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Plowright RK, Ahmed AN, Coulson T, Crowther TW, Ejotre I, Faust CL, Frick WF, Hudson PJ, Kingston T, Nameer PO, O'Mara MT, Peel AJ, Possingham H, Razgour O, Reeder DM, Ruiz-Aravena M, Simmons NB, Srinivas PN, Tabor GM, Tanshi I, Thompson IG, Vanak AT, Vora NM, Willison CE, Keeley ATH. Ecological countermeasures to prevent pathogen spillover and subsequent pandemics. Nat Commun 2024; 15:2577. [PMID: 38531842 DOI: 10.1038/s41467-024-46151-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 02/16/2024] [Indexed: 03/28/2024] Open
Abstract
Substantial global attention is focused on how to reduce the risk of future pandemics. Reducing this risk requires investment in prevention, preparedness, and response. Although preparedness and response have received significant focus, prevention, especially the prevention of zoonotic spillover, remains largely absent from global conversations. This oversight is due in part to the lack of a clear definition of prevention and lack of guidance on how to achieve it. To address this gap, we elucidate the mechanisms linking environmental change and zoonotic spillover using spillover of viruses from bats as a case study. We identify ecological interventions that can disrupt these spillover mechanisms and propose policy frameworks for their implementation. Recognizing that pandemics originate in ecological systems, we advocate for integrating ecological approaches alongside biomedical approaches in a comprehensive and balanced pandemic prevention strategy.
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Affiliation(s)
- Raina K Plowright
- Department of Public and Ecosystem Health, Cornell University, Ithaca, NY, 14853, USA.
| | - Aliyu N Ahmed
- Medical Research Council Unit The Gambia, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Tim Coulson
- Department of Biology, University of Oxford, Oxford, OX1 3SZ, UK
| | - Thomas W Crowther
- Department of Environmental Systems Science, ETH Zürich, Zürich, 8092, Switzerland
| | - Imran Ejotre
- Department of Biology, Muni University, P.O. Box 725, Arua, Uganda
| | - Christina L Faust
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Winifred F Frick
- Bat Conservation International, Austin, TX, 78746, USA
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, 95064, USA
| | - Peter J Hudson
- Centre for Infectious Disease Dynamics, Pennsylvania State University, State College, PA, 16801, USA
| | - Tigga Kingston
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, 79409-3131, USA
| | - P O Nameer
- College of Climate Change and Environmental Science, Kerala Agricultural University, Kerala, 680 656, India
| | | | - Alison J Peel
- Centre for Planetary Health and Food Security, Griffith University, Nathan, QLD, 4111, Australia
| | - Hugh Possingham
- School of Biological Sciences, University of Queensland, Brisbane, QLD, 4072, Australia
| | - Orly Razgour
- Biosciences, University of Exeter, Exeter, EX4 4PS, UK
| | - DeeAnn M Reeder
- Department of Biology, Bucknell University, Lewisburg, PA, 17937, USA
| | - Manuel Ruiz-Aravena
- Department of Public and Ecosystem Health, Cornell University, Ithaca, NY, 14853, USA
- Centre for Planetary Health and Food Security, Griffith University, Nathan, QLD, 4111, Australia
- Department of Wildlife, Fisheries and Aquaculture, Mississippi State University, Starkville, USA
| | - Nancy B Simmons
- Department of Mammalogy, Division of Vertebrate Zoology, American Museum of Natural History, New York City, NY, 10024, USA
| | | | - Gary M Tabor
- Center for Large Landscape Conservation, Bozeman, MT, 59771, USA
| | - Iroro Tanshi
- Department of Biology, University of Washington, Seattle, WA, 98195, USA
- Small Mammal Conservation Organization, Benin City, 300251, Nigeria
- Department of Animal and Environmental Biology, University of Benin, Benin City, 300000, Nigeria
| | | | - Abi T Vanak
- Centre for Policy Design, Ashoka Trust for Research in Ecology and the Environment, Bengaluru, Karnataka, 560064, India
- School of Life Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa
| | - Neil M Vora
- Conservation International, Arlington, VA, 22202, USA
| | - Charley E Willison
- Department of Public and Ecosystem Health, Cornell University, Ithaca, NY, 14853, USA
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Raghwani J, Faust CL, François S, Nguyen D, Marsh K, Raulo A, Hill SC, Parag KV, Simmonds P, Knowles SCL, Pybus OG. Seasonal dynamics of the wild rodent faecal virome. Mol Ecol 2023; 32:4763-4776. [PMID: 36367339 PMCID: PMC7614976 DOI: 10.1111/mec.16778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 09/23/2022] [Accepted: 11/03/2022] [Indexed: 11/13/2022]
Abstract
Viral discovery studies in wild animals often rely on cross-sectional surveys at a single time point. As a result, our understanding of the temporal stability of wild animal viromes remains poorly resolved. While studies of single host-virus systems indicate that host and environmental factors influence seasonal virus transmission dynamics, comparable insights for whole viral communities in multiple hosts are lacking. Utilizing noninvasive faecal samples from a long-term wild rodent study, we characterized viral communities of three common European rodent species (Apodemus sylvaticus, A. flavicollis and Myodes glareolus) living in temperate woodland over a single year. Our findings indicate that a substantial fraction of the rodent virome is seasonally transient and associated with vertebrate or bacteria hosts. Further analyses of one of the most common virus families, Picornaviridae, show pronounced temporal changes in viral richness and evenness, which were associated with concurrent and up to ~3-month lags in host density, ambient temperature, rainfall and humidity, suggesting complex feedbacks from the host and environmental factors on virus transmission and shedding in seasonal habitats. Overall, this study emphasizes the importance of understanding the seasonal dynamics of wild animal viromes in order to better predict and mitigate zoonotic risks.
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Affiliation(s)
- Jayna Raghwani
- Department of BiologyUniversity of OxfordOxfordUK
- Department of Pathobiology and Population SciencesThe Royal Veterinary CollegeLondonUK
| | - Christina L. Faust
- Institute of Biodiversity, Animal Health, and Comparative MedicineUniversity of GlasgowGlasgowUK
| | | | - Dung Nguyen
- Nuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Kirsty Marsh
- School of BiosciencesUniversity of ExeterExeterUK
| | - Aura Raulo
- Department of BiologyUniversity of OxfordOxfordUK
- University of TurkuTurkuFinland
| | - Sarah C. Hill
- Department of Pathobiology and Population SciencesThe Royal Veterinary CollegeLondonUK
| | | | - Peter Simmonds
- Nuffield Department of MedicineUniversity of OxfordOxfordUK
| | | | - Oliver G. Pybus
- Department of BiologyUniversity of OxfordOxfordUK
- Department of Pathobiology and Population SciencesThe Royal Veterinary CollegeLondonUK
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Clark J, Moses A, Nankasi A, Faust CL, Moses A, Ajambo D, Besigye F, Atuhaire A, Wamboko A, Carruthers LV, Francoeur R, Tukahebwa EM, Prada JM, Lamberton PHL. Reconciling Egg- and Antigen-Based Estimates of Schistosoma mansoni Clearance and Reinfection: A Modeling Study. Clin Infect Dis 2022; 74:1557-1563. [PMID: 34358299 PMCID: PMC9070857 DOI: 10.1093/cid/ciab679] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Despite decades of interventions, 240 million people have schistosomiasis. Infections cannot be directly observed, and egg-based Kato-Katz thick smears lack sensitivity, affected treatment efficacy and reinfection rate estimates. The point-of-care circulating cathodic antigen (referred to from here as POC-CCA+) test is advocated as an improvement on the Kato-Katz method, but improved estimates are limited by ambiguities in the interpretation of trace results. METHOD We collected repeated Kato-Katz egg counts from 210 school-aged children and scored POC-CCA tests according to the manufacturer's guidelines (referred to from here as POC-CCA+) and the externally developed G score. We used hidden Markov models parameterized with Kato-Katz; Kato-Katz and POC-CCA+; and Kato-Katz and G-Scores, inferring latent clearance and reinfection probabilities at four timepoints over six-months through a more formal statistical reconciliation of these diagnostics than previously conducted. Our approach required minimal but robust assumptions regarding trace interpretations. RESULTS Antigen-based models estimated higher infection prevalence across all timepoints compared with the Kato-Katz model, corresponding to lower clearance and higher reinfection estimates. Specifically, pre-treatment prevalence estimates were 85% (Kato-Katz; 95% CI: 79%-92%), 99% (POC-CCA+; 97%-100%) and 98% (G-Score; 95%-100%). Post-treatment, 93% (Kato-Katz; 88%-96%), 72% (POC-CCA+; 64%-79%) and 65% (G-Score; 57%-73%) of those infected were estimated to clear infection. Of those who cleared infection, 35% (Kato-Katz; 27%-42%), 51% (POC-CCA+; 41%-62%) and 44% (G-Score; 33%-55%) were estimated to have been reinfected by 9-weeks. CONCLUSIONS Treatment impact was shorter-lived than Kato-Katz-based estimates alone suggested, with lower clearance and rapid reinfection. At 3 weeks after treatment, longer-term clearance dynamics are captured. At 9 weeks after treatment, reinfection was captured, but failed clearance could not be distinguished from rapid reinfection. Therefore, frequent sampling is required to understand these important epidemiological dynamics.
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Affiliation(s)
- Jessica Clark
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | | | | | - Christina L Faust
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Adriko Moses
- Vector Control Division, Ministry of Health, Uganda
| | - Diana Ajambo
- Vector Control Division, Ministry of Health, Uganda
| | - Fred Besigye
- Vector Control Division, Ministry of Health, Uganda
| | | | | | - Lauren V Carruthers
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Rachel Francoeur
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
- Faculty of Science & Engineering, University of Chester, Chester, United Kingdom
| | | | - Joaquin M Prada
- Faculty of Health & Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Poppy H L Lamberton
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
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Clark J, Moses A, Nankasi A, Faust CL, Adriko M, Ajambo D, Besigye F, Atuhaire A, Wamboko A, Rowel C, Carruthers LV, Francoeur R, Tukahebwa EM, Lamberton PHL, Prada JM. Translating From Egg- to Antigen-Based Indicators for Schistosoma mansoni Elimination Targets: A Bayesian Latent Class Analysis Study. Front Trop Dis 2022; 3:825721. [PMID: 35784267 PMCID: PMC7612949 DOI: 10.3389/fitd.2022.825721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Schistosomiasis is a parasitic disease affecting over 240-million people. World Health Organization (WHO) targets for Schistosoma mansoni elimination are based on Kato-Katz egg counts, without translation to the widely used, urine-based, point-of-care circulating cathodic antigen diagnostic (POC-CCA). We aimed to standardize POC-CCA score interpretation and translate them to Kato-Katz-based standards, broadening diagnostic utility in progress towards elimination. A Bayesian latent-class model was fit to data from 210 school-aged-children over four timepoints pre- to six-months-post-treatment. We used 1) Kato-Katz and established POC-CCA scoring (Negative, Trace, +, ++ and +++), and 2) Kato-Katz and G-Scores (a new, alternative POC-CCA scoring (G1 to G10)). We established the functional relationship between Kato-Katz counts and POC-CCA scores, and the score-associated probability of true infection. This was combined with measures of sensitivity, specificity, and the area under the curve to determine the optimal POC-CCA scoring system and positivity threshold. A simulation parametrized with model estimates established antigen-based elimination targets. True infection was associated with POC-CCA scores of ≥ + or ≥G3. POC-CCA scores cannot predict Kato-Katz counts because low infection intensities saturate the POC-CCA cassettes. Post-treatment POC-CCA sensitivity/specificity fluctuations indicate a changing relationship between egg excretion and antigen levels (living worms). Elimination targets can be identified by the POC-CCA score distribution in a population. A population with ≤2% ++/+++, or ≤0.5% G7 and above, indicates achieving current WHO Kato-Katz-based elimination targets. Population-level POC-CCA scores can be used to access WHO elimination targets prior to treatment. Caution should be exercised on an individual level and following treatment, as POC-CCAs lack resolution to discern between WHO Kato-Katz-based moderate- and high-intensity-infection categories, with limited use in certain settings and evaluations.
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Affiliation(s)
- Jessica Clark
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
- Correspondence: Jessica Clark, ; Joaquin M. Prada,
| | - Arinaitwe Moses
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Andrina Nankasi
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Christina L. Faust
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Moses Adriko
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Diana Ajambo
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Fred Besigye
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Arron Atuhaire
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Aidah Wamboko
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Candia Rowel
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Lauren V. Carruthers
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Rachel Francoeur
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
- Faculty of Science and Engineering, University of Chester, Chester, United Kingdom
| | | | - Poppy H. L. Lamberton
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Joaquin M. Prada
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
- Correspondence: Jessica Clark, ; Joaquin M. Prada,
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Trienekens SCM, Faust CL, Besigye F, Pickering L, Tukahebwa EM, Seeley J, Lamberton PHL. Variation in water contact behaviour and risk of Schistosoma mansoni (re)infection among Ugandan school-aged children in an area with persistent high endemicity. Parasit Vectors 2022; 15:15. [PMID: 34991702 PMCID: PMC8734346 DOI: 10.1186/s13071-021-05121-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 12/11/2021] [Indexed: 11/29/2022] Open
Abstract
Background Annual mass drug administration with praziquantel has reduced schistosomiasis transmission in some highly endemic areas, but areas with persistent high endemicity have been identified across sub-Saharan Africa, including Uganda. In these areas many children are rapidly reinfected post treatment, while some children remain uninfected or have low-intensity infections. The aim of this mixed-methods study was to better understand variation in water contact locations, behaviours and infection risk in school-aged children within an area with persistent high endemicity to inform additional control efforts. Methods Data were collected in Bugoto, Mayuge District, Uganda. Two risk groups were identified from a longitudinal cohort, and eight children with no/low-intensity infections and eight children with reinfections were recruited. Individual structured day-long observations with a focus on water contact were conducted over two periods in 2018. In all identified water contact sites, four snail surveys were conducted quarterly over 1 year. All observed Biomphalaria snails were collected, counted and monitored in the laboratory for Schistosoma mansoni cercarial shedding for 3 weeks. Results Children came into contact with water for a range of purposes, either directly at the water sources or by coming into contact with water collected previously. Although some water contact practices were similar between the risk groups, only children with reinfection were observed fetching water for commercial purposes and swimming in water sources; this latter group of children also came into contact with water at a larger variety and number of sites compared to children with no/low-intensity infection. Households with children with no/low-intensity infections collected rainwater more often. Water contact was observed at 10 sites throughout the study, and a total of 9457 Biomphalaria snails were collected from these sites over four sampling periods. Four lake sites had a significantly higher Biomphalaria choanomphala abundance, and reinfected children came into contact with water at these sites more often than children with no/low-intensity infections. While only six snails shed cercariae, four were from sites only contacted by reinfected children. Conclusions Children with reinfection have more high-risk water contact behaviours and accessed water sites with higher B. choanomphala abundance, demonstrating that specific water contact behaviours interact with environmental features to explain variation in risk within areas with persistent high endemicity. Targeted behaviour change, vector control and safe water supplies could reduce reinfection in school-aged children in these settings. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-021-05121-6.
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Affiliation(s)
- Suzan C M Trienekens
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK. .,Wellcome Centre for Integrative Parasitology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK. .,Institute of Health & Wellbeing, College of Social Sciences, University of Glasgow, Glasgow, UK.
| | - Christina L Faust
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.,Wellcome Centre for Integrative Parasitology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Fred Besigye
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Lucy Pickering
- Institute of Health & Wellbeing, College of Social Sciences, University of Glasgow, Glasgow, UK
| | | | - Janet Seeley
- Medical Research Council/Uganda Virus Research Institute, Entebbe, Uganda.,Department of Global Health and Development, Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK
| | - Poppy H L Lamberton
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.,Wellcome Centre for Integrative Parasitology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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Moses A, Adriko M, Kibwika B, Tukahebwa EM, Faust CL, Lamberton PHL. Residence Time, Water Contact, and Age-driven Schistosoma mansoni Infection in Hotspot Communities in Uganda. Am J Trop Med Hyg 2021; 105:1772-1781. [PMID: 34662868 PMCID: PMC8641335 DOI: 10.4269/ajtmh.21-0391] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 08/06/2021] [Indexed: 12/05/2022] Open
Abstract
Schistosomiasis is the second most important parasitic infection after malaria in terms of its socioeconomic impact and is endemic in 78 countries. It affects more than 240 million people worldwide, with 90% of cases occurring in sub-Saharan Africa. In Uganda, Schistosoma mansoni is the most common species, with more than seven million people infected and 17 million living at risk despite mass drug administration (MDA) of praziquantel initiated more than 16 years ago. There has been a shift in the WHO schistosomiasis goals from controlling morbidity to elimination as a public health problem. Understanding the drivers of infection in persistent transmission hotspots despite ongoing control interventions is paramount. We conducted a cross-sectional epidemiological study of 381 individuals in Bugoto community, Mayuge district, Eastern Uganda, along with a structured survey to ascertain drivers of S. mansoni infection. Bugoto has had community-wide MDA since 2004. We detected a S. mansoni prevalence of 52% across the whole community and a prevalence of 71% in school-age children. This qualifies Bugoto as a highly endemic community according to WHO guidelines. Using a multivariate logistic regression, we found that S. mansoni infection was best explained by age group, longer residence times, and any daily contact with lake water. Schistosoma mansoni infection remains a large burden across this community. This study identifies opportunities for interventions that reduce lake water contact, expand treatment eligibility to all at risk, and improve MDA coverage for long-term residents in these settings to control schistosomiasis in persistent transmission hotspots.
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Affiliation(s)
- Arinaitwe Moses
- Vector Borne and Neglected Tropical Diseases Control Division, Ministry of Health, Kampala, Uganda.,Cavendish University Uganda, Kampala, Uganda
| | - Moses Adriko
- Vector Borne and Neglected Tropical Diseases Control Division, Ministry of Health, Kampala, Uganda
| | | | - Edridah M Tukahebwa
- Vector Borne and Neglected Tropical Diseases Control Division, Ministry of Health, Kampala, Uganda
| | - Christina L Faust
- Institute for Biodiversity, Animal Health and Comparative Medicine and Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, United Kingdom
| | - Poppy H L Lamberton
- Institute for Biodiversity, Animal Health and Comparative Medicine and Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, United Kingdom
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7
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Faust CL, Brunker K, Ajambo D, Ryan M, Moses A, Rowel C, Wangoola RM, Wampande EM, Guma A, Adriko M, Lamberton PHL, Tukahebwa EM, Mugenyi A, Waiswa C. Harnessing technology and portability to conduct molecular epidemiology of endemic pathogens in resource-limited settings. Trans R Soc Trop Med Hyg 2021; 115:3-5. [PMID: 32945867 PMCID: PMC7788292 DOI: 10.1093/trstmh/traa086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 08/10/2020] [Accepted: 08/21/2020] [Indexed: 11/12/2022] Open
Abstract
Improvements in genetic and genomic technology have enabled field-deployable molecular laboratories and these have been deployed in a variety of epidemics that capture headlines. In this editorial, we highlight the importance of building physical and personnel capacity in low and middle income countries to deploy these technologies to improve diagnostics, understand transmission dynamics and provide feedback to endemic communities on actionable timelines. We describe our experiences with molecular field research on schistosomiasis, trypanosomiasis and rabies and urge the wider tropical medicine community to embrace these methods and help build capacity to benefit communities affected by endemic infectious diseases.
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Affiliation(s)
- Christina L Faust
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow G12 8QQ, UK
| | - Kirstyn Brunker
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - Diana Ajambo
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Mary Ryan
- Glasgow Centre for International Development, University of Glasgow, Glasgow G12 8QQ, UK
| | - Arinaitwe Moses
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Candia Rowel
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | | | - Eddie M Wampande
- Department of Biotechnical and Diagnostic Sciences, Makerere University, Kampala, Uganda
| | - Andrew Guma
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Moses Adriko
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Poppy H L Lamberton
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow G12 8QQ, UK
| | | | - Albert Mugenyi
- Coordinating Office for the Control of Trypanosomiasis in Uganda, Kampala, Uganda
| | - Charles Waiswa
- Coordinating Office for the Control of Trypanosomiasis in Uganda, Kampala, Uganda
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Faust CL, Osakunor DNM, Downs JA, Kayuni S, Stothard JR, Lamberton PHL, Reinhard-Rupp J, Rollinson D. Schistosomiasis Control: Leave No Age Group Behind. Trends Parasitol 2020; 36:582-591. [PMID: 32430274 DOI: 10.1016/j.pt.2020.04.012] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/15/2020] [Accepted: 04/17/2020] [Indexed: 01/11/2023]
Abstract
Despite accelerating progress towards schistosomiasis control in sub-Saharan Africa, several age groups have been eclipsed by current treatment and monitoring strategies that mainly focus on school-aged children. As schistosomiasis poses a threat to people of all ages, unfortunate gaps exist in current treatment coverage and associated monitoring efforts, preventing subsequent health benefits to preschool-aged children as well as certain adolescents and adults. Expanding access to younger ages through the forthcoming pediatric praziquantel formulation and improving treatment coverage in older ages is essential. This should occur alongside formal inclusion of these groups in large-scale monitoring and evaluation activities. Current omission of these age groups from treatment and monitoring exacerbates health inequities and has long-term consequences for sustainable schistosomiasis control.
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Affiliation(s)
- Christina L Faust
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK.
| | - Derick N M Osakunor
- Institute of Immunology and Infection Research, University of Edinburgh, Ashworth Laboratories, King's Buildings, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK
| | - Jennifer A Downs
- Center for Global Health, Department of Medicine, Weill Cornell Medicine, New York, NY 10065, USA
| | - Sekeleghe Kayuni
- Department of Tropical Disease Biology, Centre for Neglected Tropical Diseases, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK; MASM Medi Clinics Limited, Medical Aid Society of Malawi (MASM), Blantyre, Malawi
| | - J Russell Stothard
- Department of Tropical Disease Biology, Centre for Neglected Tropical Diseases, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| | - Poppy H L Lamberton
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | | | - David Rollinson
- Global Schistosomiasis Alliance, Natural History Museum, London SW7 5BD, UK
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9
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Greischar MA, Alexander HK, Bashey F, Bento AI, Bhattacharya A, Bushman M, Childs LM, Daversa DR, Day T, Faust CL, Gallagher ME, Gandon S, Glidden CK, Halliday FW, Hanley KA, Kamiya T, Read AF, Schwabl P, Sweeny AR, Tate AT, Thompson RN, Wale N, Wearing HJ, Yeh PJ, Mideo N. Evolutionary consequences of feedbacks between within-host competition and disease control. Evol Med Public Health 2020; 2020:30-34. [PMID: 32099654 PMCID: PMC7027713 DOI: 10.1093/emph/eoaa004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/21/2020] [Accepted: 01/22/2020] [Indexed: 11/14/2022]
Abstract
Lay Summary: Competition often occurs among diverse parasites within a single host, but control efforts could change its strength. We examined how the interplay between competition and control could shape the evolution of parasite traits like drug resistance and disease severity.
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Affiliation(s)
- Megan A Greischar
- Department of Ecology & Evolutionary Biology, University of Toronto, 25 Willcocks St., Toronto, ON M5S 3B2, Canada
| | - Helen K Alexander
- Department of Zoology, University of Oxford, Zoology Research and Administration Building, 11a Mansfield Road, Oxford OX1 3SZ, UK
| | - Farrah Bashey
- Department of Biology, Indiana University, 1001 E. 3rd St., Bloomington, IN 47405, USA
| | - Ana I Bento
- Odum School of Ecology and the Center for the Ecology of Infectious Diseases, University of Georgia, 140 E Green St., Athens, GA 30602, USA
| | - Amrita Bhattacharya
- Department of Biology, Indiana University, 1001 E. 3rd St., Bloomington, IN 47405, USA
| | - Mary Bushman
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | - Lauren M Childs
- Department of Mathematics, McBryde Hall, Virginia Tech, Blacksburg, VA 24061, USA
| | - David R Daversa
- Institute of Integrative Biology, University of Liverpool, Liverpool, L69 3BX, UK.,Institute of Zoology, Zoological Society of London, Regent's Park, NW1 4RY, UK
| | - Troy Day
- Departments of Mathematics & Biology, Jeffery Hall, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Christina L Faust
- Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | | | - Sylvain Gandon
- CEFE UMR 5175, CNRS - Université de Montpellier, Université Paul-Valéry Montpellier, EPHE, 1919, Route de Mende, 34293 Montpellier Cedex 5, France
| | - Caroline K Glidden
- Department of Integrative Biology, Oregon State University, 3029 Cordley Hall Corvallis, OR 97331, USA
| | - Fletcher W Halliday
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Zürich, 8057, Switzerland
| | - Kathryn A Hanley
- Department of Biology, New Mexico State University, Foster Hall, Las Cruces, NM 88003, USA
| | - Tsukushi Kamiya
- Department of Ecology & Evolutionary Biology, University of Toronto, 25 Willcocks St., Toronto, ON M5S 3B2, Canada
| | - Andrew F Read
- Center for Infectious Disease Dynamics, Huck Institutes for the Life Sciences; Departments of Biology and Entomology, Pennsylvania State University, University Park, PA 16802, USA
| | - Philipp Schwabl
- Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - Amy R Sweeny
- Department of Zoology, University of Oxford, Zoology Research and Administration Building, 11a Mansfield Road, Oxford OX1 3SZ, UK
| | - Ann T Tate
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
| | - Robin N Thompson
- Department of Zoology, University of Oxford, Zoology Research and Administration Building, 11a Mansfield Road, Oxford OX1 3SZ, UK.,Mathematical Institute, University of Oxford, Woodstock Road, Oxford OX2 6GG, UK.,Christ Church, University of Oxford, St Aldates, Oxford OX1 1DP, UK
| | - Nina Wale
- Department of Ecology & Evolutionary Biology, University of Michigan, 1105 North University Ave, Biological Sciences Building, Ann Arbor, MI 48109, USA
| | - Helen J Wearing
- Departments of Biology and Mathematics & Statistics, The University of New Mexico, Albuquerque, NM 87131, USA
| | - Pamela J Yeh
- Department of Ecology & Evolutionary Biology, University of California, Los Angeles, 621 Charles E Young Dr South, Los Angeles, CA 90095, USA
| | - Nicole Mideo
- Department of Ecology & Evolutionary Biology, University of Toronto, 25 Willcocks St., Toronto, ON M5S 3B2, Canada
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10
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Faust CL, Crotti M, Moses A, Oguttu D, Wamboko A, Adriko M, Adekanle EK, Kabatereine N, Tukahebwa EM, Norton AJ, Gower CM, Webster JP, Lamberton PHL. Two-year longitudinal survey reveals high genetic diversity of Schistosoma mansoni with adult worms surviving praziquantel treatment at the start of mass drug administration in Uganda. Parasit Vectors 2019; 12:607. [PMID: 31881923 PMCID: PMC6935072 DOI: 10.1186/s13071-019-3860-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Accepted: 12/17/2019] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND A key component of schistosomiasis control is mass drug administration with praziquantel. While control interventions have been successful in several endemic regions, mass drug administration has been less effective in others. Here we focus on the impact of repeated praziquantel treatment on the population structure and genetic diversity of Schistosoma mansoni. METHODS We examined S. mansoni epidemiology, population genetics, and variation in praziquantel susceptibility in parasites isolated from children across three primary schools in a high endemicity region at the onset of the Ugandan National Control Programme. Children were sampled at 11 timepoints over two years, including one week and four weeks post-praziquantel treatment to evaluate short-term impacts on clearance and evidence of natural variation in susceptibility to praziquantel. RESULTS Prevalence of S. mansoni was 85% at baseline. A total of 3576 miracidia larval parasites, isolated from 203 individual children, were genotyped at seven loci. Overall, genetic diversity was high and there was low genetic differentiation, indicating high rates of parasite gene flow. Schistosome siblings were found both pre-treatment and four weeks post-treatment, demonstrating adult worms surviving treatment and natural praziquantel susceptibility variation in these populations at the beginning of mass drug administration. However, we did not find evidence for selection on these parasites. While genetic diversity decreased in the short-term (four weeks post-treatment), diversity did not decrease over the entire period despite four rounds of mass treatment. Furthermore, within-host genetic diversity was affected by host age, host sex, infection intensity and recent praziquantel treatment. CONCLUSIONS Our findings suggest that praziquantel treatments have short-term impacts on these parasite populations but impacts were transient and no long-term reduction in genetic diversity was observed. High gene flow reduces the likelihood of local adaptation, so even though parasites surviving treatment were observed, these were likely to be diluted at the beginning of the Ugandan National Control Programme. Together, these results suggest that MDA in isolation may be insufficient to reduce schistosome populations in regions with high genetic diversity and gene flow.
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Affiliation(s)
- Christina L. Faust
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | - Marco Crotti
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Arinaitwe Moses
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - David Oguttu
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Aidah Wamboko
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Moses Adriko
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Elizabeth K. Adekanle
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | | | | | - Alice J. Norton
- Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Charlotte M. Gower
- Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Joanne P. Webster
- Department of Infectious Disease Epidemiology, Imperial College London, London, UK
- Department of Pathobiology and Population Sciences, Royal Veterinary College, Hawkshead, UK
| | - Poppy H. L. Lamberton
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
- Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
- Department of Infectious Disease Epidemiology, Imperial College London, London, UK
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11
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Carruthers LV, Moses A, Adriko M, Faust CL, Tukahebwa EM, Hall LJ, Ranford-Cartwright LC, Lamberton PHL. The impact of storage conditions on human stool 16S rRNA microbiome composition and diversity. PeerJ 2019; 7:e8133. [PMID: 31824766 PMCID: PMC6894433 DOI: 10.7717/peerj.8133] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 11/01/2019] [Indexed: 12/14/2022] Open
Abstract
Background Multiple factors can influence stool sample integrity upon sample collection. Preservation of faecal samples for microbiome studies is therefore an important step, particularly in tropical regions where resources are limited and high temperatures may significantly influence microbiota profiles. Freezing is the accepted standard to preserve faecal samples however, cold chain methods are often unfeasible in fieldwork scenarios particularly in low and middle-income countries and alternatives are required. This study therefore aimed to address the impact of different preservative methods, time-to-freezing at ambient tropical temperatures, and stool heterogeneity on stool microbiome diversity and composition under real-life physical environments found in resource-limited fieldwork conditions. Methods Inner and outer stool samples collected from one specimen obtained from three children were stored using different storage preservation methods (raw, ethanol and RNAlater) in a Ugandan field setting. Mixed stool was also stored using these techniques and frozen at different time-to-freezing intervals post-collection from 0-32 h. Metataxonomic profiling was used to profile samples, targeting the V1-V2 regions of 16S rRNA with samples run on a MiSeq platform. Reads were trimmed, combined and aligned to the Greengenes database. Microbial diversity and composition data were generated and analysed using Quantitative Insights Into Microbial Ecology and R software. Results Child donor was the greatest predictor of microbiome variation between the stool samples, with all samples remaining identifiable to their child of origin despite the stool being stored under a variety of conditions. However, significant differences were observed in composition and diversity between preservation techniques, but intra-preservation technique variation was minimal for all preservation methods, and across the time-to-freezing range (0-32 h) used. Stool heterogeneity yielded no apparent microbiome differences. Conclusions Stool collected in a fieldwork setting for comparative microbiome analyses should ideally be stored as consistently as possible using the same preservation method throughout.
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Affiliation(s)
- Lauren V Carruthers
- Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK.,Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | - Arinaitwe Moses
- Vector Control Divison, Ugandan Ministry of Health, Kampala, Uganda
| | - Moses Adriko
- Vector Control Divison, Ugandan Ministry of Health, Kampala, Uganda
| | - Christina L Faust
- Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK.,Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | | | - Lindsay J Hall
- Gut Microbes & Health, Quadram Institute Bioscience, Norwich, UK
| | - Lisa C Ranford-Cartwright
- Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Poppy H L Lamberton
- Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK.,Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
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12
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Becker DJ, Washburne AD, Faust CL, Pulliam JRC, Mordecai EA, Lloyd-Smith JO, Plowright RK. Dynamic and integrative approaches to understanding pathogen spillover. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190014. [PMID: 31401959 PMCID: PMC6711302 DOI: 10.1098/rstb.2019.0014] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2019] [Indexed: 12/23/2022] Open
Affiliation(s)
- Daniel J. Becker
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA
- Center for the Ecology of Infectious Diseases, University of Georgia, Athens, GA, USA
- Department of Biology, Indiana University, Bloomington, IN, USA
| | - Alex D. Washburne
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA
| | - Christina L. Faust
- Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Juliet R. C. Pulliam
- South African Centre for Epidemiological Modelling and Analysis (SACEMA), Stellenbosch University, Stellenbosch, South Africa
| | | | - James O. Lloyd-Smith
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, CA, USA
- Fogarty International Center, National Institutes of Health, Bethesda, MD, USA
| | - Raina K. Plowright
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA
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13
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Becker DJ, Washburne AD, Faust CL, Mordecai EA, Plowright RK. The problem of scale in the prediction and management of pathogen spillover. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190224. [PMID: 31401958 PMCID: PMC6711304 DOI: 10.1098/rstb.2019.0224] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2019] [Indexed: 01/28/2023] Open
Abstract
Disease emergence events, epidemics and pandemics all underscore the need to predict zoonotic pathogen spillover. Because cross-species transmission is inherently hierarchical, involving processes that occur at varying levels of biological organization, such predictive efforts can be complicated by the many scales and vastness of data potentially required for forecasting. A wide range of approaches are currently used to forecast spillover risk (e.g. macroecology, pathogen discovery, surveillance of human populations, among others), each of which is bound within particular phylogenetic, spatial and temporal scales of prediction. Here, we contextualize these diverse approaches within their forecasting goals and resulting scales of prediction to illustrate critical areas of conceptual and pragmatic overlap. Specifically, we focus on an ecological perspective to envision a research pipeline that connects these different scales of data and predictions from the aims of discovery to intervention. Pathogen discovery and predictions focused at the phylogenetic scale can first provide coarse and pattern-based guidance for which reservoirs, vectors and pathogens are likely to be involved in spillover, thereby narrowing surveillance targets and where such efforts should be conducted. Next, these predictions can be followed with ecologically driven spatio-temporal studies of reservoirs and vectors to quantify spatio-temporal fluctuations in infection and to mechanistically understand how pathogens circulate and are transmitted to humans. This approach can also help identify general regions and periods for which spillover is most likely. We illustrate this point by highlighting several case studies where long-term, ecologically focused studies (e.g. Lyme disease in the northeast USA, Hendra virus in eastern Australia, Plasmodium knowlesi in Southeast Asia) have facilitated predicting spillover in space and time and facilitated the design of possible intervention strategies. Such studies can in turn help narrow human surveillance efforts and help refine and improve future large-scale, phylogenetic predictions. We conclude by discussing how greater integration and exchange between data and predictions generated across these varying scales could ultimately help generate more actionable forecasts and interventions. This article is part of the theme issue 'Dynamic and integrative approaches to understanding pathogen spillover'.
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Affiliation(s)
- Daniel J. Becker
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
- Center for the Ecology of Infectious Diseases, University of Georgia, Athens, GA, USA
- Department of Biology, Indiana University, Bloomington, IN, USA
| | - Alex D. Washburne
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Christina L. Faust
- Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | | | - Raina K. Plowright
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
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14
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Viana M, Faust CL, Haydon DT, Webster JP, Lamberton PHL. The effects of subcurative praziquantel treatment on life-history traits and trade-offs in drug-resistant Schistosoma mansoni. Evol Appl 2018; 11:488-500. [PMID: 29636801 PMCID: PMC5891057 DOI: 10.1111/eva.12558] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 08/24/2017] [Indexed: 02/03/2023] Open
Abstract
Natural selection acts on all organisms, including parasites, to maximize reproductive fitness. Drug resistance traits are often associated with life-history costs in the absence of treatment. Schistosomiasis control programmes rely on mass drug administration to reduce human morbidity and mortality. Although hotspots of reduced drug efficacy have been reported, resistance is not widespread. Using Bayesian state-space models (SSMs) fitted to data from an in vivo laboratory system, we tested the hypothesis that the spread of resistant Schistosoma mansoni may be limited by life-history costs not present in susceptible counterparts. S. mansoni parasites from a praziquantel-susceptible (S), a praziquantel-resistant (R) or a mixed line of originally resistant and susceptible parasites (RS) were exposed to a range of praziquantel doses. Parasite numbers at each life stage were quantified in their molluscan intermediate and murine definitive hosts across four generations, and SSMs were used to estimate key life-history parameters for each experimental group over time. Model outputs illustrated that parasite adult survival and fecundity in the murine host decreased across all lines, including R, with increasing drug pressure. Trade-offs between adult survival and fecundity were observed in all untreated lines, and these remained strong in S with praziquantel pressure. In contrast, trade-offs between adult survival and fecundity were lost under praziquantel pressure in R. As expected, parasite life-history traits within the molluscan host were complex, but trade-offs were demonstrated between parasite establishment and cercarial output. The observed trade-offs between generations within hosts, which were modified by praziquantel treatment in the R line, could limit the spread of R parasites under praziquantel pressure. Whilst such complex life-history costs may be difficult to detect using standard empirical methods, we demonstrate that SSMs provide robust estimates of life-history parameters, aiding our understanding of costs and trade-offs of resistant parasites within this system and beyond.
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Affiliation(s)
- Mafalda Viana
- Institute for Biodiversity, Animal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
| | - Christina L. Faust
- Institute for Biodiversity, Animal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
- Wellcome Centre for Molecular ParasitologyUniversity of GlasgowGlasgowUK
| | - Daniel T. Haydon
- Institute for Biodiversity, Animal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
| | - Joanne P. Webster
- London Centre for Neglected Tropical Disease ResearchDepartment of Infectious Disease EpidemiologySchool of Public HealthImperial College LondonLondonUK
- Centre for Endemic, Emerging and Exotic DiseasesThe Royal Veterinary CollegeUniversity of LondonLondonUK
| | - Poppy H. L. Lamberton
- Institute for Biodiversity, Animal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
- London Centre for Neglected Tropical Disease ResearchDepartment of Infectious Disease EpidemiologySchool of Public HealthImperial College LondonLondonUK
- Wellcome Centre for Molecular ParasitologyUniversity of GlasgowGlasgowUK
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15
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Faust CL, McCallum HI, Bloomfield LSP, Gottdenker NL, Gillespie TR, Torney CJ, Dobson AP, Plowright RK. Pathogen spillover during land conversion. Ecol Lett 2018; 21:471-483. [DOI: 10.1111/ele.12904] [Citation(s) in RCA: 117] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 12/04/2017] [Indexed: 12/19/2022]
Affiliation(s)
- Christina L. Faust
- Department of Microbiology and Immunology; Montana State University; Montana MT USA
- Department of Ecology and Evolutionary Biology; Princeton University; Princeton NJ USA
- Institute of Biodiversity, Animal Health and Comparative Medicine; Universtiy of Glasgow; Glasgow UK
| | - Hamish I. McCallum
- Environmental Futures Research Institute and Griffith School of Environment; Griffith University; Griffith Qld. Australia
| | - Laura S. P. Bloomfield
- Emmett Interdisciplinary Program in Environment and Resources; Stanford University; Stanford CA USA
| | - Nicole L. Gottdenker
- Department of Veterinary Pathology; College of Veterinary Medicine; University of Georgia; Athens GA USA
| | - Thomas R. Gillespie
- Department of Environmental Sciences; Department of Environmental Health; Rollins School of Public Health; Program In Population; Biology, Ecology and Evolution; Emory University; Athens GA USA
| | - Colin J. Torney
- School of Mathematics and Statistics; University of Glasgow; Glasgow UK
| | - Andrew P. Dobson
- Department of Ecology and Evolutionary Biology; Princeton University; Princeton NJ USA
| | - Raina K. Plowright
- Department of Microbiology and Immunology; Montana State University; Montana MT USA
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16
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Faust CL, Dobson AP, Gottdenker N, Bloomfield LSP, McCallum HI, Gillespie TR, Diuk-Wasser M, Plowright RK. Null expectations for disease dynamics in shrinking habitat: dilution or amplification? Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0173. [PMID: 28438921 DOI: 10.1098/rstb.2016.0173] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/02/2016] [Indexed: 11/12/2022] Open
Abstract
As biodiversity declines with anthropogenic land-use change, it is increasingly important to understand how changing biodiversity affects infectious disease risk. The dilution effect hypothesis, which points to decreases in biodiversity as critical to an increase in infection risk, has received considerable attention due to the allure of a win-win scenario for conservation and human well-being. Yet some empirical data suggest that the dilution effect is not a generalizable phenomenon. We explore the response of pathogen transmission dynamics to changes in biodiversity that are driven by habitat loss using an allometrically scaled multi-host model. With this model, we show that declining habitat, and thus declining biodiversity, can lead to either increasing or decreasing infectious-disease risk, measured as endemic prevalence. Whether larger habitats, and thus greater biodiversity, lead to a decrease (dilution effect) or increase (amplification effect) in infection prevalence depends upon the pathogen transmission mode and how host competence scales with body size. Dilution effects were detected for most frequency-transmitted pathogens and amplification effects were detected for density-dependent pathogens. Amplification effects were also observed over a particular range of habitat loss in frequency-dependent pathogens when we assumed that host competence was greatest in large-bodied species. By contrast, only amplification effects were observed for density-dependent pathogens; host competency only affected the magnitude of the effect. These models can be used to guide future empirical studies of biodiversity-disease relationships across gradients of habitat loss. The type of transmission, the relationship between host competence and community assembly, the identity of hosts contributing to transmission, and how transmission scales with area are essential factors to consider when elucidating the mechanisms driving disease risk in shrinking habitat.This article is part of the themed issue 'Conservation, biodiversity and infectious disease: scientific evidence and policy implications'.
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Affiliation(s)
- Christina L Faust
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA .,Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA
| | - Andrew P Dobson
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
| | - Nicole Gottdenker
- Department of Veterinary Pathology, University of Georgia, Athens, GA 30602, USA
| | - Laura S P Bloomfield
- Emmett Interdisciplinary Program in Environment and Resources, Stanford University, Stanford, CA 94305, USA
| | - Hamish I McCallum
- Environmental Futures Research Institute and Griffith School of Environment, Griffith University, Brisbane, Queensland 4222, Australia
| | - Thomas R Gillespie
- Department of Environmental Sciences, Rollins School of Public Health; Program In Population, Biology, Ecology and Evolution; Emory University, Atlanta, GA 30322, USA.,Department of Environmental Health, Rollins School of Public Health; Program In Population, Biology, Ecology and Evolution; Emory University, Atlanta, GA 30322, USA
| | - Maria Diuk-Wasser
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY 10027, USA
| | - Raina K Plowright
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA
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17
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Lamberton PHL, Faust CL, Webster JP. Praziquantel decreases fecundity in Schistosoma mansoni adult worms that survive treatment: evidence from a laboratory life-history trade-offs selection study. Infect Dis Poverty 2017. [PMID: 28622767 PMCID: PMC5472905 DOI: 10.1186/s40249-017-0324-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Background Mass drug administration of praziquantel is the World Health Organization’s endorsed control strategy for schistosomiasis. A decade of annual treatments across sub-Saharan Africa has resulted in significant reductions of infection prevalence and intensity levels, although ‘hotspots’ remain. Repeated drug treatments place strong selective pressures on parasites, which may affect life-history traits that impact transmission dynamics. Understanding drug treatment responses and the evolution of such traits can help inform on how to minimise the risk of drug resistance developing, maximise sustainable control programme success, and improve diagnostic protocols. Methods We performed a four-generation Schistosoma mansoni praziquantel selection experiment in mice and snails. We used three S. mansoni lines: a praziquantel-resistant isolate (R), a praziquantel-susceptible isolate (S), and a co-infected line (RS), under three treatment regimens: untreated, 25 mg/kg praziquantel, or 50 mg/kg praziquantel. Life-history traits, including parasite adult-worm establishment, survival, reproduction (fecundity), and associated morbidity, were recorded in mice across all four generations. Predictor variables were tested in a series of generalized linear mixed effects models to determine which factors had a significant influence on parasite life-history traits in definitive hosts under different selection regimes. Results Praziquantel pressure significantly reduced adult-worm burdens across all generations and isolates, including within R-lines. However, previous drug treatment resulted in an increase in adult-worm establishment with increasing generation from P1 to F3. The highest worm numbers were in the co-infected RS line. Praziquantel treatment decreased adult-worm burden, but had a larger negative impact on the mean daily number of miracidia, a proxy for fecundity, across all three parasite isolates. Conclusions Our predicted cost of resistance was not supported by the traits we measured within the murine host. We did not find evidence for negative adult worm density-dependent effects on fecundity. In contrast, of the adult worms that survived treatment, even low doses of praziquantel significantly reduced adult-worm fecundity. Such reductions in worm fecundity post treatment suggest that egg - based measures of drug efficacy, such as Kato-Katz, may overestimate the short-term effect of praziquantel on adult - worm burdens. These findings have important implications for S. mansoni transmission control, diagnostic protocols, and the potential for undetected selection toward drug resistance. Electronic supplementary material The online version of this article (doi:10.1186/s40249-017-0324-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Poppy H L Lamberton
- Institute for Biodiversity, Animal Health, and Comparative Medicine & Wellcome Centre for Molecular Parasitology, College of Medical, Veterinary & Life Sciences, University of Glasgow, G12 8QQ, Glasgow, UK. .,London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, St Mary's Campus, W2 1PG, London, UK.
| | - Christina L Faust
- Institute for Biodiversity, Animal Health, and Comparative Medicine & Wellcome Centre for Molecular Parasitology, College of Medical, Veterinary & Life Sciences, University of Glasgow, G12 8QQ, Glasgow, UK
| | - Joanne P Webster
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, St Mary's Campus, W2 1PG, London, UK.,Centre for Endemic, Emerging and Exotic Diseases, The Royal Veterinary College, University of London, London, AL9 7TA, UK
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Siregar JE, Faust CL, Murdiyarso LS, Rosmanah L, Saepuloh U, Dobson AP, Iskandriati D. Non-invasive surveillance for Plasmodium in reservoir macaque species. Malar J 2015; 14:404. [PMID: 26459307 PMCID: PMC4603874 DOI: 10.1186/s12936-015-0857-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Accepted: 08/22/2015] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Primates are important reservoirs for human diseases, but their infection status and disease dynamics are difficult to track in the wild. Within the last decade, a macaque malaria, Plasmodium knowlesi, has caused disease in hundreds of humans in Southeast Asia. In order to track cases and understand zoonotic risk, it is imperative to be able to quantify infection status in reservoir macaque species. In this study, protocols for the collection of non-invasive samples and isolation of malaria parasites from naturally infected macaques are optimized. METHODS Paired faecal and blood samples from 60 Macaca fascicularis and four Macaca nemestrina were collected. All animals came from Sumatra or Java and were housed in semi-captive breeding colonies around West Java. DNA was extracted from samples using a modified protocol. Nested polymerase chain reactions (PCR) were run to detect Plasmodium using primers targeting mitochondrial DNA. Sensitivity of screening faecal samples for Plasmodium was compared to other studies using Kruskal Wallis tests and logistic regression models. RESULTS The best primer set was 96.7 % (95 % confidence intervals (CI): 83.3-99.4 %) sensitive for detecting Plasmodium in faecal samples of naturally infected macaques (n = 30). This is the first study to produce definitive estimates of Plasmodium sensitivity and specificity in faecal samples from naturally infected hosts. The sensitivity was significantly higher than some other studies involving wild primates. CONCLUSIONS Faecal samples can be used for detection of malaria infection in field surveys of macaques, even when there are no parasites visible in thin blood smears. Repeating samples from individuals will improve inferences of the epidemiology of malaria in wild primates.
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Affiliation(s)
| | - Christina L Faust
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, 08544, USA.
| | | | - Lis Rosmanah
- Pusat Studi Satwa Primata, Institut Pertanian Bogor, Bogor, Indonesia.
| | - Uus Saepuloh
- Pusat Studi Satwa Primata, Institut Pertanian Bogor, Bogor, Indonesia.
| | - Andrew P Dobson
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, 08544, USA.
| | - Diah Iskandriati
- Pusat Studi Satwa Primata, Institut Pertanian Bogor, Bogor, Indonesia.
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Gottdenker NL, Streicker DG, Faust CL, Carroll CR. Anthropogenic land use change and infectious diseases: a review of the evidence. Ecohealth 2014; 11:619-32. [PMID: 24854248 DOI: 10.1007/s10393-014-0941-z] [Citation(s) in RCA: 194] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2013] [Revised: 03/25/2014] [Accepted: 04/29/2014] [Indexed: 05/19/2023]
Abstract
Humans have altered ecosystems worldwide, and it is important to understand how this land use change impacts infectious disease transmission in humans and animals. We conducted a systematic review 305 scientific articles investigating how specific types of anthropogenic land use change influence infectious disease dynamics. We summarized findings, highlighted common themes, and drew attention to neglected areas of research. There was an increase in publications on this topic over the last 30 years spanning diseases of humans, livestock, and wildlife, including a large number of zoonotic pathogens. Most papers (66.9%) were observational, 30.8% were review or concept papers, and few studies (2.3%) were experimental in nature, with most studies focusing on vector-borne and/or multi-host pathogens. Common land use change types related to disease transmission were deforestation/forest fragmentation/habitat fragmentation, agricultural development/irrigation, and urbanization/suburbanization. In response to anthropogenic change, more than half of the studies (56.9%) documented increased pathogen transmission, 10.4% of studies observed decreased pathogen transmission, 30.4% had variable and complex pathogen responses, and 2.4% showed no detectable changes. Commonly reported mechanisms by which land use change altered infectious disease transmission included alteration of the vector, host, and pathogen niche, changes in host and vector community composition, changes in behavior or movement of vectors and/or hosts, altered spatial distribution of hosts and/or vectors, and socioeconomic factors, and environmental contamination. We discussed observed patterns in the literature and make suggestions for future research directions, emphasizing the importance of ecological and evolutionary theory to understand pathogen responses in changing landscapes.
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Affiliation(s)
- Nicole L Gottdenker
- Department of Veterinary Pathology, College of Veterinary Medicine, The University of Georgia, 501 DW Brooks Drive, Athens, GA, 30602, USA,
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Richter LL, Berk HW, Teates CD, Friesen EJ, Faust CL, Edlich RF. Immediate care of patients after a radiation accident. EMT J 1980; 4:21-5. [PMID: 10248882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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