstract
Schistosomiasis is a serious and neglected global tropical disease, affecting upwards of 230 million people, with more than 95% of infections concentrated in Africa. For many years, the main schistosomiasis control strategy in Africa focused on mass drug administration (MDA). The aim of this study was to compare the difference between MDA alone and alongside another intervention, namely snail control, by exploring effective measures for eliminating schistosomiasis. Retrospective data of human prevalence on Schistosoma haematobium and major control measures were collected from the China-Zanzibar-WHO Cooperation Project for Schistosomiasis Elimination (CZW) and the Zanzibar Elimination of Schistosomiasis Transmission (ZEST) project since 2012. The optimal order polynomial regression fitting model and joinpoint regression model (JRM) were used to analyze trends in schistosomiasis prevalence and the consistency of change points with strengthening of the control measures. In Unguja Island, the main control measure was MDA, and prevalence decreased to a nadir in 2019, and then rebounded. The R2 value of the optimal fitting model was 0.6641. There was a single JRM changepoint in 2019, the annual percent change (APC) was −19.3% (p < 0.05) from 2012 to 2019, and the APC was 59.7% (p > 0.05) from 2019 to 2021. In Pemba Island, the main control measures until 2016 was MDA, while integrated measures of MDA and snail control were implemented from 2017, the prevalence continuously decreased, and the R2 value was 0.8673. There was also a single JRM changepoint in 2017, the APC was −22.2% (p < 0.05) from 2012 to 2017, and was maintained at −8.6% (p > 0.05) from 2017 to 2021. Our data indicate that, while it is challenging to eliminate schistosomiasis by MDA alone, integrated measures, including both MDA and snail control, can prevent reinfection and help to eliminate the diseases in Africa.
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Affiliation(s)
- Mtumweni Ali Muhsin
- School of Medicine, Jiangnan University, Wuxi 214122, China
- Neglected Tropical Disease Control Programme, Ministry of Health, Mnazi Mmoja, Zanzibar 16108, Tanzania
| | - Xinyao Wang
- Jiangsu Institute of Parasitic Diseases, Wuxi 214064, China
- Key Laboratory of National Health and Family Planning, Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi 214064, China
| | - Fatma Mohammed Kabole
- Neglected Tropical Disease Control Programme, Ministry of Health, Mnazi Mmoja, Zanzibar 16108, Tanzania
| | - January Zilabumba
- Neglected Tropical Disease Control Programme, Ministry of Health, Mnazi Mmoja, Zanzibar 16108, Tanzania
| | - Kun Yang
- School of Medicine, Jiangnan University, Wuxi 214122, China
- Jiangsu Institute of Parasitic Diseases, Wuxi 214064, China
- Key Laboratory of National Health and Family Planning, Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi 214064, China
- School of Public Health, Nanjing Medical University, Nanjing 211166, China
- Correspondence:
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Stanicka A, Cichy A, Bulantová J, Labecka AM, Ćmiel AM, Templin J, Horák P, Żbikowska E. Thinking "outside the box": The effect of nontarget snails in the aquatic community on mollusc-borne diseases. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 845:157264. [PMID: 35820526 DOI: 10.1016/j.scitotenv.2022.157264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 07/05/2022] [Accepted: 07/06/2022] [Indexed: 06/15/2023]
Abstract
There is a great need to understand the impact of complex communities on the free-living parasite stages that are part of them. This task becomes more complex as nonnative species emerge, changing existing relationships and shaping new interactions in the community. A relevant question would be: Can the coexistence of nontarget snails with the target hosts contribute to trematodasis control? We used field and experimental approaches to investigate nonnative competitor-induced parasite dilution. During a three-year field study, we investigated digenean infection in Lymnaea stagnalis from eight Polish lakes inhabited or uninhabited by Potamopyrgus antipodarum. Additionally, we verified the presence of digenean infections in the populations of P. antipodarum. Moreover, we conducted an experimental infection of L. stagnalis with miracidia of Trichobilharzia szidati under increasing densities of P. antipodarum and aimed to infect P. antipodarum with them separately. The prevalence of avian schistosomes in lymnaeid snails was significantly higher in uninhabited lakes than in lakes inhabited by P. antipodarum. Our study indicates that waters with a higher density of invaders have a lower prevalence of avian schistosomes in lymnaeid hosts. The results of experimental studies confirmed that the presence of high densities of P. antipodarum reduces the probability of target host infection. Both field and experimental studies rule out the role of P. antipodarum as a source of avian schistosome cercariae. Here, a nonnative species was tested as a diluter, which in practice may be harmful to the local environment. This work is not a call for the introduction of nonnative species; it is intended to be a stimulus for researchers to continue searching for natural enemies of parasites because, as our results show, they exist. Finding natural enemies to the most dangerous species of human and animal parasites that will pose no threat to the local environment could be groundbreaking.
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Affiliation(s)
- Anna Stanicka
- Department of Invertebrate Zoology and Parasitology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland.
| | - Anna Cichy
- Department of Invertebrate Zoology and Parasitology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland
| | - Jana Bulantová
- Department of Parasitology, Faculty of Science, Charles University, Viničná 7, 128 44 Prague, Czechia
| | - Anna Maria Labecka
- Institute of Environmental Sciences, Faculty of Biology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland
| | - Adam Marcin Ćmiel
- Institute of Nature Conservation, Polish Academy of Sciences, al. A. Mickiewicza 33, 31-120 Kraków, Poland
| | - Julita Templin
- Department of Invertebrate Zoology and Parasitology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland
| | - Petr Horák
- Department of Parasitology, Faculty of Science, Charles University, Viničná 7, 128 44 Prague, Czechia
| | - Elżbieta Żbikowska
- Department of Invertebrate Zoology and Parasitology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland
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10
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Environmental DNA in human and veterinary parasitology - Current applications and future prospects for monitoring and control. Food Waterborne Parasitol 2022; 29:e00183. [DOI: 10.1016/j.fawpar.2022.e00183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 11/04/2022] [Accepted: 11/09/2022] [Indexed: 11/15/2022] Open
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11
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Modeling the efficacy of CRISPR gene drive for snail immunity on schistosomiasis control. PLoS Negl Trop Dis 2022; 16:e0010894. [DOI: 10.1371/journal.pntd.0010894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 11/10/2022] [Accepted: 10/14/2022] [Indexed: 11/05/2022] Open
Abstract
CRISPR gene drives could revolutionize the control of infectious diseases by accelerating the spread of engineered traits that limit parasite transmission in wild populations. Gene drive technology in mollusks has received little attention despite the role of freshwater snails as hosts of parasitic flukes causing 200 million annual cases of schistosomiasis. A successful drive in snails must overcome self-fertilization, a common feature of host snails which could prevents a drive’s spread. Here we developed a novel population genetic model accounting for snails’ mixed mating and population dynamics, susceptibility to parasite infection regulated by multiple alleles, fitness differences between genotypes, and a range of drive characteristics. We integrated this model with an epidemiological model of schistosomiasis transmission to show that a snail population modification drive targeting immunity to infection can be hindered by a variety of biological and ecological factors; yet under a range of conditions, disease reduction achieved by chemotherapy treatment of the human population can be maintained with a drive. Alone a drive modifying snail immunity could achieve significant disease reduction in humans several years after release. These results indicate that gene drives, in coordination with existing public health measures, may become a useful tool to reduce schistosomiasis burden in selected transmission settings with effective CRISPR construct design and evaluation of the genetic and ecological landscape.
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12
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Liu Z, Zhang L, Liang Y, Lu L. Pathology and molecular mechanisms of Schistosoma japonicum-associated liver fibrosis. Front Cell Infect Microbiol 2022; 12:1035765. [PMID: 36389166 PMCID: PMC9650140 DOI: 10.3389/fcimb.2022.1035765] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Accepted: 10/13/2022] [Indexed: 11/23/2022] Open
Abstract
Schistosomiasis has been widely disseminated around the world, and poses a significant threat to human health. Schistosoma eggs and soluble egg antigen (SEA) mediated inflammatory responses promote the formation of egg granulomas and liver fibrosis. With continuous liver injuries and inflammatory stimulation, liver fibrosis can develop into liver cirrhosis and liver cancer. Therefore, anti-fibrotic therapy is crucial to increase the survival rate of patients. However, current research on antifibrotic treatments for schistosomiasis requires further exploration. In the complicated microenvironment of schistosome infections, it is important to understand the mechanism and pathology of schistosomiasis-associated liver fibrosis(SSLF). In this review, we discuss the role of SEA in inhibiting liver fibrosis, describe its mechanism, and comprehensively explore the role of host-derived and schistosome-derived microRNAs (miRNAs) in SSLF. Inflammasomes and cytokines are significant factors in promoting SSLF, and we discuss the mechanisms of some critical inflammatory signals and pro-fibrotic cytokines. Natural killer(NK) cells and Natural killer T(NKT) cells can inhibit SSLF but are rarely described, therefore, we highlight their significance. This summarizes and provides insights into the mechanisms of key molecules involved in SSLF development.
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Affiliation(s)
- Zhilong Liu
- Laboratory of Genetic Regulators in the Immune System, Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory Medicine, School of Laboratory Medicine, Xinxiang Medical University, Xinxiang, China
- Henan Key Laboratory of Immunology and Targeted Therapy, Xinxiang Medical University, Xinxiang, China
| | - Lichen Zhang
- Laboratory of Genetic Regulators in the Immune System, Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory Medicine, School of Laboratory Medicine, Xinxiang Medical University, Xinxiang, China
- Henan Key Laboratory of Immunology and Targeted Therapy, Xinxiang Medical University, Xinxiang, China
| | - Yinming Liang
- Laboratory of Genetic Regulators in the Immune System, Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory Medicine, School of Laboratory Medicine, Xinxiang Medical University, Xinxiang, China
- Henan Key Laboratory of Immunology and Targeted Therapy, Xinxiang Medical University, Xinxiang, China
- Institute of Psychiatry and Neuroscience, Xinxiang Medical University, Xinxiang, China
- *Correspondence: Yinming Liang, ; Liaoxun Lu,
| | - Liaoxun Lu
- Laboratory of Genetic Regulators in the Immune System, Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory Medicine, School of Laboratory Medicine, Xinxiang Medical University, Xinxiang, China
- Henan Key Laboratory of Immunology and Targeted Therapy, Xinxiang Medical University, Xinxiang, China
- Institute of Psychiatry and Neuroscience, Xinxiang Medical University, Xinxiang, China
- *Correspondence: Yinming Liang, ; Liaoxun Lu,
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13
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Alene KA, Gordon CA, Clements ACA, Williams GM, Gray DJ, Zhou XN, Li Y, Utzinger J, Kurscheid J, Forsyth S, Zhou J, Li Z, Li G, Lin D, Lou Z, Li S, Ge J, Xu J, Yu X, Hu F, Xie S, McManus DP. Spatial Analysis of Schistosomiasis in Hunan and Jiangxi Provinces in the People's Republic of China. Diseases 2022; 10:93. [PMID: 36278592 PMCID: PMC9590053 DOI: 10.3390/diseases10040093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/30/2022] [Accepted: 10/11/2022] [Indexed: 11/07/2023] Open
Abstract
Understanding the spatial distribution of schistosome infection is critical for tailoring preventive measures to control and eliminate schistosomiasis. This study used spatial analysis to determine risk factors that may impact Schistosoma japonicum infection and predict risk in Hunan and Jiangxi Provinces in the People's Republic of China. The study employed survey data collected in Hunan and Jiangxi in 2016. Independent variable data were obtained from publicly available sources. Bayesian-based geostatistics was used to build models with covariate fixed effects and spatial random effects to identify factors associated with the spatial distribution of infection. Prevalence of schistosomiasis was higher in Hunan (12.8%) than Jiangxi (2.6%). Spatial distribution of schistosomiasis varied at pixel level (0.1 × 0.1 km), and was significantly associated with distance to nearest waterbody (km, β = -1.158; 95% credible interval [CrI]: -2.104, -0.116) in Hunan and temperature (°C, β = -4.359; 95% CrI: -9.641, -0.055) in Jiangxi. The spatial distribution of schistosomiasis in Hunan and Jiangxi varied substantially and was significantly associated with distance to nearest waterbody. Prevalence of schistosomiasis decreased with increasing distance to nearest waterbody in Hunan, indicating that schistosomiasis control should target individuals in close proximity to open water sources as they are at highest risk of infection.
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Affiliation(s)
| | - Catherine A. Gordon
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane 4006, Australia
| | | | - Gail M. Williams
- School of Population Health, University of Queensland, Brisbane 4072, Australia
| | - Darren J. Gray
- Department of Global Health, Australian National University, Canberra 0200, Australia
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai 200025, China
| | - Yuesheng Li
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane 4006, Australia
- Hunan Institute of Schistosomiasis Control, Yueyang 414000, China
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, CH-4051 Allschwil, Switzerland
- University of Basel, CH-4003 Basel, Switzerland
| | - Johanna Kurscheid
- School of Population Health, University of Queensland, Brisbane 4072, Australia
- Swiss Tropical and Public Health Institute, CH-4051 Allschwil, Switzerland
| | - Simon Forsyth
- School of Population Health, University of Queensland, Brisbane 4072, Australia
| | - Jie Zhou
- Hunan Institute of Schistosomiasis Control, Yueyang 414000, China
| | - Zhaojun Li
- Jiangxi Institute of Parasitic Diseases, Nanchang 330096, China
| | - Guangpin Li
- Hunan Institute of Schistosomiasis Control, Yueyang 414000, China
| | - Dandan Lin
- Jiangxi Institute of Parasitic Diseases, Nanchang 330096, China
| | - Zhihong Lou
- Hunan Institute of Schistosomiasis Control, Yueyang 414000, China
| | - Shengming Li
- Hunan Institute of Schistosomiasis Control, Yueyang 414000, China
| | - Jun Ge
- Jiangxi Institute of Parasitic Diseases, Nanchang 330096, China
| | - Jing Xu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, NHC Key Laboratory of Parasite and Vector Biology, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai 200025, China
| | - Xinling Yu
- Hunan Institute of Schistosomiasis Control, Yueyang 414000, China
| | - Fei Hu
- Jiangxi Institute of Parasitic Diseases, Nanchang 330096, China
| | - Shuying Xie
- Jiangxi Institute of Parasitic Diseases, Nanchang 330096, China
| | - Donald P. McManus
- Infection and Inflammation Program, QIMR Berghofer Medical Research Institute, Brisbane 4006, Australia
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14
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Wheeler NJ, Hallem EA, Zamanian M. Making sense of sensory behaviors in vector-borne helminths. Trends Parasitol 2022; 38:841-853. [PMID: 35931639 PMCID: PMC9481669 DOI: 10.1016/j.pt.2022.07.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 07/07/2022] [Accepted: 07/10/2022] [Indexed: 10/16/2022]
Abstract
Migrations performed by helminths are impressive and diverse, and accumulating evidence shows that many are controlled by sophisticated sensory programs. The migrations of vector-borne helminths are particularly complex, requiring precise, stage-specific regulation. We review the contrasting states of knowledge on snail-borne schistosomes and mosquito-borne filarial nematodes. Rich observational data exist for the chemosensory behaviors of schistosomes, while the molecular sensory pathways in nematodes are well described. Recent investigations on the molecular mechanisms of sensation in schistosomes and filarial nematodes have revealed some features conserved within their respective phyla, but adaptations correlated with parasitism are pronounced. Technological developments are likely to extend these advances, and we forecast how these technologies may be applied.
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Affiliation(s)
- Nicolas J Wheeler
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Elissa A Hallem
- Department of Microbiology, Immunology & Molecular Genetics and Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Mostafa Zamanian
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, USA.
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15
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Bu L, Zhong D, Lu L, Loker ES, Yan G, Zhang SM. Compatibility between snails and schistosomes: insights from new genetic resources, comparative genomics, and genetic mapping. Commun Biol 2022; 5:940. [PMID: 36085314 PMCID: PMC9463173 DOI: 10.1038/s42003-022-03844-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 08/15/2022] [Indexed: 11/09/2022] Open
Abstract
The freshwater snail Biomphalaria glabrata is an important intermediate host of the parasite Schistosoma mansoni that causes human intestinal schistosomiasis. To better understand vector snail biology and help advance innovative snail control strategies, we have developed a new snail model consisting of two homozygous B. glabrata lines (iM line and iBS90) with sharply contrasting schistosome-resistance phenotypes. We produced and compared high-quality genome sequences for iM line and iBS90 which were assembled from 255 (N50 = 22.7 Mb) and 346 (N50 = 19.4 Mb) scaffolds, respectively. Using F2 offspring bred from the two lines and the newly generated iM line genome, we constructed 18 linkage groups (representing the 18 haploid chromosomes) covering 96% of the genome and identified three new QTLs (quantitative trait loci), two involved in snail resistance/susceptibility and one relating to body pigmentation. This study provides excellent genomic resources for unveiling complex vector snail biology, reveals genomic difference between resistant and susceptible lines, and offers novel insights into genetic mechanism of the compatibility between snail and schistosome.
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Affiliation(s)
- Lijing Bu
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Daibin Zhong
- Program in Public Health, College of Health Sciences, University of California, Irvine, CA, 92697, USA
| | - Lijun Lu
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Eric S Loker
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Guiyun Yan
- Program in Public Health, College of Health Sciences, University of California, Irvine, CA, 92697, USA
| | - Si-Ming Zhang
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, NM, 87131, USA.
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16
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Thiam F, Fall CB, Gaye PM, Senghor B, Diamanka A, Wotodjo AN, Abotsi K, Parola P, Faye B, Sokhna C, Sow D, Doucouré S. Study of the behavior of snails intermediate hosts of Schistosoma spp . under different maintenance conditions and their resistance to salinity in an african laboratory environment. Heliyon 2022; 8:e10289. [PMID: 36033271 PMCID: PMC9404331 DOI: 10.1016/j.heliyon.2022.e10289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 08/24/2021] [Accepted: 08/10/2022] [Indexed: 11/17/2022] Open
Abstract
Background The control of snails intermediate hosts remains an effective strategy to limit schistosomiasis transmission despite the widespread mass de-worming campaign based on praziquantel. Therefore, the study of snail biology could help to improve snails control strategies. This study evaluated the development of Biomphalaria pfeifferi, Bulinus senegalensis and Bulinus truncatus in various water sources and their resistance to salinity. Methods Five day-old juveniles individuals issued from adult snails non-shedding Schistosoma spp cercariae were breed in distilled water, commercial mineral water, ground pump water and well water. Snail’s survival rate and size were measured over a period of 40 days. These two parameters were also measured over 30 days in increasing saline solutions (1 g/l, 3.5 g/l and 4 g/l) made of well water to which sodium chloride was added. Results B. truncatus growth was not hampered by any water sources with a survival rate between 68% and 84% (log rank X2 = 1.86, df = 3, p = 0.60). Despite a poor survival rate (8%) in distilled water, B. pfeifferi, has adapted to other water sources with a survival fraction between 88% and 96% (log rank X2 = 61.94, df = 3, p < 0.0001). B. senegalensis development was very delicate with low survival rate of 4% in distilled water, 20% in well water and 24% in commercial mineral water and ground pump water (log rank X2 = 13.24, df = 3, p = 0,004). For each species, even if the difference is not significant, the size of snails is larger with well water and pump water compared to distilled and commercial mineral water. B. pfeifferi survival rate was at 45% in both three saline solutions at day 30. B. senegalensis population collapsed at day 10 in 4 g/l saline solution and persisted until day 30 in both 1.5 g/l and 3.5 g/l solution. B. truncatus also persisted with a survival rate at 20% in 1.5 g/l but collapsed at day 5 and 15 in 4 g/l and 3.5 g/l solution, respectively. Conclusion The differences in adaptation between snails species show the need to take into account the water sources for snail breeding in the laboratory. Further studies could help to determine the optimal water quality for each snail species in order to standardize breeding conditions. This study could contribute to the understanding of the dynamics and distribution of snails in natural conditions. The knowledge of snail breeding conditions could represent a breakthrough for schistosomiasis control The survival rate of B. truncatus, B. senegalensis and B. pfeifferi depended on the origin of the water used for snails breeding Only B. truncatus displayed relatively high survival rate to both distilled water, commercial mineral water, ground pump water and well water The survival of B. pfeifferi is less hampered in saline water compared to B. truncatus and B. senegalensis
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Affiliation(s)
- Fatou Thiam
- VITROME, IRD-UCAD International Campus of the Institute of Research for Development, Dakar, Senegal.,Department of Animal Biology, Faculty of Sciences and Techniques, University Cheikh Anta Diop of Dakar, Senegal
| | - Cheikh Bintou Fall
- Department of Parasitology-Mycology, Faculty of Medicine, Pharmacy and Odontology, University Cheikh Anta Diop of Dakar, Senegal
| | - Papa M Gaye
- VITROME, IRD-UCAD International Campus of the Institute of Research for Development, Dakar, Senegal.,Aix-Marseille University, IRD, AP-HM, SSA, VITROME, Marseille, France.,Institut Hospital-University (IHU)-Mediterranean Infection, Marseille, France
| | - Bruno Senghor
- VITROME, IRD-UCAD International Campus of the Institute of Research for Development, Dakar, Senegal
| | - Arfang Diamanka
- Department of Animal Biology, Faculty of Sciences and Techniques, University Cheikh Anta Diop of Dakar, Senegal
| | - Amélé N Wotodjo
- VITROME, IRD-UCAD International Campus of the Institute of Research for Development, Dakar, Senegal
| | - Kokou Abotsi
- VITROME, IRD-UCAD International Campus of the Institute of Research for Development, Dakar, Senegal
| | - Philippe Parola
- VITROME, IRD-UCAD International Campus of the Institute of Research for Development, Dakar, Senegal.,Aix-Marseille University, IRD, AP-HM, SSA, VITROME, Marseille, France.,Institut Hospital-University (IHU)-Mediterranean Infection, Marseille, France
| | - Babacar Faye
- Department of Parasitology-Mycology, Faculty of Medicine, Pharmacy and Odontology, University Cheikh Anta Diop of Dakar, Senegal
| | - Cheikh Sokhna
- VITROME, IRD-UCAD International Campus of the Institute of Research for Development, Dakar, Senegal.,Aix-Marseille University, IRD, AP-HM, SSA, VITROME, Marseille, France.,Institut Hospital-University (IHU)-Mediterranean Infection, Marseille, France
| | - Doudou Sow
- Department of Parasitology-Mycology, Faculty of Medicine, Pharmacy and Odontology, University Cheikh Anta Diop of Dakar, Senegal.,Department of Parasitology-Mycology, UFR Health Sciences, University Gaston Berger, Saint-Louis, Senegal
| | - Souleymane Doucouré
- VITROME, IRD-UCAD International Campus of the Institute of Research for Development, Dakar, Senegal
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17
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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] [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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18
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Loker ES, DeJong RJ, Brant SV. Scratching the Itch: Updated Perspectives on the Schistosomes Responsible for Swimmer's Itch around the World. Pathogens 2022; 11:587. [PMID: 35631108 PMCID: PMC9144223 DOI: 10.3390/pathogens11050587] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 05/09/2022] [Accepted: 05/13/2022] [Indexed: 01/01/2023] Open
Abstract
Although most studies of digenetic trematodes of the family Schistosomatidae dwell on representatives causing human schistosomiasis, the majority of the 130 identified species of schistosomes infect birds or non-human mammals. The cercariae of many of these species can cause swimmer's itch when they penetrate human skin. Recent years have witnessed a dramatic increase in our understanding of schistosome diversity, now encompassing 17 genera with eight more lineages awaiting description. Collectively, schistosomes exploit 16 families of caenogastropod or heterobranch gastropod intermediate hosts. Basal lineages today are found in marine gastropods and birds, but subsequent diversification has largely taken place in freshwater, with some reversions to marine habitats. It seems increasingly likely that schistosomes have on two separate occasions colonized mammals. Swimmer's itch is a complex zoonotic disease manifested through several different routes of transmission involving a diversity of different host species. Swimmer's itch also exemplifies the value of adopting the One Health perspective in understanding disease transmission and abundance because the schistosomes involved have complex life cycles that interface with numerous species and abiotic components of their aquatic environments. Given the progress made in revealing their diversity and biology, and the wealth of questions posed by itch-causing schistosomes, they provide excellent models for implementation of long-term interdisciplinary studies focused on issues pertinent to disease ecology, the One Health paradigm, and the impacts of climate change, biological invasions and other environmental perturbations.
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Affiliation(s)
- Eric S. Loker
- Center for Evolutionary and Theoretical Immunology, Parasites Division, Museum of Southwestern Biology, Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA;
| | - Randall J. DeJong
- Department of Biology, Calvin University, Grand Rapids, MI 49546, USA;
| | - Sara V. Brant
- Center for Evolutionary and Theoretical Immunology, Parasites Division, Museum of Southwestern Biology, Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA;
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Deep Learning Segmentation of Satellite Imagery Identifies Aquatic Vegetation Associated with Snail Intermediate Hosts of Schistosomiasis in Senegal, Africa. REMOTE SENSING 2022. [DOI: 10.3390/rs14061345] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Schistosomiasis is a debilitating parasitic disease of poverty that affects more than 200 million people worldwide, mostly in sub-Saharan Africa, and is clearly associated with the construction of dams and water resource management infrastructure in tropical and subtropical areas. Changes to hydrology and salinity linked to water infrastructure development may create conditions favorable to the aquatic vegetation that is suitable habitat for the intermediate snail hosts of schistosome parasites. With thousands of small and large water reservoirs, irrigation canals, and dams developed or under construction in Africa, it is crucial to accurately assess the spatial distribution of high-risk environments that are habitat for freshwater snail intermediate hosts of schistosomiasis in rapidly changing ecosystems. Yet, standard techniques for monitoring snails are labor-intensive, time-consuming, and provide information limited to the small areas that can be manually sampled. Consequently, in low-income countries where schistosomiasis control is most needed, there are formidable challenges to identifying potential transmission hotspots for targeted medical and environmental interventions. In this study, we developed a new framework to map the spatial distribution of suitable snail habitat across large spatial scales in the Senegal River Basin by integrating satellite data, high-definition, low-cost drone imagery, and an artificial intelligence (AI)-powered computer vision technique called semantic segmentation. A deep learning model (U-Net) was built to automatically analyze high-resolution satellite imagery to produce segmentation maps of aquatic vegetation, with a fast and robust generalized prediction that proved more accurate than a more commonly used random forest approach. Accurate and up-to-date knowledge of areas at highest risk for disease transmission can increase the effectiveness of control interventions by targeting habitat of disease-carrying snails. With the deployment of this new framework, local governments or health actors might better target environmental interventions to where and when they are most needed in an integrated effort to reach the goal of schistosomiasis elimination.
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Transmission potential of human schistosomes can be driven by resource competition among snail intermediate hosts. Proc Natl Acad Sci U S A 2022; 119:2116512119. [PMID: 35121663 PMCID: PMC8833218 DOI: 10.1073/pnas.2116512119] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/03/2022] [Indexed: 11/18/2022] Open
Abstract
Predicting and disrupting transmission of human parasites from wildlife hosts or vectors remains challenging because ecological interactions can influence their epidemiological traits. Human schistosomes, parasitic flatworms that cycle between freshwater snails and humans, typify this challenge. Human exposure risk, given water contact, is driven by the production of free-living cercariae by snail populations. Conventional epidemiological models and management focus on the density of infected snails under the assumption that all snails are equally infectious. However, individual-level experiments contradict this assumption, showing increased production of schistosome cercariae with greater access to food resources. We built bioenergetics theory to predict how resource competition among snails drives the temporal dynamics of transmission potential to humans and tested these predictions with experimental epidemics and demonstrated consistency with field observations. This resource-explicit approach predicted an intense pulse of transmission potential when snail populations grow from low densities, i.e., when per capita access to resources is greatest, due to the resource-dependence of cercarial production. The experiment confirmed this prediction, identifying a strong effect of infected host size and the biomass of competitors on per capita cercarial production. A field survey of 109 waterbodies also found that per capita cercarial production decreased as competitor biomass increased. Further quantification of snail densities, sizes, cercarial production, and resources in diverse transmission sites is needed to assess the epidemiological importance of resource competition and support snail-based disruption of schistosome transmission. More broadly, this work illustrates how resource competition can sever the correspondence between infectious host density and transmission potential.
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21
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Sublethal concentrations of usnic acid potassium salt impairs physiological parameters of Biomphalaria glabrata (Say, 1818) (Pulmonata: Planorbidae) infected and not infected with Schistosoma mansoni. Acta Trop 2021; 222:106067. [PMID: 34303689 DOI: 10.1016/j.actatropica.2021.106067] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 07/07/2021] [Accepted: 07/18/2021] [Indexed: 12/13/2022]
Abstract
Schistosomiasis is a public health problem in many developing countries. The mollusc Biomphalaria glabrata is the most important vector of Schistosoma mansoni in South America. The population control of this vector to prevent the spread of schistosomiasis is currently done with the application of highly toxic molluscicide to the environment. The screening of substances in sublethal concentrations that have deleterious effects on physiological parameters is very relevant for the control of schistosomiasis, since the effectiveness of disease prevention increases if it acts on population control of the vector and on reproduction and elimination in S. mansoni cercariae. The objective of this study was to evaluate the reproductive parameters (fecundity and fertility), intra-mollusk effect (sporocysts I (72 h) and II (14 days after)) on the development of cercariae of S. mansoni and the immune cell profile of B. glabrata exposed to sublethal concentrations (LC25 - 0.5 µg/mL and LC50 - 0.92 µg/mL) of the usnic acid potassium salt (potassium usnate). LC 25 and LC 50 significantly reduced (p < 0.05) the fecundity of B. glabrata when treated infected and/or not exposed to infection, while unviable embryos were not observed in sporocyst stage I, being only significant (p < 0.05) for mollusks infected and treated with LC50 on sporocyst II. LC25 and LC50 of the potassium usnate caused significant reductions (p < 0.05) in the production and cercarial shedding when evaluated on sporocysts I and II. In addition, the mortality of infected and treated B. glabrata in the sporocyst II phase was quite marked after the 9th week of infection. Regarding the immunological cell profile of uninfected B. glabrata, both concentrations led to immunomodulatory responses, with significant morphological changes predominant of hemocytes that entered programmed cell death (apoptosis). It was concluded that the application of LC25 and LC50 from the potassium usnate could be useful in the population control of B. glabrata, since it interferes both in their biology and physiology and in the reproduction of the infectious agent of schistosomiasis mansoni.
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22
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Jones IJ, Sokolow SH, Chamberlin AJ, Lund AJ, Jouanard N, Bandagny L, Ndione R, Senghor S, Schacht AM, Riveau G, Hopkins SR, Rohr JR, Remais JV, Lafferty KD, Kuris AM, Wood CL, De Leo G. Schistosome infection in Senegal is associated with different spatial extents of risk and ecological drivers for Schistosoma haematobium and S. mansoni. PLoS Negl Trop Dis 2021; 15:e0009712. [PMID: 34570777 PMCID: PMC8476036 DOI: 10.1371/journal.pntd.0009712] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 08/06/2021] [Indexed: 11/17/2022] Open
Abstract
Schistosome parasites infect more than 200 million people annually, mostly in sub-Saharan Africa, where people may be co-infected with more than one species of the parasite. Infection risk for any single species is determined, in part, by the distribution of its obligate intermediate host snail. As the World Health Organization reprioritizes snail control to reduce the global burden of schistosomiasis, there is renewed importance in knowing when and where to target those efforts, which could vary by schistosome species. This study estimates factors associated with schistosomiasis risk in 16 villages located in the Senegal River Basin, a region hyperendemic for Schistosoma haematobium and S. mansoni. We first analyzed the spatial distributions of the two schistosomes’ intermediate host snails (Bulinus spp. and Biomphalaria pfeifferi, respectively) at village water access sites. Then, we separately evaluated the relationships between human S. haematobium and S. mansoni infections and (i) the area of remotely-sensed snail habitat across spatial extents ranging from 1 to 120 m from shorelines, and (ii) water access site size and shape characteristics. We compared the influence of snail habitat across spatial extents because, while snail sampling is traditionally done near shorelines, we hypothesized that snails further from shore also contribute to infection risk. We found that, controlling for demographic variables, human risk for S. haematobium infection was positively correlated with snail habitat when snail habitat was measured over a much greater radius from shore (45 m to 120 m) than usual. S. haematobium risk was also associated with large, open water access sites. However, S. mansoni infection risk was associated with small, sheltered water access sites, and was not positively correlated with snail habitat at any spatial sampling radius. Our findings highlight the need to consider different ecological and environmental factors driving the transmission of each schistosome species in co-endemic landscapes. Schistosome parasites infect more than 200 million people worldwide, mainly in sub-Saharan Africa, where many people are at-risk for infection by multiple schistosome species simultaneously. To reduce the global burden of schistosomiasis, control of the parasites’ intermediate host–specific species of freshwater snails–has been elevated in priority to complement mass drug administration campaigns in endemic areas. To maximize the efficacy and efficiency of snail control efforts, a better understanding of where to target intermediate host snails is badly needed. This includes a better understanding of the spatial scale at which snails in the environment contribute to human infection risk, and, in co-endemic settings, how ecological determinants of infection risk vary by schistosome species. We used quantitative snail sampling and remotely-sensed data at 16 villages in the Senegal River Basin to compare and contrast ecological correlates and spatial scales of infection risk from freshwater snails that transmit Schistosoma haematobium versus S. mansoni. We found that infection risk for S. haematobium was associated with snail habitat at a larger spatial radius than is typically considered for schistosomiasis monitoring and control, whereas infection risk for S. mansoni was not positively correlated with snail habitat at any spatial sampling radius, but was associated with small water access sites enclosed by emergent vegetation. Our findings highlight the need to consider the different ecological and environmental factors driving the transmission of each schistosome species in co-endemic landscapes.
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Affiliation(s)
- Isabel J Jones
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
| | - Susanne H Sokolow
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America.,Stanford Woods Institute for the Environment, Stanford University, Stanford, California, United States of America
| | - Andrew J Chamberlin
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America
| | - Andrea J Lund
- Emmett Interdisciplinary Program in Environment and Resources, Stanford University, Stanford, California, United States of America
| | - Nicolas Jouanard
- Biomedical Research Center EPLS, Saint-Louis, Senegal.,Station d'Innovation Aquacole, Saint-Louis, Senegal
| | | | | | - Simon Senghor
- Biomedical Research Center EPLS, Saint-Louis, Senegal
| | - Anne-Marie Schacht
- Biomedical Research Center EPLS, Saint-Louis, Senegal.,Université Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, U1019-UMR 9017-CIIL-Center for Infection and Immunity of Lille, Lille, France
| | - Gilles Riveau
- Biomedical Research Center EPLS, Saint-Louis, Senegal.,Université Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, U1019-UMR 9017-CIIL-Center for Infection and Immunity of Lille, Lille, France
| | - Skylar R Hopkins
- National Center for Ecological Analysis and Synthesis, Santa Barbara, California, United States of America.,Department of Applied Ecology, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Jason R Rohr
- Department of Biological Science, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Justin V Remais
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, Berkeley, California, United States of America
| | - Kevin D Lafferty
- Western Ecological Research Center, United States Geological Survey at Marine Science Institute, University of California, Santa Barbara, California, United States of America
| | - Armand M Kuris
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, California, United States of America
| | - Chelsea L Wood
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington, United States of America
| | - Giulio De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, California, United States of America.,Stanford Woods Institute for the Environment, Stanford University, Stanford, California, United States of America
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23
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Panzner U, Excler JL, Kim JH, Marks F, Carter D, Siddiqui AA. Recent Advances and Methodological Considerations on Vaccine Candidates for Human Schistosomiasis. FRONTIERS IN TROPICAL DISEASES 2021. [DOI: 10.3389/fitd.2021.719369] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Schistosomiasis remains a neglected tropical disease of major public health concern with high levels of morbidity in various parts of the world. Although considerable efforts in implementing mass drug administration programs utilizing praziquantel have been deployed, schistosomiasis is still not contained. A vaccine may therefore be an essential part of multifaceted prevention control efforts. In the 1990s, a joint United Nations committee promoting parasite vaccines shortlisted promising candidates including for schistosomiasis discussed below. After examining the complexity of immune responses in human hosts infected with schistosomes, we review and discuss the antigen design and preclinical and clinical development of the four leading vaccine candidates: Sm-TSP-2 in Phase 1b/2b, Sm14 in Phase 2a/2b, Sm-p80 in Phase 1 preparation, and Sh28GST in Phase 3. Our assessment of currently leading vaccine candidates revealed some methodological issues that preclude a fair comparison between candidates and the rationale to advance in clinical development. These include (1) variability in animal models - in particular non-human primate studies - and predictive values of each for protection in humans; (2) lack of consensus on the assessment of parasitological and immunological parameters; (3) absence of reliable surrogate markers of protection; (4) lack of well-designed parasitological and immunological natural history studies in the context of mass drug administration with praziquantel. The controlled human infection model - while promising and unique - requires validation against efficacy outcomes in endemic settings. Further research is also needed on the impact of advanced adjuvants targeting specific parts of the innate immune system that may induce potent, protective and durable immune responses with the ultimate goal of achieving meaningful worm reduction.
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24
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Wang W, Bergquist R, King CH, Yang K. Elimination of schistosomiasis in China: Current status and future prospects. PLoS Negl Trop Dis 2021; 15:e0009578. [PMID: 34351907 PMCID: PMC8341657 DOI: 10.1371/journal.pntd.0009578] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Elimination of schistosomiasis as a public health problem among all disease-endemic countries in 2030 is an ambitious goal. Recent achievements resulting from mass drug administration (MDA) with praziquantel is promising but may need to be complemented with also other means. Schistosomiasis was highly prevalent in China before the initiation of the national schistosomiasis control program in the mid-1950s, and, at that time, the country bore the world's highest burden of schistosomiasis. The concerted control efforts, upheld without interruption for more than a half century, have resulted in elimination of the disease as a public health problem in China as of 2015. Here, we describe the current status of schistosomiasis in China, analyze the potential challenges affecting schistosomiasis elimination, and propose the future research needs and priorities for the country, aiming to provide more universal insights into the structures needed for a global schistosomiasis elimination encompassing also other endemic regions.
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Affiliation(s)
- Wei Wang
- Key Laboratory of National Health Commission of Parasitic Disease Prevention and Control, Jiangsu Provincial Key Laboratory of Parasites and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu Province, China
| | - Robert Bergquist
- Ingerod, Brastad, Sweden (formerly with the UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases), World Health Organization, Geneva, Switzerland
| | - Charles H. King
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Kun Yang
- Key Laboratory of National Health Commission of Parasitic Disease Prevention and Control, Jiangsu Provincial Key Laboratory of Parasites and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu Province, China
- Center for Global Health, Nanjing Medical University, Nanjing, Jiangsu Province, China
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25
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Panzner U, Boissier J. Natural Intra- and Interclade Human Hybrid Schistosomes in Africa with Considerations on Prevention through Vaccination. Microorganisms 2021; 9:microorganisms9071465. [PMID: 34361901 PMCID: PMC8305539 DOI: 10.3390/microorganisms9071465] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/05/2021] [Accepted: 07/06/2021] [Indexed: 12/04/2022] Open
Abstract
Causal agents of schistosomiasis are dioecious, digenean schistosomes affecting mankind in 76 countries. Preventive measures are manifold but need to be complemented by vaccination for long-term protection; vaccine candidates in advanced pre-clinical/clinical stages include Sm14, Sm-TSP-2/Sm-TSP-2Al®, Smp80/SchistoShield®, and Sh28GST/Bilhvax®. Natural and anthropogenic changes impact on breaking species isolation barriers favoring introgressive hybridization, i.e., allelic exchange among gene pools of sympatric, interbreeding species leading to instant large genetic diversity. Phylogenetic distance matters, thus the less species differ phylogenetically the more likely they hybridize. PubMed and Embase databases were searched for publications limited to hybridale confirmation by mitochondrial cytochrome c oxidase (COX) and/or nuclear ribosomal internal transcribed spacer (ITS). Human schistosomal hybrids are predominantly reported from West Africa with clustering in the Senegal River Basin, and scattering to Europe, Central and Eastern Africa. Noteworthy is the dominance of Schistosoma haematobium interbreeding with human and veterinary species leading due to hybrid vigor to extinction and homogenization as seen for S. guineensis in Cameroon and S. haematobium in Niger, respectively. Heterosis seems to advantage S. haematobium/S. bovis interbreeds with dominant S. haematobium-ITS/S. bovis-COX1 profile to spread from West to East Africa and reoccur in France. S. haematobium/S. mansoni interactions seen among Senegalese and Côte d’Ivoirian children are unexpected due to their high phylogenetic distance. Detecting pure S. bovis and S. bovis/S. curassoni crosses capable of infecting humans observed in Corsica and Côte d’Ivoire, and Niger, respectively, is worrisome. Taken together, species hybridization urges control and preventive measures targeting human and veterinary sectors in line with the One-Health concept to be complemented by vaccination protecting against transmission, infection, and disease recurrence. Functional and structural diversity of naturally occurring human schistosomal hybrids may impact current vaccine candidates requiring further research including natural history studies in endemic areas targeted for clinical trials.
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Affiliation(s)
- Ursula Panzner
- Division of Infectious Diseases and Tropical Medicine, Ludwig Maximilian University of Munich, 80539 Munich, Germany
- Swiss Tropical and Public Health Institute, University of Basel, 4002 Basel, Switzerland
- Correspondence: ; Tel.: +49-176-6657-2910
| | - Jerome Boissier
- IHPE, University of Montpellier, CNRS, Ifremer, University of Perpignan, 66860 Perpignan, France;
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26
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Davison A, Neiman M. Mobilizing molluscan models and genomes in biology. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200163. [PMID: 33813892 PMCID: PMC8059959 DOI: 10.1098/rstb.2020.0163] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2020] [Indexed: 12/11/2022] Open
Abstract
Molluscs are among the most ancient, diverse, and important of all animal taxa. Even so, no individual mollusc species has emerged as a broadly applied model system in biology. We here make the case that both perceptual and methodological barriers have played a role in the relative neglect of molluscs as research organisms. We then summarize the current application and potential of molluscs and their genomes to address important questions in animal biology, and the state of the field when it comes to the availability of resources such as genome assemblies, cell lines, and other key elements necessary to mobilising the development of molluscan model systems. We conclude by contending that a cohesive research community that works together to elevate multiple molluscan systems to 'model' status will create new opportunities in addressing basic and applied biological problems, including general features of animal evolution. This article is part of the Theo Murphy meeting issue 'Molluscan genomics: broad insights and future directions for a neglected phylum'.
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Affiliation(s)
- Angus Davison
- School of Life Sciences, University Park, University of Nottingham, Nottingham NG7 2RD, UK
| | - Maurine Neiman
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA
- Department of Gender, Women's, and Sexuality Studies, University of Iowa, Iowa City, IA 52242, USA
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27
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Mtemeli FL, Walter I, Tinago T, Shoko R. An assessment of the molluscicidal potential of Cucurbita maxima seed extracts on Biomphalaria pfeifferi and Bulinus globosus snails. ALL LIFE 2021. [DOI: 10.1080/26895293.2021.1901788] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Affiliation(s)
- Floryn L. Mtemeli
- Department of Biology, Chinhoyi University of Technology, Chinhoyi, Zimbabwe
| | - Irene Walter
- Department of Biology, Chinhoyi University of Technology, Chinhoyi, Zimbabwe
| | - Tawanda Tinago
- Department of Biology, Chinhoyi University of Technology, Chinhoyi, Zimbabwe
| | - Ryman Shoko
- Department of Biology, Chinhoyi University of Technology, Chinhoyi, Zimbabwe
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28
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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] [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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29
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Interventions can shift the thermal optimum for parasitic disease transmission. Proc Natl Acad Sci U S A 2021; 118:2017537118. [PMID: 33836584 DOI: 10.1073/pnas.2017537118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Temperature constrains the transmission of many pathogens. Interventions that target temperature-sensitive life stages, such as vector control measures that kill intermediate hosts, could shift the thermal optimum of transmission, thereby altering seasonal disease dynamics and rendering interventions less effective at certain times of the year and with global climate change. To test these hypotheses, we integrated an epidemiological model of schistosomiasis with empirically determined temperature-dependent traits of the human parasite Schistosoma mansoni and its intermediate snail host (Biomphalaria spp.). We show that transmission risk peaks at 21.7 °C (T opt ), and simulated interventions targeting snails and free-living parasite larvae increased T opt by up to 1.3 °C because intervention-related mortality overrode thermal constraints on transmission. This T opt shift suggests that snail control is more effective at lower temperatures, and global climate change will increase schistosomiasis risk in regions that move closer to T opt Considering regional transmission phenologies and timing of interventions when local conditions approach T opt will maximize human health outcomes.
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31
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Colley DG, Fleming FM, Matendechero SH, Knopp S, Rollinson D, Utzinger J, Castleman JD, Kittur N, King CH, Campbell CH, Kabole FM, Kinung'hi S, Ramzy RMR, Binder S. Contributions of the Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) to Schistosomiasis Control and Elimination: Key Findings and Messages for Future Goals, Thresholds, and Operational Research. Am J Trop Med Hyg 2020; 103:125-134. [PMID: 32400345 PMCID: PMC7351304 DOI: 10.4269/ajtmh.19-0787] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Herein, we summarize what we consider are major contributions resulting from the Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) program, including its key findings and key messages from those findings. Briefly, SCORE's key findings are as follows: i) biennial mass drug administration (MDA) with praziquantel can control schistosomiasis to moderate levels of prevalence; ii) MDA alone will not achieve elimination; iii) to attain and sustain control throughout endemic areas, persistent hotspots need to be identified following a minimal number of years of annual MDA and controlled through adaptive strategies; iv) annual MDA is more effective than biennial MDA in high-prevalence areas; v) the current World Health Organization thresholds for decision-making based on the prevalence of heavy infections should be redefined; and vi) point-of-care circulating cathodic antigen urine assays are useful for Schistosoma mansoni mapping in low-to-moderate prevalence areas. The data and specimens collected and curated through SCORE efforts will continue to be critical resource for future research. Besides providing useful information for program managers and revision of guidelines for schistosomiasis control and elimination, SCORE research and outcomes have identified additional questions that need to be answered as the schistosomiasis community continues to implement effective, evidence-based programs. An overarching contribution of SCORE has been increased cohesiveness within the schistosomiasis field-oriented community, thereby fostering new and productive collaborations. Based on SCORE's findings and experiences, we propose new approaches, thresholds, targets, and goals for control and elimination of schistosomiasis, and recommend research and evaluation activities to achieve these targets and goals.
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Affiliation(s)
- Daniel G Colley
- Department of Microbiology, University of Georgia, Athens, Georgia.,Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia
| | - Fiona M Fleming
- Department of Infectious Disease Epidemiology, Schistosomiasis Control Initiative, London, United Kingdom
| | - Sultani H Matendechero
- Division of Communicable Disease Prevention and Control, Neglected Tropical Diseases Unit, Ministry of Health, Nairobi, Kenya
| | - Stefanie Knopp
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute, Basel, Switzerland.,Department of Life Sciences, Wolfson Wellcome Biomedical Laboratories, Natural History Museum, London, United Kingdom
| | - David Rollinson
- Department of Life Sciences, Wolfson Wellcome Biomedical Laboratories, Natural History Museum, London, United Kingdom
| | - Jürg Utzinger
- University of Basel, Basel, Switzerland.,Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Jennifer D Castleman
- Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia
| | - Nupur Kittur
- Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia
| | - Charles H King
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio.,Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia
| | - Carl H Campbell
- Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia
| | - Fatma M Kabole
- Neglected Diseases Programme, Ministry of Health of Zanzibar, Zanzibar, United Republic of Tanzania
| | - Safari Kinung'hi
- National Institute for Medical Research (NIMR), Mwanza Centre, Mwanza, United Republic of Tanzania
| | - Reda M R Ramzy
- National Nutrition Institute, General Organization for Teaching Hospitals and Institutes, Cairo, Egypt
| | - Sue Binder
- Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia
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Abstract
The innate immune system in the central nervous system (CNS) is mainly represented by specialized tissue-resident macrophages, called microglia. In the past years, various species-, host- and tissue-specific as well as environmental factors were recognized that essentially affect microglial properties and functions in the healthy and diseased brain. Host microbiota are mostly residing in the gut and contribute to microglial activation states, for example, via short-chain fatty acids (SCFAs) or aryl hydrocarbon receptor (AhR) ligands. Thereby, the gut microorganisms are deemed to influence numerous CNS diseases mediated by microglia. In this review, we summarize recent findings of the interaction between the host microbiota and the CNS in health and disease, where we specifically highlight the resident gut microbiota as a crucial environmental factor for microglial function as what we coin "the microbiota-microglia axis."
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Affiliation(s)
- Omar Mossad
- Institute of NeuropathologyFaculty of MedicineUniversity of FreiburgFreiburgGermany
- Faculty of BiologyUniversity of FreiburgFreiburgGermany
| | - Daniel Erny
- Institute of NeuropathologyFaculty of MedicineUniversity of FreiburgFreiburgGermany
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Monnier N, Barth-Jaeggi T, Knopp S, Steinmann P. Core components, concepts and strategies for parasitic and vector-borne disease elimination with a focus on schistosomiasis: A landscape analysis. PLoS Negl Trop Dis 2020; 14:e0008837. [PMID: 33125375 PMCID: PMC7598467 DOI: 10.1371/journal.pntd.0008837] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 10/01/2020] [Indexed: 12/19/2022] Open
Abstract
Efforts to control and eliminate human schistosomiasis have accelerated over the past decade. In a number of endemic countries and settings, interruption of schistosome transmission has been achieved. In others, Schistosoma infections continue to challenge program managers at different levels, from the complexity of the transmission cycle, over limited treatment options and lack of field-friendly accurate diagnostics, to controversy around adequate intervention strategies. We conducted a landscape analysis on parasitic and vector-borne disease elimination approaches with the aim to identify evidence-based strategies, core components and key concepts for achieving and sustaining schistosomiasis control and for progressing elimination efforts towards interruption of transmission in sub-Saharan Africa. A total of 118 relevant publications were identified from Web of Science, Pubmed and the grey literature and reviewed for their content. In addition, we conducted in-depth interviews with 23 epidemiologists, program managers, policymakers, donors and field researchers. Available evidence emphasizes the need for comprehensive, multipronged and long-term strategies consisting of multiple complementary interventions that must be sustained over time by political commitment and adequate funding in order to reach interruption of transmission. Based on the findings of this landscape analysis, we propose a comprehensive set of intervention strategies for schistosomiasis control and elimination. Before deployment, the proposed interventions will require review, evaluation and validation in the frame of an expert consultation as a step towards adaptation to specific contexts, conditions and settings. Field testing to ensure local relevance and effectiveness is paramount given the diversity of socio-ecological and epidemiological contexts. This landscape analysis explored successful concepts, approaches and interventions of past and ongoing parasitic and vector-borne disease elimination efforts and programs with regard to relevance for progress in the elimination of human schistosome infections. Schistosomiasis is a disabling, water borne parasitic disease of public health concern with an estimated 250 million people infected worldwide. The long-term morbidity of this neglected tropical disease significantly impacts growth, cognition and socioeconomic development at all ages. Despite increased global efforts to control morbidity and advance elimination, challenges in view of the complex life cycle which involves freshwater sources, intermediate snail hosts and humans, remain. This calls for targeted interventions and concerted programs. According to the evidence from the literature and as proposed by a wide range of key informants, comprehensive, multipronged and long-term strategies supported by strong political commitment and adequate funding are required in order to achieve and sustain the set goals. Based on the findings, we propose here a comprehensive set of intervention strategies for schistosomiasis control and elimination for review and evaluation to inform implementation research needs and elimination program design.
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Affiliation(s)
- Nora Monnier
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- * E-mail:
| | - Tanja Barth-Jaeggi
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Stefanie Knopp
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Peter Steinmann
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
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Allan ERO, Blouin MS. Heat shock increases hydrogen peroxide release from circulating hemocytes of the snail Biomphalaria glabrata. FISH & SHELLFISH IMMUNOLOGY 2020; 105:203-208. [PMID: 32702479 PMCID: PMC7501213 DOI: 10.1016/j.fsi.2020.07.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 07/01/2020] [Accepted: 07/14/2020] [Indexed: 06/11/2023]
Abstract
Planorbid freshwater snails are important intermediate hosts for parasitic diseases caused by parasitic worms, most notably schistosomiasis. There are numerous reports of snails, specifically Biomphalaria glabrata, having compromised defences against schistosomes after being exposed to thermal stress. Environmental modifications to the defenses of schistosome transmitting snails could have negative ramifications for human disease risk in the context of climate change. Here the effects of heat shock on the production of hydrogen peroxide, a primary anti-microbial effector in many molluscs, were examined. The present findings show that heat shock increases NADPH oxidase 2 mRNA levels and hydrogen peroxide produced by snail hemocytes, and that both of these phenotypes could be reversed by an HSP-90 inhibitor. These findings indicate that snail defense systems are altered by heat shock at a molecular level in B. glabrata, and that snail immunity to many pathogens may be altered by the rapid variations in temperature that are associated with global climate change.
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Affiliation(s)
- Euan R O Allan
- Department of Pathobiology, School of Veterinary Medicine, St. George's University, West Indies, Grenada.
| | - Michael S Blouin
- Department of Integrative Biology, College of Science, Oregon State University, Corvallis, OR, USA
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Prevalence of Schistosoma mansoni and S. haematobium in Snail Intermediate Hosts in Africa: A Systematic Review and Meta-analysis. J Trop Med 2020; 2020:8850840. [PMID: 32963554 PMCID: PMC7492904 DOI: 10.1155/2020/8850840] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 08/26/2020] [Accepted: 08/28/2020] [Indexed: 12/23/2022] Open
Abstract
Background Schistosomiasis is caused by Schistosoma mansoni and S. haematobium in Africa. These schistosome parasites use freshwater snail intermediate hosts to complete their lifecycle. Varied prevalence rates of these parasites in the snail intermediate hosts were reported from several African countries, but there were no summarized data for policymakers. Therefore, this study was aimed to systematically summarize the prevalence and geographical distribution of S. mansoni and S. haematobium among freshwater snails in Africa. Methods Literature search was carried out from PubMed, Science Direct, and Scopus which reported the prevalence of S. mansoni and S. haematobium among freshwater snails in Africa. The pooled prevalence was determined using a random-effect model, while heterogeneities between studies were evaluated by I2 test. The meta-analyses were conducted using Stata software, metan command. Results A total of 273,643 snails were examined for the presence of S. mansoni and S. haematobium cercaria in the eligible studies. The pooled prevalence of schistosome cercaria among freshwater snails was 5.5% (95% CI: 4.9–6.1%). The pooled prevalence of S. mansoni and S. haematobium cercaria was 5.6% (95% CI: 4.9–6.3%) and 5.2% (95% CI: 4.6–5.7%), respectively. The highest pooled prevalence was observed from Nigeria (19.0%; 95% CI: 12.7–25.3%), while the lowest prevalence was reported from Chad (0.05%; 95% CI: 0.03–0.13). Higher prevalence of schistosome cercaria was observed from Bulinus globosus (12.3%; 95% CI: 6.2–18.3%) followed by Biomphalaria sudanica (6.7%; 95% CI: 4.5–9.0%) and Biomphalaria pfeifferi (5.1%; 95% CI: 4.1–6.2%). The pooled prevalence of schistosome cercaria obtained using PCR was 26.7% in contrast to 4.5% obtained by shedding cercariae. Conclusion This study revealed that nearly 6% of freshwater snails in Africa were infected by either S. haematobium or S. mansoni. The high prevalence of schistosomes among freshwater snails highlights the importance of appropriate snail control strategies in Africa.
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Tennessen JA, Bollmann SR, Peremyslova E, Kronmiller BA, Sergi C, Hamali B, Blouin MS. Clusters of polymorphic transmembrane genes control resistance to schistosomes in snail vectors. eLife 2020; 9:59395. [PMID: 32845238 PMCID: PMC7494358 DOI: 10.7554/elife.59395] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 08/25/2020] [Indexed: 12/14/2022] Open
Abstract
Schistosomiasis is a debilitating parasitic disease infecting hundreds of millions of people. Schistosomes use aquatic snails as intermediate hosts. A promising avenue for disease control involves leveraging innate host mechanisms to reduce snail vectorial capacity. In a genome-wide association study of Biomphalaria glabrata snails, we identify genomic region PTC2 which exhibits the largest known correlation with susceptibility to parasite infection (>15 fold effect). Using new genome assemblies with substantially higher contiguity than the Biomphalaria reference genome, we show that PTC2 haplotypes are exceptionally divergent in structure and sequence. This variation includes multi-kilobase indels containing entire genes, and orthologs for which most amino acid residues are polymorphic. RNA-Seq annotation reveals that most of these genes encode single-pass transmembrane proteins, as seen in another resistance region in the same species. Such groups of hyperdiverse snail proteins may mediate host-parasite interaction at the cell surface, offering promising targets for blocking the transmission of schistosomiasis.
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Affiliation(s)
- Jacob A Tennessen
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, United States.,Department of Integrative Biology, Oregon State University, Corvallis, United States
| | - Stephanie R Bollmann
- Department of Integrative Biology, Oregon State University, Corvallis, United States
| | - Ekaterina Peremyslova
- Department of Integrative Biology, Oregon State University, Corvallis, United States
| | - Brent A Kronmiller
- Department of Integrative Biology, Oregon State University, Corvallis, United States.,Center for Genome Research and Biocomputing, Oregon State University, Corvallis, United States
| | - Clint Sergi
- Department of Integrative Biology, Oregon State University, Corvallis, United States
| | - Bulut Hamali
- Department of Integrative Biology, Oregon State University, Corvallis, United States
| | - Michael Scott Blouin
- Department of Integrative Biology, Oregon State University, Corvallis, United States
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Qiu J, Li R, Zhu H, Xia J, Xiao Y, Huang D, Wang Y. The effect of ecological environmental changes and mollusciciding on snail intermediate host of Schistosoma in Qianjiang city of China from 1985 to 2015. Parasit Vectors 2020; 13:397. [PMID: 32758280 PMCID: PMC7409449 DOI: 10.1186/s13071-020-04273-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 07/30/2020] [Indexed: 12/31/2022] Open
Abstract
Background Schistosomiasis remains prevalent in Africa, Asia and South America with an estimated burden of 1.9 million disability-adjusted life years in 2016. Targeting snails as a key to success for schistosomiasis control has been widely approved, but the long-term quantitative effects of interventions on snail control that would inform and improve future control programmes are unclear. Over the last six decades, schistosomiasis in China had been brought largely under control, and snail control as supplementary methods or part of integrated multisectoral approaches in different historical periods has played an essential role. Methods Ecological environment factors, prevalence and control data on Oncomelania hupensis between 1985 and 2015 at 5-year intervals in Qianjiang city, China, were collected. A multilevel growth model approach was used to examine the long-term effects of ecological environmental changes and mollusciciding on snail-infested area (SIA) and living snail density (LSD) during the 30 years. Results The variation of SIA was 68.4% in spatial distribution, while the variation of LSD was 68.4% in temporal distribution. Continuous mollusciciding could result in significant LSD reduction, but may not lead to significant SIA reduction. The normalized difference vegetation index (NDVI), patch size coefficient of variation (PSCoV) and mean patch size (MPS) reduction, slightly due to eco-environmental changes decreased SIA, while mean perimeter-area ratio (MPAR) and dry farm-land proportion (DFLP) reduction might increase SIA. Only NDVI and MPAR reduction led to a lower LSD. Conclusions Mollusciciding was more effective in reducing snail density, but it is not easy to eliminate snails completely. Environmental modifications could completely change the snail breeding environment and reduce its infestation area. Due to difficulty of scaling-up the current environmental modifications in waterway network regions, more effective snail control methods are needed. The experience in China could thereby provide guidance for other schistosomiasis endemic areas with a high snail prevalence.![]()
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Affiliation(s)
- Juan Qiu
- Key Laboratory of Monitoring and Estimate for Environment and Disaster of Hubei Province, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, People's Republic of China.
| | - Rendong Li
- Key Laboratory of Monitoring and Estimate for Environment and Disaster of Hubei Province, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, People's Republic of China
| | - Hong Zhu
- Hubei Center for Disease Control and Prevention, Hubei Provincial Academy of Preventive Medicine, Wuhan, People's Republic of China
| | - Jing Xia
- Hubei Center for Disease Control and Prevention, Hubei Provincial Academy of Preventive Medicine, Wuhan, People's Republic of China
| | - Ying Xiao
- Hubei Center for Disease Control and Prevention, Hubei Provincial Academy of Preventive Medicine, Wuhan, People's Republic of China
| | - Duan Huang
- Faculty of Geomatics, East China University of Technology, Nanchang, People's Republic of China
| | - Yong Wang
- State Key Laboratory of Resources and Environmental Information Systems, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, People's Republic of China.
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Malishev M, Civitello DJ. Modelling how resource competition among snail hosts affects the mollusciciding frequency and intensity needed to control human schistosomes. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Effectiveness analysis of spatially targeted mollusciciding for Oncomelania snail control. Epidemiol Infect 2020; 148:e152. [PMID: 32605678 PMCID: PMC7374813 DOI: 10.1017/s0950268820001466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
A new developed spatially targeted mollusciciding technology for snail control was utilised in a research site. This study aims to analyse whether this technology can achieve rational effectiveness compared with the routine method. Snail density was monitored every spring and autumn from 2010 to 2017 at the research site and routine mollusciciding for snail control was then performed. After snail density monitoring in spring 2018, spatially targeted mollusciciding technology was adopted. Log-linear regression and nonlinear regression models were used for snail density prediction in autumn 2018 and the predicted value was compared with the actual snail density in autumn 2018 to verify the effectiveness of the spatially targeted mollusciciding. Monitoring results showed that overall snail density in the research site decreased from 2010 to 2018. The monitored snail density in autumn 2018 was 0.014/0.1 m2. Predicted by the log-linear regression model, the snail density in autumn 2018 would be 0.028 (95% CI 0.11–0.072)/0.1 m2. Predicted by the nonlinear regression model, the snail density growth in autumn 2018 in contrast to spring 2018 would be 79.79% (95% CI 54.81%–104.77%) and the actual value was 55.56%. Therefore, the effectiveness of the first application of spatially targeted mollusciciding was acceptable. However, the validation of its sustainable effectiveness still needs a replicated study comparing areas where targeted and untargeted methods are applied simultaneously and both snail abundance and human infection are monitored.
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40
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Allan F, Ame SM, Tian-Bi YNT, Hofkin BV, Webster BL, Diakité NR, N’Goran EK, Kabole F, Khamis IS, Gouvras AN, Emery AM, Pennance T, Rabone M, Kinung’hi S, Hamidou AA, Mkoji GM, McLaughlin JP, Kuris AM, Loker ES, Knopp S, Rollinson D. Snail-Related Contributions from the Schistosomiasis Consortium for Operational Research and Evaluation Program Including Xenomonitoring, Focal Mollusciciding, Biological Control, and Modeling. Am J Trop Med Hyg 2020; 103:66-79. [PMID: 32400353 PMCID: PMC7351297 DOI: 10.4269/ajtmh.19-0831] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 02/14/2020] [Indexed: 01/05/2023] Open
Abstract
The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) was created in 2008 to answer questions of importance to program managers working to reduce the burden of schistosomiasis in Africa. In the past, intermediate host snail monitoring and control was an important part of integrated schistosomiasis control. However, in Africa, efforts to control snails have declined dramatically over the last 30 years. A resurgence of interest in the control of snails has been prompted by the realization, backed by a World Health Assembly resolution (WHA65.21), that mass drug administration alone may be insufficient to achieve schistosomiasis elimination. SCORE has supported work on snail identification and mapping and investigated how xenomonitoring techniques can aid in the identification of infected snails and thereby identify potential transmission areas. Focal mollusciciding with niclosamide was undertaken in Zanzibar and Côte d'Ivoire as a part of elimination studies. Two studies involving biological control of snails were conducted: one explored the association of freshwater riverine prawns and snail hosts in Côte d'Ivoire and the other assessed the current distribution of Procambarus clarkii, the invasive Louisiana red swamp crayfish, in Kenya and its association with snail hosts and schistosomiasis transmission. SCORE also supported modeling studies on the importance of snail control in achieving elimination and a meta-analysis of the impact of molluscicide-based snail control programs on human schistosomiasis prevalence and incidence. SCORE's snail control studies contributed to increased investment in building capacity, and specimens collected during SCORE research deposited in the Schistosomiasis Collections at the Natural History Museum (SCAN) will provide a valuable resource for the years to come.
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Affiliation(s)
- Fiona Allan
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Shaali M. Ame
- Public Health Laboratory - Ivo de Carneri, Pemba, United Republic of Tanzania
| | - Yves-Nathan T. Tian-Bi
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d’Ivoire
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
| | - Bruce V. Hofkin
- Department of Biology, University of New Mexico, Albuquerque, New Mexico
| | - Bonnie L. Webster
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Nana R. Diakité
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d’Ivoire
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
| | - Eliezer K. N’Goran
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d’Ivoire
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
| | - Fatma Kabole
- Neglected Tropical Disease Unit, Unguja, Ministry of Health, Zanzibar, United Republic of Tanzania
| | - Iddi S. Khamis
- Neglected Tropical Disease Unit, Unguja, Ministry of Health, Zanzibar, United Republic of Tanzania
| | - Anouk N. Gouvras
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Aidan M. Emery
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Tom Pennance
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Muriel Rabone
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Safari Kinung’hi
- National Institute of Medical Research (NIMR) Mwanza Centre, Mwanza, United Republic of Tanzania
| | - Amina Amadou Hamidou
- Réseau International Schistosomoses, Environnement, Aménagement et Lutte (RISEAL-Niger), Niamey, Niger
| | - Gerald M. Mkoji
- Center for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - John P. McLaughlin
- Department of Ecology, Evolution and Marine Biology and Marine Science Institute, University of California, Santa Barbara, California
| | - Armand M. Kuris
- Department of Ecology, Evolution and Marine Biology and Marine Science Institute, University of California, Santa Barbara, California
| | - Eric S. Loker
- Department of Biology, University of New Mexico, Albuquerque, New Mexico
| | - Stefanie Knopp
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - David Rollinson
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
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A New Method to Test Molluscicides against the Philippine Schistosomiasis Snail Vectors. J Parasitol Res 2020; 2020:3827125. [PMID: 32411420 PMCID: PMC7204092 DOI: 10.1155/2020/3827125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 08/29/2019] [Accepted: 10/04/2019] [Indexed: 11/17/2022] Open
Abstract
To expedite the discovery of novel molluscicides in the laboratory, this study aimed to evaluate the performance of a new molluscicidal assay. This assay is based on Oncomelania hupensis quadrasi snails and is called miniaturized plate test or mpt. To perform this assay, a 12-well plate, 3 snails per well, and 24-h exposure period were used. The performance of mpt was evaluated using niclosamide and Ardisia plant extract (tagpo extract) as test substances while WHO's guidelines for a conventional plate test (cpt) served as standard. One cpt and four mpt independent trials were performed for niclosamide and tagpo extract. Probit analysis of dose–response data was run in R to generate lethal concentrations (LC50 and LC90), while lethal ratio test was performed to detect significant difference between paired LC50s (or LC90s). Using niclosamide, the calculated LC50 values were 0.104, 0.127, 0.136, 0.139, and 0.140 g/m2 for cpt, mpt 1, mpt 2, mpt 3, and mpt 4, respectively, while the LC90 values were 0.266, 0.268, 0.244, 0.251, and 0.261 g/m2, using the same sequence, respectively. For tagpo extract, the LC50 values were 1.467, 1.547, 1.659, 1.797, and 1.659 g/m2, for cpt, mpt 1, mpt 2, mpt 3, and mpt 4, respectively, and the LC90s were 2.188, 2.195, 2.501, 2.358, and 2.501 g/m2, respectively. The lethal ratio test revealed that a significant difference exists between the LC50s of cpt and mpt 1 when using niclosamide with a lethal ratio and confidence limits of 0.820 (0.663, 0.977, p < 0.05) and another significant difference between LC50s of mpt 1 and mpt 3 using tagpo extract with computed lethal ratio and confidence limits of 0.861 (0.782, 0.939, p < 0.05). Taken together, the results point out that mpt generates accurate and reproducible lethal concentration values. Hence, mpt may be used as an alternative method to screen molluscicides that are active against schistosome snail vectors.
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Alzaylaee H, Collins RA, Shechonge A, Ngatunga BP, Morgan ER, Genner MJ. Environmental DNA-based xenomonitoring for determining Schistosoma presence in tropical freshwaters. Parasit Vectors 2020; 13:63. [PMID: 32051004 PMCID: PMC7017522 DOI: 10.1186/s13071-020-3941-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Accepted: 02/03/2020] [Indexed: 02/07/2023] Open
Abstract
Background Schistosomiasis is a neglected tropical disease that infects over 200 million people worldwide. Control measures can benefit from improved surveillance methods in freshwaters, with environmental DNA (eDNA) surveys having the potential to offer effective and rapid detection of schistosomes. However, sampling eDNA directly from natural water bodies can lead to inaccurate estimation of infection risk if schistosome eDNA is rare in the environment. Here we report a xenomonitoring method that allows schistosome infections of host snail species to be determined from eDNA in water used to house those snails. Methods Host snail species were collected and placed in containers of water and allowed to shed cercariae, and then water samples were filtered and tested using qPCR assays specific to the African species Schistosoma mansoni and Schistosoma haematobium. We evaluated this “eDNA-based xenomonitoring” approach by experimentally comparing the results to those obtained from direct qPCR screening of tissue sourced from the snails in the experiment. Results We found that our method accurately diagnosed the presence of S. mansoni-infected snails in all tests, and S. haematobium-infected snails in 92% of tests. Moreover, we found that the abundance of Schistosoma eDNA in experiments was directly dependent on the number and biomass of infected snails. Conclusions These results provide a strong indication that this surveillance method combining the utility of eDNA-based monitoring with the reliability of traditional xenomonitoring approaches could be used to accurately assay the presence of Schistosoma species in natural habitats. This approach may be well-suited for epidemiological studies and monitoring in endemic areas, where it can assist schistosomiasis control by indicating infection risk from freshwaters and guiding necessary interventions to eliminate the disease.![]()
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Affiliation(s)
- Hind Alzaylaee
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK.,Biology Department, Faculty of Sciences, Prince Nourah Bin Abdulrahman University, Riyadh, Saudi Arabia
| | - Rupert A Collins
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK
| | - Asilatu Shechonge
- Tanzania Fisheries Research Institute (TAFIRI), PO Box 9750, Dar es Salaam, Tanzania
| | - Benjamin P Ngatunga
- Tanzania Fisheries Research Institute (TAFIRI), PO Box 9750, Dar es Salaam, Tanzania
| | - Eric R Morgan
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK.,School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, UK
| | - Martin J Genner
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK.
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The Stakeholders' Views on Planting Trees to Control Schistosomiasis in China. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17030939. [PMID: 32028713 PMCID: PMC7036940 DOI: 10.3390/ijerph17030939] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 01/29/2020] [Accepted: 02/01/2020] [Indexed: 12/23/2022]
Abstract
China has initiated a tree planting program in epidemic regions of schistosomiasis as a part of efforts to eliminate schistosomiasis. More than 518,900 ha of tree plantations have been planted through the program between 2006 and 2015. However, whether the planting program has fulfilled its mission or not is an open question. In this study, we intended to get the answer from the main stakeholders of the planting program through a large-scale survey. Based on interviews with 80 administrators of the planting program and 1440 farmers in 24 counties and districts in four provinces, we found that most stakeholders viewed the planting program positively. Nearly 92% of farmers and all administrators believed that the planting program had reduced snail densities, while 94.3% of farmers and all administrators believed that the program had lowered the incidences of schistosomiasis. In addition, they reported that the impacts on farmers’ living and local environments by the tree planting program were mainly positive. Based on the stakeholders’ responses, we conclude that the tree planting program has been perceived by the main stakeholders as an effective environmental control measure of schistosomiasis. However, certain places and people that may be impacted negatively by the program should be given more attention when implementing the program.
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Tan Z, Lei Z, Zhang Z, Zhang H, Shu K, Hu F, Lei T. Identification and characterization of microglia/macrophages in the granuloma microenvironment of encephalic schistosomiasis japonicum. BMC Infect Dis 2019; 19:1088. [PMID: 31888505 PMCID: PMC6937796 DOI: 10.1186/s12879-019-4725-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 12/22/2019] [Indexed: 12/15/2022] Open
Abstract
Background Egg-induced immune response and granuloma formation are thought to be the basis of central nervous system (CNS)-related clinical symptoms of Schistosoma japonicum. Microglia/macrophages are the major immune cells involved in detection and subsequent elimination of pathogens and injured tissue in the brain. However, little is known about their role in the pathogenesis of neuroschistosomiasis. The main purpose of the study is to clarify the pathological involvement of microglia/macrophages in the pathogenesis of neuroschistosomiasis (NS). Methods Staining techniques were applied to the granuloma tissues excised from 4 patients, as well as mice model which was established by microinjecting viable S. japonicum eggs into the brain. Clinical features of the patients and neurological symptoms in mice were also collected and analyzed in terms of their correlation with microglia/macrophages. Results Microglia/macrophages constituted the major portions of the granulomas surrounding the eggs in both all human cases and S. japonicum egg-injected mice. Granuloma persisted in all patients accompanied by unremitted neurological symptoms, while in mice granuloma formation initiated on day 3, peaked on day 7 and subsided on day 30 post injection with S. japonicum eggs. No neurological abnormalities were observed in egg-injected mice except for significant weight decrease on day 3 compared with saline-injected control. M1 polarization of microglia/macrophages was confirmed in egg-injected mice 3 days post injection and in all human cases. M2 polarization was absent in human patients despite the duration of complaints but dominated in the whole progression of egg-induced pathology in mice until the elimination of eggs and subsidence of neuroinflammation on day 30 post injection. Conclusions Microglia/macrophages participated actively in the granuloma microenvironment of encephalic schistosomiasis japonicum in both human and mice. The polarization pattern of microglia/macrophages coincided with the symptomatic features in human cases and S. japonicum egg-injected mice, indicating M2 instead of M1 activation as a probably more important mediator in the battle against egg-induced pathology and concomitant manifestations. These new findings will shed light on the pathogenesis of NS from a brand-new perspective, and may contribute to the immunotherapy development for such disease, favoring perhaps M2 polarization of microglia/macrophages as a feasible strategy.
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Affiliation(s)
- Zhoubin Tan
- Sino-German Neuro-Oncology Molecular Laboratory, Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhuowei Lei
- Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhuo Zhang
- Sino-German Neuro-Oncology Molecular Laboratory, Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Present Address: Department of Neurosurgery, Philipps University Marburg, Baldingerstr, Marburg, Germany
| | - Huaqiu Zhang
- Sino-German Neuro-Oncology Molecular Laboratory, Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Kai Shu
- Sino-German Neuro-Oncology Molecular Laboratory, Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Feng Hu
- Sino-German Neuro-Oncology Molecular Laboratory, Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Ting Lei
- Sino-German Neuro-Oncology Molecular Laboratory, Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
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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] [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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Perez-Saez J, Mande T, Zongo D, Rinaldo A. Comparative analysis of time-based and quadrat sampling in seasonal population dynamics of intermediate hosts of human schistosomes. PLoS Negl Trop Dis 2019; 13:e0007938. [PMID: 31860653 PMCID: PMC6957212 DOI: 10.1371/journal.pntd.0007938] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 01/13/2020] [Accepted: 11/20/2019] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Despite their importance for designing and evaluating schistosomiasis control trials, little attention in the literature has been dedicated to sampling protocols for the parasite's snail intermediate hosts since their first development. We propose a comparative analysis of time-based and quadrat sampling protocols to quantify the seasonal variations in the abundance of these aquatic snail species of medical importance. METHODOLOGY/PRINCIPAL FINDINGS Snail populations were monitored during 42 consecutive months in three types of habitats (ephemeral pond, ephemeral river and permanent stream) in two sites covering different climatic zones in Burkina Faso. We employed both a widely used time-based protocol of 30min of systematic collection at a weekly interval, and a quadrat protocol of 8 replicates per sample at a monthly interval. The correspondence between the two protocols was evaluated using an ensemble of statistical models including linear and saturating-type functional forms as well as allowing for count zero-inflation. The quadrat protocol yielded on average a relative standard error of 40%, for a mean snail density of 16.7 snails/m2 and index of dispersion of 1.51. Both protocols yielded similar seasonal patterns in snail abundance, confirming the asynchrony between permanent and ephemeral habitats with respect to the country's seasonal rainfall patterns. Formal model comparison of the link between time vs. quadrat counts showed strong support of saturation for the latter and measurement zero-inflation, providing important evidence for the presence of density feedbacks in the snail's population dynamics, as well as for spatial clustering. CONCLUSIONS/SIGNIFICANCE In addition to the agreement with the time-based method, quadrat sampling provided insight into snail population dynamics and comparable density estimates across sites. The re-evaluation of these "traditional" sampling protocols, as well as the correspondence between their outputs, is of practical importance for the design and evaluation of schistosomiasis control trials.
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Affiliation(s)
- Javier Perez-Saez
- Laboratory of Ecohydrology, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Théophile Mande
- Laboratory of Ecohydrology, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Dramane Zongo
- Départemente Biomédical et Santé publique, Institut de Recherche en Sciences de la Santé, Ouagadougou, Burkina Faso
| | - Andrea Rinaldo
- Laboratory of Ecohydrology, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Dipartimento ICEA, Università di Padova, Padova, Italy
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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] [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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Rabone M, Wiethase JH, Allan F, Gouvras AN, Pennance T, Hamidou AA, Webster BL, Labbo R, Emery AM, Garba AD, Rollinson D. Freshwater snails of biomedical importance in the Niger River Valley: evidence of temporal and spatial patterns in abundance, distribution and infection with Schistosoma spp. Parasit Vectors 2019; 12:498. [PMID: 31640811 PMCID: PMC6805334 DOI: 10.1186/s13071-019-3745-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 10/09/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Sound knowledge of the abundance and distribution of intermediate host snails is key to understanding schistosomiasis transmission and to inform effective interventions in endemic areas. METHODS A longitudinal field survey of freshwater snails of biomedical importance was undertaken in the Niger River Valley (NRV) between July 2011 and January 2016, targeting Bulinus spp. and Biomphalaria pfeifferi (intermediate hosts of Schistosoma spp.), and Radix natalensis (intermediate host of Fasciola spp.). Monthly snail collections were carried out in 92 sites, near 20 localities endemic for S. haematobium. All bulinids and Bi. pfeifferi were inspected for infection with Schistosoma spp., and R. natalensis for infection with Fasciola spp. RESULTS Bulinus truncatus was the most abundant species found, followed by Bulinus forskalii, R. natalensis and Bi. pfeifferi. High abundance was associated with irrigation canals for all species with highest numbers of Bulinus spp. and R. natalensis. Seasonality in abundance was statistically significant in all species, with greater numbers associated with dry season months in the first half of the year. Both B. truncatus and R. natalensis showed a negative association with some wet season months, particularly August. Prevalences of Schistosoma spp. within snails across the entire study were as follows: Bi. pfeifferi: 3.45% (79/2290); B. truncatus: 0.8% (342/42,500); and B. forskalii: 0.2% (24/11,989). No R. natalensis (n = 2530) were infected. Seasonality of infection was evident for B. truncatus, with highest proportions shedding in the middle of the dry season and lowest in the rainy season, and month being a significant predictor of infection. Bulinus spp. and Bi. pfeifferi showed a significant correlation of snail abundance with the number of snails shedding. In B. truncatus, both prevalence of Schistosoma spp. infection, and abundance of shedding snails were significantly higher in pond habitats than in irrigation canals. CONCLUSIONS Evidence of seasonality in both overall snail abundance and infection with Schistosoma spp. in B. truncatus, the main intermediate host in the region, has significant implications for monitoring and interrupting transmission of Schistosoma spp. in the NRV. Monthly longitudinal surveys, representing intensive sampling effort have provided the resolution needed to ascertain both temporal and spatial trends in this study. These data can inform planning of interventions and treatment within the region.
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Affiliation(s)
- Muriel Rabone
- Department of Life Sciences, Natural History Museum, Cromwell Rd, South Kensington, London, SW7 5BD UK
| | - Joris Hendrik Wiethase
- Department of Life Sciences, Natural History Museum, Cromwell Rd, South Kensington, London, SW7 5BD UK
| | - Fiona Allan
- Department of Life Sciences, Natural History Museum, Cromwell Rd, South Kensington, London, SW7 5BD UK
| | - Anouk Nathalie Gouvras
- Department of Life Sciences, Natural History Museum, Cromwell Rd, South Kensington, London, SW7 5BD UK
| | - Tom Pennance
- Department of Life Sciences, Natural History Museum, Cromwell Rd, South Kensington, London, SW7 5BD UK
- School of Biosciences, Cardiff University, Cardiff, CF10 3AT UK
| | - Amina Amadou Hamidou
- Réseau International Schistosomoses, Environnement Aménagement et Lutte (RISEAL-Niger), 333, Avenue des Zarmakoye, B.P. 13724, Niamey, Niger
| | - Bonnie Lee Webster
- Department of Life Sciences, Natural History Museum, Cromwell Rd, South Kensington, London, SW7 5BD UK
| | - Rabiou Labbo
- Réseau International Schistosomoses, Environnement Aménagement et Lutte (RISEAL-Niger), 333, Avenue des Zarmakoye, B.P. 13724, Niamey, Niger
- Centre de Recherche Médicale et Sanitaire (CERMES), Institut Pasteur International Network, 634 Bd de la Nation, BP 10887, Niamey, Niger
| | - Aidan Mark Emery
- Department of Life Sciences, Natural History Museum, Cromwell Rd, South Kensington, London, SW7 5BD UK
| | - Amadou Djirmay Garba
- Réseau International Schistosomoses, Environnement Aménagement et Lutte (RISEAL-Niger), 333, Avenue des Zarmakoye, B.P. 13724, Niamey, Niger
- World Health Organization, Geneva, Switzerland
| | - David Rollinson
- Department of Life Sciences, Natural History Museum, Cromwell Rd, South Kensington, London, SW7 5BD UK
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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] [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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Allan ERO, Yang L, Tennessen JA, Blouin MS. Allelic variation in a single genomic region alters the hemolymph proteome in the snail Biomphalaria glabrata. FISH & SHELLFISH IMMUNOLOGY 2019; 88:301-307. [PMID: 30849501 PMCID: PMC6687060 DOI: 10.1016/j.fsi.2019.02.065] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Revised: 02/26/2019] [Accepted: 02/28/2019] [Indexed: 05/04/2023]
Abstract
Freshwater snails are obligate intermediate hosts for numerous parasitic trematodes, most notably schistosomes. Schistosomiasis is a devastating human and veterinary illness, which is primarily controlled by limiting the transmission of these parasites from their intermediate snail hosts. Understanding how this transmission occurs, as well as the basic immunobiology of these snails may be important for controlling this disease in the future. Allelic variation in the Guadeloupe resistance complex (GRC) of Biomphalaria glabrata partially determines their susceptibility to parasitic infection, and can influence the microbiome diversity and microbial defenses in the hemolymph of these snails. In the present study, we examine the most abundant proteins present in the hemolymph of snails that are resistant or susceptible to schistosomes, as determined by their GRC genotype. Using proteomic analysis, we found that snails with different GRC genotypes have differentially abundant hemolymph proteins that are not explained by differences in transcription. There are 13 revealed hemolymph proteins that differ significantly between resistant and susceptible genotypes, nearly 40% of which are involved in immune responses. These findings build on the mounting evidence that genes in the GRC region have multiple physiological roles, and likely contribute more extensively to the general immune response than previously believed. These data also raise the intriguing possibility that the GRC region controls resistance to schistosomes, not directly, but indirectly via its effects on the snail's proteome and potentially its microbiome.
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Affiliation(s)
- Euan R O Allan
- Department of Pathobiology, School of Veterinary Medicine, St. George's University, Grenada.
| | - Liping Yang
- Mass Spectrometry Center, Department of Chemistry, Oregon State University, Corvallis, OR, USA
| | - Jacob A Tennessen
- Department of Integrative Biology, College of Science, Oregon State University, Corvallis, OR, USA
| | - Michael S Blouin
- Department of Integrative Biology, College of Science, Oregon State University, Corvallis, OR, USA
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