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Gichuki PM, Kibe L, Mwatele C, Mwangangi J, Mbogo CM. Towards an integrated vector management approach for sustainable control of schistosomiasis and malaria in Mwea, Kirinyaga County, Kenya: Baseline epidemiological and vector results. Heliyon 2023; 9:e20966. [PMID: 37876477 PMCID: PMC10590948 DOI: 10.1016/j.heliyon.2023.e20966] [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: 02/02/2023] [Revised: 10/12/2023] [Accepted: 10/12/2023] [Indexed: 10/26/2023] Open
Abstract
Background Vector control is an important approach in the control of most parasitic and vector-borne diseases including malaria, and schistosomiasis. Distribution of these two infections often overlaps and in such areas it's more economically viable to employ an integrated approach in the control of their vectors which largely shares the same breeding ecosystem. We carried out a baseline epidemiological and vector surveys for malaria and schistosomiasis in Mwea, Kirinyaga County, in preparation for the upscaling of integrated vector management (IVM) for the two diseases. Methods This was a repeated cross sectional survey, where mosquito and snails were sampled during dry and wet seasons in three different ecological zones, Kiamaciri, Thiba and Murinduko to identify possible breeding sites. Mosquito larvae were collected using standard dippers, adults using CDC miniature light traps while snail vectors were sampled using standard snail scoops in different breeding habitats. A total of 1200 pupils from 12 primary schools were tested for malaria using rapid diagnostic tests (Malaria Pf/PAN Ag combo). Stool samples were processed using the Kato Katz technique for intestinal schistosomiasis. Results The overall prevalence of intestinal schistosomiasis was 9.08 % (95 % CI: 07.00-11.00), with Kiamaciri zone recording the highest prevalence at 19 % (95%CI: 15.00-23.00) and Murinduko zone the least at 0.17 % (95%CI: 0.00-0.01). Majority of the infections were of light intensity 78.9 % (95%CI: 70.04-86.13). There was no positive malaria case detected in this study. Of the 3208 adult mosquitoes sampled during the dry season, 20.6 % (95 % CI: 19.25-22.08) were Anopheles gambiae s.l while 79.4 % (95 % CI: 77.92-80.75) were culicines. During the wet season, 3378 adult mosquitoes were collected, of which 14.7 % (95 % CI: 13.56-15.98) were Anopheles gambiae s.l and 85.3 % (95 % CI: 84.02-86.44) culicines. Overall, 4085 mosquito larvae were collected during the two seasons, of which, 57.3 % and 42.7 % were anopheles and culicine respectively. Majority of the larvae (85.1 % (95%CI: 84.01-86.10) were collected during the wet season, with only 14.9 % (95%CI: 14.10-16.00) being collected during the dry season. A total of 2292 fresh water vector snails were collected with a majority (69.6 % (95%CI: 68.00-71.10) being Biomphalaria pffeiferi responsible for transmission of intestinal schistosomiasis. Conclusion This study demonstrates that intestinal schistosomiasis is prevalent in Kiamaciri and Thiba zones, and points to the possibility of active transmission of schistosomiasis in Murinduko zone. Malaria vectors were predominantly observed in all sites despite there being no malaria positive case. Culex quinquefaciatus responsible for the spread of several arboviruses was also observed. The presence of these vectors may lead to future disease outbreaks in the area if concerted control initiatives are not undertaken. The disease vectors shared the same breeding sites and thus its economical and feasible to adopt an integrated vector management approach in control efforts for these disease in the study area.
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Affiliation(s)
- Paul M. Gichuki
- Kenya Medical Research Institute (KEMRI), Eastern & Southern Africa Centre of International Parasite Control (ESACIPAC), Nairobi, P.O BOX 54840-00200 Nairobi, Kenya
- School of Health Sciences, Meru University of Science and Technology, P.O BOX 972-60200 Meru, Kenya
| | - Lydia Kibe
- Kenya Medical Research Institute (KEMRI), Eastern & Southern Africa Centre of International Parasite Control (ESACIPAC), Nairobi, P.O BOX 54840-00200 Nairobi, Kenya
| | - Cassian Mwatele
- Kenya Medical Research Institute (KEMRI), Eastern & Southern Africa Centre of International Parasite Control (ESACIPAC), Nairobi, P.O BOX 54840-00200 Nairobi, Kenya
| | - Joseph Mwangangi
- KEMRI-Wellcome Trust Research Programme, Public Health Unit, PO Box 43640 - 00100, Nairobi, Kenya
- Kenya Medical Research Institute (KEMRI), Centre for Geographical Medicine Research-Coast (CGMR-C). P.O Box 230- 80108 Kilifi, Kenya
| | - Charles M. Mbogo
- Kenya Medical Research Institute (KEMRI), Eastern & Southern Africa Centre of International Parasite Control (ESACIPAC), Nairobi, P.O BOX 54840-00200 Nairobi, Kenya
- KEMRI-Wellcome Trust Research Programme, Public Health Unit, PO Box 43640 - 00100, Nairobi, Kenya
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Petukhova VZ, Aboagye SY, Ardini M, Lullo RP, Fata F, Byrne ME, Gabriele F, Martin LM, Harding LNM, Gone V, Dangi B, Lantvit DD, Nikolic D, Ippoliti R, Effantin G, Ling WL, Johnson JJ, Thatcher GRJ, Angelucci F, Williams DL, Petukhov PA. Non-covalent inhibitors of thioredoxin glutathione reductase with schistosomicidal activity in vivo. Nat Commun 2023; 14:3737. [PMID: 37349300 PMCID: PMC10287695 DOI: 10.1038/s41467-023-39444-y] [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: 10/28/2022] [Accepted: 06/12/2023] [Indexed: 06/24/2023] Open
Abstract
Only praziquantel is available for treating schistosomiasis, a disease affecting more than 200 million people. Praziquantel-resistant worms have been selected for in the lab and low cure rates from mass drug administration programs suggest that resistance is evolving in the field. Thioredoxin glutathione reductase (TGR) is essential for schistosome survival and a validated drug target. TGR inhibitors identified to date are irreversible and/or covalent inhibitors with unacceptable off-target effects. In this work, we identify noncovalent TGR inhibitors with efficacy against schistosome infections in mice, meeting the criteria for lead progression indicated by WHO. Comparisons with previous in vivo studies with praziquantel suggests that these inhibitors outperform the drug of choice for schistosomiasis against juvenile worms.
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Grants
- R33 AI127635 NIAID NIH HHS
- Division of Intramural Research, National Institute of Allergy and Infectious Diseases (Division of Intramural Research of the NIAID)
- Oncomelania hupensis subsp. hupensis, Chinese strain, infected with S. japonicum, Chinese strain, and Biomphalaria glabrata, strain NMRI, infected with S. mansoni, strain NMRI, were provided by the NIAID Schistosomiasis Resource Center for distribution through BEI Resources, NIAID, NIH. We are grateful to Dr. Guy Schoehn (Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, Grenoble, France), Prof. Beatrice Vallone (Sapienza University of Rome, Italy) and Dr. Linda C. Montemiglio (IBPM, National Research Council, Italy) for helpful discussions of the cryo-EM studies. We acknowledge the Elettra-Sincrotrone Trieste (Italy) for support in X-ray data collections and the European Synchrotron Radiation Facility for provision of microscope time on CM01. The study was funded in part by US NIH/NIAID R33AI127635 to F.A., P.A.P., G.R.T. and D.L.W. This work benefited from access to Research Resources Centre and UICentre at University of Illinois at Chicago and used the platforms of the Grenoble Instruct-ERIC center (ISBG; UAR 3518 CNRS-CEA-UGA-EMBL) within the Grenoble Partnership for Structural Biology (PSB), supported by FRISBI (ANR-10-INBS-0005-02) and GRAL, financed within the University Grenoble Alpes graduate school (Ecoles Universitaires de Recherche) CBH-EUR-GS (ANR-17-EURE-0003). The IBS Electron Microscope facility is supported by the Auvergne Rhône-Alpes Region, the Fonds Feder, the Fondation pour la Recherche Médicale and GIS-IBiSA. The IBS acknowledges integration into the Interdisciplinary Research Institute of Grenoble (IRIG, CEA). M.A. has been supported by MIUR - Ministero dell'Istruzione Ministero dell'Università e della Ricerca (Ministry of Education, University and Research) under the national project FSE/FESR - PON Ricerca e Innovazione 2014-2020 (N° AIM1887574, CUP: E18H19000350007). We acknowledge OpenEye/Cadence for providing us with an academic license for the software used in these studies.
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Affiliation(s)
- Valentina Z Petukhova
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Sammy Y Aboagye
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL, USA
| | - Matteo Ardini
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Rachel P Lullo
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL, USA
| | - Francesca Fata
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Margaret E Byrne
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL, USA
| | - Federica Gabriele
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Lucy M Martin
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL, USA
| | - Luke N M Harding
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Vamshikrishna Gone
- UICentre, Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Bikash Dangi
- Department of Pharmacy Practice, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Daniel D Lantvit
- UICentre, Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Dejan Nikolic
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Rodolfo Ippoliti
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Grégory Effantin
- University of Grenoble Alpes, CEA, CNRS, IBS, F-38000, Grenoble, France
| | - Wai Li Ling
- University of Grenoble Alpes, CEA, CNRS, IBS, F-38000, Grenoble, France
| | - Jeremy J Johnson
- Department of Pharmacy Practice, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Gregory R J Thatcher
- Department of Pharmacology & Toxicology, R. Ken Coit College of Pharmacy, University of Arizona, Tucson, AZ, USA
| | - Francesco Angelucci
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy.
| | - David L Williams
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL, USA.
| | - Pavel A Petukhov
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA.
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Chanhanga N, Mindu T, Mogaka J, Chimbari M. The Impact of Targeted Treatment and Mass Drug Administration Delivery Strategies on the Prevalence and Intensity of Schistosomiasis in School Aged Children in Africa: A Systematic Review. Infect Drug Resist 2023; 16:2453-2466. [PMID: 37138838 PMCID: PMC10150034 DOI: 10.2147/idr.s395382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 03/16/2023] [Indexed: 05/05/2023] Open
Abstract
Schistosomiasis is a public health problem in more than 78 countries in the world. The disease is most prevalent among children than adults due to their high exposure to infectious water sources. Various interventions such as mass drug administration (MDA), snail control, safe water provision and health education have been implemented independently or jointly to control, reduce and ultimately eliminate Schistosomiasis. This scoping review focused on studies reporting the impact of different delivery strategies of targeted treatment and MDA on the prevalence and intensity of schistosomiasis infection in school aged children in Africa. The review focused on Schistosoma haematobium and Schistosoma mansoni species. A systematic search for eligible literature from peer-reviewed articles was done from Google Scholar, Medline, PubMed and EBSCO host databases. The search yielded twenty-seven peer-reviewed articles. All articles found reported a decrease in the prevalence of schistosomiasis infection. Five studies (18.5%) reported a prevalence change below 40%, eighteen studies (66.7%) reported a change between 40% and 80%, and four studies (14.8%) reported a change above 80%. The infection intensity post-treatment was varied: twenty-four studies reported a decrease, while two studies reported an increase. The review showed that the impact of targeted treatment on the prevalence and intensity of schistosomiasis depended on the frequency at which it was offered, complementary interventions, and its uptake by the target population. Targeted treatment can significantly control the infection burden, but cannot eliminate the disease. Constant MDA programs coupled with preventative and health promotional programs are required to reach the elimination stage.
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Affiliation(s)
- Nathan Chanhanga
- School of Nursing and Public Health, University of KwaZulu Natal, Durban, South Africa
| | - Tafadzwa Mindu
- School of Nursing and Public Health, University of KwaZulu Natal, Durban, South Africa
- Correspondence: Tafadzwa Mindu, Email
| | - John Mogaka
- School of Nursing and Public Health, University of KwaZulu Natal, Durban, South Africa
| | - Moses Chimbari
- School of Nursing and Public Health, University of KwaZulu Natal, Durban, South Africa
- Research and Innovation, Great Zimbabwe University, Masvingo, Zimbabwe
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Summers S, Bhattacharyya T, Allan F, Stothard JR, Edielu A, Webster BL, Miles MA, Bustinduy AL. A review of the genetic determinants of praziquantel resistance in Schistosoma mansoni: Is praziquantel and intestinal schistosomiasis a perfect match? FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2022.933097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Schistosomiasis is a neglected tropical disease (NTD) caused by parasitic trematodes belonging to the Schistosoma genus. The mainstay of schistosomiasis control is the delivery of a single dose of praziquantel (PZQ) through mass drug administration (MDA) programs. These programs have been successful in reducing the prevalence and intensity of infections. Due to the success of MDA programs, the disease has recently been targeted for elimination as a public health problem in some endemic settings. The new World Health Organization (WHO) treatment guidelines aim to provide equitable access to PZQ for individuals above two years old in targeted areas. The scale up of MDA programs may heighten the drug selection pressures on Schistosoma parasites, which could lead to the emergence of PZQ resistant schistosomes. The reliance on a single drug to treat a disease of this magnitude is worrying should drug resistance develop. Therefore, there is a need to detect and track resistant schistosomes to counteract the threat of drug resistance to the WHO 2030 NTD roadmap targets. Until recently, drug resistance studies have been hindered by the lack of molecular markers associated with PZQ resistance. This review discusses recent significant advances in understanding the molecular basis of PZQ action in S. mansoni and proposes additional genetic determinants associated with PZQ resistance. PZQ resistance will also be analyzed in the context of alternative factors that may decrease efficacy within endemic field settings, and the most recent treatment guidelines recommended by the WHO.
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5
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Vianney TJ, Berger DJ, Doyle SR, Sankaranarayanan G, Serubanja J, Nakawungu PK, Besigye F, Sanya RE, Holroyd N, Allan F, Webb EL, Elliott AM, Berriman M, Cotton JA. Genome-wide analysis of Schistosoma mansoni reveals limited population structure and possible praziquantel drug selection pressure within Ugandan hot-spot communities. PLoS Negl Trop Dis 2022; 16:e0010188. [PMID: 35981002 PMCID: PMC9426917 DOI: 10.1371/journal.pntd.0010188] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 08/30/2022] [Accepted: 07/05/2022] [Indexed: 12/23/2022] Open
Abstract
Populations within schistosomiasis control areas, especially those in Africa, are recommended to receive regular mass drug administration (MDA) with praziquantel (PZQ) as the main strategy for controlling the disease. The impact of PZQ treatment on schistosome genetics remains poorly understood, and is limited by a lack of high-resolution genetic data on the population structure of parasites within these control areas. We generated whole-genome sequence data from 174 individual miracidia collected from both children and adults from fishing communities on islands in Lake Victoria in Uganda that had received either annual or quarterly MDA with PZQ over four years, including samples collected immediately before and four weeks after treatment. Genome variation within and between samples was characterised and we investigated genomic signatures of natural selection acting on these populations that could be due to PZQ treatment. The parasite population on these islands was more diverse than found in nearby villages on the lake shore. We saw little or no genetic differentiation between villages, or between the groups of villages with different treatment intensity, but slightly higher genetic diversity within the pre-treatment compared to post-treatment parasite populations. We identified classes of genes significantly enriched within regions of the genome with evidence of recent positive selection among post-treatment and intensively treated parasite populations. The differential selection observed in post-treatment and pre-treatment parasite populations could be linked to any reduced susceptibility of parasites to praziquantel treatment.
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Affiliation(s)
- Tushabe John Vianney
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and the London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe, Uganda
| | - Duncan J. Berger
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
| | - Stephen R. Doyle
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
| | | | - Joel Serubanja
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and the London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe, Uganda
| | - Prossy Kabuubi Nakawungu
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and the London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe, Uganda
| | - Fred Besigye
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and the London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe, Uganda
| | - Richard E. Sanya
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and the London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe, Uganda
- Health and Systems for Health Unit, African Population and Health Research Center, Nairobi, Kenya
| | - Nancy Holroyd
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
| | - Fiona Allan
- Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Emily L. Webb
- MRC International Statistics and Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Alison M. Elliott
- Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and the London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe, Uganda
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Matthew Berriman
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
| | - James A. Cotton
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
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Platt RN, Le Clec'h W, Chevalier FD, McDew‐White M, LoVerde PT, Ramiro de Assis R, Oliveira G, Kinung'hi S, Djirmay AG, Steinauer ML, Gouvras A, Rabone M, Allan F, Webster BL, Webster JP, Emery AM, Rollinson D, Anderson TJC. Genomic analysis of a parasite invasion: Colonization of the Americas by the blood fluke Schistosoma mansoni. Mol Ecol 2022; 31:2242-2263. [PMID: 35152493 PMCID: PMC9305930 DOI: 10.1111/mec.16395] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 01/25/2022] [Accepted: 01/31/2022] [Indexed: 11/29/2022]
Abstract
Schistosoma mansoni, a snail-borne, blood fluke that infects humans, was introduced into the Americas from Africa during the Trans-Atlantic slave trade. As this parasite shows strong specificity to the snail intermediate host, we expected that adaptation to South American Biomphalaria spp. snails would result in population bottlenecks and strong signatures of selection. We scored 475,081 single nucleotide variants in 143 S. mansoni from the Americas (Brazil, Guadeloupe and Puerto Rico) and Africa (Cameroon, Niger, Senegal, Tanzania, and Uganda), and used these data to ask: (i) Was there a population bottleneck during colonization? (ii) Can we identify signatures of selection associated with colonization? (iii) What were the source populations for colonizing parasites? We found a 2.4- to 2.9-fold reduction in diversity and much slower decay in linkage disequilibrium (LD) in parasites from East to West Africa. However, we observed similar nuclear diversity and LD in West Africa and Brazil, suggesting no strong bottlenecks and limited barriers to colonization. We identified five genome regions showing selection in the Americas, compared with three in West Africa and none in East Africa, which we speculate may reflect adaptation during colonization. Finally, we infer that unsampled populations from central African regions between Benin and Angola, with contributions from Niger, are probably the major source(s) for Brazilian S. mansoni. The absence of a bottleneck suggests that this is a rare case of a serendipitous invasion, where S. mansoni parasites were pre-adapted to the Americas and able to establish with relative ease.
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Affiliation(s)
- Roy N. Platt
- Texas Biomedical Research InstituteSan AntonioTexasUSA
| | | | | | | | | | | | - Guilherme Oliveira
- Centro de Pesquisas René Rachou—Fiocruz/MGBelo HorizonteBrazil
- Instituto Tecnológico ValeBelémBrazil
| | | | - Amadou Garba Djirmay
- Réseau International Schistosomiases Environnemental Aménagement et Lutte (RISEAL)NiameyNiger
| | | | | | | | - Fiona Allan
- Department of Pathobiology and Population SciencesRoyal Veterinary College, Centre for Emerging, Endemic and Exotic DiseasesUniversity of LondonHertfordshireUK
- London Centre for Neglected Tropical Disease Research, Imperial College LondonSchool of Public HealthLondonUK
| | - Bonnie L. Webster
- Natural History MuseumLondonUK
- London Centre for Neglected Tropical Disease Research, Imperial College LondonSchool of Public HealthLondonUK
| | - Joanne P. Webster
- Department of Pathobiology and Population SciencesRoyal Veterinary College, Centre for Emerging, Endemic and Exotic DiseasesUniversity of LondonHertfordshireUK
- London Centre for Neglected Tropical Disease Research, Imperial College LondonSchool of Public HealthLondonUK
| | - Aidan M. Emery
- Natural History MuseumLondonUK
- London Centre for Neglected Tropical Disease Research, Imperial College LondonSchool of Public HealthLondonUK
| | - David Rollinson
- Natural History MuseumLondonUK
- London Centre for Neglected Tropical Disease Research, Imperial College LondonSchool of Public HealthLondonUK
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Ismail HAHA, Ahmed AEAAERM, Cha S, Jin Y. The Life Histories of Intermediate Hosts and Parasites of Schistosoma haematobium and Schistosoma mansoni in the White Nile River, Sudan. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19031508. [PMID: 35162527 PMCID: PMC8835159 DOI: 10.3390/ijerph19031508] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 01/25/2022] [Accepted: 01/26/2022] [Indexed: 02/05/2023]
Abstract
Background: The epidemiology of schistosomiasis transmission varies depending on the circumstances of the surrounding water bodies and human behaviors. We aimed to explore cercarial emergence patterns from snails that are naturally affected by human schistosomiasis and non-human trematodes. In addition, this study aimed to explore how schistosomiasis infection affects snail survival, reproduction, and growth. Methods: We measured the survival rate, fecundity, and size of Biomphalaria pfeifferi snails and the cercarial rhythmicity of S. haematobium and S. mansoni. The number of egg masses, eggs per egg mass, and snail deaths were counted for 7 weeks. The survival rate and cumulative hazard were assessed for infected and non-infected snails. Results: S. haematobium and S. mansoni cercariae peaked at 9:00–11:00 a.m. Infection significantly reduced the survival rate of B. pfeifferi, which was 35% and 51% for infected and non-infected snails, respectively (p = 0.02), at 7 weeks after infection. The hazard ratio of death for infected snails compared to non-infected snails was 1.65 (95% confidence interval: 1.35–1.99; p = 0.01). Conclusions: An understanding of the dynamics of schistosomiasis transmission will be helpful for formulating schistosomiasis control and elimination strategies. Cercarial rhythmicity can be reflected in health education, and the reproduction and survival rate of infected snails can be used as parameters for developing disease modeling.
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Affiliation(s)
| | | | - Seungman Cha
- Department of Global Development and Entrepreneurship, Graduate School of Global Development and Entrepreneurship, Handong Global University, Pohang 37554, Korea;
- Department of Disease Control, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK
| | - Yan Jin
- Department of Microbiology, College of Medicine, Dongguk University, Gyeongju 38066, Korea
- Correspondence: ; Tel.: +82-10-3375-3118
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8
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Berger DJ, Crellen T, Lamberton PHL, Allan F, Tracey A, Noonan JD, Kabatereine NB, Tukahebwa EM, Adriko M, Holroyd N, Webster JP, Berriman M, Cotton JA. Whole-genome sequencing of Schistosoma mansoni reveals extensive diversity with limited selection despite mass drug administration. Nat Commun 2021; 12:4776. [PMID: 34362894 PMCID: PMC8346512 DOI: 10.1038/s41467-021-24958-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 07/06/2021] [Indexed: 02/07/2023] Open
Abstract
Control and elimination of the parasitic disease schistosomiasis relies on mass administration of praziquantel. Whilst these programmes reduce infection prevalence and intensity, their impact on parasite transmission and evolution is poorly understood. Here we examine the genomic impact of repeated mass drug administration on Schistosoma mansoni populations with documented reduced praziquantel efficacy. We sequenced whole-genomes of 198 S. mansoni larvae from 34 Ugandan children from regions with contrasting praziquantel exposure. Parasites infecting children from Lake Victoria, a transmission hotspot, form a diverse panmictic population. A single round of treatment did not reduce this diversity with no apparent population contraction caused by long-term praziquantel use. We find evidence of positive selection acting on members of gene families previously implicated in praziquantel action, but detect no high frequency functionally impactful variants. As efforts to eliminate schistosomiasis intensify, our study provides a foundation for genomic surveillance of this major human parasite.
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Affiliation(s)
- Duncan J Berger
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK.
- Department of Pathology and Pathogen Biology, Centre for Emerging, Endemic and Exotic Diseases, Royal Veterinary College, University of London, Herts, UK.
| | - Thomas Crellen
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
- Imperial College London, Department of Infectious Disease Epidemiology, London, UK
- Big Data Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Poppy H L Lamberton
- Imperial College London, Department of Infectious Disease Epidemiology, London, UK
- Institute for Biodiversity, Animal Health, and Comparative Medicine, and Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | - Fiona Allan
- The Natural History Museum, Department of Life Sciences, London, UK
| | - Alan Tracey
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
| | - Jennifer D Noonan
- Institute of Parasitology, Faculty of Agricultural and Environmental Sciences, McGill University, Montreal, Quebec, Canada
| | - Narcis B Kabatereine
- Vector Borne & Neglected Tropical Disease Control Division, Ministry of Health, Kampala, Uganda
| | - Edridah M Tukahebwa
- Vector Borne & Neglected Tropical Disease Control Division, Ministry of Health, Kampala, Uganda
| | - Moses Adriko
- Vector Borne & Neglected Tropical Disease Control Division, Ministry of Health, Kampala, Uganda
| | - Nancy Holroyd
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
| | - Joanne P Webster
- Department of Pathology and Pathogen Biology, Centre for Emerging, Endemic and Exotic Diseases, Royal Veterinary College, University of London, Herts, UK.
- Imperial College London, Department of Infectious Disease Epidemiology, London, UK.
| | - Matthew Berriman
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK.
| | - James A Cotton
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK.
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9
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Ejike CU, Oluwole AS, Omitola OO, Bayegun AA, Shoneye IY, Akeredolu-Ale BI, Idowu OA, Mafiana CF, Ekpo UF. Schisto and Ladders version 2: a health educational board game to support compliance with school-based mass drug administration with praziquantel - a pilot study. Int Health 2021; 13:281-290. [PMID: 32918827 PMCID: PMC8079310 DOI: 10.1093/inthealth/ihaa057] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 06/09/2020] [Accepted: 08/14/2020] [Indexed: 01/03/2023] Open
Abstract
Background We redesigned the Schisto and Ladders health educational board game and evaluated its potential to encourage compliance to school-based mass drug administration with praziquantel. Methods Two hundred and seventy-five children from six schools who rejected praziquantel treatment were divided into intervention and control groups. Before the intervention, preassessment interviews were conducted on their knowledge about praziquantel treatment and schistosomiasis. The Schisto and Ladders version 2 game as an intervention, and the Snakes and Ladders game as a control, were played for 6 mo. Postassessment interviews, including focus group discussions, were conducted. Results At preassessment, 0/98 (0.0%) children in the intervention group had heard of praziquantel compared with 2/177 (1.1%) in the control group. Similarly, 0/98 (0.0%) children in the intervention group did not know that praziquantel does not kill compared with 4/177 (2.3%) in the control group. The postassessment showed that 53/78 (67.9%) in the intervention group were aware of praziquantel compared with 2/177 (1.1%) in the control group (p=0.000). Similarly, 53 (69.7%) in the intervention group knew about the safety of praziquantel compared with 0/177 (0.0%) in the control group (p=0.000). Sixty-four children (65.3%) from the intervention group sought praziquantel treatment after the trial. Conclusions Schisto and Ladders version 2 is a useful sensitisation tool with which to encourage compliance to praziquantel treatment in schools.
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Affiliation(s)
| | - Akinola Stephen Oluwole
- COUNTDOWN implementation research Consortium, Ogun State.,Sightsavers Nigeria Country Office, 1 Golf Course Road, PO Box 503, Kaduna State, Nigeria
| | - Olaitan Olamide Omitola
- Department of Pure and Applied Zoology, Federal University of Agriculture, Abeokuta, Nigeria
| | | | | | | | | | - Chiedu Felix Mafiana
- Research Administration and Advancement, National Open University of Nigeria, Abuja, Nigeria
| | - Uwem Friday Ekpo
- Department of Pure and Applied Zoology, Federal University of Agriculture, Abeokuta, Nigeria
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10
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Mawa PA, Kincaid-Smith J, Tukahebwa EM, Webster JP, Wilson S. Schistosomiasis Morbidity Hotspots: Roles of the Human Host, the Parasite and Their Interface in the Development of Severe Morbidity. Front Immunol 2021; 12:635869. [PMID: 33790908 PMCID: PMC8005546 DOI: 10.3389/fimmu.2021.635869] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 02/25/2021] [Indexed: 12/14/2022] Open
Abstract
Schistosomiasis is the second most important human parasitic disease in terms of socioeconomic impact, causing great morbidity and mortality, predominantly across the African continent. For intestinal schistosomiasis, severe morbidity manifests as periportal fibrosis (PPF) in which large tracts of macro-fibrosis of the liver, visible by ultrasound, can occlude the main portal vein leading to portal hypertension (PHT), sequelae such as ascites and collateral vasculature, and ultimately fatalities. For urogenital schistosomiasis, severe morbidity manifests as pathology throughout the urinary system and genitals, and is a definitive cause of squamous cell bladder carcinoma. Preventative chemotherapy (PC) programmes, delivered through mass drug administration (MDA) of praziquantel (PZQ), have been at the forefront of schistosomiasis control programmes in sub-Saharan Africa since their commencement in Uganda in 2003. However, despite many successes, 'biological hotspots' (as distinct from 'operational hotspots') of both persistent high transmission and morbidity remain. In some areas, this failure to gain control of schistosomiasis has devastating consequences, with not only persistently high infection intensities, but both "subtle" and severe morbidity remaining prevalent. These hotspots highlight the requirement to revisit research into severe morbidity and its mechanisms, a topic that has been out of favor during times of PC implementation. Indeed, the focality and spatially-structured epidemiology of schistosomiasis, its transmission persistence and the morbidity induced, has long suggested that gene-environmental-interactions playing out at the host-parasite interface are crucial. Here we review evidence of potential unique parasite factors, host factors, and their gene-environmental interactions in terms of explaining differential morbidity profiles in the human host. We then take the situation of schistosomiasis mansoni within the Albertine region of Uganda as a case study in terms of elucidating the factors behind the severe morbidity observed and the avenues and directions for future research currently underway within a new research and clinical trial programme (FibroScHot).
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Affiliation(s)
- Patrice A. Mawa
- Immunomodulation and Vaccines Programme, Medical Research Council-Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine (MRC/UVRI and LSHTM) Uganda Research Unit, Entebbe, Uganda
- Department of Immunology, Uganda Virus Research Institute, Entebbe, Uganda
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Julien Kincaid-Smith
- Centre for Emerging, Endemic and Exotic Diseases (CEEED), Department of Pathobiology and Population Sciences (PPS), Royal Veterinary College, University of London, Herts, United Kingdom
| | | | - Joanne P. Webster
- Centre for Emerging, Endemic and Exotic Diseases (CEEED), Department of Pathobiology and Population Sciences (PPS), Royal Veterinary College, University of London, Herts, United Kingdom
| | - Shona Wilson
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
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11
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Rey O, Webster BL, Huyse T, Rollinson D, Van den Broeck F, Kincaid-Smith J, Onyekwere A, Boissier J. Population genetics of African Schistosoma species. INFECTION GENETICS AND EVOLUTION 2021; 89:104727. [PMID: 33486128 DOI: 10.1016/j.meegid.2021.104727] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 01/09/2021] [Accepted: 01/13/2021] [Indexed: 02/06/2023]
Abstract
Blood flukes within the genus Schistosoma (schistosomes) are responsible for the major disease, schistosomiasis, in tropical and sub-tropical areas. This disease is predominantly present on the African continent with more than 85% of the human cases. Schistosomes are also parasites of veterinary importance infecting livestock and wildlife. Schistosoma population genetic structure and diversity are important characteristics that may reflect variations in selection pressures such as those induced by host (mammalian and snail) environments, habitat change, migration and also treatment/control interventions, all of which also shape speciation and evolution of the whole Schistosoma genus. Investigations into schistosome population genetic structure, diversity and evolution has been an area of important debate and research. Supported by advances in molecular techniques with capabilities for multi-locus genetic analyses for single larvae schistosome genetic investigations have greatly progressed in the last decade. This paper aims to review the genetic studies of both animal and human infecting schistosome. Population genetic structures are reviewed at different spatial scales: local, regional or continental (i.e. phylogeography). Within species genetic diversities are discussed compared and the compounding factors discussed, including the effect of mass drug administration. Finally, the ability for intra-species hybridisation questions species integrities and poses many questions in relation to the natural epidemiology of co-endemic species. Here we review molecularly confirmed hybridisation events (in relation to human disease) and discuss the possible impact for ongoing and future control and elimination.
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Affiliation(s)
- O Rey
- Univ. Montpellier, CNRS, IFREMER, UPVD, IHPE, F-66000 Perpignan, France
| | - B L 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
| | - T Huyse
- Department of Biology, Royal Museum for Central Africa, Leuvensesteenweg 13, B-3080 Tervuren, Belgium; Laboratory of Biodiversity and Evolutionary Genomics, Department of Biology, KU Leuven, Ch. Deberiotstraat 32, B-3000 Leuven, Belgium
| | - D Rollinson
- 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
| | - F Van den Broeck
- Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, University of Leuven, Leuven, Belgium; Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | - J Kincaid-Smith
- Centre for Emerging, Endemic and Exotic Diseases (CEEED), Department of Pathobiology and Population Sciences (PPS), Royal Veterinary College, University of London, Hawkshead Campus, Herts AL9 7TA, United Kingdom
| | - A Onyekwere
- Univ. Montpellier, CNRS, IFREMER, UPVD, IHPE, F-66000 Perpignan, France
| | - J Boissier
- Univ. Montpellier, CNRS, IFREMER, UPVD, IHPE, F-66000 Perpignan, France.
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12
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Cunningham LJ, Campbell SJ, Armoo S, Koukounari A, Watson V, Selormey P, Stothard JR, Idun B, Asiedu M, Ashong Y, Adams ER, Osei-Atweneboana MY. Assessing expanded community wide treatment for schistosomiasis: Baseline infection status and self-reported risk factors in three communities from the Greater Accra region, Ghana. PLoS Negl Trop Dis 2020; 14:e0007973. [PMID: 32339185 PMCID: PMC7205311 DOI: 10.1371/journal.pntd.0007973] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 05/07/2020] [Accepted: 12/05/2019] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND This paper reports on the baseline prevalence and associated risk factor findings of a pilot, longitudinal study exploring community-wide treatment of schistosomiasis and soil-transmitted helminthiasis, using albendazole plus praziquantel in the Greater Accra region of Ghana. METHOD From three communities, at least, 658 individuals were enrolled into the study via random household selection. Prevalence and intensity of schistosomiasis and STH infection were determined from stool and urine samples with a questionnaire being administered in order to explore other morbidities and risk factors. Factor analysis of household demographic variables was undertaken to generate a socioeconomic score; this was then further categorised into tertiles. Proportional-odds cumulative logit generalised estimating equation (GEE) models were used to investigate categorical ordinal intensity of infection associations with morbidity. Separately, logistic GEE models were used to investigate risk factor associations with infection prevalence. RESULTS Both Schistosoma haematobium and S. mansoni were prevalent in the three communities, with the prevalence of S. haematobium ranging from 3.3% (24/679; 95% CI = 1.9-4.7) to 19% (114/632; 95% CI = 15.8-22.2) and S. mansoni ranging from 30% (202/679; 95% CI = 26.5-33.5) to 78.3% (409/536; 95% CI = 74.7-81.9). The total prevalence of STH across all three sites was negligible at 1.3% (24/1847; 95% CI = 0.8-1.9) comprising mainly hookworm (10/1847). Multivariable statistical models indicated males to be 2.3 (95% CI = 1.7-3.3) times more likely to have a high intensity S. mansoni infection and 1.5 (95% CI = 1.1-2) times more likely to have a high intensity of S. haematobium infection compared to females. There was no significant difference in the likelihood of infection with S. mansoni between adults and school age children (SAC), however S. haematobium infections were found to be 2.5 (95% CI = 1.8-3.5) times more likely to occur in school age children than in adults. Multivariable statistical models (adjusted for age and sex) indicated an association between schistosomiasis and a number of self-reported morbidity indicators (notably diarrhoea and blood in stool and urine). Low socio-economic status was also associated with SCH infection (OR: 2; 95% CI = 1.3-3.2). CONCLUSION The communities targeted by this study showed a range of Schistosoma prevalence's of infection, from hypo-endemic through to meso-endemic and hyper-endemic. The prevalence of SCH across the different age groups in the study locations highlights the large number of individuals currently being left out of the standard morbidity control method of annual treatment of the SAC.
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Affiliation(s)
- Lucas J. Cunningham
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | | | - Samuel Armoo
- Department of Biomedical and Public Health Research, Council for Scientific and Industrial Research—Water Research Institute, Council Close, Accra, Ghana
| | - Artemis Koukounari
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, Keppel Street, London, United Kingdom
| | - Victoria Watson
- Department of Biostatistics, University of Liverpool, Liverpool, United Kingdom
| | - Pamela Selormey
- Department of Biomedical and Public Health Research, Council for Scientific and Industrial Research—Water Research Institute, Council Close, Accra, Ghana
| | - J. Russell Stothard
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Bright Idun
- Department of Biomedical and Public Health Research, Council for Scientific and Industrial Research—Water Research Institute, Council Close, Accra, Ghana
| | - Manfred Asiedu
- Department of Biomedical and Public Health Research, Council for Scientific and Industrial Research—Water Research Institute, Council Close, Accra, Ghana
| | - Yvonne Ashong
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Emily R. Adams
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Mike Yaw Osei-Atweneboana
- Department of Biomedical and Public Health Research, Council for Scientific and Industrial Research—Water Research Institute, Council Close, Accra, Ghana
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13
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Mollinedo S, Gutierrez P, Azurduy R, Valle F, Salas A, Mollinedo Z, Soto P, Villarroel CF, Ransom J, Lawrence R, Berman J, Soto J. Mass Drug Administration of Triclabendazole for Fasciola Hepatica in Bolivia. Am J Trop Med Hyg 2020; 100:1494-1497. [PMID: 31115295 DOI: 10.4269/ajtmh.19-0060] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Human infection with Fasciola hepatica leads to obstruction of the common bile duct by adult worms and disease characterized by biliary colic, epigastric pain, and nausea. Recommended treatment is a single dose of triclabendazole (TCBZ) (10 mg/kg). Because in the 1990s the Bolivian Altiplano bordering Lake Titicaca was thought to have the highest prevalence of human fascioliasis worldwide, the Bolivian Ministry of Health instituted TCBZ mass drug administration (MDA). From 2008 to 2016 (excepting 2015), one dose of 250 mg was administered, usually in September/October, to each resident of highly endemic regions willing to participate. This is apparently the first reported use of MDA for Fasciola. The proportion of persons in key regions receiving TCBZ MDA was 87% in 2016. In 2017, we resurveyed key regions, and found that the MDA program had been dramatically successful. Whereas Fasciola prevalence was reported as 26.9% in Huacullani/Tiahuanaco and 12.6% in Batallas in 1999, there was 0.7% prevalence in Huacullani/Tiahuanaco and 1% in Batallas in 2017. However, lessons from schistosomiasis control efforts suggest that for sustained control of Fasciola infection, Fasciola MDA needs to be maintained and coupled with measures to control infection in the intermediary snail and in the animal hosts of F. hepatica.
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Affiliation(s)
| | | | - Rosa Azurduy
- Servicio Departamental de Salud (SEDES), La Paz, Bolivia
| | - Freddy Valle
- Servicio Departamental de Salud (SEDES), La Paz, Bolivia
| | | | | | - Paula Soto
- FUNDERMA (Fundación Nacional de Dermatología), Santa Cruz, Bolivia
| | | | - Janet Ransom
- Fast-Track Drugs and Biologics, North Potomac, Maryland
| | | | | | - Jaime Soto
- FUNDERMA (Fundación Nacional de Dermatología), Santa Cruz, Bolivia
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14
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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] [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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15
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Blanton RE. Population Structure and Dynamics of Helminthic Infection: Schistosomiasis. Microbiol Spectr 2019; 7:10.1128/microbiolspec.ame-0009-2019. [PMID: 31325285 PMCID: PMC6650164 DOI: 10.1128/microbiolspec.ame-0009-2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Indexed: 11/20/2022] Open
Abstract
While disease and outbreaks are mainly clonal for bacteria and other asexually reproducing organisms, sexual reproduction in schistosomes and other helminths usually results in unique individuals. For sexually reproducing organisms, the traits conserved in clones will instead be conserved in the group of organisms that tends to breed together, the population. While the same tools are applied to characterize DNA, how results are interpreted can be quite different at times (see another article in this collection, http://www.asmscience.org/content/journal/microbiolspec/10.1128/microbiolspec.AME-0002-2018). It is difficult to know what the real effect any control program has on the parasite population without assessing the health of this population, how they respond to the control measure, and how they recover, if they do. This review, part of the Microbiology Spectrum Curated Collection: Advances in Molecular Epidemiology of Infectious Diseases, concentrates on one approach using pooled samples to study schistosome populations and shows how this and other approaches have contributed to our understanding of this parasite family's biology and epidemiology. *This article is part of a curated collection.
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Affiliation(s)
- Ronald E Blanton
- Center for Global Health and Diseases, Department of Pathology, Case Western Reserve University, Cleveland, OH 44120
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16
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Gichuki PM, Kepha S, Mulewa D, Masaku J, Kwoba C, Mbugua G, Mazigo HD, Mwandawiro C. Association between Schistosoma mansoni infection and access to improved water and sanitation facilities in Mwea, Kirinyaga County, Kenya. BMC Infect Dis 2019; 19:503. [PMID: 31174478 PMCID: PMC6556037 DOI: 10.1186/s12879-019-4105-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 05/17/2019] [Indexed: 11/24/2022] Open
Abstract
Background Schistosomiasis remains a public health problem in Central Kenya despite concerted control efforts. Access to improved water and sanitation has been emphasized as important control measures. Few studies have assessed the association between access to improved water sources and sanitation facilities with Schistosoma mansoni infection in different environmental settings. This study assessed the association between S. mansoni infection and household access to improved water sources and sanitation facilities in Mwea, Kirinyaga County, Kenya. Methods A cross sectional study was conducted between the months of August and October 2017. A total of 905 household heads from seven villages were interviewed and their stool samples screened for S. mansoni using the Kato Katz technique. Comparisons of demographic factors by S. mansoni infection were tested for significance using the chi-square test (χ2) or the Fisher exact test for categorical variables. Variables associated with S. mansoni infection were analyzed using univariable analysis and the strength of the association measured as odds ratio (OR) using mixed effects logistic regression at 95% CI, with values considered significant at p < 0.05. Results The overall prevalence of S. mansoni was, 23.1% (95% CI: 20.5–26.0%), with majority of the infections being of light intensity. Rurumi village had the highest prevalence at 33.3%, with Kirogo village having the least prevalence at 7.0%. Majority (84.1%) of the households lacked access to improved water sources but had access to improved sanitation facilities (75%). Households with access to piped water had the lowest S. mansoni infections. However, there was no significant association between S. mansoni infections with either the main source of water in the household (Odds Ratio (OR) =0.782 (95% CI: 0.497–1.229) p = 0.285 or sanitation facilities (OR = 1.018 (95% CI: 0.705–1.469) p = 0.926. Conclusion Our study suggests that S. mansoni is still a public health problem among all age groups in Mwea irrigation scheme, Kirinyaga County, Central Kenya. Majority of the households lacks access to improved water sources but have access to improved sanitation facilities. This study recommends initiatives to ensure adequate provision of improved water sources, and the inclusion of the adult community in preventive chemotherapy programs. Electronic supplementary material The online version of this article (10.1186/s12879-019-4105-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Paul M Gichuki
- Eastern and Southern Africa Center for International Parasite Control (ESACIPAC), Kenya Medical Research Institute (KEMRI), P.O BOX 54840-00200, Nairobi, Kenya. .,School of Health Sciences, Meru University of Science and Technology, P.O BOX 972-60200, Meru, Kenya.
| | - Stella Kepha
- London School of Tropical Medicine and Hygiene, Keppel St, Bloomsbury, London, WCIE 7HT, UK.,School of Public Health, Pwani University, P.O BOX 195-80108, Mombasa, Kenya
| | - Damaris Mulewa
- Eastern and Southern Africa Center for International Parasite Control (ESACIPAC), Kenya Medical Research Institute (KEMRI), P.O BOX 54840-00200, Nairobi, Kenya
| | - Janet Masaku
- Eastern and Southern Africa Center for International Parasite Control (ESACIPAC), Kenya Medical Research Institute (KEMRI), P.O BOX 54840-00200, Nairobi, Kenya
| | - Celestine Kwoba
- Vectorborne diseases Control Unit, Ministry of Health, P.o box 86-10303, Wanguru, Kenya
| | - Gabriel Mbugua
- School of Health Sciences, Meru University of Science and Technology, P.O BOX 972-60200, Meru, Kenya
| | - Humphrey D Mazigo
- Department of Medical Parasitology, School of Medicine, Catholic University of Health and Allied Sciences, P.O. Box 1464, Mwanza, Tanzania
| | - Charles Mwandawiro
- Eastern and Southern Africa Center for International Parasite Control (ESACIPAC), Kenya Medical Research Institute (KEMRI), P.O BOX 54840-00200, Nairobi, Kenya
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17
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Nascimento GL, Pegado HM, Domingues ALC, Ximenes RADA, Itria A, Cruz LN, Oliveira MRFD. The cost of a disease targeted for elimination in Brazil: the case of schistosomiasis mansoni. Mem Inst Oswaldo Cruz 2019; 114:e180347. [PMID: 30652735 PMCID: PMC6340134 DOI: 10.1590/0074-02760180347] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 12/10/2018] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Schistosomiasis mansoni is a poverty-related parasitic infection that has a
variety of clinical manifestations. We consider the disability and deaths
caused by schistosomiasis unacceptable for a tool-ready disease. Its
condition in Brazil warrants an analysis that will enable better
understanding of the local health losses and contribute to the complex
decision-making process. OBJECTIVE This study estimates the cost of schistosomiasis in Brazil in 2015. METHODS We conducted a cost of illness study of schistosomiasis mansoni in Brazil in
2015 based on a prevalence approach and from a societal perspective. The
study included 26,499 schistosomiasis carriers, 397 hepatosplenic cases, 48
cases with the neurological form, 284 hospitalisations, and 11,368.26 years
of life lost (YLL) of which 5,187 years are attributable to economically
active age groups. RESULTS The total cost of schistosomiasis mansoni in Brazil was estimated to be US$
41,7million in 2015 with 94.61% of this being indirect costs. CONCLUSIONS The economic burden of schistosomiasis mansoni in Brazil is high and results
in the loss of productivity. Its persistence in Brazil is a challenge to
public health and requires inter-sectorial interventions in areas such as
indoor water supply, basic sanitation, and education.
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Affiliation(s)
| | | | | | | | - Alexander Itria
- Universidade Federal de Goiás, Goiânia, GO, Brasil.,Instituto de Avaliação de Tecnologias em Saúde, Porto Alegre, RS, Brasil
| | | | - Maria Regina Fernandes de Oliveira
- Universidade de Brasília, Núcleo de Medicina Tropical, Brasília, DF, Brasil.,Instituto de Avaliação de Tecnologias em Saúde, Porto Alegre, RS, Brasil
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Ricciardi A, Zelt NH, Visitsunthorn K, Dalton JP, Ndao M. Immune Mechanisms Involved in Schistosoma mansoni-Cathepsin B Vaccine Induced Protection in Mice. Front Immunol 2018; 9:1710. [PMID: 30090103 PMCID: PMC6068236 DOI: 10.3389/fimmu.2018.01710] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 07/11/2018] [Indexed: 01/13/2023] Open
Abstract
A vaccine against schistosomiasis would contribute to a long-lasting decrease in disease spectrum and transmission. Our previous protection studies in mice using Schistosoma mansoni Cathepsin B (Sm-Cathepsin B) resulted in 59 and 60% worm burden reduction with CpG oligodeoxynucleotides and Montanide ISA720 VG as adjuvants, respectively. While both formulations resulted in significant protection in a mouse model of schistosomiasis, the elicited immune responses differed. Therefore, in this study, we aimed to decipher the mechanisms involved in Sm-Cathepsin B vaccine-mediated protection. We performed in vitro killing assays using schistosomula stage parasites as targets for lung-derived leukocytes and serum obtained from mice immunized with Sm-Cathepsin B adjuvanted with either Montanide ISA 720 VG or CpG and from non-vaccinated controls. Lung cells and immune sera from the Sm-Cathepsin B + Montanide group induced the highest killing (63%) suggesting the importance of antibodies in cell-mediated parasite killing. By contrast, incubation with lung cells from Sm-Cathepsin B + CpG immunized animals induced significant parasite killing (53%) independent of the addition of immune serum. Significant parasite killing was also observed in the animals immunized with Sm-Cathepsin B alone (41%). For the Sm-Cathepsin B + Montanide group, the high level killing effect was lost after the depletion of CD4+ T cells or natural killer (NK) cells from the lung cell preparation. For the Sm-Cathepsin B + CpG group, high parasite killing was lost after CD8+ T cell depletion, and a reduction to 39% was observed upon depletion of NK cells. Finally, the parasite killing in the Sm-Cathepsin B alone group was lost after the depletion of CD4+ T cells. Our results demonstrate how the different Sm-Cathepsin B formulations influence the immune mechanisms involved in parasite killing and protection against schistosomiasis.
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Affiliation(s)
- Alessandra Ricciardi
- Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada.,Research Institute of the McGill University Health Center, Infectious Diseases and Immunity in Global Health (IDIGH) Program, National Reference Center for Parasitology, Montreal, QC, Canada
| | - Nicholas H Zelt
- Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada.,Research Institute of the McGill University Health Center, Infectious Diseases and Immunity in Global Health (IDIGH) Program, National Reference Center for Parasitology, Montreal, QC, Canada
| | | | - John P Dalton
- School of Biological Sciences, Medical Biology Centre (MBC), Queen's University Belfast, Belfast, Ireland
| | - Momar Ndao
- Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada.,Research Institute of the McGill University Health Center, Infectious Diseases and Immunity in Global Health (IDIGH) Program, National Reference Center for Parasitology, Montreal, QC, Canada
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19
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Freer JB, Bourke CD, Durhuus GH, Kjetland EF, Prendergast AJ. Schistosomiasis in the first 1000 days. THE LANCET. INFECTIOUS DISEASES 2018; 18:e193-e203. [PMID: 29170089 DOI: 10.1016/s1473-3099(17)30490-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 07/02/2017] [Accepted: 07/13/2017] [Indexed: 12/29/2022]
Abstract
Infections during the first 1000 days-the period from conception to a child's second birthday-can have lifelong effects on health, because this is a crucial phase of growth and development. There is increasing recognition of the burden and potential effects of schistosomiasis in women of reproductive age and young children. Exposure to schistosomes during pregnancy can modulate infant immune development and schistosomiasis can occur from early infancy, such that the high disease burden found in adolescents is often due to accumulation of infections with long-lived schistosomes from early life. Women of reproductive age and young children are largely neglected in mass drug administration programmes, but early treatment could avert subsequent disease. We evaluate the evidence that early schistosomiasis has adverse effects on birth, growth, and development. We also discuss the case for expanding public health interventions for schistosomiasis in women of reproductive age and preschool-age children, and the need for further research to evaluate the potential of treating women pre-conception to maximise health across the life course.
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Affiliation(s)
- Joseph B Freer
- Zvitambo Institute for Maternal and Child Health Research, Harare, Zimbabwe; Blizard Institute, Queen Mary University of London, London, UK.
| | - Claire D Bourke
- Blizard Institute, Queen Mary University of London, London, UK
| | - Gunn H Durhuus
- Department of Internal Medicine, Sorlandet Hospital, Kristiansand, Norway
| | - Eyrun F Kjetland
- Norwegian Centre for Imported and Tropical Diseases, Department of Infectious Diseases Ullevaal, Oslo University Hospital, Oslo, Norway; Discipline of Public Health Medicine, Nelson R Mandela School of Medicine, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Andrew J Prendergast
- Zvitambo Institute for Maternal and Child Health Research, Harare, Zimbabwe; Blizard Institute, Queen Mary University of London, London, UK
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20
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Coulibaly JT, Panic G, Yapi RB, Kovač J, Barda B, N'Gbesso YK, Hattendorf J, Keiser J. Efficacy and safety of ascending doses of praziquantel against Schistosoma haematobium infection in preschool-aged and school-aged children: a single-blind randomised controlled trial. BMC Med 2018; 16:81. [PMID: 29855373 PMCID: PMC5984412 DOI: 10.1186/s12916-018-1066-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 05/01/2018] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Despite decades of experience with praziquantel treatment in school-aged children (SAC) and adults, we still face considerable knowledge gaps relevant to the successful treatment of preschool-aged children (PSAC). This study aimed to assess the efficacy and safety of escalating praziquantel dosages in PSAC infected with Schistosoma haematobium. METHODS We conducted a randomised, dose-finding trial in PSAC (2-5 years) and as comparator a cohort of SAC (6-15 years) infected with S. haematobium in Côte d'Ivoire. A total of 186 PSAC and 195 SAC were randomly assigned to 20, 40 or 60 mg/kg praziquantel or placebo. The nature of the dose-response relationship in terms of cure rate (CR) was the primary objective. Egg reduction rate (ERR) and tolerability were secondary outcomes. CRs and ERRs were assessed using triplicate urine filtration over 3 consecutive days. Available-case analysis was performed including all participants with primary endpoint data. RESULTS A total of 170 PSAC and 174 SAC received treatment. Almost 90% of PSAC and three quarters of SAC were lightly infected with S. haematobium. Follow-up data were available for 157 PSAC and 166 SAC. In PSAC, CRs of praziquantel were 85.7% (30/35), 78.0% (32/41) and 68.3% (28/41) at 20, 40 and 60 mg/kg and 47.5% (19/40) for placebo. In SAC, CRs were 10.8% for placebo (4/37), 55.6% for 20 mg/kg (25/45), 68.3% for 40 mg/kg (28/41) and 60.5% for 60 mg/kg (26/43). ERRs based on geometric means ranged between 96.5% (60 mg/kg) and 98.3% (20 mg/kg) in PSAC and between 97.6% (20 mg/kg and 60 mg/kg) and 98.6% (40 mg/kg) in SAC. Adverse events were mild and transient. CONCLUSIONS Praziquantel revealed dose-independent efficacy against light infections of S. haematobium. Over the dose range tested, praziquantel displayed a ceiling effect with the highest response for 20 mg/kg in PSAC. In SAC maximum efficacy was obtained with 40 mg/kg praziquantel. Further investigations are required in children with moderate to heavy infections. TRIAL REGISTRATION This trial is registered with International Standard Randomised Controlled Trial Number ISRCTN15280205 .
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Affiliation(s)
- Jean T Coulibaly
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, P.O. Box, CH-4002, Basel, Switzerland.,University of Basel, Basel, Switzerland.,Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire
| | - Gordana Panic
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, P.O. Box, CH-4002, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Richard B Yapi
- Centre Suisse de Recherches Scientifiques, Abidjan, Côte d'Ivoire
| | - Jana Kovač
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, P.O. Box, CH-4002, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Beatrice Barda
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, P.O. Box, CH-4002, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Yves K N'Gbesso
- Departement d'Agboville, Centre de Santé Urbain d'Azaguié, Azaguié, Côte d'Ivoire
| | - Jan Hattendorf
- University of Basel, Basel, Switzerland.,Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, P.O. Box, CH-4002, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
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21
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He P, Gordon CA, Williams GM, Li Y, Wang Y, Hu J, Gray DJ, Ross AG, Harn D, McManus DP. Real-time PCR diagnosis of Schistosoma japonicum in low transmission areas of China. Infect Dis Poverty 2018; 7:8. [PMID: 29394958 PMCID: PMC5796516 DOI: 10.1186/s40249-018-0390-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 01/17/2018] [Indexed: 01/22/2023] Open
Abstract
Background Schistosomiasis in the People’s Republic of China (PRC) can be traced back to antiquity. In the past 60 years, the Chinese government has made great efforts to control this persistent disease with elimination slated by 2020 through the implementation of a comprehensive control strategy. This strategy aims to reduce the role of bovines and humans as sources of infection as a pre-requisite for elimination through transmission interruption. The goal of elimination will be achievable only by the implementation of a sustainable surveillance and control system, with sensitive diagnosis a key feature so that the true disease burden is not underestimated. Currently used diagnostics lack the necessary sensitivity to accurately determine the prevalence of Schistosoma japonicum infection in areas with low infection intensities. It is of critical importance to find and treat people and to identify animals with low-level infections if the National Control Programme for China is to achieve schistosomiasis elimination. Methods We evaluated a real-time polymerase chain reaction (qPCR) assay using 633 human stool samples collected from five villages in Hunan, Anhui, Hubei, and Jiangxi provinces, and 182 bovine (70 cattle and 112 buffalo) stool samples obtained from four villages in Hunan, Anhui, and Jiangxi provinces in the PRC. All stool samples were subjected to the miracidium hatching test (MHT, a diagnostic procedure used in the National Schistosomiasis Control Programme) and the qPCR assay. Samples positive by MHT were subjected to either the Kato-Katz technique for humans, or the formalin-ethyl acetate sedimentation-digestion (FEA-SD) procedure for bovines, to determine infection intensities. Results The qPCR assay exhibited a high level of sensitivity in the detection of S. japonicum infections. With both the human and bovine samples, a significantly higher prevalence was determined using the qPCR assay (11.06% humans, 24.73% bovines) than with the MHT (0.93% humans, 7.69% bovines). The animal contamination index (calculated using data obtained with the qPCR technique) for all positive bovines was 27 618 000 eggs per day, indicating a considerable amount of environmental egg contamination that would be underestimated using less sensitive diagnostic procedures. Conclusions The qPCR assay we have evaluated will be applicable as a future field diagnostic and surveillance tool in low-transmission zones where schistosomiasis elimination is targeted and for monitoring post-intervention areas to verify that elimination has been maintained. Electronic supplementary material The online version of this article (10.1186/s40249-018-0390-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Pei He
- Hunan Institute of Parasitic Diseases, Yueyang, People's Republic of China
| | - Catherine A Gordon
- Molecular Parasitology Laboratory, Infectious Diseases Division, QIMR Berghofer Medical Research Institute, Brisbane, Australia.
| | - Gail M Williams
- Discipline of Epidemiology and Biostatistics, School of Population Health, University of Queensland, Brisbane, Australia
| | - Yuesheng Li
- Hunan Institute of Parasitic Diseases, Yueyang, People's Republic of China.,Molecular Parasitology Laboratory, Infectious Diseases Division, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Yuanyuan Wang
- Hunan Institute of Parasitic Diseases, Yueyang, People's Republic of China
| | - Junjian Hu
- Hunan Institute of Parasitic Diseases, Yueyang, People's Republic of China
| | - Darren J Gray
- Molecular Parasitology Laboratory, Infectious Diseases Division, QIMR Berghofer Medical Research Institute, Brisbane, Australia.,Discipline of Epidemiology and Biostatistics, School of Population Health, University of Queensland, Brisbane, Australia.,Research School of Population Health, The Australian National University, Canberra, Australia
| | - Allen G Ross
- Menzies Health Institute Queensland, Griffith University, Gold Coast, QLD, Australia
| | - Donald Harn
- University of Georgia, College of Veterinary Medicine, Athens, GA, USA
| | - Donald P McManus
- Molecular Parasitology Laboratory, Infectious Diseases Division, QIMR Berghofer Medical Research Institute, Brisbane, Australia.
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22
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Impact and cost-effectiveness of snail control to achieve disease control targets for schistosomiasis. Proc Natl Acad Sci U S A 2018; 115:E584-E591. [PMID: 29301964 PMCID: PMC5789907 DOI: 10.1073/pnas.1708729114] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Schistosomiasis is an infectious disease that affects over 240 million people living in low- and middle-income countries, and is caused by parasitic worms that require snail hosts to complete its lifecycle. To improve public health control of this disease, there is growing interest in using chemical-based snail control that kills snail populations in environmental water sources, which will reduce infection rate in people. We modeled transmission of schistosomiasis and cost-effectiveness of various strategies with data from low- and high-prevalence rural Kenyan communities. Adding snail control alongside conventional mass treatment programs (instead of mass treatment programs alone) was found to be cost-effective, especially in settings with high disease burden and nonparticipation in mass treatment programs. Schistosomiasis is a parasitic disease that affects over 240 million people globally. To improve population-level disease control, there is growing interest in adding chemical-based snail control interventions to interrupt the lifecycle of Schistosoma in its snail host to reduce parasite transmission. However, this approach is not widely implemented, and given environmental concerns, the optimal conditions for when snail control is appropriate are unclear. We assessed the potential impact and cost-effectiveness of various snail control strategies. We extended previously published dynamic, age-structured transmission and cost-effectiveness models to simulate mass drug administration (MDA) and focal snail control interventions against Schistosoma haematobium across a range of low-prevalence (5–20%) and high-prevalence (25–50%) rural Kenyan communities. We simulated strategies over a 10-year period of MDA targeting school children or entire communities, snail control, and combined strategies. We measured incremental cost-effectiveness in 2016 US dollars per disability-adjusted life year and defined a strategy as optimally cost-effective when maximizing health gains (averted disability-adjusted life years) with an incremental cost-effectiveness below a Kenya-specific economic threshold. In both low- and high-prevalence settings, community-wide MDA with additional snail control reduced total disability by an additional 40% compared with school-based MDA alone. The optimally cost-effective scenario included the addition of snail control to MDA in over 95% of simulations. These results support inclusion of snail control in global guidelines and national schistosomiasis control strategies for optimal disease control, especially in settings with high prevalence, “hot spots” of transmission, and noncompliance to MDA.
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23
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Mass drug administration and the global control of schistosomiasis: successes, limitations and clinical outcomes. Curr Opin Infect Dis 2018; 29:595-608. [PMID: 27584590 DOI: 10.1097/qco.0000000000000312] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
PURPOSE OF REVIEW Preventive chemotherapy is advocated for the global control and elimination of schistosomiasis. Despite the well known short-term benefits of treating patients for schistosomiasis, the impact of mass drug administration (MDA) campaigns to control the disease in the long term remains unresolved. RECENT FINDINGS Many studies have advocated the success of MDA programs in order to attract donor funds for elimination efforts but such successes are often short-lived given the drug does not alter the life cycle of the organism or prevent reinfection. Within a matter of months to years after halting treatment, the prevalence, intensity of infection and morbidity of disease return to baseline levels. Other mitigating factors contribute to the failings of MDA campaigns namely: poverty, poor drug coverage, poor drug compliance, and, in the case of Asiatic schistosomiasis, zoonotic transmission. Genetic and innate and acquired immunologic mechanisms complicate the epidemiologic picture of schistosomiasis globally, and may contribute indirectly to MDA shortcomings. The possibility of drug resistance is an ever present concern because of the sole reliance on one drug, praziquantel. SUMMARY Preventive chemotherapy is advocated for the global control and elimination of schistosomiasis. The short-term benefits of MDA campaigns are well documented but the long-term benefits are questionable.
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Candido RRF, Morassutti AL, Graeff-Teixeira C, St Pierre TG, Jones MK. Exploring Structural and Physical Properties of Schistosome Eggs: Potential Pathways for Novel Diagnostics? ADVANCES IN PARASITOLOGY 2018; 100:209-237. [PMID: 29753339 DOI: 10.1016/bs.apar.2018.03.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In this era of increasing demand for sensitive techniques to diagnose schistosomiasis, there is a need for an increased focus on the properties of the parasite eggs. The eggs are not only directly linked to the morbidity of chronic infection but are also potential key targets for accurate diagnostics. Eggs were the primary target of diagnostic tools in the past and we argue they could be the target of highly sensitive tools in the future if we focus on characteristics of their structure and shell surface that could be exploited for enhanced detection. In this review, we discuss the current state of knowledge of the physical structures of schistosome eggs and eggshells with a view to identifying pathways to a comprehensive understanding of their role in the host-parasite relationship and pathogenesis of infection, and pathways to new strategies for development of diagnostics.
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Affiliation(s)
- Renata R F Candido
- School of Physics, The University of Western Australia, Crawley, WA, Australia.
| | - Alessandra L Morassutti
- School of Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Carlos Graeff-Teixeira
- School of Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Timothy G St Pierre
- School of Physics, The University of Western Australia, Crawley, WA, Australia
| | - Malcolm K Jones
- School of Veterinary Sciences, The University of Queensland, Brisbane, QLD, Australia
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25
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Gower CM, Gehre F, Marques SR, Lamberton PHL, Lwambo NJ, Webster JP. Phenotypic and genotypic monitoring of Schistosoma mansoni in Tanzanian schoolchildren five years into a preventative chemotherapy national control programme. Parasit Vectors 2017; 10:593. [PMID: 29197426 PMCID: PMC5712074 DOI: 10.1186/s13071-017-2533-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 11/13/2017] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Schistosoma mansoni is a parasite of profound medical importance. Current control focusses on mass praziquantel (PZQ) treatment of populations in endemic areas, termed Preventative Chemotherapy (PC). Large-scale PC programmes exert prolonged selection pressures on parasites with the potential for, direct and/or indirect, emergence of drug resistance. Molecular methods can help monitor genetic changes of schistosome populations over time and in response to drug treatment, as well as estimate adult worm burdens through parentage analysis. Furthermore, methods such as in vitro drug sensitivity assays help phenotype in vivo parasite genotypic drug efficacy. METHODS We conducted combined in vitro PZQ efficacy testing with population genetic analyses of S. mansoni collected from children from two schools in 2010, five years after the introduction of a National Control Programme. Children at one school had received four annual PZQ treatments and the other school had received two mass treatments in total. We compared genetic differentiation, indices of genetic diversity, and estimated adult worm burden from parasites collected in 2010 with samples collected in 2005 (before the control programme began) and in 2006 (six months after the first PZQ treatment). Using 2010 larval samples, we also compared the genetic similarity of those with high and low in vitro sensitivity to PZQ. RESULTS We demonstrated that there were individual parasites with reduced PZQ susceptibility in the 2010 collections, as evidenced by our in vitro larval behavioural phenotypic assay. There was no evidence, however, that miracidia showing phenotypically reduced susceptibility clustered together genetically. Molecular analysis also demonstrated a significant reduction of adult worm load over time, despite little evidence of reduction in parasite infection intensity, as measured by egg output. Genetic diversity of infections did not reduce over time, despite changes in the genetic composition of the parasite populations. CONCLUSIONS Genotypic and phenotypic monitoring did not indicate a selective sweep, as may be expected if PZQ treatment was selecting a small number of related "resistant" parasites, but there was evidence of genetic changes at the population level over time. Genetic data were used to estimate adult worm burdens, which unlike parasite infection intensity, showed reductions over time, suggesting the relaxation of negative density-dependent constraints on parasite fecundity with PZQ treatment. We thereby demonstrated that density-dependence in schistosome populations may complicate evaluation and monitoring of control programmes.
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Affiliation(s)
- Charlotte M. Gower
- Centre for Endemic, Emerging and Exotic Diseases, The Royal Veterinary College, University of London, London, AL9 7TA UK
- Department of Infectious Disease Epidemiology, Imperial College, Faculty of Medicine, W2 1PG, London, UK
| | - Florian Gehre
- Department of Infectious Disease Epidemiology, Imperial College, Faculty of Medicine, W2 1PG, London, UK
- Mycobacteriology Unit, Institute of Tropical Medicine, Antwerp, Belgium
| | - Sara R. Marques
- Department of Life Sciences, Imperial College, Faculty of Medicine, London, UK
| | - Poppy H. L. Lamberton
- Department of Infectious Disease Epidemiology, Imperial College, Faculty of Medicine, W2 1PG, London, UK
- Institute of Biodiversity, Animal Health & Comparative Medicine & Wellcome Centre for Molecular Parasitology, University of Glasgow, G12 8QQ, Glasgow, UK
| | - Nicholas J. Lwambo
- Mwanza Research Centre, National Institute for Medical Research, Mwanza, Tanzania
| | - Joanne P. Webster
- Centre for Endemic, Emerging and Exotic Diseases, The Royal Veterinary College, University of London, London, AL9 7TA UK
- Department of Infectious Disease Epidemiology, Imperial College, Faculty of Medicine, W2 1PG, London, UK
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Mutuku MW, Lu L, Otiato FO, Mwangi IN, Kinuthia JM, Maina GM, Laidemitt MR, Lelo EA, Ochanda H, Loker ES, Mkoji GM. A Comparison of Kenyan Biomphalaria pfeifferi and B. Sudanica as Vectors for Schistosoma mansoni, Including a Discussion of the Need to Better Understand the Effects of Snail Breeding Systems on Transmission. J Parasitol 2017; 103:669-676. [PMID: 28708450 DOI: 10.1645/17-72] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024] Open
Abstract
In Kenya, schistosomes infect an estimated 6 million people with >30 million people at risk of infection. We compared compatibility with, and ability to support and perpetuate, Schistosoma mansoni of Biomphalaria pfeifferi and Biomphalaria sudanica, 2 prominent freshwater snail species involved in schistosomiasis transmission in Kenya. Field-derived B. pfeifferi (from a stream in Mwea, central Kenya) and B. sudanica (from Nawa, Lake Victoria, in western Kenya) were exposed to S. mansoni miracidia isolated from fecal samples of naturally infected humans from Mwea or Nawa. Juvenile (<6 mm shell diameter), young adult (6-9 mm), and adult snails (>9 mm) were each exposed to a single miracidium. Schistosoma mansoni developed faster and consistently had higher infection rates (39.6-80.7%) in B. pfeifferi than in B. sudanica (2.4-21.5%), regardless of the source of S. mansoni or the size of the snails used. Schistosoma mansoni from Nawa produced higher infection rates in both B. pfeifferi and B. sudanica than did S. mansoni from Mwea. Mean daily cercariae production was greater for B. pfeifferi exposed to sympatric than allopatric S. mansoni (583-1,686 vs. 392-1,232), and mean daily cercariae production among B. sudanica were consistently low (50-590) with no significant differences between sympatric or allopatric combinations. Both non-miracidia-exposed and miracidia-exposed B. pfeifferi had higher mortality rates than for B. sudanica, but mean survival time of shedding snails (9.3-13.7 wk) did not differ significantly between the 2 species. A small proportion (1.5%) of the cercariae shedding B. pfeifferi survived up to 40 wk post-exposure. Biomphalaria pfeifferi was more likely to become infected and to shed more cercariae than B. sudanica, suggesting that the risk per individual snail of perpetuating transmission in Kenyan streams or lacustrine habitats may differ considerably. High infection rates exhibited by the preferential self-fertilizing B. pfeifferi relative to the out-crossing B. sudanica point to the need to investigate further the role of host breeding systems in influencing transmission of schistosomiasis by snail hosts.
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Affiliation(s)
- Martin W Mutuku
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya
| | - Lijun Lu
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya
| | - Fredrick O Otiato
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya
| | - Ibrahim N Mwangi
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya
| | - Joseph M Kinuthia
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya
| | - Geoffrey M Maina
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya
| | - Martina R Laidemitt
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya
| | - Eric A Lelo
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya
| | - Horace Ochanda
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya
| | - Eric S Loker
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya
| | - Gerald M Mkoji
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya
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Buddenborg SK, Bu L, Zhang SM, Schilkey FD, Mkoji GM, Loker ES. Transcriptomic responses of Biomphalaria pfeifferi to Schistosoma mansoni: Investigation of a neglected African snail that supports more S. mansoni transmission than any other snail species. PLoS Negl Trop Dis 2017; 11:e0005984. [PMID: 29045404 PMCID: PMC5685644 DOI: 10.1371/journal.pntd.0005984] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 11/14/2017] [Accepted: 09/20/2017] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Biomphalaria pfeifferi is highly compatible with the widespread human-infecting blood fluke Schistosoma mansoni and transmits more cases of this parasite to people than any other snail species. For these reasons, B. pfeifferi is the world's most important vector snail for S. mansoni, yet we know relatively little at the molecular level regarding the interactions between B. pfeifferi and S. mansoni from early-stage sporocyst transformation to the development of cercariae. METHODOLOGY/PRINCIPAL FINDINGS We sought to capture a portrait of the response of B. pfeifferi to S. mansoni as it occurs in nature by undertaking Illumina dual RNA-Seq on uninfected control B. pfeifferi and three intramolluscan developmental stages (1- and 3-days post infection and patent, cercariae-producing infections) using field-derived west Kenyan specimens. A high-quality, well-annotated de novo B. pfeifferi transcriptome was assembled from over a half billion non-S. mansoni paired-end reads. Reads associated with potential symbionts were noted. Some infected snails yielded fewer normalized S. mansoni reads and showed different patterns of transcriptional response than others, an indication that the ability of field-derived snails to support and respond to infection is variable. Alterations in transcripts associated with reproduction were noted, including for the oviposition-related hormone ovipostatin and enzymes involved in metabolism of bioactive amines like dopamine or serotonin. Shedding snails exhibited responses consistent with the need for tissue repair. Both generalized stress and immune factors immune factors (VIgLs, PGRPs, BGBPs, complement C1q-like, chitinases) exhibited complex transcriptional responses in this compatible host-parasite system. SIGNIFICANCE This study provides for the first time a large sequence data set to help in interpreting the important vector role of the neglected snail B. pfeifferi in transmission of S. mansoni, including with an emphasis on more natural, field-derived specimens. We have identified B. pfeifferi targets particularly responsive during infection that enable further dissection of the functional role of these candidate molecules.
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Affiliation(s)
- Sarah K. Buddenborg
- Department of Biology, Center for Evolutionary and Theoretical Immunology, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Lijing Bu
- Department of Biology, Center for Evolutionary and Theoretical Immunology, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Si-Ming Zhang
- Department of Biology, Center for Evolutionary and Theoretical Immunology, University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Faye D. Schilkey
- National Center for Genome Resources, Santa Fe, New Mexico, United States of America
| | - Gerald M. Mkoji
- Center for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, KEN
| | - Eric S. Loker
- Department of Biology, Center for Evolutionary and Theoretical Immunology, University of New Mexico, Albuquerque, New Mexico, United States of America
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Ejike CU, Oluwole AS, Mogaji HO, Adeniran AA, Alabi OM, Ekpo UF. Development and testing of Schisto and Ladders™, an innovative health educational game for control of schistosomiasis in schoolchildren. BMC Res Notes 2017; 10:236. [PMID: 28659195 PMCID: PMC5490240 DOI: 10.1186/s13104-017-2545-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 06/17/2017] [Indexed: 11/29/2022] Open
Abstract
Background Schistosomiasis remains a public health problem in many regions of the world, including Nigeria. Current control strategy involves mass drug administration with praziquantel to the endemic population. To complement and sustain on-going preventive chemotherapy, we developed a health educational game named Schisto and Ladders™ and tested its potential for the control of schistosomiasis among schoolchildren living in Imala-Odo, a highly endemic community near Abeokuta, Nigeria. Methods One hundred school children were randomly selected and divided into intervention and control groups through balloting. Their knowledge, attitudes and practices (KAP) concerning schistosomiasis transmission, control and prevention were assessed using structured questionnaires. Schisto and Ladders™ game were given to the intervention group and the popular Snake and Ladders™ game to the control group. Both games were played for 2 months under the supervision of their class teachers. A post-KAP assessment was carried out in both groups, including focus group discussions (FGDs) to investigate knowledge and the impact of the games. Results Knowledge about urinary schistosomiasis and its transmission significantly improved (P = 0.000) in the intervention group (68.0%) compared to the control group (8.0%). FGDs showed that the frequency of visits to dam water also significantly reduced (P = 0.048) in the intervention group (18.0%) compared to the control group (40.0%). There was a significant increase in knowledge regarding risk behaviours, prevention and control of schistosomiasis among the intervention group, but no new knowledge gained in the control group. Conclusions This study demonstrates the potential of the health education game Schisto and Ladders™ for teaching basic health education and promoting behavioural changes among schoolchildren in endemic communities.
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Affiliation(s)
- Cynthia Uchechukwu Ejike
- Spatial Parasitology and Health GIS Group, Department of Pure and Applied Zoology, Federal University of Agriculture, Abeokuta, Nigeria
| | - Akinola Stephen Oluwole
- Spatial Parasitology and Health GIS Group, Department of Pure and Applied Zoology, Federal University of Agriculture, Abeokuta, Nigeria
| | - Hammed Oladeji Mogaji
- Spatial Parasitology and Health GIS Group, Department of Pure and Applied Zoology, Federal University of Agriculture, Abeokuta, Nigeria
| | - Adebiyi Abdulhakeem Adeniran
- Spatial Parasitology and Health GIS Group, Department of Pure and Applied Zoology, Federal University of Agriculture, Abeokuta, Nigeria
| | - Oladimeji Michael Alabi
- Spatial Parasitology and Health GIS Group, Department of Pure and Applied Zoology, Federal University of Agriculture, Abeokuta, Nigeria
| | - Uwem Friday Ekpo
- Spatial Parasitology and Health GIS Group, Department of Pure and Applied Zoology, Federal University of Agriculture, Abeokuta, Nigeria.
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Lo NC, Addiss DG, Hotez PJ, King CH, Stothard JR, Evans DS, Colley DG, Lin W, Coulibaly JT, Bustinduy AL, Raso G, Bendavid E, Bogoch II, Fenwick A, Savioli L, Molyneux D, Utzinger J, Andrews JR. A call to strengthen the global strategy against schistosomiasis and soil-transmitted helminthiasis: the time is now. THE LANCET. INFECTIOUS DISEASES 2016; 17:e64-e69. [PMID: 27914852 DOI: 10.1016/s1473-3099(16)30535-7] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 11/17/2016] [Accepted: 11/22/2016] [Indexed: 01/01/2023]
Abstract
In 2001, the World Health Assembly (WHA) passed the landmark WHA 54.19 resolution for global scale-up of mass administration of anthelmintic drugs for morbidity control of schistosomiasis and soil-transmitted helminthiasis, which affect more than 1·5 billion of the world's poorest people. Since then, more than a decade of research and experience has yielded crucial knowledge on the control and elimination of these helminthiases. However, the global strategy has remained largely unchanged since the original 2001 WHA resolution and associated WHO guidelines on preventive chemotherapy. In this Personal View, we highlight recent advances that, taken together, support a call to revise the global strategy and guidelines for preventive chemotherapy and complementary interventions against schistosomiasis and soil-transmitted helminthiasis. These advances include the development of guidance that is specific to goals of morbidity control and elimination of transmission. We quantify the result of forgoing this opportunity by computing the yearly disease burden, mortality, and lost economic productivity associated with maintaining the status quo. Without change, we estimate that the population of sub-Saharan Africa will probably lose 2·3 million disability-adjusted life-years and US$3·5 billion of economic productivity every year, which is comparable to recent acute epidemics, including the 2014 Ebola and 2015 Zika epidemics. We propose that the time is now to strengthen the global strategy to address the substantial disease burden of schistosomiasis and soil-transmitted helminthiasis.
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Affiliation(s)
- Nathan C Lo
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, CA, USA; Division of Epidemiology, Stanford University School of Medicine, Stanford, CA, USA.
| | - David G Addiss
- Children Without Worms, Task Force for Global Health, Decatur, GA, USA
| | - Peter J Hotez
- Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, National School of Tropical Medicine at Baylor College of Medicine, Houston, TX, USA; Department of Biology, Baylor University, Waco, TX, USA; James A Baker III Institute for Public Policy, Rice University, Houston, TX, USA
| | - Charles H King
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
| | - J Russell Stothard
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Darin S Evans
- United States Agency for International Development, Global Health, Washington, DC, USA
| | - Daniel G Colley
- Center for Tropical and Emerging Global Diseases and the Department of Microbiology, University of Georgia, Athens, GA, USA
| | - William Lin
- Global Public Health, Johnson & Johnson, New Brunswick, NJ, USA
| | - Jean T Coulibaly
- 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; Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland
| | - Amaya L Bustinduy
- Clinical Research Department, London School of Hygiene & Tropical Medicine, London, UK
| | - Giovanna Raso
- Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland
| | - Eran Bendavid
- Division of General Medical Disciplines, Stanford University, Stanford, CA, USA; Center for Health Policy and the Center for Primary Care and Outcomes Research, Stanford University, Stanford, CA, USA
| | - Isaac I Bogoch
- Department of Medicine, University of Toronto, Toronto, ON, Canada; Division of Internal Medicine and Infectious Diseases, Toronto General Hospital, University Health Network, Toronto, ON, Canada
| | - Alan Fenwick
- Schistosomiasis Control Initiative, Imperial College London, London, UK
| | - Lorenzo Savioli
- Global Schistosomiasis Alliance, Chavannes de Bogis, Switzerland
| | - David Molyneux
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland
| | - Jason R Andrews
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, CA, USA
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Knight M, Ittiprasert W, Arican-Goktas HD, Bridger JM. Epigenetic modulation, stress and plasticity in susceptibility of the snail host, Biomphalaria glabrata, to Schistosoma mansoni infection. Int J Parasitol 2016; 46:389-94. [DOI: 10.1016/j.ijpara.2016.03.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 03/14/2016] [Accepted: 03/15/2016] [Indexed: 12/11/2022]
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Lu L, Zhang SM, Mutuku MW, Mkoji GM, Loker ES. Relative compatibility of Schistosoma mansoni with Biomphalaria sudanica and B. pfeifferi from Kenya as assessed by PCR amplification of the S. mansoni ND5 gene in conjunction with traditional methods. Parasit Vectors 2016; 9:166. [PMID: 27000855 PMCID: PMC4802880 DOI: 10.1186/s13071-016-1457-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 03/16/2016] [Indexed: 12/02/2022] Open
Abstract
Background Schistosoma mansoni is hosted by several species of Biomphalaria spp. snails in Africa. We were interested in determining if there were differences in compatibility of S. mansoni with Biomphalaria sudanica from Lake Victoria, or with B. pfeifferi from streams and smaller water bodies in Kenya. Does this parasite develop with equal efficiency in both snail species, and does this have implications for transmission in different habitat types? Methods Primers for PCR amplification of the S. mansoni ND5 gene were designed and tested for sensitivity and specificity. We exposed laboratory-reared B. sudanica and field-derived B. pfeifferi to single miracidium infections and at 1, 2, 4, 8, 16 and 24 days post-exposure (dpe), snails were extracted for the PCR assay. Snails were also shed for cercariae and/or dissected prior to extraction. Additionally, B. sudanica and B. pfeifferi were collected from field locations and tested with the PCR assay. Results The ND5 PCR assay was sensitive (>0.1 fg S. mansoni genomic DNA) and allowed S. mansoni to be differentiated from other relevant schistosome species or snails. The number of PCR positive snails at 1–4 dpe was higher for B. pfeifferi than for B. sudanica, but not significantly so (P = 0.052). From 8–24 dpe, more B. pfeifferi harbored successfully developing parasites (positive by both dissection and PCR) than did B. sudanica (P = 0.008). At 40 dpe, more B. pfeifferi than B. sudanica shed cercariae or harbored dissection positive/PCR positive infections (P < 0.001). Both immature and failed (dissection negative but PCR positive) S. mansoni infections could also be detected in naturally infected snails of both species. Conclusions The PCR assay detected S. mansoni infections in snails exposed to one miracidium for one day. Both B. sudanica and B. pfeifferi supported full development of S. mansoni, but B. pfeifferi was more compatible, with significantly more dissection positive/PCR positive or shedding infections, and significantly fewer failed infections (dissection negative/PCR positive). This highlights the relatively lower compatibility of B. sudanica with S. mansoni, and suggests the factors responsible for incompatibility and how they might affect transmission of S. mansoni in habitats like Lake Victoria deserve additional study.
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Affiliation(s)
- Lijun Lu
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, 87131, USA.
| | - Si-Ming Zhang
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, 87131, USA
| | - Martin W Mutuku
- Center for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), P.O Box 54840-00200, Nairobi, Kenya
| | - Gerald M Mkoji
- Center for Biotechnology Research and Development, Kenya Medical Research Institute (KEMRI), P.O Box 54840-00200, Nairobi, Kenya
| | - Eric S Loker
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, 87131, USA.,Parasitology Division, Museum of Southwestern Biology, University of New Mexico, Albuquerque, 87131, USA
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Barbosa LM, Reis EA, Dos Santos CRA, Costa JM, Carmo TM, Aminu PT, Pitanga TN, Ponce-Terashima R, Blank WA, Silva LK, Reis MG, Blanton RE. Repeated praziquantel treatments remodel the genetic and spatial landscape of schistosomiasis risk and transmission. Int J Parasitol 2016; 46:343-50. [PMID: 26953255 DOI: 10.1016/j.ijpara.2016.01.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Revised: 01/25/2016] [Accepted: 01/28/2016] [Indexed: 11/19/2022]
Abstract
Repeated treatments with praziquantel reduce schistosomiasis prevalence and morbidity, but transmission persists and populations often recover within a few years. To identify factors associated with persistence, we surveyed and treated all identified Schistosoma mansoni infections in two rural Brazilian communities (Jenipapo and Volta do Rio) in 2009, 2012 and 2013. Eggs were collected from all infected individuals and genotyped with 11 microsatellite markers to evaluate parasite differentiation and diversity. After successive rounds of community-wide treatment, prevalence decreased from 45% to 24% then 16%. Intensity of infection decreased by 57% over this period, and the number of eggs transmitted to the environment decreased by 92%. During all time periods the majority of eggs were excreted by those >15years of age. The incidence was 23% in 2012 and 15% in 2013, consistent with a decrease in transmission. There was little immigration or gene flow over a distance of 6km. On reinfection, infrapopulations were moderately differentiated indicating that pretreatment multilocus genotypes were not fully reacquired. The effective population size responded to census population decline more rapidly than differentiation. Reinfection was concentrated in the downstream portion of Jenipapo, consistent with the observed increased human fecal contamination. At this scale and in this area S. mansoni infections exist on a fragmented landscape with a highly focal pattern of transmission that may facilitate future elimination.
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Affiliation(s)
- Lúcio M Barbosa
- Gonçalo Moniz Research Centre, Oswaldo Cruz Foundation, Rua Waldemar Falcão, 121 Brotas, Salvador, Bahia 40296-710, Brazil; Bahiana School of Medicine and Public Health, Av. Silveira Martins, n° 3386, Salvador, Bahia 41150-100, Brazil
| | - Eliana A Reis
- Gonçalo Moniz Research Centre, Oswaldo Cruz Foundation, Rua Waldemar Falcão, 121 Brotas, Salvador, Bahia 40296-710, Brazil
| | - Cláudio R A Dos Santos
- Gonçalo Moniz Research Centre, Oswaldo Cruz Foundation, Rua Waldemar Falcão, 121 Brotas, Salvador, Bahia 40296-710, Brazil
| | - Jackson M Costa
- Gonçalo Moniz Research Centre, Oswaldo Cruz Foundation, Rua Waldemar Falcão, 121 Brotas, Salvador, Bahia 40296-710, Brazil
| | - Theomira M Carmo
- Gonçalo Moniz Research Centre, Oswaldo Cruz Foundation, Rua Waldemar Falcão, 121 Brotas, Salvador, Bahia 40296-710, Brazil
| | - Peace T Aminu
- Center for Global Health and Diseases, Case Western Reserve University, Biomedical Research Building, 2109 Adelbert Rd., Cleveland, OH 44106, USA
| | - Thassila N Pitanga
- Gonçalo Moniz Research Centre, Oswaldo Cruz Foundation, Rua Waldemar Falcão, 121 Brotas, Salvador, Bahia 40296-710, Brazil
| | | | - Walter A Blank
- Center for Global Health and Diseases, Case Western Reserve University, Biomedical Research Building, 2109 Adelbert Rd., Cleveland, OH 44106, USA
| | - Luciano K Silva
- Gonçalo Moniz Research Centre, Oswaldo Cruz Foundation, Rua Waldemar Falcão, 121 Brotas, Salvador, Bahia 40296-710, Brazil
| | - Mitermayer G Reis
- Gonçalo Moniz Research Centre, Oswaldo Cruz Foundation, Rua Waldemar Falcão, 121 Brotas, Salvador, Bahia 40296-710, Brazil; Bahiana School of Medicine and Public Health, Av. Silveira Martins, n° 3386, Salvador, Bahia 41150-100, Brazil
| | - Ronald E Blanton
- Center for Global Health and Diseases, Case Western Reserve University, Biomedical Research Building, 2109 Adelbert Rd., Cleveland, OH 44106, USA.
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Something old, something new: is praziquantel enough for schistosomiasis control? Future Med Chem 2016; 7:681-4. [PMID: 25996059 DOI: 10.4155/fmc.15.9] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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Rasoamanamihaja CF, Rahetilahy AM, Ranjatoarivony B, Dhanani N, Andriamaro L, Andrianarisoa SH, Jourdan PM. Baseline prevalence and intensity of schistosomiasis at sentinel sites in Madagascar: Informing a national control strategy. Parasit Vectors 2016; 9:50. [PMID: 26822783 PMCID: PMC4730633 DOI: 10.1186/s13071-016-1337-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 01/21/2016] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Schistosomiasis affects more than 800 million people, mostly in sub-Saharan Africa. A baseline sentinel site study was conducted in the Western half of Madagascar to determine the prevalence and intensity of schistosomiasis and soil-transmitted helminth (STH) infections prior to mass drug administration, and to explore the associations between infection and school attendance, and access to water, sanitation and hygiene (WASH) facilities. METHODS A three-stage, cluster-randomised cross-sectional study was conducted in 29 sentinel sites in October 2015. Twenty school attending and 4 non-attending children in each of the age groups from 7 to 10 years old were randomly selected at each site for detection of Schistosoma haematobium eggs in a single urine slide by filtration, and of S. mansoni, Ascaris lumbricoides, Trichuris trichiura and hookworm eggs in duplicate Kato-Katz slides from a single stool sample. School attendance was registered individually, and school-level access to WASH facilities was scored through pre-defined observed and reported factors. Logistic regression analysis was performed, adjusting for gender, age and study site. School-level WASH status was analysed using Spearman's rank correlation coefficient. RESULTS A total of 1,958 children were included. The prevalence of S. haematobium infection and heavy-intensity infection was 30.5% and 15.1%, respectively. The prevalence of S. mansoni infection and heavy-intensity infection was 5.0% and 0.9%, respectively. The prevalence of any STH infection was 4.7%. There was no significant difference in prevalence of infection or heavy-intensity infection of either schistosome species between attending and non-attending children, apart from heavy-intensity S. mansoni infection that was significantly more common in children who did not attend school regularly (aOR = 7.5 (95% CI = 1.1-49.5); p = 0.037). Only a minority of schools had adequate access to WASH facilities, and in this study, we found no significant association between school-level WASH status and schistosomiasis. CONCLUSIONS This study found an alarmingly high prevalence and intensity of schistosomiasis, and the results warrant urgent scale-up of the national NTD control programme that will need to include both non-attending and attending school-age children in order to reach WHO roadmap targets for the control of schistosomiasis by 2020.
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Affiliation(s)
| | | | | | - Neerav Dhanani
- Schistosomiasis Control Initiative (SCI), Imperial College London, London, UK.
| | - Luciano Andriamaro
- Réseau International Schistosomose Environnement Aménagement et Lutte (RISEAL) Madagascar, Antananarivo, Madagascar.
| | | | - Peter Mark Jourdan
- Schistosomiasis Control Initiative (SCI), Imperial College London, London, UK.
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Abstract
Mass drug administration using praziquantel is the backbone of the current strategy for the control of schistosomiasis. As the theoretical plans have moved into practical application, certain challenges with this approach have surfaced, and it is likely that annual mass drug administration alone may not be sufficient to achieve program goals. However, mass drug administration is still the only available intervention that can be readily used in the wide variety of settings where schistosomiasis is endemic. The task then becomes how to improve this approach and identify what adjuncts to mass drug administration are effective, as programs move from morbidity control to elimination goals. Other aspects worthy of consideration include how best to employ new diagnostic tools to more easily identify where treatment is needed, and new formulations of praziquantel to extend the availability of treatment to all age groups. The aim of this review is to highlight both areas of challenge and of opportunity to improve the public health impact of schistosomiasis control programs.
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Affiliation(s)
- W Evan Secor
- Parasitic Diseases Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, 30329, USA
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Zhang SM, Buddenborg SK, Adema CM, Sullivan JT, Loker ES. Altered Gene Expression in the Schistosome-Transmitting Snail Biomphalaria glabrata following Exposure to Niclosamide, the Active Ingredient in the Widely Used Molluscicide Bayluscide. PLoS Negl Trop Dis 2015; 9:e0004131. [PMID: 26452273 PMCID: PMC4599737 DOI: 10.1371/journal.pntd.0004131] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 09/09/2015] [Indexed: 11/18/2022] Open
Abstract
In view of the call by the World Health Organization (WHO) for elimination of schistosomiasis as a public health problem by 2025, use of molluscicides in snail control to supplement chemotherapy–based control efforts is likely to increase in the coming years. The mechanisms of action of niclosamide, the active ingredient in the most widely used molluscicides, remain largely unknown. A better understanding of its toxicology at the molecular level will both improve our knowledge of snail biology and may offer valuable insights into the development of better chemical control methods for snails. We used a recently developed Biomphalaria glabrata oligonucleotide microarray (31K features) to investigate the effect of sublethal exposure to niclosamide on the transcriptional responses of the snail B. glabrata relative to untreated snails. Most of the genes highly upregulated following exposure of snails to niclosamide are involved in biotransformation of xenobiotics, including genes encoding cytochrome P450s (CYP), glutathione S-transferases (GST), and drug transporters, notably multi-drug resistance protein (efflux transporter) and solute linked carrier (influx transporter). Niclosamide also induced stress responses. Specifically, six heat shock protein (HSP) genes from three super-families (HSP20, HSP40 and HSP70) were upregulated. Genes encoding ADP-ribosylation factor (ARF), cAMP response element-binding protein (CREB) and coatomer, all of which are involved in vesicle trafficking in the Golgi of mammalian cells, were also upregulated. Lastly, a hemoglobin gene was downregulated, suggesting niclosamide may affect oxygen transport. Our results show that snails mount substantial responses to sublethal concentrations of niclosamide, at least some of which appear to be protective. The topic of how niclosamide’s lethality at higher concentrations is determined requires further study. Given that niclosamide has also been used as an anthelmintic drug for decades and has been found to have activity against several types of cancer, our findings may be of relevance in understanding how both parasites and neoplastic cells respond to this compound. Schistosomes are snail-transmitted parasites that continue to infect over 230 million people worldwide and cause the disease schistosomiasis. Currently there is no effective vaccine against the disease. Control programs have relied primarily on use of chemotherapy with praziquantel to eliminate adult worms from infected people. An increasing body of evidence, however, suggests that praziquantel-based control programs are not likely to be sufficient to achieve sustainable transmission control. Snail control achieved by focal use of molluscicides, especially in combination with other methods like chemotherapy, sanitation and health education, offers considerable promise for reduction of disease transmission. Consequently, use of molluscicides in snail control is likely to increase in the coming years. We undertook a microarray study to assess transcriptional responses to niclosamide, the active ingredient in commonly-used molluscicides, in the schistosome-transmitting snail Biomphalaria glabrata. We show that niclosamide activates components in snails’ pathways known to be involved in biotransformation of xenobiotics and stress responses. We suggest that major alterations in vesicle trafficking and interference with oxygen transport also follow niclosamide exposure. The results contribute to our understanding of molecular impacts of niclosamide exposure on snails, and provide a basis for further studies to define the mode of action of niclosamide and other molluscicides in the future.
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Affiliation(s)
- Si-Ming Zhang
- Center for Evolutionary and Theoretical Immunology, Department of Biology, The University of New Mexico, Albuquerque, New Mexico, United States of America
- * E-mail:
| | - Sarah K. Buddenborg
- Center for Evolutionary and Theoretical Immunology, Department of Biology, The University of New Mexico, Albuquerque, New Mexico, United States of America
| | - Coen M. Adema
- Center for Evolutionary and Theoretical Immunology, Department of Biology, The University of New Mexico, Albuquerque, New Mexico, United States of America
| | - John T. Sullivan
- Department of Biology, University of San Francisco, San Francisco, California, United States of America
| | - Eric S. Loker
- Center for Evolutionary and Theoretical Immunology, Department of Biology, The University of New Mexico, Albuquerque, New Mexico, United States of America
- Parasite Division, Museum of Southwestern Biology, Department of Biology, The University of New Mexico, Albuquerque, New Mexico, United States of America
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Modelling the effects of mass drug administration on the molecular epidemiology of schistosomes. ADVANCES IN PARASITOLOGY 2015; 87:293-327. [PMID: 25765198 DOI: 10.1016/bs.apar.2014.12.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
As national governments scale up mass drug administration (MDA) programs aimed to combat neglected tropical diseases (NTDs), novel selection pressures on these parasites increase. To understand how parasite populations are affected by MDA and how to maximize the success of control programmes, it is imperative for epidemiological, molecular and mathematical modelling approaches to be combined. Modelling of parasite population genetic and genomic structure, particularly of the NTDs, has been limited through the availability of only a few molecular markers to date. The landscape of infectious disease research is being dramatically reshaped by next-generation sequencing technologies and our understanding of how repeated selective pressures are shaping parasite populations is radically altering. Genomics can provide high-resolution data on parasite population structure, and identify how loci may contribute to key phenotypes such as virulence and/or drug resistance. We discuss the incorporation of genetic and genomic data, focussing on the recently sequenced Schistosoma spp., into novel mathematical transmission models to inform our understanding of the impact of MDA and other control methods. We summarize what is known to date, the models that exist and how population genetics has given us an understanding of the effects of MDA on the parasites. We consider how genetic and genomic data have the potential to shape future research, highlighting key areas where data are lacking, and how future molecular epidemiology knowledge can aid understanding of transmission dynamics and the effects of MDA, ultimately informing public health policy makers of the best interventions for NTDs.
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