1
|
Dos Santos Nascimento IJ, Albino SL, da Silva Menezes KJ, de Azevedo Teotônio Cavalcanti M, de Oliveira MS, Mali SN, de Moura RO. Targeting SmCB1: Perspectives and Insights to Design Antischistosomal Drugs. Curr Med Chem 2024; 31:2264-2284. [PMID: 37921174 DOI: 10.2174/0109298673255826231011114249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 09/01/2023] [Accepted: 09/14/2023] [Indexed: 11/04/2023]
Abstract
Neglected tropical diseases (NTDs) are prevalent in tropical and subtropical countries, and schistosomiasis is among the most relevant diseases worldwide. In addition, one of the two biggest problems in developing drugs against this disease is related to drug resistance, which promotes the demand to develop new drug candidates for this purpose. Thus, one of the drug targets most explored, Schistosoma mansoni Cathepsin B1 (SmCB1 or Sm31), provides new opportunities in drug development due to its essential functions for the parasite's survival. In this way, here, the latest developments in drug design studies targeting SmCB1 were approached, focusing on the most promising analogs of nitrile, vinyl sulphones, and peptidomimetics. Thus, it was shown that despite being a disease known since ancient times, it remains prevalent throughout the world, with high mortality rates. The therapeutic arsenal of antischistosomal drugs (ASD) consists only of praziquantel, which is widely used for this purpose and has several advantages, such as efficacy and safety. However, it has limitations, such as the impossibility of acting on the immature worm and exploring new targets to overcome these limitations. SmCB1 shows its potential as a cysteine protease with a catalytic triad consisting of Cys100, His270, and Asn290. Thus, design studies of new inhibitors focus on their catalytic mechanism for designing new analogs. In fact, nitrile and sulfonamide analogs show the most significant potential in drug development, showing that these chemical groups can be better exploited in drug discovery against schistosomiasis. We hope this manuscript guides the authors in searching for promising new antischistosomal drugs.
Collapse
Affiliation(s)
- Igor José Dos Santos Nascimento
- Pharmacy Department, Cesmac University Center, Maceió, 57051-160, Brazil
- Laboratório de Desenvolvimento e Síntese de Fármacos, Departamento de Farmácia, Universidade Estadual da Paraíba, Campina Grande 58429-500, Brazil
- Programa de Pós Graduação em Ciências Farmacêuticas, Universidade Estadual da Paraíba, Campina Grande, 58429-500, Brazil
| | - Sonaly Lima Albino
- Laboratório de Desenvolvimento e Síntese de Fármacos, Departamento de Farmácia, Universidade Estadual da Paraíba, Campina Grande 58429-500, Brazil
| | - Karla Joane da Silva Menezes
- Laboratório de Desenvolvimento e Síntese de Fármacos, Departamento de Farmácia, Universidade Estadual da Paraíba, Campina Grande 58429-500, Brazil
- Programa de Pós Graduação em Ciências Farmacêuticas, Universidade Estadual da Paraíba, Campina Grande, 58429-500, Brazil
| | - Misael de Azevedo Teotônio Cavalcanti
- Laboratório de Desenvolvimento e Síntese de Fármacos, Departamento de Farmácia, Universidade Estadual da Paraíba, Campina Grande 58429-500, Brazil
- Programa de Pós Graduação em Ciências Farmacêuticas, Universidade Estadual da Paraíba, Campina Grande, 58429-500, Brazil
| | - Mozaniel Santana de Oliveira
- Coordination of Botany-Laboratory Adolpho Ducke, Avenida Perimetral, Museu Paraense Emílio Goeldi, 1901, Belém, 66077-530, PA Brazil
| | - Suraj N Mali
- Department of Pharmaceutical Sciences and Technology, Institute of Chemical Technology, Matunga East, Mumbai, 400019, India
| | - Ricardo Olimpio de Moura
- Laboratório de Desenvolvimento e Síntese de Fármacos, Departamento de Farmácia, Universidade Estadual da Paraíba, Campina Grande 58429-500, Brazil
- Programa de Pós Graduação em Ciências Farmacêuticas, Universidade Estadual da Paraíba, Campina Grande, 58429-500, Brazil
| |
Collapse
|
2
|
Njikho SL, Quan VC, Mbonane TP, Van Wyk RH. Evaluating the Prevalence and Risk Factors of Schistosomiasis Amongst School-Aged Children in Low- and Middle-Income Communities: Ehlanzeni District Municipality, South Africa, 2015-2021. Trop Med Infect Dis 2023; 8:522. [PMID: 38133454 PMCID: PMC10748275 DOI: 10.3390/tropicalmed8120522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 12/23/2023] Open
Abstract
This study aimed to assess the prevalence and identify risk factors of schistosomiasis among school-aged children in low- and middle-income communities. A retrospective cross-sectional study was conducted to review patient records of school-age children. Data on gender, age, sub-district, area residing in, patient status, history of bilharzia, presence of blood in the urine, and schistosomiasis diagnoses were collected. The data were analyzed using IBM Statistical Package for the Social Sciences (SPSS) version 27. Logistic regression was employed to determine the factors associated with schistosomiasis. The overall prevalence of schistosomiasis in the study population was 75%, with higher prevalence observed among male children (89%), children aged between 10 and 14 years (59%), urban areas (51%), and rural-dominated districts, particularly Bushbuckridge (42%) and City of Mbombela (51%). Age, especially 10-14 years old (p ˂ 0.01; 95%CI: 1.98-2.29), a history of bilharzia (p = 0.01; 95%CI: 1.15-1.96), and the presence of blood in urine (p ˂ 0.01; 95%CI: 2.02-2.40) were significantly associated with schistosomiasis while being a female child was found to be a protective factor (AOR: 0.35; CI 0.35-0.41). This study underscores the importance of implementing robust screening procedures and the necessity for health education to mitigate the high prevalence of schistosomiasis and prevent its further spread.
Collapse
Affiliation(s)
- Sunnieboy Lot Njikho
- Department of Environmental Health, Faculty of Health Sciences, University of Johannesburg, Johannesburg 2001, South Africa; (S.L.N.); (T.P.M.)
- Public Health Surveillance and Response, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg 2001, South Africa;
| | - Vanessa Cecilia Quan
- Public Health Surveillance and Response, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg 2001, South Africa;
| | - Thokozani Patrick Mbonane
- Department of Environmental Health, Faculty of Health Sciences, University of Johannesburg, Johannesburg 2001, South Africa; (S.L.N.); (T.P.M.)
| | - Renay Helouise Van Wyk
- Department of Environmental Health, Faculty of Health Sciences, University of Johannesburg, Johannesburg 2001, South Africa; (S.L.N.); (T.P.M.)
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
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.
Collapse
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.
| |
Collapse
|
5
|
Fukushige M, Chase-Topping M, Woolhouse MEJ, Mutapi F. Efficacy of praziquantel has been maintained over four decades (from 1977 to 2018): A systematic review and meta-analysis of factors influence its efficacy. PLoS Negl Trop Dis 2021; 15:e0009189. [PMID: 33730095 PMCID: PMC7968639 DOI: 10.1371/journal.pntd.0009189] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 02/01/2021] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND The antihelminthic drug praziquantel has been used as the drug of choice for treating schistosome infection for more than 40 years. Although some epidemiological studies have reported low praziquantel efficacy in cure rate (CR) and/or egg reduction rate (ERR), there is no consistent robust evidence of the development of schistosome resistance to praziquantel (PZQ). There is need to determine factors that lead to variable treatment CR and/or ERR. Therefore, we conducted a systematic review and meta-analysis to review CR and ERR as well as identify their predictors. METHODOLOGY/PRINCIPAL FINDINGS In this systematic review and meta-analysis, a literature review was conducted using Biosis Citation Index, Data Citation Index, MEDLINE, and Web of Science Core Collection all of which were provided through Web of Science. Alongside these, EMBASE, and CAB abstracts were searched to identify relevant articles. Random effect meta-regression models were used to identify the factors that influence CR and/or ERR by considering differences in host characteristics and drug dose. In total, 12,127 potential articles were screened and 146 eligible articles (published from 1979 to 2020) were identified and included for the meta-analysis. We found that there has been no significant reduction in CR or ERR over the study period. The results showed more variability in CR, compared with ERR which was more consistent and remained high. The results showed a positive effect of "PZQ treatment dose" with the current recommended dose of 40 mg/kg body weight achieving 57% to 88% CR depending on schistosome species, age of participants, and number of parasitological samples used for diagnosis, and ERR of 95%. CONCLUSIONS/SIGNIFICANCE Based on a review of over 40 years of research there is no evidence to support concerns about schistosomes developing resistance to PZQ. These results indicate that PZQ remains effective in treating schistosomiasis.
Collapse
Affiliation(s)
- Mizuho Fukushige
- Institute of Immunology and Infection Research, Centre for Immunity, Infection & Evolution, Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Margo Chase-Topping
- Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | | | - Francisca Mutapi
- Institute of Immunology and Infection Research, Centre for Immunity, Infection & Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
- NIHR Global Health Research Unit Tackling Infections to Benefit Africa (TIBA), University of Edinburgh, Edinburgh, United Kingdom
| |
Collapse
|
6
|
Anemia in preschool children from Angola: a review of the evidence. Porto Biomed J 2020; 5:e60. [PMID: 33299941 PMCID: PMC7722406 DOI: 10.1097/j.pbj.0000000000000060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 01/06/2020] [Indexed: 11/26/2022] Open
Abstract
Angola is one of the southern African countries with the highest prevalence of anemia, and despite the high geographic heterogeneity of its distribution across the country, it was reported to be indicative of a severe public health problem in some areas, mainly in children. Despite the relevance of this condition in the country there is still an important gap regarding scientific evidences and knowledge systematization in the indexed literature, that could be used to inform and optimize national public health policies willing to address it. Furthermore, the changes in anemia epidemiology among African preschool children and the late updates in nutrition-specific and nutrition-sensitive preventive strategies in the continent are of imperative relevance, as they could contribute to design context-specific national approaches to reduce anemia's morbidity and mortality. In this study we intent to perform a systematic review regarding the sparse evidence available on the country regarding the prevalence of anemia, its associated factors, the prevention, and/or control strategies with potential to reduce anemia that were implemented, and to discuss interventions targeting infections and/or nutrition conducted in other African countries.
Collapse
|
7
|
Archer J, O’Halloran L, Al-Shehri H, Summers S, Bhattacharyya T, Kabaterine NB, Atuhaire A, Adriko M, Arianaitwe M, Stewart M, LaCourse EJ, Webster BL, Bustinduy AL, Stothard JR. Intestinal Schistosomiasis and Giardiasis Co-Infection in Sub-Saharan Africa: Can a One Health Approach Improve Control of Each Waterborne Parasite Simultaneously? Trop Med Infect Dis 2020; 5:E137. [PMID: 32854435 PMCID: PMC7558413 DOI: 10.3390/tropicalmed5030137] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 08/16/2020] [Accepted: 08/19/2020] [Indexed: 12/14/2022] Open
Abstract
Both intestinal schistosomiasis and giardiasis are co-endemic throughout many areas of sub-Saharan Africa, significantly impacting the health of millions of children in endemic areas. While giardiasis is not considered a neglected tropical disease (NTD), intestinal schistosomiasis is formally grouped under the NTD umbrella and receives significant advocacy and financial support for large-scale control. Although there are differences in the epidemiology between these two diseases, there are also key similarities that might be exploited within potential integrated control strategies permitting tandem interventions. In this review, we highlight these similarities and discuss opportunities for integrated control of giardiasis in low and middle-income countries where intestinal schistosomiasis is co-endemic. By applying new, advanced methods of disease surveillance, and by improving the provision of water, sanitation and hygiene (WASH) initiatives, (co)infection with intestinal schistosomiasis and/or giardiasis could not only be more effectively controlled but also better understood. In this light, we appraise the suitability of a One Health approach targeting both intestinal schistosomiasis and giardiasis, for if adopted more broadly, transmission of both diseases could be reduced to gain improvements in health and wellbeing.
Collapse
Affiliation(s)
- John Archer
- Wolfson Wellcome Biomedical Laboratories, Department of Zoology, Natural History Museum, Cromwell Road, London SW7 5BD, UK; (J.A.); (B.L.W.)
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK; (L.O.); (H.A.-S.); (M.S.); (E.J.L.)
| | - Lisa O’Halloran
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK; (L.O.); (H.A.-S.); (M.S.); (E.J.L.)
| | - Hajri Al-Shehri
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK; (L.O.); (H.A.-S.); (M.S.); (E.J.L.)
- Department of Tropical Infectious Diseases, Ministry of Health, Asir District, Abha 61411, Saudi Arabia
| | - Shannan Summers
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK; (S.S.); (T.B.); (A.L.B.)
| | - Tapan Bhattacharyya
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK; (S.S.); (T.B.); (A.L.B.)
| | - Narcis B. Kabaterine
- Vector Control Division, Ministry of Health, Kampala 759125, Uganda; (N.B.K.); (A.A.); (M.A.); (M.A.)
| | - Aaron Atuhaire
- Vector Control Division, Ministry of Health, Kampala 759125, Uganda; (N.B.K.); (A.A.); (M.A.); (M.A.)
| | - Moses Adriko
- Vector Control Division, Ministry of Health, Kampala 759125, Uganda; (N.B.K.); (A.A.); (M.A.); (M.A.)
| | - Moses Arianaitwe
- Vector Control Division, Ministry of Health, Kampala 759125, Uganda; (N.B.K.); (A.A.); (M.A.); (M.A.)
| | - Martyn Stewart
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK; (L.O.); (H.A.-S.); (M.S.); (E.J.L.)
| | - E. James LaCourse
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK; (L.O.); (H.A.-S.); (M.S.); (E.J.L.)
| | - Bonnie L. Webster
- Wolfson Wellcome Biomedical Laboratories, Department of Zoology, Natural History Museum, Cromwell Road, London SW7 5BD, UK; (J.A.); (B.L.W.)
| | - Amaya L. Bustinduy
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK; (S.S.); (T.B.); (A.L.B.)
| | - J. Russell Stothard
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK; (L.O.); (H.A.-S.); (M.S.); (E.J.L.)
| |
Collapse
|
8
|
How can schistosome circulating antigen assays be best applied for diagnosing male genital schistosomiasis (MGS): an appraisal using exemplar MGS cases from a longitudinal cohort study among fishermen on the south shoreline of Lake Malawi. Parasitology 2019; 146:1785-1795. [PMID: 31452477 PMCID: PMC6939168 DOI: 10.1017/s0031182019000969] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We provide an update on diagnostic methods for the detection of urogenital schistosomiasis (UGS) in men and highlight that satisfactory urine-antigen diagnostics for UGS lag much behind that for intestinal schistosomiasis, where application of a urine-based point-of-care strip assay, the circulating cathodic antigen (CCA) test, is now advocated. Making specific reference to male genital schistosomiasis (MGS), we place greater emphasis on parasitological detection methods and clinical assessment of internal genitalia with ultrasonography. Unlike the advances made in defining a clinical standard protocol for female genital schistosomiasis, MGS remains inadequately defined. Whilst urine filtration with microscopic examination for ova of Schistosoma haematobium is a convenient but error-prone proxy of MGS, we describe a novel low-cost sampling and direct visualization method for the enumeration of ova in semen. Using exemplar clinical cases of MGS from our longitudinal cohort study among fishermen along the shoreline of Lake Malawi, the portfolio of diagnostic needs is appraised including: the use of symptomatology questionnaires, urine analysis (egg count and CCA measurement), semen analysis (egg count, circulating anodic antigen measurement and real-time polymerase chain reaction analysis) alongside clinical assessment with portable ultrasonography.
Collapse
|
9
|
Obonyo CO, Muok EMO, Were V. Biannual praziquantel treatment for schistosomiasis. Hippokratia 2019. [DOI: 10.1002/14651858.cd013412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Charles O Obonyo
- Kenya Medical Research Institute; Centre for Global Health Research; P.O. Box 1578 Kisumu Kenya 40100
| | - Erick MO Muok
- Kenya Medical Research Institute; Centre for Global Health Research; P.O. Box 1578 Kisumu Kenya 40100
| | - Vincent Were
- Kenya Medical Research Institute; Centre for Global Health Research; P.O. Box 1578 Kisumu Kenya 40100
| |
Collapse
|
10
|
Sousa MS, van Dam GJ, Pinheiro MCC, de Dood CJ, Peralta JM, Peralta RHS, Daher EDF, Corstjens PLAM, Bezerra FSM. Performance of an Ultra-Sensitive Assay Targeting the Circulating Anodic Antigen (CAA) for Detection of Schistosoma mansoni Infection in a Low Endemic Area in Brazil. Front Immunol 2019; 10:682. [PMID: 31019510 PMCID: PMC6458306 DOI: 10.3389/fimmu.2019.00682] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 03/13/2019] [Indexed: 12/03/2022] Open
Abstract
Techniques with high sensitivity and specificity are required for an accurate diagnosis in low-transmission settings, where the conventional parasitological methods are insensitive. We determined the accuracy of an up-converting phosphor-lateral flow circulating anodic antigen (UCP-LF CAA) assay in urine and serum for Schistosoma mansoni diagnosis in low-prevalence settings in Ceará, Brazil, before and after praziquantel treatment. Clinical samples of a total of 258 individuals were investigated by UCP-LF CAA, point-of-care-circulating cathodic antigen (POC-CCA), soluble worm antigen preparation (SWAP)-ELISA and Kato-Katz (KK); a selection of 128 stools by real-time PCR technique. Three and 6-weeks after treatment, samples were collected and evaluated by detection Schistosoma circulating antigens (CAA and CCA). The UCP-LF CAA assays detected 80 positives (31%) with urine and 82 positives (31.8%) with serum. The urine POC-CCA and serum SWAP-ELISA assays detected 30 (11.6%) and 107 (40.7%) positives, respectively. The Kato-Katz technique revealed only 4 positive stool samples (1.6%). Among the 128 individuals with complete data records, 19 cases were identified by PCR (14.8%); Sensitivities and specificities of the UCP-LF CAA assays, determined versus a combined reference standard based on CCA/KK/PCR positivity, ranged from 60-68% to 68-77%, respectively. In addition only for comparative purposes, sensitivities of the different assays were determined vs. a comparative reference based on CAA/KK/PCR positivity, showing the highest sensitivity for the urine CAA assay (80%), followed by the serum CAA (70.9%), SWAP-ELISA (43.6%), PCR (34.5%), POC-CCA (29.1%), whilst triplicate Kato-Katz thick smears had a very low sensitivity (3.6%). CAA concentrations were higher in serum than in urine and were significantly correlated. There was a significant decrease in urine and serum CAA levels 3 and 6-weeks after treatment. The UCP-LF CAA assays revealed 33 and 28 S. mansoni-infected patients at the 3- and 6-week post-treatment follow-up, respectively. The UCP-LF CAA assays show high sensitivity for the diagnosis of S. mansoni in low-endemicity settings. It detects a considerably higher number of infections than microscopy, POC-CCA or PCR. Also it shows to be very useful for evaluating cure rates after treatment. Hence, the UCP-LF CAA assay is a robust and promising diagnostic approach in low-transmission settings.
Collapse
Affiliation(s)
- Mariana Silva Sousa
- Medical Sciences Post Graduate Program, Department of Internal Medicine, School of Medicine, Federal University of Ceará, Fortaleza, Brazil
- Parasitology and Mollusks Biology Research Laboratory, Department of Clinical Analysis and Toxicology, Federal University of Ceará, Fortaleza, Brazil
| | - Govert J. van Dam
- Department of Parasitology, Leiden University Medical Center, Leiden, Netherlands
| | - Marta Cristhiany Cunha Pinheiro
- Parasitology and Mollusks Biology Research Laboratory, Department of Clinical Analysis and Toxicology, Federal University of Ceará, Fortaleza, Brazil
| | - Claudia J. de Dood
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, Netherlands
| | - Jose Mauro Peralta
- Department of Immunology, Institute of Microbiology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Elizabeth de Francesco Daher
- Medical Sciences Post Graduate Program, Department of Internal Medicine, School of Medicine, Federal University of Ceará, Fortaleza, Brazil
| | - Paul L. A. M. Corstjens
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, Netherlands
| | - Fernando Schemelzer Moraes Bezerra
- Medical Sciences Post Graduate Program, Department of Internal Medicine, School of Medicine, Federal University of Ceará, Fortaleza, Brazil
- Parasitology and Mollusks Biology Research Laboratory, Department of Clinical Analysis and Toxicology, Federal University of Ceará, Fortaleza, Brazil
- Pathology Post Graduate Program, Department of Pathology and Legal Medicine, Federal University of Ceará, Fortaleza, Brazil
| |
Collapse
|
11
|
Abstract
Schistosomiasis (bilharzia) is a neglected tropical disease caused by parasitic flatworms (blood flukes) of the genus Schistosoma, with considerable morbidity in parts of the Middle East, South America, Southeast Asia and, particularly, in sub-Saharan Africa. Infective larvae grow in an intermediate host (fresh-water snails) before penetrating the skin of the definitive human host. Mature adult worms reside in the mesenteric (Schistosoma mansoni and Schistosoma japonicum) or pelvic (Schistosoma haematobium) veins, where female worms lay eggs, which are secreted in stool or urine. Eggs trapped in the surrounding tissues and organs, such as the liver and bladder, cause inflammatory immune responses (including granulomas) that result in intestinal, hepato-splenic or urogenital disease. Diagnosis requires the detection of eggs in excreta or worm antigens in the serum, and sensitive, rapid, point-of-care tests for populations living in endemic areas are needed. The anti-schistosomal drug praziquantel is safe and efficacious against adult worms of all the six Schistosoma spp. infecting humans; however, it does not prevent reinfection and the emergence of drug resistance is a concern. Schistosomiasis elimination will require a multifaceted approach, including: treatment; snail control; information, education and communication; improved water, sanitation and hygiene; accurate diagnostics; and surveillance-response systems that are readily tailored to social-ecological settings.
Collapse
Affiliation(s)
- Donald P McManus
- Immunology Department, QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland, Australia.
| | - David W Dunne
- Department of Pathology, University of Cambridge, Cambridge, UK
| | - Moussa Sacko
- Department of Diagnostic and Biomedical Research, Institut National de Recherche en Santé Publique, Bamako, Mali
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Birgitte J Vennervald
- Department of Veterinary and Animal Science, University of Copenhagen, Copenhagen, Denmark
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Shanghai, People's Republic of China
| |
Collapse
|
12
|
Evaluating a point-of-care circulating cathodic antigen test (POC-CCA) to detect Schistosoma mansoni infections in a low endemic area in north-eastern Brazil. Acta Trop 2018. [PMID: 29526480 DOI: 10.1016/j.actatropica.2018.03.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Schistosomiasis is still a public health problem in Brazil. The Kato-Katz test is the most frequently used diagnostic method for Schistosoma mansoni infection. However, it lacks sensitivity in areas of low prevalence. We have assessed the positivity rate of S. mansoni infection in Bananeiras, a village on Capistrano, Ceara, Brazil by performing a point-of-care test in urine to determine the circulating cathodic antigens (POC-CCA), and we compared the findings with those of the Kato-Katz technique for egg detection in stool and an enzyme-linked immunosorbent assay for specific antibodies against adult worms (SWAP-ELISA) in serum before treatment (baseline). Additionally, the POC-CCA and Kato-Katz test results were compared at one and two years post-treatment, and only POC-CCA strips were utilised for follow-up testing on urine samples at 3-6 weeks. Only one sample of stool and urine was collected per event. Overall, 258 individuals were investigated at the baseline. The POC-CCA test detected 10 (3.9%) positive cases; however, this amount increased to 30 (11.6%) when considering trace readings as positive (t + ), whereas the Kato-Katz method found only 4 (1.6%) positive cases and the SWAP-ELISA detected 105 (40.7%) positive cases. The consistency observed between a single POC-CCA (t + ) or (t-) and the Kato-Katz (three slides) was poor (Kappa indexes <0.20). The highest positivity rate as determined by CCA and Kato-Katz was found in adults. At the baseline, a praziquantel treatment was administered to all individuals regardless of their infection status. According to the POC-CCA test, 93% of the previous positive cases became negative by the third week after the treatment; this rate reached 100% at the sixth week assessment. The follow-up showed that of the 175 individuals evaluated at one year post-treatment, only one (0.6%) showed 'trace' results, and all the individuals were negative for eggs in the stool. At two years, all 185 examined individuals were negative by the Kato-Katz method, and 11 (5.9%) presented traces by POC-CCA. Our results indicate that a single POC-CCA test reveals a significantly higher number of positive cases than the Kato-Katz technique for diagnosing S. mansoni in a low endemic setting, when trace results are considered as positive cases. Nevertheless, the true significance of the trace is not clear. These findings reinforce the need to associate different tools for improved schistosomiasis diagnosis in individuals with low parasite burdens.
Collapse
|
13
|
Surveillance of intestinal schistosomiasis during control: a comparison of four diagnostic tests across five Ugandan primary schools in the Lake Albert region. Parasitology 2018; 145:1715-1722. [PMID: 29560841 PMCID: PMC6533640 DOI: 10.1017/s003118201800029x] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Programmatic surveillance of intestinal schistosomiasis during control can typically use four diagnostic tests, either singularly or in combination, but these have yet to be cross-compared directly. Our study assembled a complete diagnostic dataset, inclusive of infection intensities, from 258 children from five Ugandan primary schools. The schools were purposely selected as typical of the endemic landscape near Lake Albert and reflective of high- and low-transmission settings. Overall prevalence was: 44.1% (95% CI 38.0–50.2) by microscopy of duplicate Kato-Katz smears from two consecutive stools, 56.9% (95% CI 50.8–63.0) by urine-circulating cathodic antigen (CCA) dipstick, 67.4% (95% CI 61.6–73.1) by DNA-TaqMan® and 75.1% (95% CI 69.8–80.4) by soluble egg antigen enzyme-linked immunosorbent assay (SEA-ELISA). A cross-comparison of diagnostic sensitivities, specificities, positive and negative predictive values was undertaken, inclusive of a latent class analysis (LCA) with a LCA-model estimate of prevalence by each school. The latter ranged from 9.6% to 100.0%, and prevalence by school for each diagnostic test followed a static ascending order or monotonic series of Kato-Katz, urine-CCA dipstick, DNA-TaqMan® and SEA-ELISA. We confirm that Kato-Katz remains a satisfactory diagnostic standalone in high-transmission settings but in low-transmission settings should be augmented or replaced by urine-CCA dipsticks. DNA-TaqMan® appears suitable in both endemic settings though is only implementable if resources permit. In low-transmission settings, SEA-ELISA remains the method of choice to evidence an absence infection. We discuss the pros and cons of each method concluding that future surveillance of intestinal schistosomiasis would benefit from a flexible, context-specific approach both in choice and application of each diagnostic method, rather than a single one-size fits all approach.
Collapse
|
14
|
Bustinduy AL, Stothard JR, Friedman JF. Paediatric and maternal schistosomiasis: shifting the paradigms. Br Med Bull 2017; 123:115-125. [PMID: 28910994 PMCID: PMC6279106 DOI: 10.1093/bmb/ldx028] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 07/16/2017] [Indexed: 11/13/2022]
Abstract
BACKGROUND In endemic areas, schistosomiasis causes both overt and subclinical disease in young children and their mothers, as well as in returned travellers. SOURCES OF DATA Key recently published literature. AREAS OF AGREEMENT An action plan for paediatric schistosomiasis and female genital schistosomiasis (FGS) is needed with expanded access to praziquantel (PZQ) treatment required. AREAS OF CONTROVERSY Schistosomiasis-related morbidity is underappreciated. Present and future demand for PZQ treatment is bottlenecked, imbalanced and inequitable. Current dosing, treatment algorithms and access plans are suboptimal with treatment stalled during pregnancy. GROWING POINTS Raised dosing of PZQ (>40 mg/kg) is being explored in young children. Surveillance of female genital schistosomiasis FGS is increasing. Use of PZQ in pregnancy is safe and preventive chemotherapy guidelines are being revised in morbidity- and transmission-control settings. AREAS TIMELY FOR DEVELOPING RESEARCH Shifting focus of population-level control to individual-case management. Detection and prevention of FGS within general health services and integration of PZQ treatment for women and children in antenatal clinics. Feasibility studies assessing alternative and expanded access to PZQ treatment to at-risk children and mothers and pregnant women.
Collapse
Affiliation(s)
- Amaya L Bustinduy
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK
| | - J Russell Stothard
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Jennifer F Friedman
- Center for International Health Research, Rhode Island Hospital, 55 Claverick Street, Suite 101, Providence, RI 02903, USA
| |
Collapse
|
15
|
HEALTH EDUCATION AND THE CONTROL OF UROGENITAL SCHISTOSOMIASIS: ASSESSING THE IMPACT OF THE JUMA NA KICHOCHO COMIC-STRIP MEDICAL BOOKLET IN ZANZIBAR. J Biosoc Sci 2017; 48 Suppl 1:S40-55. [PMID: 27428065 DOI: 10.1017/s0021932016000122] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Endeavours to control urogenital schistosomiasis on Unguja Island (Zanzibar) have focused on school-aged children. To assess the impact of an associated health education campaign, the supervised use of the comic-strip medical booklet Juma na Kichocho by Class V pupils attending eighteen primary schools was investigated. A validated knowledge and attitudes questionnaire was completed at baseline and repeated one year later following the regular use of the booklet during the calendar year. A scoring system (ranging from 0.0 to 5.0) measured children's understandings of schistosomiasis and malaria, with the latter being a neutral comparator against specific changes for schistosomiasis. In 2006, the average score from 751 children (328 boys and 423 girls) was 2.39 for schistosomiasis and 3.03 for malaria. One year later, the score was 2.43 for schistosomiasis and 2.70 for malaria from 779 children (351 boys and 428 girls). As might be expected, knowledge and attitudes scores for schistosomiasis increased (+0.05), but not as much as originally hoped, while the score for malaria decreased (-0.33). According to a Kolmogorov-Smirnov test, neither change was statistically significant. Analysis also revealed that 75% of school children misunderstood the importance of reinfection after treatment with praziquantel. These results are disappointing. They demonstrate that it is mistaken to assume that knowledge conveyed in child-friendly booklets will necessarily be interpreted, and acted upon, in the way intended. If long-term sustained behavioural change is to be achieved, health education materials need to engage more closely with local understandings and responses to urogenital schistosomiasis. This, in turn, needs to be part of the development of a more holistic, biosocial approach to the control of schistosomiasis.
Collapse
|
16
|
Tchuem Tchuenté LA, Rollinson D, Stothard JR, Molyneux D. Moving from control to elimination of schistosomiasis in sub-Saharan Africa: time to change and adapt strategies. Infect Dis Poverty 2017; 6:42. [PMID: 28219412 PMCID: PMC5319063 DOI: 10.1186/s40249-017-0256-8] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Accepted: 02/08/2017] [Indexed: 11/17/2022] Open
Abstract
Schistosomiasis is a water borne parasitic disease of global importance and with ongoing control the disease endemic landscape is changing. In sub-Saharan Africa, for example, the landscape is becoming ever more heterogeneous as there are several species of Schistosoma that respond in different ways to ongoing preventive chemotherapy and the inter-sectoral interventions currently applied. The major focus of preventive chemotherapy is delivery of praziquantel by mass drug administration to those shown to be, or presumed to be, at-risk of infection and disease. In some countries, regional progress may be uneven but in certain locations there are very real prospects to transition from control into interruption of transmission, and ultimately elimination. To manage this transition requires reconsideration of some of the currently deployed diagnostic tools used in surveillance and downward realignment of existing prevalence thresholds to trigger mass treatment. A key challenge will be maintaining and if possible, expanding the current donation of praziquantel to currently overlooked groups, then judging when appropriate to move from mass drug administration to selective treatment. In so doing, this will ensure the health system is adapted, primed and shown to be cost-effective to respond to these changing disease dynamics as we move forward to 2020 targets and beyond.
Collapse
Affiliation(s)
- Louis-Albert Tchuem Tchuenté
- National Programme for the Control of Schistosomiasis and STH, Ministry of Public Health, Yaoundé, Cameroon. .,Centre for Schistosomiasis and Parasitology, University of Yaoundé I, Yaoundé, Cameroon.
| | - David Rollinson
- Department of Life Sciences, The Natural History Museum, London, SW7 5BD, UK
| | - J Russell Stothard
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - David Molyneux
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| |
Collapse
|
17
|
Stanton MC, Adriko M, Arinaitwe M, Howell A, Davies J, Allison G, LaCourse EJ, Muheki E, Kabatereine NB, Stothard JR. Intestinal schistosomiasis in Uganda at high altitude (>1400 m): malacological and epidemiological surveys on Mount Elgon and in Fort Portal crater lakes reveal extra preventive chemotherapy needs. Infect Dis Poverty 2017; 6:34. [PMID: 28162096 PMCID: PMC5292801 DOI: 10.1186/s40249-017-0248-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 01/19/2017] [Indexed: 01/24/2023] Open
Abstract
Background Intestinal schistosomiasis is of public health importance in Uganda but communities living above 1400 m are not targeted for control as natural transmission is thought unlikely. To assess altitudinal boundaries and at-risk populations, conjoint malacological and epidemiological surveys were undertaken on Mount Elgon (1139 m–3937 m), in Fort Portal crater lakes and in the Rwenzori Mountains (1123 m–4050 m). Methods Seventy freshwater habitats [Mount Elgon (37), Fort Portal crater lakes (23), Rwenzori Mountains (8) and Lake Albert (2)] were inspected for Biomphalaria species. Water temperature, pH and conductivity were recorded. A parasitological examination of 756 schoolchildren [Mount Elgon (300), Fort Portal crater lakes (456)] by faecal microscopy of duplicate Kato-Katz smears from two consecutive stool samples was bolstered by antigen (urine-CCA dipstick) and antibody (SEA-ELISA) diagnostic assays. Results Biomphalaria spp. was found up to 1951 m on Mount Elgon and 1567 m in the Fort Portal crater lakes. Although no snail from Mount Elgon shed cercariae, molecular analysis judged 7.1% of snails sampled at altitudes above 1400 m as having DNA of Schistosoma mansoni; in Fort Portal crater lakes three snails shed schistosome cercariae. Prevalence of intestinal schistosomiasis as measured in schoolchildren by Kato-Katz (Mount Elgon = 5.3% v. Fort Portal crater lakes = 10.7%), CCA urine-dipsticks (18.3% v. 34.4%) and SEA-ELISA (42.3% v. 63.7%) showed negative associations with increasing altitude with some evidence of infection up to 2000 m. Conclusions Contrary to expectations, these surveys clearly show that natural transmission of intestinal schistosomiasis occurs above 1400 m, possibly extending up to 2000 m. Using spatial epidemiological predictions, this now places some extra six million people at-risk, denoting an expansion of preventive chemotherapy needs in Uganda. Electronic supplementary material The online version of this article (doi:10.1186/s40249-017-0248-8) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Michelle C Stanton
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Moses Adriko
- Vector Control Division, Ministry of Health, Kampala, P.O. Box 1661, Uganda
| | - Moses Arinaitwe
- Vector Control Division, Ministry of Health, Kampala, P.O. Box 1661, Uganda
| | - Alison Howell
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Juliet Davies
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Gillian Allison
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - E James LaCourse
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Edridah Muheki
- Vector Control Division, Ministry of Health, Kampala, P.O. Box 1661, Uganda
| | - Narcis B Kabatereine
- Vector Control Division, Ministry of Health, Kampala, P.O. Box 1661, Uganda.,Schistosomiasis Control Initiative, Imperial College London, London, W2 1PG, UK
| | - J Russell Stothard
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
| |
Collapse
|
18
|
Zwang J, Olliaro P. Efficacy and safety of praziquantel 40 mg/kg in preschool-aged and school-aged children: a meta-analysis. Parasit Vectors 2017; 10:47. [PMID: 28126024 PMCID: PMC5270314 DOI: 10.1186/s13071-016-1958-7] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Accepted: 12/27/2016] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Children carry most of the schistosomiasis burden. While school-aged children are the principal target group of preventive chemotherapy with praziquantel, limited information on efficacy and safety exists for preschool-aged children. METHODS Here, we conducted a meta-analysis of clinical trials of praziquantel for treating children with any form of schistosomiasis. Efficacy was reported as cure rate (CR) and egg reduction rates (ERR); statistical corrections were applied based on methodological disparities across trials to derive the predicted geometrical mean ERR (pERRgm). Safety was reported as frequencies of adverse events. RESULTS Forty-seven comparative and non-comparative studies were identified, enrolling 15,549 children of whom 14,340 (92%) were assessed between 3 and 8 weeks post-treatment with praziquantel 40 mg/kg (the WHO-recommended treatment, n = 8,380, 56%) or comparators (n = 5,960, 44%). The median age was 10 years (range 1-19), 11% (n = 1,694) were preschool-aged. The CR and pERRgm with praziquantel 40 mg/kg were respectively: S. haematobium, 73.6% (95% CI: 63.5-81.40, 25 study arms) and 94.7% (95% CI: 92.7-96.4); S. mansoni, 76.4% (95% CI: 71.5-81.0, 34 arms) and 95.3% (95% CI: 94.2-96.2); S. mansoni/S. haematobium, 67.6% (95% CI: 54.1-80.7, 5 arms) and 93.4% (95% CI: 89.9-96.2); S. japonicum, 94.7% (95% CI: 92.2-98.0) and 98.7% (95% CI: 98.3-99.2). Mixed-effect multivariate analysis found no significant difference between preschool- and school-aged children for CR or pERRgm in S. haematobium (P = 0.309 and P = 0.490, respectively) or S. mansoni (P = 0.982 and P = 0.895) after controlling for time of assessment, formulation, intensity of infection and detection method. Praziquantel was reportedly safe at all ages, with only mild reported adverse events which cleared rapidly after treatment. CONCLUSIONS Praziquantel 40 mg/kg was effective at reducing infection intensity in all Schistosoma species without differences between preschool- and school-aged children. However, conclusions should be tempered because of the limited number of preschool-aged children enrolled, disparities in study procedures and limited information made available in publications, as well as the current imperfect test-of-cure. Also, although reportedly well-tolerated, safety was inconsistently assessed. Studies in target groups, individual-data meta-analysis and standardised methodologies are needed for more robust evidence-base.
Collapse
Affiliation(s)
| | - Piero Olliaro
- UNICEF/UNDP/World Bank/WHO Special Programme for Research & Training in Tropical Diseases (TDR), Geneva, Switzerland
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| |
Collapse
|
19
|
Barda B, Coulibaly JT, Puchkov M, Huwyler J, Hattendorf J, Keiser J. Efficacy and Safety of Moxidectin, Synriam, Synriam-Praziquantel versus Praziquantel against Schistosoma haematobium and S. mansoni Infections: A Randomized, Exploratory Phase 2 Trial. PLoS Negl Trop Dis 2016; 10:e0005008. [PMID: 27636542 PMCID: PMC5026339 DOI: 10.1371/journal.pntd.0005008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 08/28/2016] [Indexed: 12/30/2022] Open
Abstract
Background Schistosomiasis affects millions of people, yet treatment options are limited. The antimalarial Synriam (piperaquine 150 mg/arterolane 750 mg) and the anthelminthic moxidectin revealed promising antischistosomal properties in preclinical or clinical studies. Methodology We conducted two single-blind, randomized exploratory Phase 2 trials in Schistosoma mansoni and S. haematobium-infected adolescents in northern and central Côte d’Ivoire. Our primary endpoints were cure rates (CRs) and egg reduction rates (ERRs) based on geometric mean and safety. Each subject was asked to provide two stool samples (S. mansoni trial) for Kato-Katz analysis or three urine samples (S. haematobium trial) for urine filtration and one finger prick for malaria screening at baseline and follow-up. Participants were randomly assigned to either moxidectin, Synriam, Synriam plus praziquantel or praziquantel. Principal Findings 128 adolescents (age: 12–17 years) were included in each study. Against S. haematobium moxidectin and Synriam revealed low efficacy. On the other hand, Synriam plus praziquantel and praziquantel yielded CRs of 60.0% and 38.5% and ERRs of 96.0% and 93.5%, respectively. CRs observed in the treatment of S. mansoni were 13.0%, 6.7%, 27.0%, and 27.6% for moxidectin, Synriam, Synriam plus praziquantel and praziquantel, respectively. ERRs ranged from 64.9% (Synriam) to 87.5% (praziquantel). Conclusion/Significance Synriam and moxidectin show low efficacy against S. haematobium, hence an ancillary benefit is not expected when these drugs are used for treating onchocerciasis and malaria in co-endemic settings. Further studies are needed to corroborate our findings that moxidectin and Synriam show moderate ERRs against S. mansoni. Schistosomiasis is a parasitic infection that affects millions of people all over the world and it is due to schistosomes, helminths (worms) that infect the intestine and the urinary bladder. Treatment options are limited, with praziquantel being the only used drug. The antimalarial Synriam and the anthelminthic moxidectin revealed good action against this worm in previous studies. We conducted two studies in Schistosoma mansoni and S. haematobium-infected adolescents in Côte d’Ivoire. Subjects positive for the infection were allocated by chance to the four groups of treatment (moxidectin, Synriam, Synriam plus praziquantel or praziquantel); participants did not know which drug they took. Our aim was to calculate how many participants were negative after the treatment and how did the intensity of infection change before and after treatment. Each subject provided stools and urines for examination. 128 adolescents were included in each study. Moxidectin and Synriam did not work well against S. haematobium. Against S. mansoni, only a small part of the participants were negative after treatment in all treatment groups, but the intensity of infections were reduced. Further studies are needed to better understand this result.
Collapse
Affiliation(s)
- Beatrice Barda
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Jean T. Coulibaly
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Unite´ de Formation et de Recherche Biosciences, Universite´ Felix Houphouët-Boigny, Abidjan, Côte d’Ivoire
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
| | - Maxim Puchkov
- Department of Pharmaceutical Technology, University of Basel, Basel, Switzerland
| | - Jörg Huwyler
- Department of Pharmaceutical Technology, University of Basel, Basel, Switzerland
| | - Jan Hattendorf
- 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, Basel, Switzerland
- University of Basel, Basel, Switzerland
- * E-mail:
| |
Collapse
|
20
|
Comparative Assessment of Health Benefits of Praziquantel Treatment of Urogenital Schistosomiasis in Preschool and Primary School-Aged Children. BIOMED RESEARCH INTERNATIONAL 2016; 2016:9162631. [PMID: 27631011 PMCID: PMC5007301 DOI: 10.1155/2016/9162631] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 06/21/2016] [Accepted: 07/05/2016] [Indexed: 12/15/2022]
Abstract
Schistosomiasis is a major public health problem in Africa. However, it is only recently that its burden has become recognised as a significant component impacting on the health and development of preschool-aged children. A longitudinal study was conducted in Zimbabwean children to determine the effect of single praziquantel treatment on Schistosoma haematobium-related morbidity markers: microhaematuria, proteinuria, and albuminuria. Changes in these indicators were compared in 1-5 years versus 6-10 years age groups to determine if treatment outcomes differed by age. Praziquantel was efficacious at reducing infection 12 weeks after treatment: cure rate = 94.6% (95% CI: 87.9-97.7%). Infection rates remained lower at 12 months after treatment compared to baseline in both age groups. Among treated children, the odds of morbidity at 12 weeks were significantly lower compared to baseline for proteinuria: odds ratio (OR) = 0.54 (95% CI: 0.31-0.95) and albuminuria: OR = 0.05 (95% CI: 0.02-0.14). Microhaematuria significantly reduced 12 months after treatment, and the effect of treatment did not differ by age group: OR = 0.97 (95% CI: 0.50-1.87). In conclusion, praziquantel treatment has health benefits in preschool-aged children exposed to S. haematobium and its efficacy on infection and morbidity is not age-dependent.
Collapse
|
21
|
Niessen L, Stothard R. Equitable control of schistosomiasis and helminthiasis. THE LANCET. INFECTIOUS DISEASES 2016; 16:990-992. [PMID: 27286969 DOI: 10.1016/s1473-3099(16)30124-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 05/13/2016] [Indexed: 11/13/2022]
Affiliation(s)
- Louis Niessen
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK.
| | - Russell Stothard
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| |
Collapse
|
22
|
Xu J, Bergquist R, Qian YJ, Wang Q, Yu Q, Peeling R, Croft S, Guo JG, Zhou XN. China-Africa and China-Asia Collaboration on Schistosomiasis Control: A SWOT Analysis. ADVANCES IN PARASITOLOGY 2016; 92:435-66. [PMID: 27137455 DOI: 10.1016/bs.apar.2016.02.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Schistosomiasis, a disease caused by a trematode, parasitic worm, is a worldwide public health problem. In spite of great progress with regard to morbidity control, even elimination of this infection in recent decades, there are still challenges to overcome in sub-Saharan Africa and endemic areas in Southeast Asia. Regarded as one of the most successful countries with respect to schistosomiasis control, The People's Republic of China has accumulated considerable experience and learnt important lessons in various local settings that could benefit schistosomiasis control in other endemic countries. Based on an analysis of conceived strengths, weaknesses, opportunities and threats (SWOT) of potential collaborative activities with regard to schistosomiasis in Africa and Asia, this article addresses the importance of collaborative efforts and explores the priorities that would be expected to facilitate the transfer of Chinese experience to low- and middle-income countries in Africa and Asia.
Collapse
Affiliation(s)
- J Xu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, The People's Republic of China; Key Laboratory of Parasite & Vector Biology, Ministry of Public Health, Shanghai, The People's Republic of China; WHO Collaborating Center for Tropical Diseases, Shanghai, The People's Republic of China
| | - R Bergquist
- Geospatial Health, University of Naples Federico II, Naples, Italy
| | - Y-J Qian
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, The People's Republic of China; Key Laboratory of Parasite & Vector Biology, Ministry of Public Health, Shanghai, The People's Republic of China; WHO Collaborating Center for Tropical Diseases, Shanghai, The People's Republic of China
| | - Q Wang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, The People's Republic of China; Key Laboratory of Parasite & Vector Biology, Ministry of Public Health, Shanghai, The People's Republic of China; WHO Collaborating Center for Tropical Diseases, Shanghai, The People's Republic of China
| | - Q Yu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, The People's Republic of China; Key Laboratory of Parasite & Vector Biology, Ministry of Public Health, Shanghai, The People's Republic of China; WHO Collaborating Center for Tropical Diseases, Shanghai, The People's Republic of China
| | - R Peeling
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - S Croft
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - J-G Guo
- World Health Organization, Geneva, Switzerland
| | - X-N Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, The People's Republic of China; Key Laboratory of Parasite & Vector Biology, Ministry of Public Health, Shanghai, The People's Republic of China; WHO Collaborating Center for Tropical Diseases, Shanghai, The People's Republic of China
| |
Collapse
|
23
|
Epidemiological Interactions between Urogenital and Intestinal Human Schistosomiasis in the Context of Praziquantel Treatment across Three West African Countries. PLoS Negl Trop Dis 2015; 9:e0004019. [PMID: 26469347 PMCID: PMC4607489 DOI: 10.1371/journal.pntd.0004019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 07/30/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND In many parts of sub-Saharan Africa, urogenital and intestinal schistosomiasis co-occur, and mixed species infections containing both Schistosoma haematobium and S. mansoni can be common. During co-infection, interactions between these two species are possible, yet the extent to which such interactions influence disease dynamics or the outcome of control efforts remains poorly understood. METHODOLOGY/PRINCIPAL FINDINGS Here we analyse epidemiological data from three West African countries co-endemic for urogenital and intestinal schistosomiasis (Senegal, Niger and Mali) to test whether the impact of praziquantel (PZQ) treatment, subsequent levels of re-infection or long-term infection dynamics are altered by co-infection. In all countries, positive associations between the two species prevailed at baseline: infection by one species tended to predict infection intensity for the other, with the strength of association varying across sites. Encouragingly, we found little evidence that co-infection influenced PZQ efficacy: species-specific egg reduction rates (ERR) and cure rates (CR) did not differ significantly with co-infection, and variation in treatment success was largely geographical. In Senegal, despite positive associations at baseline, children with S. mansoni co-infection at the time of treatment were less intensely re-infected by S. haematobium than those with single infections, suggesting competition between the species may occur post-treatment. Furthermore, the proportion of schistosome infections attributable to S. mansoni increased over time in all three countries examined. CONCLUSIONS/SIGNIFICANCE These findings suggest that while co-infection between urinary and intestinal schistosomes may not directly affect PZQ treatment efficacy, competitive interspecific interactions may influence epidemiological patterns of re-infection post-treatment. While re-infection patterns differed most strongly according to geographic location, interspecific interactions also seem to play a role, and could cause the community composition in mixed species settings to shift as disease control efforts intensify, a situation with implications for future disease management in this multi-species system.
Collapse
|
24
|
Olliaro PL, Vaillant M, Diawara A, Coulibaly JT, Garba A, Keiser J, King CH, Knopp S, Landouré A, N’Goran EK, Raso G, Scherrer AU, Sousa-Figueiredo JC, Stete K, Zhou XN, Utzinger J. Toward Measuring Schistosoma Response to Praziquantel Treatment with Appropriate Descriptors of Egg Excretion. PLoS Negl Trop Dis 2015; 9:e0003821. [PMID: 26086551 PMCID: PMC4473103 DOI: 10.1371/journal.pntd.0003821] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Accepted: 05/10/2015] [Indexed: 01/05/2023] Open
Abstract
Background The control of schistosomiasis emphasizes preventive chemotherapy with praziquantel, which aims at decreasing infection intensity and thus morbidity in individuals, as well as transmission in communities. Standardizing methods to assess treatment efficacy is important to compare trial outcomes across settings, and to monitor program effectiveness consistently. We compared customary methods and looked at possible complementary approaches in order to derive suggestions for standardizing outcome measures. Methodology/Principal Findings We analyzed data from 24 studies conducted at African, Asian, and Latin American sites, enrolling overall 4,740 individuals infected with Schistosoma mansoni, S. haematobium, or S. japonicum, and treated with praziquantel at doses of 40–80 mg/kg. We found that group-based arithmetic and geometric means can be used interchangeably to express egg reduction rates (ERR) only if treatment efficacy is high (>95%). For lower levels of efficacy, ERR estimates are higher with geometric than arithmetic means. Using the distribution of individual responses in egg excretion, 6.3%, 1.7% and 4.3% of the subjects treated for S. haematobium, S. japonicum and S. mansoni infection, respectively, had no reduction in their egg counts (ERR = 0). The 5th, 10th, and 25th centiles of the subjects treated for S. haematobium had individual ERRs of 0%, 49.3%, and 96.5%; the corresponding values for S. japonicum were 75%, 99%, and 99%; and for S. mansoni 18.2%, 65.3%, and 99.8%. Using a single rather than quadruplicate Kato-Katz thick smear excluded 19% of S. mansoni-infected individuals. Whilst the effect on estimating ERR was negligible by individual studies, ERR estimates by arithmetic means were 8% lower with a single measurement. Conclusions/Significance Arithmetic mean calculations of Schistosoma ERR are more sensitive and therefore more appropriate to monitor drug performance than geometric means. However, neither are satisfactory to identify poor responders. Group-based response estimated by arithmetic mean and the distribution of individual ERRs are correlated, but the latter appears to be more apt to detect the presence and to quantitate the magnitude of suboptimal responses to praziquantel. To identify whether a person is infected with parasitic worms, stool or urine samples are examined for worm eggs. The drug praziquantel is used against the parasitic disease schistosomiasis. However, there is no definitive agreement as to how the efficacy of praziquantel is best expressed. We put together a database from various studies of the efficacy of praziquantel against schistosomiasis. Efficacy was measured using customary methods: cure rate (CR: percentage of people with eggs in their stool/urine before treatment who became egg-negative after treatment); and egg reduction rate (ERR; percentage reduction in the number of eggs in the stool/urine after treatment, where the mean number of eggs from all people treated is calculated using either geometric or arithmetic means). We found that arithmetic and geometric means can be used interchangeably only if treatment efficacy is very high; arithmetic means are more sensitive to capture drops in efficacy expressed by ERR. A valid complement for drug efficacy monitoring is to study the distribution of individual responses in egg excretion that allows identifying in a single measure both those who had an adequate response to treatment and those who respond less well; e.g., the 5% of the patients with the lowest ERRs.
Collapse
Affiliation(s)
- Piero L. Olliaro
- UNICEF/UNDP/World Bank/WHO Special Programme on Research and Training in Tropical Diseases (TDR), World Health Organization, Geneva, Switzerland
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- * E-mail:
| | - Michel Vaillant
- Centre of Competence for Methodology and Statistics (CCMS), Luxembourg Institute of Health (LIH), Strassen, Luxembourg
| | - Aïssatou Diawara
- Department of Biology, Division of Science and Mathematics, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - 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
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Amadou Garba
- University of Basel, Basel, Switzerland
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- Réseau International Schistosomoses, Environnement, Aménagement et Lutte (RISEAL-Niger), Niamey, Niger
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Charles H. King
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio, United States of America
- Schistosomiasis Consortium for Operational Research and Evaluation, University of Georgia, Athens, Georgia, United States of America
| | - Stefanie Knopp
- University of Basel, Basel, Switzerland
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Aly Landouré
- Institut National de Recherche en Santé Publique, Bamako, Mali
| | - Eliézer K. N’Goran
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d’Ivoire
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
| | - Giovanna Raso
- University of Basel, Basel, Switzerland
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Alexandra U. Scherrer
- Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - José Carlos Sousa-Figueiredo
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Katarina Stete
- University of Basel, Basel, Switzerland
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- Center for Infectious Diseases and Travel Medicine, Department of Medicine, University Hospital Freiburg, Freiburg im Breisgau, Germany
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, People’s Republic of China
- Key Laboratory of Parasite and Vector Biology of the Chinese Ministry of Health, WHO Collaborating Center for Malaria, Schistosomiasis and Filariasis, Shanghai, People’s Republic of China
| | - Jürg Utzinger
- University of Basel, Basel, Switzerland
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
| |
Collapse
|
25
|
Nalugwa A, Nuwaha F, Tukahebwa EM, Olsen A. Single Versus Double Dose Praziquantel Comparison on Efficacy and Schistosoma mansoni Re-Infection in Preschool-Age Children in Uganda: A Randomized Controlled Trial. PLoS Negl Trop Dis 2015; 9:e0003796. [PMID: 26011733 PMCID: PMC4444284 DOI: 10.1371/journal.pntd.0003796] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 04/28/2015] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Schistosoma mansoni infection is proven to be a major health problem of preschool-age children in sub-Saharan Africa, yet this age category is not part of the schistosomiasis control program. The objective of this study was to compare the impact of single and double dose praziquantel (PZQ) treatment on cure rates (CRs), egg reduction rates (ERRs) and re-infection rates 8 months later, in children aged 1-5 years living along Lake Victoria, Uganda. METHODOLOGY/PRINCIPAL FINDINGS Infected children (n= 1017) were randomized to receive either a single or double dose of PZQ. Initially all children were treated with a single standard oral dose 40 mg/kg body weight of PZQ. Two weeks later a second dose was administered to children in the double dose treatment arm. Side effects were monitored at 30 minutes to 24 hours after each treatment. Efficacy in terms of CRs and ERRs for the two treatments was assessed and compared 1 month after the second treatment. Re-infection with S. mansoni was assessed in the same children 8 months following the second treatment. CRs were non-significantly higher in children treated with two 40 mg/kg PZQ doses (85.5%; 290/339) compared to a single dose (83.2%; 297/357). ERRs were significantly higher in the double dose with 99.3 (95%CI: 99.2-99.5) compared with 98.9 (95%CI: 98.7-99.1) using a single dose, (P = 0.01). Side effects occurred more frequently during the first round of drug administration and were mild and short-lived; these included vomiting, abdominal pain and bloody diarrhea. Overall re-infection rate 8 months post treatment was 44.5%. CONCLUSIONS PZQ is efficacious and relatively safe to use in preschool-age children but there is still an unmet need to improve its formulation to suit small children. Two PZQ doses lead to significant reduction in egg excretion compared to a single dose. Re-infection rates with S. mansoni 8 months post treatment is the same among children irrespective of the treatment regimen.
Collapse
Affiliation(s)
- Allen Nalugwa
- Child Health and Development Centre, Makerere University, Kampala, Uganda
| | - Fred Nuwaha
- Disease Control and Prevention, Makerere University, Kampala, Uganda
| | | | - Annette Olsen
- Department of Veterinary Disease Biology, University of Copenhagen, Frederiksberg, Denmark
| |
Collapse
|
26
|
Abstract
Schistosomiasis is a chronic disease that affects ∼200 million people. The extended health impact of the disease has been estimated to exceed that of malaria or tuberculosis and to be nearer to that of HIV/AIDS. Within endemic areas, children carry the heaviest burden of infection. Infection/disease is controlled by the treatment of infected subjects with the anthelminthic drug praziquantel. Global initiatives from Partners of Parasite Control, including the World Health Organization (WHO), advocate regular school-based deworming strategies to reduce the development of severe morbidity, promote school-child health and development, and improve the cognitive potential of children. Until recently, preschool-aged children were excluded from schistosome treatment, creating a health inequity in affected populations. In 2010, the WHO updated their recommendations for the treatment of schistosomiasis in preschool-aged children (ie, children aged ≤5 years). This change was the culmination of several decades of research on schistosome epidemiology, immunology, and pathology in this age group. The recent development of a pediatric formulation of praziquantel (soon to enter clinical trials) should advance control efforts in preschool-aged children, with the goal of including these children in preventative chemotherapy (as currently occurs for soil-transmitted helminths). This review discusses the research work supporting the WHO revision of recommendations for treating preschool-aged children, as well as current barriers and knowledge gaps in pediatric schistosomiasis control.
Collapse
Affiliation(s)
- Francisca Mutapi
- Institute of Immunology and Infection Research, Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| |
Collapse
|
27
|
Inobaya MT, Olveda RM, Chau TNP, Olveda DU, Ross AGP. Prevention and control of schistosomiasis: a current perspective. Res Rep Trop Med 2014; 2014:65-75. [PMID: 25400499 PMCID: PMC4231879 DOI: 10.2147/rrtm.s44274] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 04/23/2014] [Indexed: 11/23/2022] Open
Abstract
Schistosomiasis is a neglected tropical disease that ranks second only to malaria in terms of human suffering in the tropics and subtropics. Five species are known to infect man and there are currently over 240 million people infected worldwide. The cornerstone of control to date has been mass drug administration with 40 mg/kg of praziquantel but there are problems with this approach. Human and bovine vaccines are in various stages of development. Integrated control, targeting the life cycle, is the only approach that will lead to sustainability and future elimination.
Collapse
Affiliation(s)
- Marianette T Inobaya
- Department of Health, Research Institute for Tropical Medicine, Muntinlupa City, Philippines
| | - Remigio M Olveda
- Department of Health, Research Institute for Tropical Medicine, Muntinlupa City, Philippines
| | - Thao NP Chau
- Discipline of Public Health, Flinders University, Adelaide, Australia
| | - David U Olveda
- Griffith Health Institute, School of Medical Sciences, Gold Coast Campus, Griffith University, Southport, Australia
| | - Allen GP Ross
- Griffith Health Institute, School of Medical Sciences, Gold Coast Campus, Griffith University, Southport, Australia
| |
Collapse
|
28
|
Diagnostics for schistosomiasis in Africa and Arabia: a review of present options in control and future needs for elimination. Parasitology 2014; 141:1947-61. [PMID: 25158604 DOI: 10.1017/s0031182014001152] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Within the World Health Organization 2012-2020 roadmap for control and elimination of schistosomiasis, the scale-up of mass drug administration with praziquantel is set to change the epidemiological landscape across Africa and Arabia. Central in measuring progress is renewed emphasis upon diagnostics which operate at individual, community and environmental levels by assessing reductions in disease, infections and parasite transmission. However, a fundamental tension is revealed between levels for present diagnostic tools, and methods applied in control settings are not necessarily adequate for application in elimination scenarios. Indeed navigating the transition from control to elimination needs careful consideration and planning. In the present context of control, we review current options for diagnosis of schistosomiasis at different levels, highlighting several strengths and weaknesses therein. Future challenges in elimination are raised and we propose that more cost-effective diagnostics and clinical staging algorithms are needed. Using the Kingdom of Saudi Arabia as a contemporary example, embedding new diagnostic methods within the primary care health system is discussed with reference to both urogenital and intestinal schistosomiasis.
Collapse
|
29
|
Keiser J, Silué KD, Adiossan LK, N'Guessan NA, Monsan N, Utzinger J, N'Goran EK. Praziquantel, mefloquine-praziquantel, and mefloquine-artesunate-praziquantel against Schistosoma haematobium: a randomized, exploratory, open-label trial. PLoS Negl Trop Dis 2014; 8:e2975. [PMID: 25033291 PMCID: PMC4102459 DOI: 10.1371/journal.pntd.0002975] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 05/11/2014] [Indexed: 11/28/2022] Open
Abstract
Background Treatment and morbidity control of schistosomiasis relies on a single drug, praziquantel. Hence, there is a pressing need to develop additional therapeutics against schistosomiasis. The antimalarial drug mefloquine shows antischistosomal activity in animal models and clinical trials, which calls for further investigations. Methodology We comparatively assessed the efficacy and tolerability of the following treatments against Schistosoma haematobium in school-aged children in Côte d'Ivoire: (i) praziquantel (40 mg/kg; standard treatment); (ii) mefloquine (25 mg/kg) combined with praziquantel (40 mg/kg); and (iii) mefloquine-artesunate (3× (100 mg artesunate +250 mg mefloquine)) combined with praziquantel (40 mg/kg) (treatments administered on subsequent days). Two urine samples were collected before, and on days 21–22 and 78–79 after the first dosing. Principal Findings Sixty-one children were present on all examination time points and had complete datasets. No difference in efficacy was observed between the three treatment groups on either follow-up. On the 21–22 day posttreatment follow-up, based on available case analysis, cure rates of 33% (95% confidence interval (CI) 11–55%), 29% (95% CI 8–50%), and 26% (95% CI 5–48%) were observed for praziquantel, mefloquine-artesunate-praziquantel, and mefloquine-praziquantel, respectively. The corresponding egg reduction rates were 94% and above. On the second follow-up, observed cure rates ranged from 19% (praziquantel) to 33% (mefloquine-artesunate-praziquantel), and egg reduction rates were above 90%. Praziquantel monotherapy was the best tolerated treatment. In the mefloquine-artesunate-praziquantel group, adverse events were reported by 91% of the participants, and in the mefloquine-praziquantel group, 95% experienced adverse events. With the exception of abdominal pain at moderate severity, adverse events were mild. Conclusions/Significance The addition of mefloquine or mefloquine-artesunate does not increase the efficacy of praziquantel against chronic S. haematobium infection. Additional studies are necessary to elucidate the effect of the combinations against acute schistosomiasis. The antimalarial drug mefloquine shows activity against blood flukes that cause the disease schistosomiasis. In animal studies it has been found that a mefloquine-praziquantel combination kills blood flukes more effectively than praziquantel alone. Combining praziquantel with another drug might therefore increase efficacy, broaden the spectrum of activity, and delay the development of drug resistance. We designed a study in Ivorian school children to assess the efficacy and tolerability of mefloquine and mefloquine-artesunate combined with praziquantel against the blood fluke Schistosoma haematobium. The administration of the antimalarials and praziquantel was spaced by a day. Treatment outcomes were assessed twice, on days 21–22 and 78–79 after the first dosing to determine the effect against adult and juvenile S. haematobium, respectively. At both follow-ups, high reduction in the intensity of infection (egg reduction rates of 94–96%), but low cure rates (26–33%) were observed in the three treatment groups. Adverse events were common, particularly in children treated with mefloquine-praziquantel and mefloquine-artesunate-praziquantel. Our study suggests that the addition of mefloquine and mefloquine-artesunate to praziquantel has no benefit in the treatment of chronic S. haematobium infection. However, further investigations are warranted to evaluate the effect of combination therapy on juvenile flukes and longer-term morbidity profiles.
Collapse
Affiliation(s)
- Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- * E-mail:
| | - Kigbafori D. Silué
- 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
| | | | - Nicaise A. N'Guessan
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire
| | - N'Chou Monsan
- Institut National de la Santé Publique, Abidjan, Côte d'Ivoire
| | - Jürg Utzinger
- University of Basel, Basel, Switzerland
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Eliézer K. N'Goran
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire
- Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire
| |
Collapse
|
30
|
Poole H, Terlouw DJ, Naunje A, Mzembe K, Stanton M, Betson M, Lalloo DG, Stothard JR. Schistosomiasis in pre-school-age children and their mothers in Chikhwawa district, Malawi with notes on characterization of schistosomes and snails. Parasit Vectors 2014; 7:153. [PMID: 24690282 PMCID: PMC4230191 DOI: 10.1186/1756-3305-7-153] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 03/17/2014] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND To complement ongoing schistosomiasis control within national control programmes (NCPs) that administer praziquantel to school-age children, assessing the risk and extent of schistosomiasis in pre-school-age children (PSAC) is important. METHODS In June 2012, schistosomiasis in Chikhwawa district, Malawi was assessed across 12 villages examining pre-school-age children (PSAC) and their mothers by serological and parasitological diagnosis, as supplemented with urine-antigen and questionnaire-interview methods. Urinary tract morbidity was inferred by haematuria and albuminuria assays. RESULTS In total, 49.5% (CI₉₅ 42.6-56.4) of 208 PSAC and 94.5% (CI₉₅ 90.9-98.1) of 165 mothers were seropositive for schistosomiasis, in 2 villages seroprevalence exceeded 75% in PSAC. Egg-patent urogenital and intestinal schistosomiasis was observed; 17.7% (CI₉₅ 12.4-23.2) of PSAC and 45.1% (CI₉₅ 37.4-52.8) of mothers having active schistosomiasis by parasitological and urine-antigen testing combined. PSAC often had extensive daily water contact and many (~25%) had haematuria and albuminuria. As eggs with an atypical morphology of Schistosoma haematobium were observed, a general selection of schistosome eggs was characterized by DNA barcoding, finding Group I S. haematobium and Group IV and V S. mansoni. Malacological surveys encountered several populations of Bulinus globosus but failed to find Biomphalaria. CONCLUSIONS Both PSAC and their mothers appear to be at significant risk of schistosomiasis and should be considered for treatment within the NCP of Malawi.
Collapse
Affiliation(s)
- Helen Poole
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Dianne J Terlouw
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, PO Box 30096, Chichiri, Blantyre 3, Malawi
| | - Andrew Naunje
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, PO Box 30096, Chichiri, Blantyre 3, Malawi
| | - Kondwani Mzembe
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, PO Box 30096, Chichiri, Blantyre 3, Malawi
| | - Michelle Stanton
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Martha Betson
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - David G Lalloo
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - J Russell Stothard
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| |
Collapse
|
31
|
Preventive chemotherapy for schistosomiasis and soil-transmitted helminthiasis by cotreatment with praziquantel and albendazole. ACTA ACUST UNITED AC 2014. [DOI: 10.4155/cli.13.128] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
32
|
Olliaro P, Delgado-Romero P, Keiser J. The little we know about the pharmacokinetics and pharmacodynamics of praziquantel (racemate and R-enantiomer). J Antimicrob Chemother 2014; 69:863-70. [PMID: 24390933 DOI: 10.1093/jac/dkt491] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Praziquantel has been the mainstay of schistosomiasis control since 1984 and widely distributed since 2006 through 'preventive chemotherapy' programmes to school-aged children or at-risk populations. In addition, preschool-aged children are now recognized as a vulnerable population and a group for targeted treatment, but they may be difficult to dose correctly with the available product--a racemate, based on the biologically active enantiomer (R-praziquantel) and the inactive distomer (S-praziquantel), which contributes the bitter taste and doubles the size of the tablets. Hence, a paediatric formulation is required, possibly enantiomerically pure. Developing such a product and extending its use to younger children should be pharmacologically guided, but limited data exist on pharmacokinetics and pharmacokinetic/pharmacodynamic correlations for praziquantel. This article presents available data on the chemistry, pharmacokinetics and pharmacodynamics of praziquantel, as well as R-praziquantel, and points to gaps in our knowledge.
Collapse
Affiliation(s)
- Piero Olliaro
- UNICEF/UNDP/World Bank/WHO Special Programme on Research & Training in Tropical Diseases (TDR), World Health Organization, 20 Avenue Appia, CH-1211, Geneva 27, Switzerland
| | | | | |
Collapse
|
33
|
Knopp S, Becker SL, Ingram KJ, Keiser J, Utzinger J. Diagnosis and treatment of schistosomiasis in children in the era of intensified control. Expert Rev Anti Infect Ther 2013; 11:1237-58. [PMID: 24127662 DOI: 10.1586/14787210.2013.844066] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In the current era of intensified and integrated control against schistosomiasis and other neglected tropical diseases, there is a need to carefully rethink and take into consideration disease-specific issues pertaining to the diagnosis, prevention, control and local elimination. Here, we present a comprehensive overview about schistosomiasis including recent trends in the number of people treated with praziquantel and the latest developments in diagnosis and control. Particular emphasis is placed on children. Identified research needs are offered for consideration; namely, expanding our knowledge about schistosomiasis in preschool-aged children, assessing and quantifying the impact of schistosomiasis on infectious and noncommunicable diseases, developing new antischistosomal drugs and child-friendly formulations, designing and implementing setting-specific control packages and developing highly sensitive, but simple diagnostic tools that are able to detect very light infections in young children and in people living in areas targeted for schistosomiasis elimination.
Collapse
Affiliation(s)
- Stefanie Knopp
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, P.O. Box, CH-4002, Basel, Switzerland
| | | | | | | | | |
Collapse
|