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Zacharia A, Makene T, Haule S, Lukumay G, Omary H, Shabani M, Ngasala B. Urogenital schistosomiasis among adult male population in an endemic area of southern Tanzania: a descriptive cross-sectional study. BMJ Open 2024; 14:e079690. [PMID: 38889945 PMCID: PMC11191765 DOI: 10.1136/bmjopen-2023-079690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 04/26/2024] [Indexed: 06/20/2024] Open
Abstract
BACKGROUND Urogenital schistosomiasis (UGS) caused by Schistosoma haematobium is endemic in Southern Tanzania. The disease has significant implications for both socioeconomic and public health. Because infections with S. haematobium usually peak in childhood, the majority of studies have concentrated on school-aged children leaving other groups such as males which might be continuous reservoir of infection transmission. However, despite its chronic consequences in the male population, the disease has received insufficient attention, especially in sub-Saharan Africa. This study was conducted to describe the previous and current schistosomiasis status among adult males living in high-endemic areas of southern Tanzania DESIGN, SETTING AND PARTICIPANTS: A descriptive cross-sectional study was employed to gather data on the prevalence of UGS among adult men residing at schistosomiasis endemic in the Mtama District Council. Quantitative methods of data collection which included questionnaire and laboratory procedures were used. RESULTS Out of 245 participants, macrohaematuria and microhaematuria were found in 12 (4.9%, 95% CI 2.4% to 7.8%) and 66 (26.9%, 95% CI 21.6% to 32.7%) participants, respectively. S. haematobium ova were recovered from the urine samples of 54 (22.0%, 95% CI 16.7% to 27.3%) participants. The median intensity of infection was 20 eggs per 10 mL of urine ranging from 1 to 201 eggs per 10 mL of urine (IQR) 60.5). Out of 245 participants 33 (13.5% 95% CI 9.0% to 17.6%) had light intensity of infection and 21 (38.9%, 95% CI; 25.0% to 52.5%) had heavy intensity of infection. Overall, the prevalence of heavy intensity of infection was 8.6% (95% CI 4.9% to 12.6%). The prevalence and intensity of UGS varied significantly by age, marital status and village of residence. CONCLUSION This study sheds light on the prevalence of UGS among adult males in endemic areas of southern Tanzania. The results highlight the urgent need for comprehensive intervention strategies to address the burden of the disease.
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Affiliation(s)
- Abdallah Zacharia
- Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Dar es Salaam, Tanzania, United Republic of
| | - Twilumba Makene
- Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Dar es Salaam, Tanzania, United Republic of
| | - Stanley Haule
- Pathology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Dar es Salaam, Tanzania, United Republic of
| | - Gift Lukumay
- Community Health Nursing, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania, United Republic of
| | - Huda Omary
- Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania, United Republic of
| | - Monica Shabani
- Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Dar es Salaam, Tanzania, United Republic of
| | - Billy Ngasala
- Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Dar es Salaam, Tanzania, United Republic of
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Perera DJ, Koger-Pease C, Paulini K, Daoudi M, Ndao M. Beyond schistosomiasis: unraveling co-infections and altered immunity. Clin Microbiol Rev 2024; 37:e0009823. [PMID: 38319102 PMCID: PMC10938899 DOI: 10.1128/cmr.00098-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024] Open
Abstract
Schistosomiasis is a neglected tropical disease caused by the helminth Schistosoma spp. and has the second highest global impact of all parasites. Schistosoma are transmitted through contact with contaminated fresh water predominantly in Africa, Asia, the Middle East, and South America. Due to the widespread prevalence of Schistosoma, co-infection with other infectious agents is common but often poorly described. Herein, we review recent literature describing the impact of Schistosoma co-infection between species and Schistosoma co-infection with blood-borne protozoa, soil-transmitted helminths, various intestinal protozoa, Mycobacterium, Salmonella, various urinary tract infection-causing agents, and viral pathogens. In each case, disease severity and, of particular interest, the immune landscape, are altered as a consequence of co-infection. Understanding the impact of schistosomiasis co-infections will be important when considering treatment strategies and vaccine development moving forward.
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Affiliation(s)
- Dilhan J. Perera
- Division of Experimental Medicine, McGill University, Montreal, Canada
- Infectious Diseases and Immunity in Global Health Program, Research Institute of the McGill University Health Centre, Montreal, Canada
| | - Cal Koger-Pease
- Division of Experimental Medicine, McGill University, Montreal, Canada
- Infectious Diseases and Immunity in Global Health Program, Research Institute of the McGill University Health Centre, Montreal, Canada
| | - Kayla Paulini
- Department of Microbiology and Immunology, McGill University, Montreal, Canada
| | - Mohamed Daoudi
- Infectious Diseases and Immunity in Global Health Program, Research Institute of the McGill University Health Centre, Montreal, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, Canada
| | - Momar Ndao
- Division of Experimental Medicine, McGill University, Montreal, Canada
- Infectious Diseases and Immunity in Global Health Program, Research Institute of the McGill University Health Centre, Montreal, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, Canada
- National Reference Centre for Parasitology, Research Institute of the McGill University Health Centre, Montreal, Canada
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3
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Sánchez-Marqués R, Bocanegra C, Salvador F, Nindia A, Pintar Z, Martínez-Campreciós J, Aixut S, Mossalilo P, Sulleiro E, Espiau M, Mas-Coma S, Bargues MD, Molina I. Prevalence and morbidity of urogenital schistosomiasis among pre-school age children in Cubal, Angola. PLoS Negl Trop Dis 2023; 17:e0011751. [PMID: 37939154 PMCID: PMC10659159 DOI: 10.1371/journal.pntd.0011751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Revised: 11/20/2023] [Accepted: 10/25/2023] [Indexed: 11/10/2023] Open
Abstract
BACKGROUND Schistosomiasis is one of the most important neglected tropical diseases, with a great impact on public health and more than 200,000 deaths annually. Schistosoma haematobium causes urinary tract (UT) morbidity. Since schistosomiasis morbidity control programs focus on children older than 5 years, pre-school age children (PSAC) morbidity is not well known. METHODS We conducted a cross-sectional study in Cubal (Angola) among 245 PSAC with the objective of evaluating the prevalence of S. haematobium infection, the intensity of infection, and associated morbidity. For this purpose, urine filtration test followed by microscopic visualization and ultrasound examinations were performed. RESULTS The estimated overall prevalence of urogenital schistosomiasis was 30.2% (CI 95%; 24.5-35.9), with 20.3% (CI 95%; 15.3-25.3) of the samples analysed showing a high intensity of infection. A total of 54.5% (CI 95%; 47.6-61.8) of infected children presented UT lesions, showing a significant association between schistosomiasis infection and UT morbidity (p-value < 0.001). Bladder wall thickening was the most common lesion, being present in 100% of abnormal ultrasounds. We found that anaemia and severe malnutrition were not significantly associated with the development of UT lesions. CONCLUSIONS S. haematobium infection in PSAC causes great UT detectable morbidities. Therefore, there is an evident need of including them in mass drug administration (MDA) campaigns and consequently the development of an adapted praziquantel treatment dosage for children under 2 years of age.
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Affiliation(s)
- Raquel Sánchez-Marqués
- Departamento de Parasitología, Facultad de Farmacia, Universidad de Valencia, Valencia, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Cristina Bocanegra
- Tropical Medicine Unit Vall d’Hebron-Drassanes, Infectious Diseases Department, Vall d’Hebron University Hospital, PROSICS Barcelona, Barcelona, Spain
| | - Fernando Salvador
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
- Tropical Medicine Unit Vall d’Hebron-Drassanes, Infectious Diseases Department, Vall d’Hebron University Hospital, PROSICS Barcelona, Barcelona, Spain
| | | | | | - Joan Martínez-Campreciós
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
- Hospital Nossa Senhora da Paz, Cubal, Angola
| | - Sandra Aixut
- Department of Infectious Diseases, Vall Hebron Institut de Recerca (VHIR), Barcelona, Spain
| | | | - Elena Sulleiro
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
- Microbiology Department, Vall d’Hebron University Hospital, PROSICS Barcelona, Barcelona, Spain
| | - María Espiau
- Pediatric Infectious Diseases and Immunodeficiencies Unit, Department of Pediatrics, Vall d’Hebron University Hospital, PROSICS Barcelona, Barcelona, Spain
| | - Santiago Mas-Coma
- Departamento de Parasitología, Facultad de Farmacia, Universidad de Valencia, Valencia, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Ma. Dolores Bargues
- Departamento de Parasitología, Facultad de Farmacia, Universidad de Valencia, Valencia, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Israel Molina
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
- Tropical Medicine Unit Vall d’Hebron-Drassanes, Infectious Diseases Department, Vall d’Hebron University Hospital, PROSICS Barcelona, Barcelona, Spain
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Petukhova VZ, Aboagye SY, Ardini M, Lullo RP, Fata F, Byrne ME, Gabriele F, Martin LM, Harding LNM, Gone V, Dangi B, Lantvit DD, Nikolic D, Ippoliti R, Effantin G, Ling WL, Johnson JJ, Thatcher GRJ, Angelucci F, Williams DL, Petukhov PA. Non-covalent inhibitors of thioredoxin glutathione reductase with schistosomicidal activity in vivo. Nat Commun 2023; 14:3737. [PMID: 37349300 PMCID: PMC10287695 DOI: 10.1038/s41467-023-39444-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 06/12/2023] [Indexed: 06/24/2023] Open
Abstract
Only praziquantel is available for treating schistosomiasis, a disease affecting more than 200 million people. Praziquantel-resistant worms have been selected for in the lab and low cure rates from mass drug administration programs suggest that resistance is evolving in the field. Thioredoxin glutathione reductase (TGR) is essential for schistosome survival and a validated drug target. TGR inhibitors identified to date are irreversible and/or covalent inhibitors with unacceptable off-target effects. In this work, we identify noncovalent TGR inhibitors with efficacy against schistosome infections in mice, meeting the criteria for lead progression indicated by WHO. Comparisons with previous in vivo studies with praziquantel suggests that these inhibitors outperform the drug of choice for schistosomiasis against juvenile worms.
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Grants
- R33 AI127635 NIAID NIH HHS
- Division of Intramural Research, National Institute of Allergy and Infectious Diseases (Division of Intramural Research of the NIAID)
- Oncomelania hupensis subsp. hupensis, Chinese strain, infected with S. japonicum, Chinese strain, and Biomphalaria glabrata, strain NMRI, infected with S. mansoni, strain NMRI, were provided by the NIAID Schistosomiasis Resource Center for distribution through BEI Resources, NIAID, NIH. We are grateful to Dr. Guy Schoehn (Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, Grenoble, France), Prof. Beatrice Vallone (Sapienza University of Rome, Italy) and Dr. Linda C. Montemiglio (IBPM, National Research Council, Italy) for helpful discussions of the cryo-EM studies. We acknowledge the Elettra-Sincrotrone Trieste (Italy) for support in X-ray data collections and the European Synchrotron Radiation Facility for provision of microscope time on CM01. The study was funded in part by US NIH/NIAID R33AI127635 to F.A., P.A.P., G.R.T. and D.L.W. This work benefited from access to Research Resources Centre and UICentre at University of Illinois at Chicago and used the platforms of the Grenoble Instruct-ERIC center (ISBG; UAR 3518 CNRS-CEA-UGA-EMBL) within the Grenoble Partnership for Structural Biology (PSB), supported by FRISBI (ANR-10-INBS-0005-02) and GRAL, financed within the University Grenoble Alpes graduate school (Ecoles Universitaires de Recherche) CBH-EUR-GS (ANR-17-EURE-0003). The IBS Electron Microscope facility is supported by the Auvergne Rhône-Alpes Region, the Fonds Feder, the Fondation pour la Recherche Médicale and GIS-IBiSA. The IBS acknowledges integration into the Interdisciplinary Research Institute of Grenoble (IRIG, CEA). M.A. has been supported by MIUR - Ministero dell'Istruzione Ministero dell'Università e della Ricerca (Ministry of Education, University and Research) under the national project FSE/FESR - PON Ricerca e Innovazione 2014-2020 (N° AIM1887574, CUP: E18H19000350007). We acknowledge OpenEye/Cadence for providing us with an academic license for the software used in these studies.
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Affiliation(s)
- Valentina Z Petukhova
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Sammy Y Aboagye
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL, USA
| | - Matteo Ardini
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Rachel P Lullo
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL, USA
| | - Francesca Fata
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Margaret E Byrne
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL, USA
| | - Federica Gabriele
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Lucy M Martin
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL, USA
| | - Luke N M Harding
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Vamshikrishna Gone
- UICentre, Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Bikash Dangi
- Department of Pharmacy Practice, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Daniel D Lantvit
- UICentre, Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Dejan Nikolic
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Rodolfo Ippoliti
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - Grégory Effantin
- University of Grenoble Alpes, CEA, CNRS, IBS, F-38000, Grenoble, France
| | - Wai Li Ling
- University of Grenoble Alpes, CEA, CNRS, IBS, F-38000, Grenoble, France
| | - Jeremy J Johnson
- Department of Pharmacy Practice, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA
| | - Gregory R J Thatcher
- Department of Pharmacology & Toxicology, R. Ken Coit College of Pharmacy, University of Arizona, Tucson, AZ, USA
| | - Francesco Angelucci
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy.
| | - David L Williams
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL, USA.
| | - Pavel A Petukhov
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA.
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Limited efficacy of repeated praziquantel treatment in Schistosoma mansoni infections as revealed by highly accurate diagnostics, PCR and UCP-LF CAA (RePST trial). PLoS Negl Trop Dis 2022; 16:e0011008. [PMID: 36548444 PMCID: PMC9822103 DOI: 10.1371/journal.pntd.0011008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 01/06/2023] [Accepted: 12/06/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Most studies assessing praziquantel (PZQ) efficacy have used relatively insensitive diagnostic methods, thereby overestimating cure rate (CR) and intensity reduction rate (IRR). To determine accurately PZQ efficacy, we employed more sensitive DNA and circulating antigen detection methods. METHODOLOGY A sub-analysis was performed based on a previously published trial conducted in children from Côte d'Ivoire with a confirmed Schistosoma mansoni infection, who were randomly assigned to a standard (single dose of PZQ) or intense treatment group (4 repeated doses of PZQ at 2-week intervals). CR and IRR were estimated based on PCR detecting DNA in a single stool sample and the up-converting particle lateral flow (UCP-LF) test detecting circulating anodic antigen (CAA) in a single urine sample, and compared with traditional Kato-Katz (KK) and point-of-care circulating cathodic antigen (POC-CCA). PRINCIPAL FINDINGS Individuals positive by all diagnostic methods (i.e., KK, POC-CCA, PCR, and UCP-LF CAA) at baseline were included in the statistical analysis (n = 125). PCR showed a CR of 45% (95% confidence interval (CI) 32-59%) in the standard and 78% (95% CI 66-87%) in the intense treatment group, which is lower compared to the KK results (64%, 95% CI 52-75%) and 88%, 95% CI 78-93%). UCP-LF CAA showed a significantly lower CR in both groups, 16% (95% CI 11-24%) and 18% (95% CI 12-26%), even lower than observed by POC-CCA (31%, 95% CI 17-35% and 36%, 95% CI 26-47%). A substantial reduction in DNA and CAA-levels was observed after the first treatment, with no further decrease after additional treatment and no significant difference in IRR between treatment groups. CONCLUSION/SIGNIFICANCE The efficacy of (repeated) PZQ treatment was overestimated when using egg-based diagnostics (i.e. KK and PCR). Quantitative worm-based diagnostics (i.e. POC-CCA and UCP-LF CAA) revealed that active Schistosoma infections are still present despite multiple treatments. These results stress the need for using accurate diagnostic tools to monitor different PZQ treatment strategies, in particular when moving toward elimination of schistosomiasis. CLINICAL TRIAL REGISTRATION www.clinicaltrials.gov, NCT02868385.
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Mesquita SG, Caldeira RL, Favre TC, Massara CL, Beck LCNH, Simões TC, de Carvalho GBF, dos Santos Neves FG, de Oliveira G, de Souza Barbosa Lacerda L, de Almeida MA, dos Santos Carvalho O, Moraes Mourão M, Oliveira E, Silva-Pereira RA, Fonseca CT. Assessment of the accuracy of 11 different diagnostic tests for the detection of Schistosomiasis mansoni in individuals from a Brazilian area of low endemicity using latent class analysis. Front Microbiol 2022; 13:1048457. [PMID: 36590409 PMCID: PMC9797737 DOI: 10.3389/fmicb.2022.1048457] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 11/04/2022] [Indexed: 12/16/2022] Open
Abstract
Background Schistosomiasis is a parasitic disease associated with poverty. It is estimated that 7.1 million people are infected with Schistosoma mansoni in Latin America, with 95% of them living in Brazil. Accurate diagnosis and timely treatment are important measures to control and eliminate schistosomiasis, but diagnostic improvements are needed to detect infections, especially in areas of low endemicity. Methodology This research aimed to evaluate the performance of 11 diagnostic tests using latent class analysis (LCA). A cross-sectional survey was undertaken in a low endemicity area of the municipality of Malacacheta, Minas Gerais, Brazil. Feces, urine, and blood samples were collected from 400 residents older than 6 years of age, who had not been treated with praziquantel in the 12 months previous to the collection of their samples. The collected samples were examined using parasitological (Helm Test® kit Kato-Katz), nucleic acid amplification tests -NAATs (PCR, qPCR and LAMP on urine; PCR-ELISA, qPCR and LAMP on stool), and immunological (POC-CCA, the commercial anti-Schistosoma mansoni IgG ELISA kit from Euroimmun, and two in-house ELISA assays using either the recombinant antigen PPE or the synthetic peptide Smp150390.1) tests. Results The positivity rate of the 11 tests evaluated ranged from 5% (qPCR on urine) to 40.8% (commercial ELISA kit). The estimated prevalence of schistosomiasis was 12% (95% CI: 9-15%) according to the LCA. Among all tests assessed, the commercial ELISA kit had the highest estimated sensitivity (100%), while the Kato-Katz had the highest estimated specificity (99%). Based on the accuracy measures observed, we proposed three 2-step diagnostic approaches for the active search of infected people in endemic settings. The approaches proposed consist of combinations of commercial ELISA kit and NAATs tests performed on stool. All the approaches had higher sensitivity and specificity than the mean values observed for the 11 tests (70.4 and 89.5%, respectively). Conclusion We showed that it is possible to achieve high specificity and sensitivity rates with lower costs by combining serological and NAATs tests, which would assist in the decision-making process for appropriate allocation of public funding aiming to achieve the WHO target of eliminating schistosomiasis as a public health problem by 2030.
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Affiliation(s)
- Silvia Gonçalves Mesquita
- Grupo de Pesquisa em Helmintologia e Malacologia Médica, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Roberta Lima Caldeira
- Grupo de Pesquisa em Helmintologia e Malacologia Médica, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Tereza Cristina Favre
- Laboratório de Educação em Ambiente e Saúde, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Cristiano Lara Massara
- Grupo de Pesquisa em Helmintologia e Malacologia Médica, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | | | - Taynãna César Simões
- Núcleo de Estudos em Saúde Pública e Envelhecimento, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Gardênia Braz Figueiredo de Carvalho
- Grupo de Pesquisa em Biologia e Imunologia de Doenças Infecciosas e Parasitárias, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Flória Gabriela dos Santos Neves
- Grupo de Pesquisa em Helmintologia e Malacologia Médica, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Gabriela de Oliveira
- Grupo de Pesquisa em Biologia e Imunologia de Doenças Infecciosas e Parasitárias, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Larisse de Souza Barbosa Lacerda
- Grupo de Pesquisa em Biologia e Imunologia de Doenças Infecciosas e Parasitárias, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Matheus Alves de Almeida
- Grupo de Pesquisa em Genômica Funcional de Parasitos, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Omar dos Santos Carvalho
- Grupo de Pesquisa em Helmintologia e Malacologia Médica, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Marina Moraes Mourão
- Grupo de Pesquisa em Helmintologia e Malacologia Médica, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Edward Oliveira
- Grupo de Pesquisa em Genômica Funcional de Parasitos, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Rosiane A. Silva-Pereira
- Grupo de Pesquisa em Biologia e Imunologia de Doenças Infecciosas e Parasitárias, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Cristina Toscano Fonseca
- Grupo de Pesquisa em Biologia e Imunologia de Doenças Infecciosas e Parasitárias, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
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7
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Lo NC, Bezerra FSM, Colley DG, Fleming FM, Homeida M, Kabatereine N, Kabole FM, King CH, Mafe MA, Midzi N, Mutapi F, Mwanga JR, Ramzy RMR, Satrija F, Stothard JR, Traoré MS, Webster JP, Utzinger J, Zhou XN, Danso-Appiah A, Eusebi P, Loker ES, Obonyo CO, Quansah R, Liang S, Vaillant M, Murad MH, Hagan P, Garba A. Review of 2022 WHO guidelines on the control and elimination of schistosomiasis. THE LANCET. INFECTIOUS DISEASES 2022; 22:e327-e335. [PMID: 35594896 DOI: 10.1016/s1473-3099(22)00221-3] [Citation(s) in RCA: 71] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 03/13/2022] [Accepted: 03/21/2022] [Indexed: 01/13/2023]
Abstract
Schistosomiasis is a helminthiasis infecting approximately 250 million people worldwide. In 2001, the World Health Assembly (WHA) 54.19 resolution defined a new global strategy for control of schistosomiasis through preventive chemotherapy programmes. This resolution culminated in the 2006 WHO guidelines that recommended empirical treatment by mass drug administration with praziquantel, predominately to school-aged children in endemic settings at regular intervals. Since then, school-based and community-based preventive chemotherapy programmes have been scaled-up, reducing schistosomiasis-associated morbidity. Over the past 15 years, new scientific evidence-combined with a more ambitious goal of eliminating schistosomiasis and an increase in the global donated supply of praziquantel-has highlighted the need to update public health guidance worldwide. In February, 2022, WHO published new guidelines with six recommendations to update the global public health strategy against schistosomiasis, including expansion of preventive chemotherapy eligibility from the predominant group of school-aged children to all age groups (2 years and older), lowering the prevalence threshold for annual preventive chemotherapy, and increasing the frequency of treatment. This Review, written by the 2018-2022 Schistosomiasis Guidelines Development Group and its international partners, presents a summary of the new WHO guideline recommendations for schistosomiasis along with their historical context, supporting evidence, implications for public health implementation, and future research needs.
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Affiliation(s)
- Nathan C Lo
- Division of HIV, Infectious Diseases, and Global Medicine, University of California, San Francisco, CA, USA.
| | | | - Daniel G Colley
- Department of Microbiology, Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
| | | | - Mamoun Homeida
- Academy of Medical Sciences and Technology, Khartoum, Sudan
| | - Narcis Kabatereine
- Accelerating Resilient, Innovative, and Sustainable Elimination of NTDs, Vector Control Division, Kampala, Uganda
| | | | - Charles H King
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | | | - Nicholas Midzi
- National Institute of Health Research, Ministry of Health and Child Care, Harare, Zimbabwe
| | - Francisca Mutapi
- Institute of Immunology and Infection Research, Tackling Infections to Benefit Africa Partnership, University of Edinburgh, Edinburgh, UK
| | - Joseph R Mwanga
- Department of Epidemiology, Biostatistics and Behavioral Sciences, School of Public Health, Catholic University of Health and Allied Sciences, Mwanza, Tanzania
| | - Reda M R Ramzy
- National Nutrition Institute, General Organization for Teaching Hospitals and Institutes, Cairo, Egypt
| | - Fadjar Satrija
- School of Veterinary Medicine and Biomedicine, IPB University, Bogor, Indonesia
| | - J Russell Stothard
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | | | - Joanne P Webster
- Department of Pathobiology and Population Science, Royal Veterinary College, University of London, London, UK
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland; University of Basel, Basel, Switzerland
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China; School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | | | - Paolo Eusebi
- Department of Medicine and Surgery, University of Perugia, Perugia, Italy
| | - Eric S Loker
- Department of Biology, University of New Mexico, Albuquerque, NM, USA
| | - Charles O Obonyo
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | | | - Song Liang
- Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, FL, USA; Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
| | - Michel Vaillant
- Competence Centre for Methodology and Statistics, Luxembourg Institute of Health, Strassen, Luxembourg
| | - M Hassan Murad
- Evidence-based Practice Center, Mayo Clinic, Rochester, NY, USA
| | - Paul Hagan
- Faculty of Health Sciences, University of Hull, Hull, UK
| | - Amadou Garba
- Department of Control of Neglected Tropical Diseases, WHO, Geneva, Switzerland
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Wiegand RE, Fleming FM, de Vlas SJ, Odiere MR, Kinung'hi S, King CH, Evans D, French MD, Montgomery SP, Straily A, Utzinger J, Vounatsou P, Secor WE. Defining elimination as a public health problem for schistosomiasis control programmes: beyond prevalence of heavy-intensity infections. Lancet Glob Health 2022; 10:e1355-e1359. [PMID: 35961358 PMCID: PMC10184143 DOI: 10.1016/s2214-109x(22)00287-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 06/10/2022] [Accepted: 06/20/2022] [Indexed: 11/21/2022]
Abstract
WHO's 2021-30 road map for neglected tropical diseases (NTDs) outlines disease-specific and cross-cutting targets for the control, elimination, and eradication of NTDs in affected countries. For schistosomiasis, the criterion for elimination as a public health problem (EPHP) is defined as less than 1% prevalence of heavy-intensity infections (ie, ≥50 Schistosoma haematobium eggs per 10 mL of urine or ≥400 Schistosoma mansoni eggs per g of stool). However, we believe the evidence supporting this definition of EPHP is inadequate and the shifting distribution of schistosomiasis morbidity towards more subtle, rather than severe, morbidity in the face of large-scale control programmes requires guidelines to be adapted. In this Viewpoint, we outline the need for more accurate measures to develop a robust evidence-based monitoring and evaluation framework for schistosomiasis. Such a framework is crucial for achieving the goal of widespread EPHP of schistosomiasis and to meet the WHO road map targets. We encourage use of overall prevalence of schistosome infection (instead of the prevalence of heavy-intensity infections), development of species-dependent and age-dependent morbidity markers, and construction of a standardised monitoring and evaluation protocol.
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Affiliation(s)
- Ryan E Wiegand
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA; Swiss Tropical and Public Health Institute, Allschwil, Switzerland; University of Basel, Basel, Switzerland.
| | | | - Sake J de Vlas
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands
| | - Maurice R Odiere
- Neglected Tropical Diseases Unit, Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Safari Kinung'hi
- National Institute for Medical Research, Mwanza Centre, Mwanza, Tanzania
| | - Charles H King
- School of Medicine, Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
| | - Darin Evans
- United States Agency for International Development, Washington, DC, USA
| | | | - Susan P Montgomery
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Anne Straily
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland; University of Basel, Basel, Switzerland
| | - Penelope Vounatsou
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland; University of Basel, Basel, Switzerland
| | - W Evan Secor
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA
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9
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A simple new screening tool for diagnosing imported schistosomiasis. PUBLIC HEALTH IN PRACTICE 2022; 3:100245. [PMID: 36101771 PMCID: PMC9461506 DOI: 10.1016/j.puhip.2022.100245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 03/08/2022] [Accepted: 03/15/2022] [Indexed: 11/22/2022] Open
Abstract
Objectives We sought to test the sensitivity and feasibility of a Schistosoma infection screening process consisting of a scored patient consultation questionnaire and a serological diagnostic test. Study design Prospective cross-sectional study. Methods We collected from Schistosoma-exposed individuals a 14-point check list of clinical and laboratory data related to Schistosoma infection, alongside a serological test to detect Schistosoma spp infection. A check list score was created and compared with the risk of infection and clinical recovery through an agreement analysis. Results Two-hundred and fifty individuals were enrolled, of whom 220 (88%) were male and 30 (12%) female. The median age was 39 (range 18–78). One hundred-fifty (60%, 95% CI 54.9%–65.1%) had a check-list score ≥2. Serology test results were positive for 142 (56.8%, 95% CI 51.6%–62%). Chronic complications compatible with long-term Schistosoma infection were detected in 29 out of these 142 (20.4%, 95% CI 13.8%–27%).,. The median score value was 3, the area under the receiver operating characteristic (ROC) curve against serology results was 0.85 and the estimated intercept check-list questionnaire score value was 1.72 (95%, CI: 1.3–2.2). Participants with a positive serological test had a substantially higher check-list score (Cohen's kappa coefficient: 0.62, 95% CI: 0.54–0.70). Ninety four percent patients empirically treated showed a subsequent improvement in clinical and laboratory parameters. Conclusions A two-component process consisting of a scored patient consultation questionnaire followed by serological assay can be a suitable strategy for screening populations at high risk of schistosomiasis infection.
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10
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Meta-analysis of variable-temperature PCR technique performance for diagnosising Schistosoma japonicum infections in humans in endemic areas. PLoS Negl Trop Dis 2022; 16:e0010136. [PMID: 35030167 PMCID: PMC8794272 DOI: 10.1371/journal.pntd.0010136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 01/27/2022] [Accepted: 01/03/2022] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND As China is moving onto schistosomiasis elimination/eradication, diagnostic methods with both high sensitivity and specificity for Schistosoma japonicum infections in humans are urgently needed. Microscopic identification of eggs in stool is proven to have poor sensitivity in low endemic regions, and antibody tests are unable to distinguish between current and previous infections. Polymerase chain reaction (PCR) technologies for the detection of parasite DNA have been theoretically assumed to show high diagnostic sensitivity and specificity. However, the reported performance of PCR for detecting S. japonicum infection varied greatly among studies. Therefore, we performed a meta-analysis to evaluate the overall diagnostic performance of variable-temperature PCR technologies, based on stool or blood, for detecting S. japonicum infections in humans from endemic areas. METHODS We searched literatures in eight electronic databases, published up to 20 January 2021. The heterogeneity and publication bias of included studies were assessed statistically. The risk of bias and applicability of each eligible study were assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool (QUADAS-2). The bivariate mixed-effects model was applied to obtain the summary estimates of diagnostic performance. The hierarchical summary receiver operating characteristic (HSROC) curve was applied to visually display the results. Subgroup analyses and multivariate regression were performed to explore the source of heterogeneity. This research was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines and was registered prospectively in PROSPERO (CRD42021233165). RESULTS A total of 2791 papers were retrieved. After assessing for duplications and eligilibity a total of thirteen publications were retained for inclusion. These included eligible data from 4268 participants across sixteen studies. High heterogeneity existed among studies, but no publication bias was found. The pooled analyses of PCR data from all included studies resulted in a sensitivity of 0.91 (95% CI: 0.83 to 0.96), specificity of 0.85 (95% CI: 0.65 to 0.94), positive likelihood ratio of 5.90 (95% CI: 2.40 to 14.60), negative likelihood ratio of 0.10 (95% CI: 0.05 to 0.20) and a diagnostics odds ratio of 58 (95% CI: 19 to 179). Case-control studies showed significantly better performances for PCR diagnostics than cross-sectional studies. This was further evidenced by multivariate analyses. The four types of PCR approaches identified (conventional PCR, qPCR, Droplet digital PCR and nested PCR) differed significantly, with nested PCRs showing the best performance. CONCLUSIONS Variable-temperature PCR has a satisfactory performance for diagnosing S. japonicum infections in humans in endemic areas. More high quality studies on S. japonicum diagnostic techniques, especially in low endemic areas and for the detection of dual-sex and single-sex infections are required. These will likely need to optimise a nested PCR alongside a highly sensitive gene target. They will contribute to successfully monitoring endemic areas as they move towards the WHO 2030 targets, as well as ultimately helping areas to achieve these goals.
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11
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Hunter KS, Miller A, Mentink-Kane M, Davies SJ. Schistosome AMPK Is Required for Larval Viability and Regulates Glycogen Metabolism in Adult Parasites. Front Microbiol 2021; 12:726465. [PMID: 34539616 PMCID: PMC8440919 DOI: 10.3389/fmicb.2021.726465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 08/12/2021] [Indexed: 11/25/2022] Open
Abstract
On entering the mammalian host, schistosomes transition from a freshwater environment where resources are scarce, to an environment where there is an unlimited supply of glucose, their preferred energy substrate. Adult schistosome glycolytic activity consumes almost five times the parasite's dry weight in glucose per day to meet the parasite's energy demands, and the schistosome glycolytic enzymes and mechanisms for glucose uptake that sustain this metabolic activity have previously been identified. However, little is known of the parasite processes that regulate schistosome glucose metabolism. We previously described the Schistosoma mansoni ortholog of 5' AMP-Activated Protein Kinase (AMPK), which is a central regulator of energy metabolism in eukaryotes, and characterized the developmental regulation of its expression and activity in S. mansoni. Here we sought to explore the function of AMPK in schistosomes and test whether it regulates parasite glycolysis. Adult schistosomes mounted a compensatory response to chemical inhibition of AMPK α, resulting in increased AMPK α protein abundance and activity. RNAi inhibition of AMPK α expression, however, suggests that AMPK α is not required for adult schistosome viability in vitro. Larval schistosomula, on the other hand, are sensitive to chemical AMPK α inhibition, and this correlates with inactivity of the AMPK α gene in this life cycle stage that precludes a compensatory response to AMPK inhibition. While our data indicate that AMPK is not essential in adult schistosomes, our results suggest that AMPK regulates adult worm glycogen stores, influencing both glycogen utilization and synthesis. AMPK may therefore play a role in the ability of adult schistosomes to survive in vivo stressors such as transient glucose deprivation and oxidative stress. These findings suggest that AMPK warrants further investigation as a potential drug target, especially for interventions aimed at preventing establishment of a schistosome infection.
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Affiliation(s)
- Kasandra S Hunter
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University, Bethesda, MD, United States
| | - André Miller
- Schistosomiasis Resource Center, Biomedical Research Institute, Rockville, MD, United States
| | - Margaret Mentink-Kane
- Schistosomiasis Resource Center, Biomedical Research Institute, Rockville, MD, United States
| | - Stephen J Davies
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University, Bethesda, MD, United States
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12
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Wiegand RE, Secor WE, Fleming FM, French MD, King CH, Montgomery SP, Evans D, Utzinger J, Vounatsou P, de Vlas SJ. Control and Elimination of Schistosomiasis as a Public Health Problem: Thresholds Fail to Differentiate Schistosomiasis Morbidity Prevalence in Children. Open Forum Infect Dis 2021; 8:ofab179. [PMID: 34307724 PMCID: PMC8297701 DOI: 10.1093/ofid/ofab179] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 04/14/2021] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Current World Health Organization guidelines utilize prevalence of heavy-intensity infections (PHIs), that is, ≥50 eggs per 10 mL of urine for Schistosoma haematobium and ≥400 eggs per gram of stool for S. mansoni, to determine whether a targeted area has controlled schistosomiasis morbidity or eliminated schistosomiasis as a public health problem. The relationship between these PHI categories and morbidity is not well understood. METHODS School-age participants enrolled in schistosomiasis monitoring and evaluation cohorts from 2003 to 2008 in Burkina Faso, Mali, Niger, Tanzania, Uganda, and Zambia were surveyed for infection and morbidity at baseline and after 1 and 2 rounds of preventive chemotherapy. Logistic regression was used to compare morbidity prevalence among participants based on their school's PHI category. RESULTS Microhematuria levels were associated with the S. haematobium PHI categories at all 3 time points. For any other S. haematobium or S. mansoni morbidity that was measured, PHI categories did not differentiate morbidity prevalence levels consistently. CONCLUSIONS These analyses suggest that current PHI categorizations do not differentiate the prevalence of standard morbidity markers. A reevaluation of the criteria for schistosomiasis control is warranted.
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Affiliation(s)
- Ryan E Wiegand
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - W Evan Secor
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | | | | | - Charles H King
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio, USA
| | - Susan P Montgomery
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Darin Evans
- United States Agency for International Development, Washington, DC, USA
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Penelope Vounatsou
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Sake J de Vlas
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
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13
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Wiegand RE, Fleming FM, Straily A, Montgomery SP, de Vlas SJ, Utzinger J, Vounatsou P, Secor WE. Urogenital schistosomiasis infection prevalence targets to determine elimination as a public health problem based on microhematuria prevalence in school-age children. PLoS Negl Trop Dis 2021; 15:e0009451. [PMID: 34115760 PMCID: PMC8221785 DOI: 10.1371/journal.pntd.0009451] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 06/23/2021] [Accepted: 05/07/2021] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Recent research suggests that schistosomiasis targets for morbidity control and elimination as a public health problem could benefit from a reanalysis. These analyses would define evidence-based targets that control programs could use to confidently assert that they had controlled or eliminated schistosomiasis as a public health problem. We estimated how low Schistosoma haematobium infection levels diagnosed by urine filtration in school-age children should be decreased so that microhematuria prevalence was at, or below, a "background" level of morbidity. METHODOLOGY Data obtained from school-age children in Burkina Faso, Mali, Niger, Tanzania, and Zambia who participated in schistosomiasis monitoring and evaluation cohorts were reanalyzed before and after initiation of preventive chemotherapy. Bayesian models estimated the infection level prevalence probabilities associated with microhematuria thresholds ≤10%, 13%, or 15%. PRINCIPAL FINDINGS An infection prevalence of 5% could be a sensible target for urogenital schistosomiasis morbidity control in children as microhematuria prevalence was highly likely to be below 10% in all surveys. Targets of 8% and 11% infection prevalence were highly likely to result in microhematuria levels less than 13% and 15%, respectively. By contrast, measuring heavy-intensity infections only achieves these thresholds at impractically low prevalence levels. CONCLUSIONS/SIGNIFICANCE A target of 5%, 8%, or 11% urogenital schistosomiasis infection prevalence in school-age children could be used to determine whether a geographic area has controlled or eliminated schistosomiasis as a public health problem depending on the local background threshold of microhematuria.
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Affiliation(s)
- Ryan E. Wiegand
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | | | - Anne Straily
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Susan P. Montgomery
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Sake J. de Vlas
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Penelope Vounatsou
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - W. Evan Secor
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
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14
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Wiegand RE, Secor WE, Fleming FM, French MD, King CH, Deol AK, Montgomery SP, Evans D, Utzinger J, Vounatsou P, de Vlas SJ. Associations between infection intensity categories and morbidity prevalence in school-age children are much stronger for Schistosoma haematobium than for S. mansoni. PLoS Negl Trop Dis 2021; 15:e0009444. [PMID: 34033646 PMCID: PMC8183985 DOI: 10.1371/journal.pntd.0009444] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 06/07/2021] [Accepted: 05/04/2021] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND World Health Organization (WHO) guidelines for measuring global progress in schistosomiasis control classify individuals with Schistosoma spp. infections based on the concentration of excreted eggs. We assessed the associations between WHO infection intensity categories and morbidity prevalence for selected S. haematobium and S. mansoni morbidities in school-age children. METHODOLOGY A total of 22,488 children aged 6-15 years from monitoring and evaluation cohorts in Burkina Faso, Mali, Niger, Uganda, Tanzania, and Zambia from 2003-2008 were analyzed using Bayesian logistic regression. Models were utilized to evaluate associations between intensity categories and the prevalence of any urinary bladder lesion, any upper urinary tract lesion, microhematuria, and pain while urinating (for S. haematobium) and irregular hepatic ultrasound image pattern (C-F), enlarged portal vein, laboratory-confirmed diarrhea, and self-reported diarrhea (for S. mansoni) across participants with infection and morbidity data. PRINCIPAL FINDINGS S. haematobium infection intensity categories possessed consistent morbidity prevalence across surveys for multiple morbidities and participants with light infections had elevated morbidity levels, compared to negative participants. Conversely, S. mansoni infection intensity categories lacked association with prevalence of the morbidity measures assessed. CONCLUSIONS/SIGNIFICANCE Current status infection intensity categories for S. haematobium were associated with morbidity levels in school-age children, suggesting urogenital schistosomiasis morbidity can be predicted by an individual's intensity category. Conversely, S. mansoni infection intensity categories were not consistently indicative of childhood morbidity at baseline or during the first two years of a preventive chemotherapy control program.
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Affiliation(s)
- Ryan E. Wiegand
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - W. Evan Secor
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | | | | | - Charles H. King
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Arminder K. Deol
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Susan P. Montgomery
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Darin Evans
- United States Agency for International Development, Washington DC, United States of America
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Penelope Vounatsou
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Sake J. de Vlas
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
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15
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Rahman MO, Sassa M, Parvin N, Islam MR, Yajima A, Ota E. Diagnostic test accuracy for detecting Schistosoma japonicum and S. mekongi in humans: A systematic review and meta-analysis. PLoS Negl Trop Dis 2021; 15:e0009244. [PMID: 33730048 PMCID: PMC7968889 DOI: 10.1371/journal.pntd.0009244] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 02/17/2021] [Indexed: 02/01/2023] Open
Abstract
Background Most of national schistosomiasis elimination programmes in Asia are relying on stool examination, particularly Kato Katz stool examination technique for regular transmission monitoring. However, the Kato-Katz technique has shown low sensitivity for the detection of light-intensity infections, and therefore highly sensitive diagnostic tools are urgently required to monitor prevalence of infection in low transmission settings. The objective of this systematic review was to evaluate and synthesize the performance of diagnostic tests for detecting Schistosoma japonicum and S. mekongi infection in people living in endemic areas. Methodology/Principal findings We comprehensively searched these nine electronic databases and other resources until July 2019, with no language or publication limits: PubMed, EMBASE, MEDLINE, Web of Science, BIOSIS Citation Index, HTA, CINAHL PLUS, The Cochrane Library, and PsycINFO. We included original studies that assessed diagnostic performance using antibody, antigen, and molecular tests with stool examination test as a reference standard. Two reviewers independently extracted a standard set of data and assessed study quality. We estimated the pooled estimates of sensitivity and specificity for each index test. We used diagnostic odds ratio to determine the overall accuracy and hierarchical summary receiver operating characteristics (HSROC) curve to assess the index tests performance. Fifteen studies (S. japonicum [n = 13] and S. mekongi [n = 2]) testing 15,303 participants were included in the review. Five studies reported performance of enzyme-linked immunosorbent assay (ELISA), seven studies reported indirect hemagglutination assay (IHA), and four studies reported polymerase chain reaction (PCR) for detecting S. japonicum. The pooled sensitivity and specificity were 0.93 (95% CI: 0.84–0.98) and 0.40 (95% CI: 0.29–0.53) for ELISA, 0.97 (95% CI: 0.90–0.99) and 0.66 (95% CI: 0.58–0.73) for IHA, and 0.89 (95% CI: 0.71–0.96) and 0.49 (95% CI: 0.29–0.69) for PCR respectively. A global summary indicated the best performance for IHA, closely followed by ELISA. We were unable to perform meta-analysis for S. mekongi due to insufficient number of studies. Conclusions/Significance IHA showed the highest detection accuracy for S. japonicum. Further studies are needed to determine the suitable diagnostic methods to verify the absence of transmission of S. mekongi and also to compare detection accuracy against more sensitive reference standards such as PCR. Schistosomiasis remains a serious public health problem worldwide. Accurate diagnostic tests play a key role in control of schistosomiasis, especially in Asia where the prevalence and intensity of infection is low. As stool examination techniques, particularly the Kato-Katz technique has shown low sensitivity for the detection of light-intensity infections, highly sensitive diagnostics are urgently required to monitor prevalence of infection in low transmission settings. The purpose of this review was to assess and synthesize the performance of diagnostic tests for detecting schistosomiasis in people living in endemic areas in Asia. A comprehensive search, without any limit of language, date or types of publication, were performed for both- multiple electronic databases and other resources to identify the eligible studies. Robust analytical approaches such as diagnostic meta-analysis, HSROC curve, and diagnostic odds ratio, were used to provide more diagnostic accuracy of index tests. We assessed performance of three diagnostic tests (ELISA, IHA, and PCR) for detecting infection with S. japonicum using stool examination as a reference standard. In these meta-analyses, IHA showed the highest detection accuracy, followed by ELISA. We could not perform meta-analysis for S. mekongi due to insufficient number of studies.
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Affiliation(s)
- Md Obaidur Rahman
- Department of Global Health Nursing, Graduate School of Nursing Science, St. Luke's International University, Tokyo, Japan.,Department of Global Health Policy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Miho Sassa
- Department of Global Health Policy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Department of Parasitology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan
| | - Natasha Parvin
- Department of Accounting and Information System, Hajee Mohammad Danesh Science & Technology University, Dinajpur, Bangladesh
| | - Md Rashedul Islam
- Department of Global Health Policy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Division of Prevention, Center for Public Health Sciences, National Cancer Center, Tokyo, Japan
| | - Aya Yajima
- Malaria and Neglected Tropical Diseases Unit, Division of Progammes of Disease Control, World Health Organization Western Pacific Regional Office, World Health Organization
| | - Erika Ota
- Department of Global Health Nursing, Graduate School of Nursing Science, St. Luke's International University, Tokyo, Japan
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16
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Kamel B, Laidemitt MR, Lu L, Babbitt C, Weinbaum OL, Mkoji GM, Loker ES. Detecting and identifying Schistosoma infections in snails and aquatic habitats: A systematic review. PLoS Negl Trop Dis 2021; 15:e0009175. [PMID: 33760814 PMCID: PMC8021170 DOI: 10.1371/journal.pntd.0009175] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 04/05/2021] [Accepted: 01/26/2021] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND We were tasked by the World Health Organization (WHO) to address the following question: What techniques should be used to diagnose Schistosoma infections in snails and in the water in potential transmission sites? Our goal was to review and evaluate the available literature and provide recommendations and insights for the development of WHO's Guidelines Development Group for schistosomiasis control and elimination. METHODOLOGY We searched several databases using strings of search terms, searched bibliographies of pertinent papers, and contacted investigators who have made contributions to this field. Our search covered from 1970 to Sept 2020. All papers were considered in a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) framework, and retained papers were grouped by technique and subjected to our GRADE (Grading of Recommendations, Assessment, Development and Evaluations) evidence assessment profile determined in consultation with WHO. We also considered issues of sensitivity, specificity, coverage, cost, robustness, support needs, schistosome species discrimination, and relevant detection limits. PRINCIPAL FINDINGS Our PRISMA process began with the perusal of 949 articles, of which 158 were retained for data extraction and evaluation. We identified 25 different techniques and for each applied a GRADE assessment considering limitations, inconsistency, imprecision, indirectness, and publication bias. We also provide advantages and disadvantages for each category of techniques. CONCLUSIONS Our GRADE analysis returned an assessment of moderate quality of evidence for environmental DNA (eDNA), qPCR and LAMP (Loop-mediated isothermal amplification). No single ideal diagnostic approach has yet been developed, but considerable recent progress has been made. We note a growing trend to use eDNA techniques to permit more efficient and replicable sampling. qPCR-based protocols for follow-up detection offer a versatile, mature, sensitive, and specific platform for diagnosis though centralized facilities will be required to favor standardization. Droplet digital PCR (ddPCR) can play a complementary role if inhibitors are a concern, or more sensitivity or quantification is needed. Snail collection, followed by shedding, is encouraged to provide specimens for sequence verifications of snails or schistosomes. LAMP or other isothermal detection techniques offer the prospect of less expensive and more distributed network of analysis but may face standardization and verification challenges related to actual sequences amplified. Ability to detect schistosome infections in snails or in the water is needed if control and elimination programs hope to succeed. Any diagnostic techniques used need to be regularly verified by the acquisition of DNA sequences to confirm that the detected targets are of the expected species. Further improvements may be necessary to identify the ideal schistosome or snail sequences to target for amplification. More field testing and standardization will be essential for long-term success.
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Affiliation(s)
- Bishoy Kamel
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, NM, United States of America
| | - Martina R. Laidemitt
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, NM, United States of America
- Parasitology Division, Museum of Southwestern Biology, Department of Biology, University of New Mexico, Albuquerque, NM, United States of America
| | - Lijun Lu
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, NM, United States of America
- Parasitology Division, Museum of Southwestern Biology, Department of Biology, University of New Mexico, Albuquerque, NM, United States of America
| | - Caitlin Babbitt
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, NM, United States of America
- Parasitology Division, Museum of Southwestern Biology, Department of Biology, University of New Mexico, Albuquerque, NM, United States of America
| | - Ola Liota Weinbaum
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, NM, United States of America
| | - Gerald M. Mkoji
- Center for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya
| | - Eric S. Loker
- Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, NM, United States of America
- Parasitology Division, Museum of Southwestern Biology, Department of Biology, University of New Mexico, Albuquerque, NM, United States of America
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King CH, Bertsch D, Andrade GN, Burnim M, Ezeamama AE, Binder S, Colley DG. The Schistosomiasis Consortium for Operational Research and Evaluation Rapid Answers Project: Systematic Reviews and Meta-Analysis to Provide Policy Recommendations Based on Available Evidence. Am J Trop Med Hyg 2020; 103:92-96. [PMID: 32400346 PMCID: PMC7351305 DOI: 10.4269/ajtmh.19-0806] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) was established in late 2008 to conduct operational research to inform global health practices related to the control and elimination of schistosomiasis. The greatest part of the SCORE investment has been in multiyear, long-term efforts, including cluster-randomized trials of gaining and sustaining control of schistosomiasis, trials on elimination of schistosomiasis, and diagnostic test development and evaluation. In the course of planning and conducting SCORE studies, critical questions were raised that could be answered relatively quickly by collecting, collating, and synthesizing existing data. Through its Rapid Answers Project (RAP), the SCORE conducted seven systematic reviews, including four associated meta-analyses, on issues related to screening for schistosomiasis, enhancing mass drug administration, treatment impacts, and the efficacy of snail control for prevention of human schistosomiasis. This article summarizes the findings of the seven RAP reports and provides links to the studies and their supporting information.
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Affiliation(s)
- Charles H King
- Schistosomiasis Consortium for Operational Research and Evaluation, Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia.,Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio
| | - David Bertsch
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio
| | - Gisele N Andrade
- Escola de Enfermagem, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Michael Burnim
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio
| | - Amara E Ezeamama
- Department of Epidemiology & Biostatistics, University of Georgia, Athens, Georgia.,Department of Psychiatry, College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan
| | - Sue Binder
- Schistosomiasis Consortium for Operational Research and Evaluation, Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia
| | - Daniel G Colley
- Department of Microbiology, University of Georgia, Athens, Georgia.,Schistosomiasis Consortium for Operational Research and Evaluation, Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia
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18
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Mwanga JR, Kinung’hi SM, Mosha J, Angelo T, Maganga J, Campbell CH. Village Response to Mass Drug Administration for Schistosomiasis in Mwanza Region, Northwestern Tanzania: Are We Missing Socioeconomic, Cultural, and Political Dimensions? Am J Trop Med Hyg 2020; 103:1969-1977. [PMID: 32901610 PMCID: PMC7646777 DOI: 10.4269/ajtmh.19-0843] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 07/13/2020] [Indexed: 11/16/2022] Open
Abstract
Praziquantel (PZQ)-based mass drug administration (MDA) is the main approach for controlling schistosomiasis in endemic areas. Interventions such as provision and use of clean and safe water, minimizing contacts with infested water, disposal of human waste in latrines, and snail control provide additional key interventions to break the transmission cycle and could complement and perhaps sustain the benefits of MDA. However, all interventions deployed need to be accepted by the targeted communities. A qualitative study was conducted to examine factors that might differentiate villages which did not show a substantial decrease in Schistosoma mansoni prevalence despite repeated, high treatment coverage referred to as "persistent hotspot (PHS) villages" from villages which showed a substantial decrease in prevalence referred to as "responding (RES) villages." A convenient sample of adults was drawn from eight villages. Thirty-nine key informants were interviewed and 16 focus groups were held with a total of 123 participants. Data were analyzed manually using a thematic content approach. In both PHS and RES villages, schistosomiasis was not considered to be a priority health problem because of its chronic nature, lack of knowledge and awareness, and poverty among study communities. Persistent hotspot villages exhibited poor leadership style, lack of or insufficient social engagement, little or lack of genuine community participation, little motivation, and commitment to schistosomiasis control compared with RES villages where there were commitment and motivation to fight schistosomiasis. We support the view of scholars who advocate for the adoption of a biosocial approach for effective and sustainable PZQ-based MDA for schistosomiasis control.
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Affiliation(s)
- Joseph R. Mwanga
- Department of Epidemiology, Biostatistics and Behavioral Sciences, School of Public Health, Catholic University of Health and Allied Sciences, Mwanza, Tanzania
| | - Safari M. Kinung’hi
- National Institute of Medical Research (NIMR), Mwanza Center, Mwanza, Tanzania
| | - Justina Mosha
- National Institute of Medical Research (NIMR), Mwanza Center, Mwanza, Tanzania
| | - Teckla Angelo
- National Institute of Medical Research (NIMR), Mwanza Center, Mwanza, Tanzania
| | - Jane Maganga
- National Institute of Medical Research (NIMR), Mwanza Center, Mwanza, Tanzania
| | - Carl H. Campbell
- Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), Center for Tropical and Emerging Global Diseases (CTEGD), University of Georgia, Athens, Georgia
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19
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Abudho BO, Guyah B, Ondigo BN, Ndombi EM, Ireri E, Carter JM, Riner DK, Kittur N, Karanja DMS, Colley DG. Evaluation of morbidity in Schistosoma mansoni-positive primary and secondary school children after four years of mass drug administration of praziquantel in western Kenya. Infect Dis Poverty 2020; 9:67. [PMID: 32539826 PMCID: PMC7296924 DOI: 10.1186/s40249-020-00690-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 06/08/2020] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND World Health Organization guidelines recommend preventive chemotherapy with praziquantel to control morbidity due to schistosomiasis. The primary aim of this cross-sectional study was to determine if 4 years of annual mass drug administration (MDA) in primary and secondary schools lowered potential markers of morbidity in infected children 1 year after the final MDA compared to infected children prior to initial MDA intervention. METHODS Between 2012 and 2016 all students in two primary and three secondary schools within three kilometers of Lake Victoria in western Kenya received annual mass praziquantel administration. To evaluate potential changes in morbidity we measured height, weight, mid-upper arm circumference, hemoglobin levels, abdominal ultrasound, and quality of life in children in these schools. This study compared two cross-sectional samples of Schistosoma mansoni egg-positive children: one at baseline and one at year five, 1 year after the fourth annual MDA. Data were analyzed for all ages (6-18 years old) and stratified by primary (6-12 years old) and secondary (12-18 years old) school groups. RESULTS The prevalence of multiple potential morbidity markers did not differ significantly between the egg-positive participants at baseline and those at 5 years by Mann Whitney nonparametric analysis and Fisher's exact test for continuous and categorical data, respectively. There was a small but significantly higher score in school-related quality of life assessment by year five compared to baseline by Mann Whitney analysis (P = 0.048) in 13-18 year olds where malaria-negative. However, anemia was not positively impacted by four annual rounds of MDA, but registered a significant negative outcome. CONCLUSIONS We did not detect differences in morbidity markers measured in a population of those infected or re-infected after multiple MDA. This could have been due to their relative insensitivity or a failure of MDA to prevent morbidity among those who remain infected. High malaria transmission in this area and/or a lack of suitable methods to measure the more subtle functional morbidities caused by schistosomiasis could be a factor. Further research is needed to identify and develop well-defined, easily quantifiable S. mansoni morbidity markers for this age group.
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Affiliation(s)
- Bernard O Abudho
- Centre for Global Health Research (KEMRI-CGHR), Kenya Medical Research Institute, Kisumu, Kenya.
- Department of Biomedical Sciences and Technology, Maseno University, Maseno, Kenya.
| | - Bernard Guyah
- Department of Biomedical Sciences and Technology, Maseno University, Maseno, Kenya
| | - Bartholomew N Ondigo
- Centre for Global Health Research (KEMRI-CGHR), Kenya Medical Research Institute, Kisumu, Kenya
- Department of Biochemistry and Molecular Biology, Egerton University, Nakuru, Kenya
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, USA
| | - Eric M Ndombi
- Centre for Global Health Research (KEMRI-CGHR), Kenya Medical Research Institute, Kisumu, Kenya
- Department of Pathology, Kenyatta University, Nairobi, Kenya
| | - Edmund Ireri
- Centre for Clinical Research-Radiology Unit, Kenya Medical Research Institute, Nairobi, Kenya
| | - Jennifer M Carter
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
| | - Diana K Riner
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
| | - Nupur Kittur
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
| | - Diana M S Karanja
- Centre for Global Health Research (KEMRI-CGHR), Kenya Medical Research Institute, Kisumu, Kenya
| | - Daniel G Colley
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
- Department of Microbiology, University of Georgia, Athens, GA, USA
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20
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Secor WE, Wiegand RE, Montgomery SP, Karanja DMS, Odiere MR. Comparison of School-Based and Community-Wide Mass Drug Administration for Schistosomiasis Control in an Area of Western Kenya with High Initial Schistosoma mansoni Infection Prevalence: A Cluster Randomized Trial. Am J Trop Med Hyg 2020; 102:318-327. [PMID: 31802733 PMCID: PMC7008345 DOI: 10.4269/ajtmh.19-0626] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
We conducted a cluster randomized trial comparing the target population and timing of mass drug administration (MDA) with praziquantel for control of schistosomiasis in villages in western Kenya with high initial prevalence (> 25%) according to a harmonized protocol developed by the Schistosomiasis Consortium for Operational Research and Evaluation. A total of 150 villages were randomized into six treatment arms (25 villages per arm), were assessed at baseline, and received two or four rounds of MDA using community-wide (CWT) or school-based (SBT) treatment over 4 years. In the fifth year, a final evaluation was conducted. The primary outcomes were prevalence and intensity of Schistosoma mansoni infections in children aged 9–12 years, each year their village received MDA. Baseline and year 5 assessments of first-year students and adults were also performed. Using Poisson and negative binomial regression with generalized estimating equations, we found similar effects of CWT and SBT MDA treatment strategies in children aged 9–12 years: significant reductions of prevalence of infection in all arms and of heavy-intensity (≥ 400 eggs/gram) infections in most arms but no significant differences between arms. Combined arms of villages that received four rounds of treatment had greater reduction than villages in arms that only received two rounds of treatment. Surprisingly, we also found benefits of SBT for first-year primary students and adults, who never received treatment in those arms. Our data support the use of annual SBT for control programs when coupled with attention to infections in younger children and occasional treatment of adults.
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Affiliation(s)
- W Evan Secor
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Ryan E Wiegand
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Susan P Montgomery
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Diana M S Karanja
- Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Maurice R Odiere
- Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
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21
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Hoekstra PT, Casacuberta-Partal M, van Lieshout L, Corstjens PLAM, Tsonaka R, Assaré RK, Silué KD, Meité A, N’Goran EK, N’Gbesso YK, Amoah AS, Roestenberg M, Knopp S, Utzinger J, Coulibaly JT, van Dam GJ. Efficacy of single versus four repeated doses of praziquantel against Schistosoma mansoni infection in school-aged children from Côte d'Ivoire based on Kato-Katz and POC-CCA: An open-label, randomised controlled trial (RePST). PLoS Negl Trop Dis 2020; 14:e0008189. [PMID: 32196506 PMCID: PMC7112237 DOI: 10.1371/journal.pntd.0008189] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 04/01/2020] [Accepted: 03/02/2020] [Indexed: 11/21/2022] Open
Abstract
Background Preventive chemotherapy with praziquantel (PZQ) is the cornerstone of schistosomiasis control. However, a single dose of PZQ (40 mg/kg) does not cure all infections. Repeated doses of PZQ at short intervals might increase efficacy in terms of cure rate (CR) and intensity reduction rate (IRR). Here, we determined the efficacy of a single versus four repeated treatments with PZQ on Schistosoma mansoni infection in school-aged children from Côte d’Ivoire, using two different diagnostic tests. Methods An open-label, randomized controlled trial was conducted from October 2018 to January 2019. School-aged children with a confirmed S. mansoni infection based on Kato-Katz (KK) and point-of-care circulating cathodic antigen (POC-CCA) urine cassette test were randomly assigned to receive either a single or four repeated doses of PZQ, administered at two-week intervals. The primary outcome was the difference in CR between the two treatment arms, measured by triplicate KK thick smears 10 weeks after the first treatment. Secondary outcomes included CR estimated by POC-CCA, IRR by KK and POC-CCA, and safety of repeated PZQ administration. Principal findings During baseline screening, 1,022 children were assessed for eligibility of whom 153 (15%) had a detectable S. mansoni infection, and hence, were randomized to the standard treatment group (N = 70) and the intense treatment group (N = 83). Based on KK, the CR was 42% (95% confidence interval (CI) 31–52%) in the standard treatment group and 86% (95% CI 75–92%) in the intense treatment group. Observed IRR was 72% (95% CI 55–83%) in the standard treatment group and 95% (95% CI 85–98%) in the intense treatment group. The CR estimated by POC-CCA was 18% (95% CI 11–27%) and 36% (95% CI 26–46%) in the standard and intense treatment group, respectively. Repeated PZQ treatment did not result in a higher number of adverse events. Conclusion/significance The observed CR using KK was significantly higher after four repeated treatments compared to a single treatment, without an increase in adverse events. Using POC-CCA, the observed CR was significantly lower than measured by KK, indicating that PZQ may be considerably less efficacious as concluded by KK. Our findings highlight the need for reliable and more accurate diagnostic tools, which are essential for monitoring treatment efficacy, identifying changes in transmission, and accurately quantifying the intensity of infection in distinct populations. In addition, the higher CR in the intense treatment group suggests that more focused and intense PZQ treatment can help to advance schistosomiasis control. Trial registration www.clinicaltrials.govNCT02868385. The previously established efficacy of the widely used drug praziquantel (PZQ) against schistosomiasis might have been overestimated due to the use of inaccurate diagnostic methods. Repeated PZQ treatment at short intervals in areas with ongoing transmission could more effectively target non-susceptible schistosomula as they will have matured into drug susceptible worms within a few weeks. In the current study, we aimed to determine the cure rate (CR) of repeated PZQ, measured by the Kato-Katz (KK) technique and the point-of-care circulating cathodic antigen (POC-CCA) test, respectively. An open-label, randomized controlled trial was conducted assigning 153 school-aged children with a confirmed Schistosoma mansoni infection to two groups, one receiving a single PZQ treatment, while the second group received four repeated PZQ treatments, given at two-week intervals. Based on the KK test, the CR was significantly higher after four repeated treatments compared to a single treatment. When using POC-CCA, a diagnostic method that has not been utilized before in studies assessing the efficacy of four repeated PZQ treatments, the CR was much lower, even after four repeated PZQ treatments. Our results indicate that worms are still present after multiple PZQ treatments and that PZQ might be less efficacious than previously published.
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Affiliation(s)
- Pytsje T. Hoekstra
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
- * E-mail:
| | | | - Lisette van Lieshout
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
| | - Paul L. A. M. Corstjens
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, the Netherlands
| | - Roula Tsonaka
- Department of Biomedical Data Sciences, Leiden University Medical Center, Leiden, the Netherlands
| | - Rufin K. Assaré
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d’Ivoire
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Kigbafori D. Silué
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d’Ivoire
| | - Aboulaye Meité
- Programme National de Lutte contre les Maladies Tropicales Négligées à Chimiothérapie Préventive, Ministère de la Santé et de l’Hygiène Publique, Abidjan, Côte d’Ivoire
| | - Eliézer K. N’Goran
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d’Ivoire
| | - Yves K. N’Gbesso
- Département d’Agboville, Centre de Santé Urbain d’Azaguié, Azaguié, Côte d’Ivoire
| | - Abena S. Amoah
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
- Department of Population Health, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Malawi Epidemiology and Intervention Research Unit, Chilumba, Karonge District, Malawi
| | - Meta Roestenberg
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
- Department of Infectious Diseases, Leiden University Medical Center, Leiden, the Netherlands
| | - Stefanie Knopp
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Jean T. Coulibaly
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d’Ivoire
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Govert J. van Dam
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
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22
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Maizels RM. Regulation of immunity and allergy by helminth parasites. Allergy 2020; 75:524-534. [PMID: 31187881 DOI: 10.1111/all.13944] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 06/04/2019] [Accepted: 06/05/2019] [Indexed: 12/26/2022]
Abstract
There is increasing interest in helminth parasite modulation of the immune system, both from the fundamental perspective of the "arms race" between host and parasite, and equally importantly, to understand if parasites offer new pathways to abate and control untoward immune responses in humans. This article reviews the epidemiological and experimental evidence for parasite down-regulation of host immunity and immunopathology, in allergy and other immune disorders, and recent progress towards defining the mechanisms and molecular mediators which parasites exploit in order to modulate their host. Among these are novel products that interfere with epithelial cell alarmins, dendritic cell activation, macrophage function and T-cell responsiveness through the promotion of an immunoregulatory environment. These modulatory effects assist parasites to establish and survive, while dampening immune reactivity to allergens, autoantigens and microbiome determinants.
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Affiliation(s)
- Rick M. Maizels
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunology and Inflammation University of Glasgow Glasgow UK
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23
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Deol AK, Fleming FM, Calvo-Urbano B, Walker M, Bucumi V, Gnandou I, Tukahebwa EM, Jemu S, Mwingira UJ, Alkohlani A, Traoré M, Ruberanziza E, Touré S, Basáñez MG, French MD, Webster JP. Schistosomiasis - Assessing Progress toward the 2020 and 2025 Global Goals. N Engl J Med 2019; 381:2519-2528. [PMID: 31881138 PMCID: PMC6785807 DOI: 10.1056/nejmoa1812165] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND With the vision of "a world free of schistosomiasis," the World Health Organization (WHO) set ambitious goals of control of this debilitating disease and its elimination as a public health problem by 2020 and 2025, respectively. As these milestones become imminent, and if programs are to succeed, it is important to evaluate the WHO programmatic guidelines empirically. METHODS We collated and analyzed multiyear cross-sectional data from nine national schistosomiasis control programs (in eight countries in sub-Saharan Africa and in Yemen). Data were analyzed according to schistosome species (Schistosoma mansoni or S. haematobium), number of treatment rounds, overall prevalence, and prevalence of heavy-intensity infection. Disease control was defined as a prevalence of heavy-intensity infection of less than 5% aggregated across sentinel sites, and the elimination target was defined as a prevalence of heavy-intensity infection of less than 1% in all sentinel sites. Heavy-intensity infection was defined as at least 400 eggs per gram of feces for S. mansoni infection or as more than 50 eggs per 10 ml of urine for S. haematobium infection. RESULTS All but one country program (Niger) reached the disease-control target by two treatment rounds or less, which is earlier than projected by current WHO guidelines (5 to 10 years). Programs in areas with low endemicity levels at baseline were more likely to reach both the control and elimination targets than were programs in areas with moderate and high endemicity levels at baseline, although the elimination target was reached only for S. mansoni infection (in Burkina Faso, Burundi, and Rwanda within three treatment rounds). Intracountry variation was evident in the relationships between overall prevalence and heavy-intensity infection (stratified according to treatment rounds), a finding that highlights the challenges of using one metric to define control or elimination across all epidemiologic settings. CONCLUSIONS These data suggest the need to reevaluate progress and treatment strategies in national schistosomiasis control programs more frequently, with local epidemiologic data taken into consideration, in order to determine the treatment effect and appropriate resource allocations and move closer to achieving the global goals. (Funded by the Children's Investment Fund Foundation and others.).
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Affiliation(s)
- Arminder K Deol
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Fiona M Fleming
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Beatriz Calvo-Urbano
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Martin Walker
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Victor Bucumi
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Issah Gnandou
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Edridah M Tukahebwa
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Samuel Jemu
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Upendo J Mwingira
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Abdulhakeem Alkohlani
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Mahamadou Traoré
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Eugene Ruberanziza
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Seydou Touré
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Maria-Gloria Basáñez
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Michael D French
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
| | - Joanne P Webster
- From the Schistosomiasis Control Initiative (A.K.D., F.M.F., B.C.-U.), the London Centre for Neglected Tropical Disease Research (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), the Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London (A.K.D., F.M.F., M.W., M.-G.B., J.P.W.), and the Royal Veterinary College, the Department of Pathobiology and Population Sciences, University of London (M.W., J.P.W.) - all in London; the Ministry of Health Burundi, Bujumbura (V.B.); the Ministry of Health Niger, Niamey (I.G.); the Ministry of Health Uganda, Vector Control Division, Kampala (E.M.T.); the Ministry of Health Malawi, Lilongwe (S.J.); the Ministry of Health Tanzania and the National Institute for Medical Research, Dar es Salaam (U.J.M.); the Ministry of Health Yemen, Sana'a (A.A.); the Ministry of Public Health and Hygiene Mali, Bamako (M.T.); the Neglected Tropical Diseases Unit, Malaria and Other Parasitic Diseases Division, Institute of HIV-AIDS, Disease Prevention, and Control, Rwanda Biomedical Center, Ministry of Health, Kigali (E.R.); the National Schistosomiasis Program, Ministry of Health, Ouagadougou, Burkina Faso (S.T.); and RTI International, Washington, DC (M.D.F.)
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Kulinkina AV, Sarkar R, Mohan VR, Walz Y, Kaliappan SP, Ajjampur SSR, Ward H, Naumova EN, Kang G. Prediction of hookworm prevalence in southern India using environmental parameters derived from Landsat 8 remotely sensed data. Int J Parasitol 2019; 50:47-54. [PMID: 31756313 DOI: 10.1016/j.ijpara.2019.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 09/30/2019] [Accepted: 10/03/2019] [Indexed: 11/20/2022]
Abstract
Soil-transmitted helminth infections propagate poverty and slow economic growth in low-income countries. As with many other neglected tropical diseases, environmental conditions are important determinants of soil-transmitted helminth transmission. Hence, remotely sensed data are commonly utilised in spatial risk models intended to inform control strategies. In the present study, we build upon the existing modelling approaches by utilising fine spatial resolution Landsat 8 remotely sensed data in combination with topographic variables to predict hookworm prevalence in a hilly tribal area in southern India. Hookworm prevalence data collected from two field surveys were used in a random forest model to investigate the predictive capacity of 15 environmental variables derived from two remotely sensed images acquired during dry and rainy seasons. A variable buffer radius (100-1000 m) was applied to the point-prevalence locations in order to integrate environmental conditions around the village centroids into the modelling approach and understand where transmission is more likely. Elevation and slope were the most important variables in the models, with lower elevation and higher slope correlating with higher transmission risk. A modified normalised difference water index was among other recurring important variables, likely responsible for some seasonal differences in model performance. The 300 m buffer distance produced the best model performance in this setting, with another spike at 700 m, and a marked drop-off in R2 values at 1000 m. In addition to assessing a large number of environmental correlates with hookworm transmission, the study contributes to the development of standardised methods of spatial linkage of continuous environmental data with point-based disease prevalence measures for the purpose of spatially explicit risk profiling.
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Affiliation(s)
- Alexandra V Kulinkina
- Department of Public Health and Community Medicine, Tufts University School of Medicine, Boston, MA, USA; Partners In Health, Neno, Malawi.
| | - Rajiv Sarkar
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India
| | - Venkata R Mohan
- Department of Community Health, Christian Medical College, Vellore, Tamil Nadu, India
| | - Yvonne Walz
- Institute for Environment and Human Security, United Nations University, Bonn, Germany
| | | | - Sitara S R Ajjampur
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India
| | - Honorine Ward
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India; Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, Boston, MA, USA
| | - Elena N Naumova
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India; Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA
| | - Gagandeep Kang
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India
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Smith C, McLachlan G, Al Shehri H, Adriko M, Arinaitwe M, Atuhaire A, Muheki Tukahebwa E, LaCourse EJ, Stanton M, Stothard JR, Bustinduy AL. Schistosoma mansoni Infection as a Predictor of Low Aerobic Capacity in Ugandan Children. Am J Trop Med Hyg 2019; 100:1498-1506. [PMID: 30994097 PMCID: PMC6553905 DOI: 10.4269/ajtmh.18-0922] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 02/19/2019] [Indexed: 12/20/2022] Open
Abstract
Using the 20-meter shuttle run test (20mSRT) as a morbidity metric, we assessed whether Schistosoma mansoni infection was associated with decreased aerobic capacity in Ugandan children across a range of altitudes, either at low (∼600 m) or high (∼1,000 m) altitudes. A total of 305 children were recruited from six schools within the Buliisa District, Lake Albert, Uganda. A subset (n = 96) of these had been previously assessed and treated for schistosomiasis ± malaria 2 weeks prior. Fitness scores on the 20mSRT were translated into VO2max using a standardized equation. Unadjusted and multivariable-adjusted analyses were performed using VO2max as the primary outcome. Analysis of fitness scores from 304 children, inclusive of the subset follow-up cohort, revealed a median VO2max of 45.4 mL kg-1 min-1 (interquartile range: 42.9-48.0 mL kg-1 min-1). Children residing at high altitudes demonstrated increased aerobic capacities (46.3 versus 44.8 mL kg-1 min-1, P = 0.031). The prevalence of stunting, wasting, S. mansoni egg patent infection, malaria, giardiasis, anemia, and fecal occult blood were 36.7%, 16.1%, 44.3%, 65.2%, 21.4%, 50.6%, and 41.2%, respectively. Median VO2max was elevated in those previously treated, compared with those newly recruited (46.3 versus 44 mL kg-1 min-1, P < 0.001). Multivariable-adjusted analysis revealed a strong negative association between S. mansoni egg patent infection and VO2max at low altitude (beta coefficient: -3.96, 95% CI: -6.56 to -137, P = 0.004). This is the first study to document a negative association between S. mansoni infection and aerobic capacity at low altitudes using the 20mSRT.
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Affiliation(s)
- Courtney Smith
- Department of Clinical Research, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Georgia McLachlan
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Hajri Al Shehri
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Moses Adriko
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Moses Arinaitwe
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Aaron Atuhaire
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | | | - E. James LaCourse
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Michelle Stanton
- Lancaster Medical School, Lancaster University, Lancaster, United Kingdom
| | - J. Russell Stothard
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Amaya L. Bustinduy
- Department of Clinical Research, London School of Hygiene & Tropical Medicine, London, United Kingdom
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Sotillo J, Pearson MS, Becker L, Mekonnen GG, Amoah AS, van Dam G, Corstjens PLAM, Murray J, Mduluza T, Mutapi F, Loukas A. In-depth proteomic characterization of Schistosoma haematobium: Towards the development of new tools for elimination. PLoS Negl Trop Dis 2019; 13:e0007362. [PMID: 31091291 PMCID: PMC6538189 DOI: 10.1371/journal.pntd.0007362] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 05/28/2019] [Accepted: 04/05/2019] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Schistosomiasis is a neglected disease affecting hundreds of millions worldwide. Of the three main species affecting humans, Schistosoma haematobium is the most common, and is the leading cause of urogenital schistosomiasis. S. haematobium infection can cause different urogenital clinical complications, particularly in the bladder, and furthermore, this parasite has been strongly linked with squamous cell carcinoma. A comprehensive analysis of the molecular composition of its different proteomes will contribute to developing new tools against this devastating disease. METHODS AND FINDINGS By combining a comprehensive protein fractionation approach consisting of OFFGEL electrophoresis with high-throughput mass spectrometry, we have performed the first in-depth characterisation of the different discrete proteomes of S. haematobium that are predicted to interact with human host tissues, including the secreted and tegumental proteomes of adult flukes and secreted and soluble egg proteomes. A total of 662, 239, 210 and 138 proteins were found in the adult tegument, adult secreted, soluble egg and secreted egg proteomes, respectively. In addition, we probed these distinct proteomes with urine to assess urinary antibody responses from naturally infected human subjects with different infection intensities, and identified adult fluke secreted and tegument extracts as being the best predictors of infection. CONCLUSION We provide a comprehensive dataset of proteins from the adult and egg stages of S. haematobium and highlight their utility as diagnostic markers of infection intensity. Protein composition was markedly different between the different extracts, highlighting the distinct subsets of proteins that different development stages present in their different niches. Furthermore, we have identified adult fluke ES and tegument extracts as best predictors of infection using urine antibodies of naturally infected people. This study provides the first steps towards the development of novel tools to control this important neglected tropical disease.
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Affiliation(s)
- Javier Sotillo
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
- Laboratorio de Referencia en Parasitología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Mark S. Pearson
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| | - Luke Becker
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| | - Gebeyaw G. Mekonnen
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
| | - Abena S. Amoah
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Govert van Dam
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Paul L. A. M. Corstjens
- Department of Molecular Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Janice Murray
- Institute of Immunology & Infection Research, School of Biological Sciences, University of Edinburgh, Ashworth Laboratories, King's Buildings, Edinburgh, United Kingdom
| | - Takafira Mduluza
- Biochemistry Department, University of Zimbabwe, Mount Pleasant, Harare, Zimbabwe
- TIBA Partnership, NIHR Global Health Research Unit Tackling Infections to Benefit Africa (TIBA), University of Zimbabwe
| | - Francisca Mutapi
- Institute of Immunology & Infection Research, School of Biological Sciences, University of Edinburgh, Ashworth Laboratories, King's Buildings, Edinburgh, United Kingdom
- TIBA Partnership, NIHR Global Health Research Unit Tackling Infections to Benefit Africa (TIBA), University of Zimbabwe
| | - Alex Loukas
- Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
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Bärenbold O, Garba A, Colley DG, Fleming FM, Haggag AA, Ramzy RMR, Assaré RK, Tukahebwa EM, Mbonigaba JB, Bucumi V, Kebede B, Yibi MS, Meité A, Coulibaly JT, N’Goran EK, Tchuem Tchuenté LA, Mwinzi P, Utzinger J, Vounatsou P. Translating preventive chemotherapy prevalence thresholds for Schistosoma mansoni from the Kato-Katz technique into the point-of-care circulating cathodic antigen diagnostic test. PLoS Negl Trop Dis 2018; 12:e0006941. [PMID: 30550594 PMCID: PMC6310297 DOI: 10.1371/journal.pntd.0006941] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 12/28/2018] [Accepted: 10/23/2018] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Intervention guidelines against Schistosoma mansoni are based on the Kato-Katz technique. However, Kato-Katz thick smears show low sensitivity, especially for light-intensity infections. The point-of-care circulating cathodic antigen (POC-CCA) is a promising rapid diagnostic test detecting antigen output of living worms in urine and results are reported as trace, 1+, 2+, and 3+. The use of POC-CCA for schistosomiasis mapping, control, and surveillance requires translation of the Kato-Katz prevalence thresholds into POC-CCA relative treatment cut-offs. Furthermore, the infection status of egg-negative but antigen-positive individuals and the intensity-dependent sensitivity of POC-CCA should be estimated to determine its suitability for verification of disease elimination efforts. METHODOLOGY We used data from settings in Africa and the Americas characterized by a wide range of S. mansoni endemicity. We estimated infection intensity-dependent sensitivity and specificity of each test at the unit of the individual, using a hierarchical Bayesian egg-count model that removes the need to define a 'gold' standard applied to data with multiple Kato-Katz thick smears and POC-CCA urine cassette tests. A simulation study was carried out based on the model estimates to assess the relation of the two diagnostic tests for different endemicity scenarios. PRINCIPAL FINDINGS POC-CCA showed high specificity (> 95%), and high sensitivity (> 95%) for moderate and heavy infection intensities, and moderate sensitivity (> 75%) for light infection intensities, and even for egg-negative but antigen-positive infections. A 10% duplicate slide Kato-Katz thick smear prevalence corresponded to a 15-40% prevalence of ≥ trace-positive POC-CCA, and 10-20% prevalence of ≥ 1+ POC-CCA. The prevalence of ≥ 2+ POC-CCA corresponded directly to single slide Kato-Katz prevalence for all prevalence levels. CONCLUSIONS/SIGNIFICANCE The moderate sensitivity of POC-CCA, even for very light S. mansoni infections where the sensitivity of Kato-Katz is very low, and the identified relationship between Kato-Katz and POC-CCA prevalence thresholds render the latter diagnostic tool useful for surveillance and initial estimation of elimination of S. mansoni. For prevalence below 10% based on a duplicate slide Kato-Katz thick smear, we suggest using POC-CCA including trace results to evaluate treatment needs and propose new intervention thresholds that need to be validated in different settings.
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Affiliation(s)
- Oliver Bärenbold
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Amadou Garba
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
| | - Daniel G. Colley
- Center for Tropical and Emerging Global Diseases and Department of Microbiology, University of Georgia, Athens, GA, United States of America
| | - Fiona M. Fleming
- Schistosomiasis Control Initiative, Imperial College, London, United Kingdom
| | | | - Reda M. R. Ramzy
- National Nutrition Institute, General Organisation for Teaching Hospitals and Institutes, Cairo, Egypt
| | - Rufin K. Assaré
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d’Ivoire
| | | | | | - Victor Bucumi
- Programme National Intégré de Lutte contre les Maladies Tropicales Négligées et la Cécité au Burundi, Bujumbura, Burundi
| | | | - Makoy S. Yibi
- Neglected Tropical Disease Department, Ministry of Health, Juba, South Sudan
| | - Aboulaye Meité
- Programme National de Lutte contre les Maladies Tropicales Négligées à Chimiothérapie Préventive, Ministère de la Santé et de l’Hygiène Publique, Abidjan, Côte d’Ivoire
| | - Jean T. Coulibaly
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d’Ivoire
| | - Eliézer K. N’Goran
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d’Ivoire
| | - Louis-Albert Tchuem Tchuenté
- Laboratory of Parasitology and Ecology, University of Yaoundé I, Yaoundé, Cameroon
- Centre for Schistosomiasis and Parasitology, Yaoundé, Cameroon
| | - Pauline Mwinzi
- Centre for Global Health Research, Kenya Medical Research Institute, Nairobi, Kenya
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Penelope Vounatsou
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
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Potential Impact of Climate Change on Schistosomiasis: A Global Assessment Attempt. Trop Med Infect Dis 2018; 3:tropicalmed3040117. [PMID: 30400337 PMCID: PMC6306928 DOI: 10.3390/tropicalmed3040117] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 10/26/2018] [Accepted: 10/27/2018] [Indexed: 12/16/2022] Open
Abstract
Based on an ensemble of global circulation models (GCMs), four representative concentration pathways (RCPs) and several ongoing and planned Coupled Model Intercomparison Projects (CMIPs), the Intergovernmental Panel on Climate Change (IPCC) predicts that global, average temperatures will increase by at least 1.5 °C in the near future and more by the end of the century if greenhouse gases (GHGs) emissions are not genuinely tempered. While the RCPs are indicative of various amounts of GHGs in the atmosphere the CMIPs are designed to improve the workings of the GCMs. We chose RCP4.5 which represented a medium GHG emission increase and CMIP5, the most recently completed CMIP phase. Combining this meteorological model with a biological counterpart model accounted for replication and survival of the snail intermediate host as well as maturation of the parasite stage inside the snail at different ambient temperatures. The potential geographical distribution of the three main schistosome species: Schistosoma japonicum, S. mansoni and S. haematobium was investigated with reference to their different transmission capabilities at the monthly mean temperature, the maximum temperature of the warmest month(s) and the minimum temperature of the coldest month(s). The set of six maps representing the predicted situations in 2021⁻2050 and 2071⁻2100 for each species mainly showed increased transmission areas for all three species but they also left room for potential shrinkages in certain areas.
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King CH. Helminthiasis Epidemiology and Control: Scoring Successes and Meeting the Remaining Challenges. ADVANCES IN PARASITOLOGY 2018; 103:11-30. [PMID: 30878055 DOI: 10.1016/bs.apar.2018.08.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Parasitic helminth infections remain a significant challenge to global health. These are highly prevalent diseases, affecting over 1 billion persons worldwide. Their prevalence is closely linked to the presence of severe poverty and its associated sub-standard housing and sanitation. The last decade has seen a remarkable increase in our understanding of the true disease burden of helminth infections, and there has been increasing momentum on the part of national and non-governmental developmental organizations for prevention and control of these diseases. The expansion in mass treatment programmes for their control has yielded some significant successes. However, challenges remain in terms of ecological heterogeneity in transmission, incomplete drug uptake, and the likelihood of emerging drug resistance. The development of new, more-sensitive diagnostics is now broadening our knowledge of infection prevalence and of the risk of reinfection and has enhanced our knowledge of the prevalence of concurrent helminth infections. Adoption of these new diagnostic techniques for large-scale screening and surveillance will require adaptation of current mass treatment guidelines for control as programmes move from initial morbidity control objectives toward coordinated interventions aimed at local elimination.
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Affiliation(s)
- Charles H King
- Center for Global Health and Diseases, WHO Collaborating Centre for Research and Training on Schistosomiasis Elimination, Case Western Reserve University School of Medicine, Cleveland, OH, United States; Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), University of Georgia, Athens, GA, United States.
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Sircar AD, Mwinzi PNM, Onkanga IO, Wiegand RE, Montgomery SP, Secor WE. Schistosoma mansoni Mass Drug Administration Regimens and Their Effect on Morbidity among Schoolchildren over a 5-Year Period-Kenya, 2010-2015. Am J Trop Med Hyg 2018; 99:362-369. [PMID: 29893197 PMCID: PMC6090338 DOI: 10.4269/ajtmh.18-0067] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 03/22/2018] [Indexed: 12/24/2022] Open
Abstract
Schistosomiasis control programs are designed to reduce morbidity by providing mass drug administration (MDA) of praziquantel to at-risk populations. We compared morbidity markers between two cohorts of Kenyan schoolchildren that initially had high prevalence of Schistosoma mansoni infections. One cohort (N = 416 at year 1) received four rounds of annual MDA in a community-wide treatment (CWT) strategy. The other cohort (N = 386 at year 1) received school-based treatment (SBT) every other year over the 4-year period. We measured infection with S. mansoni and soil-transmitted helminths (STH) as well as subtle morbidity markers at year 1, year 3, and year 5 and compared cohorts with mixed models after controlling for age and gender. At year 5, neither overall S. mansoni prevalence nor the prevalence of high infection-intensity S. mansoni infection was significantly reduced compared with baseline in either the CWT cohort (N = 277 remaining) or the SBT cohort (N = 235 remaining). Nevertheless, by year 5, children in both cohorts demonstrated significant decreases in wasting, ultrasound-detected organomegaly, and STH infection along with significantly improved pediatric quality-of-life scores compared with year 1. Stunting did not change over time, but children who were S. mansoni egg-positive at year 5 had significantly more stunting than children without schistosomiasis. The only significant difference between arms at year 5 was a lower prevalence of STH infections in the CWT group.
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Affiliation(s)
- Anita D. Sircar
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Pauline N. M. Mwinzi
- Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Isaac O. Onkanga
- Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Ryan E. Wiegand
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Susan P. Montgomery
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - W. Evan Secor
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
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Marchese V, Beltrame A, Angheben A, Monteiro GB, Giorli G, Perandin F, Buonfrate D, Bisoffi Z. Schistosomiasis in immigrants, refugees and travellers in an Italian referral centre for tropical diseases. Infect Dis Poverty 2018; 7:55. [PMID: 29907162 PMCID: PMC6004084 DOI: 10.1186/s40249-018-0440-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 05/16/2018] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Schistosomiasis is one of the most important neglected tropical diseases. If unrecognised and untreated, the chronic infection can lead to irreversible complications. METHODS Retrospective observational study aimed at describing clinical history, laboratory findings and imaging presentation of imported schistosomiasis diagnosed at the Centre for Tropical Diseases, Sacro Cuore Don Calabria Hospital of Negrar, Verona, Italy from 2010 to 2014. The aim of our study was to assess differences in demographic characteristics, clinical presentation, laboratory data and ultrasound findings between immigrants/visiting friends and relatives (VFR) from endemic countries (endemic group) and expatriates/travellers (non-endemic group). RESULTS A total of 272 patients were retrieved: 234 in the endemic and 38 in the non-endemic group. Most of the patients acquired schistosomiasis in Africa (97.4%). Symptoms were reported by 52.9% of the patients; abdominal pain (36%), macroscopic hematuria (11.3%), and genito-urinary symptoms (7.4%) being the most frequently reported. Increased IgE and blood eosinophilia were observed in 169 (63.8%) and 130 (47.8%) patients, respectively. The proportion of positive serology was 250/272 (91.9%).The Circulating Cathodic Antigen CCA for Schistosoma mansoni was positive in 14/61 individuals (23%). At microscopy, infected subjects were 103/272 (37.9%). The species of Schistosoma found were S. haematobium (47.6%), S. mansoni (46.6%) or both (5.8%). Schistosomiasis was classified as confirmed in 103 (37.9%), probable in 165 (60.6%) and suspected in 4 (1.5%) cases using clinical presentation, laboratory data and ultrasound findings. The infection was further classified based on organ involvement: intestinal (17.9%), hepatosplenic (5.1%), urogenital (48.9%), and indeterminate (43.8%). The comparative analysis of endemic and non-endemic patients highlighted differences in sex and age. Endemic patients had more frequent ova identification (41.9% vs. 13.2%, P < 0.001) and increased IgE (70% vs. 26.3%, P < 0.001) when compared with non-endemic. Multivariate analyses showed that younger age, abnormal ultrasound findings and blood eosinophilia were significantly associated with positive microscopy (OR = 0.94, OR = 2.12, OR = 1.98, respectively). CONCLUSIONS Symptoms, eosinophilia and abnormal ultrasound findings were present in about half of patients, without differences between groups. Many patients had positive serology but negative microscopy, indicating that schistosomiasis might be misdiagnosed. A combination of diagnostic tools may facilitate the diagnosis.
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Affiliation(s)
- Valentina Marchese
- Centre for Tropical Diseases, Sacro Cuore Don Calabria Hospital, Via Sempreboni 5, 37024 Negrar, Italy
- University Department of Infectious and Tropical Diseases & WHO Collaborating Centre for TB/HIV and TB elimination, University of Brescia, Piazzale Spedali Civili 1, 25123 Brescia, Italy
| | - Anna Beltrame
- Centre for Tropical Diseases, Sacro Cuore Don Calabria Hospital, Via Sempreboni 5, 37024 Negrar, Italy
| | - Andrea Angheben
- Centre for Tropical Diseases, Sacro Cuore Don Calabria Hospital, Via Sempreboni 5, 37024 Negrar, Italy
| | - Geraldo Badona Monteiro
- Centre for Tropical Diseases, Sacro Cuore Don Calabria Hospital, Via Sempreboni 5, 37024 Negrar, Italy
| | - Giovanni Giorli
- Centre for Tropical Diseases, Sacro Cuore Don Calabria Hospital, Via Sempreboni 5, 37024 Negrar, Italy
| | - Francesca Perandin
- Centre for Tropical Diseases, Sacro Cuore Don Calabria Hospital, Via Sempreboni 5, 37024 Negrar, Italy
| | - Dora Buonfrate
- Centre for Tropical Diseases, Sacro Cuore Don Calabria Hospital, Via Sempreboni 5, 37024 Negrar, Italy
| | - Zeno Bisoffi
- Centre for Tropical Diseases, Sacro Cuore Don Calabria Hospital, Via Sempreboni 5, 37024 Negrar, Italy
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Freer JB, Bourke CD, Durhuus GH, Kjetland EF, Prendergast AJ. Schistosomiasis in the first 1000 days. THE LANCET. INFECTIOUS DISEASES 2018; 18:e193-e203. [PMID: 29170089 DOI: 10.1016/s1473-3099(17)30490-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 07/02/2017] [Accepted: 07/13/2017] [Indexed: 12/29/2022]
Abstract
Infections during the first 1000 days-the period from conception to a child's second birthday-can have lifelong effects on health, because this is a crucial phase of growth and development. There is increasing recognition of the burden and potential effects of schistosomiasis in women of reproductive age and young children. Exposure to schistosomes during pregnancy can modulate infant immune development and schistosomiasis can occur from early infancy, such that the high disease burden found in adolescents is often due to accumulation of infections with long-lived schistosomes from early life. Women of reproductive age and young children are largely neglected in mass drug administration programmes, but early treatment could avert subsequent disease. We evaluate the evidence that early schistosomiasis has adverse effects on birth, growth, and development. We also discuss the case for expanding public health interventions for schistosomiasis in women of reproductive age and preschool-age children, and the need for further research to evaluate the potential of treating women pre-conception to maximise health across the life course.
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Affiliation(s)
- Joseph B Freer
- Zvitambo Institute for Maternal and Child Health Research, Harare, Zimbabwe; Blizard Institute, Queen Mary University of London, London, UK.
| | - Claire D Bourke
- Blizard Institute, Queen Mary University of London, London, UK
| | - Gunn H Durhuus
- Department of Internal Medicine, Sorlandet Hospital, Kristiansand, Norway
| | - Eyrun F Kjetland
- Norwegian Centre for Imported and Tropical Diseases, Department of Infectious Diseases Ullevaal, Oslo University Hospital, Oslo, Norway; Discipline of Public Health Medicine, Nelson R Mandela School of Medicine, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Andrew J Prendergast
- Zvitambo Institute for Maternal and Child Health Research, Harare, Zimbabwe; Blizard Institute, Queen Mary University of London, London, UK
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Lothe A, Zulu N, Øyhus AO, Kjetland EF, Taylor M. Treating schistosomiasis among South African high school pupils in an endemic area, a qualitative study. BMC Infect Dis 2018; 18:239. [PMID: 29801483 PMCID: PMC5970489 DOI: 10.1186/s12879-018-3102-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Accepted: 04/17/2018] [Indexed: 12/02/2022] Open
Abstract
Background Schistosomiasis, a neglected tropical disease caused by parasites that infest open water sources such as rivers and dams may increase susceptibility to HIV. Mass-treatment with praziquantel tablets, recommended by the World Health Organization reduces the prevalence of schistosomiasis. The goal in endemic areas is 75% treatment participation in every treatment round (e.g. yearly). However, in rural Ugu district, KwaZulu-Natal, South-Africa there was low participation among pupils in a Department of Health Mass-Treatment Campaign for schistosomiasis. Methods Nested in a large study on schistosomiasis the study was conducted in 2012 over 4 months using qualitative methods with the Health Belief Model as the conceptual framework. Purposive sampling was done. Focus Group Discussions were undertaken at six schools in grades 10–12. Individual in-depth interviews were held with one teacher and two pupils at each school. In addition three traditional healers and a community health worker were interviewed. Results The severity of schistosomiasis was not recognised and neither was the pupils’ susceptibility. Barriers to treatment included confusing S, haematobium symptoms with sexually transmitted infections, teasing and stigma. Conclusions Increased knowledge, health literacy for treatment, and correct understanding about the severity of schistosomiasis may provide cues to action. The study indicates that comprehensive information may increase pupil participation in mass-treatment and decrease schistosomiasis prevalence. Trial registration This study was registered with clinicaltrials.gov registry database and the registration number is NCT01154907 30 June 2011.
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Affiliation(s)
- Andrea Lothe
- Norwegian Centre for Imported and Tropical Diseases, Department of Infectious Diseases Ullevaal, Oslo University Hospital, 0424, Oslo, Norway.,Institute for Global Development and Planning, University of Agder, 4630, Kristiansand, Norway
| | - Nqobile Zulu
- Centre for Communication, Media and Society, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Arne Olav Øyhus
- Institute for Global Development and Planning, University of Agder, 4630, Kristiansand, Norway
| | - Eyrun Floerecke Kjetland
- Norwegian Centre for Imported and Tropical Diseases, Department of Infectious Diseases Ullevaal, Oslo University Hospital, 0424, Oslo, Norway.,Discipline of Public Health Medicine, Howard College Campus, University of KwaZulu-Natal, Room 219, George Campbell Building, Science Drive, Durban, 4001, South Africa
| | - Myra Taylor
- Discipline of Public Health Medicine, Howard College Campus, University of KwaZulu-Natal, Room 219, George Campbell Building, Science Drive, Durban, 4001, South Africa.
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DiNardo AR, Nishiguchi T, Mace EM, Rajapakshe K, Mtetwa G, Kay A, Maphalala G, Secor WE, Mejia R, Orange JS, Coarfa C, Bhalla KN, Graviss EA, Mandalakas AM, Makedonas G. Schistosomiasis Induces Persistent DNA Methylation and Tuberculosis-Specific Immune Changes. THE JOURNAL OF IMMUNOLOGY 2018; 201:124-133. [PMID: 29752313 DOI: 10.4049/jimmunol.1800101] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 04/09/2018] [Indexed: 12/29/2022]
Abstract
Epigenetic mechanisms, such as DNA methylation, determine immune cell phenotype. To understand the epigenetic alterations induced by helminth coinfections, we evaluated the longitudinal effect of ascariasis and schistosomiasis infection on CD4+ T cell DNA methylation and the downstream tuberculosis (TB)-specific and bacillus Calmette-Guérin-induced immune phenotype. All experiments were performed on human primary immune cells from a longitudinal cohort of recently TB-exposed children. Compared with age-matched uninfected controls, children with active Schistosoma haematobium and Ascaris lumbricoides infection had 751 differentially DNA-methylated genes, with 72% hypermethylated. Gene ontology pathway analysis identified inhibition of IFN-γ signaling, cellular proliferation, and the Th1 pathway. Targeted real-time quantitative PCR after methyl-specific endonuclease digestion confirmed DNA hypermethylation of the transcription factors BATF3, ID2, STAT5A, IRF5, PPARg, RUNX2, IRF4, and NFATC1 and cytokines or cytokine receptors IFNGR1, TNFS11, RELT (TNF receptor), IL12RB2, and IL12B (p < 0.001; Sidak-Bonferroni). Functional blockage of the IFN-γ signaling pathway was confirmed, with helminth-infected individuals having decreased upregulation of IFN-γ-inducible genes (Mann-Whitney p < 0.05). Hypomethylation of the IL-4 pathway and DNA hypermethylation of the Th1 pathway was confirmed by Ag-specific multidimensional flow cytometry demonstrating decreased TB-specific IFN-γ and TNF and increased IL-4 production by CD4+ T cells (Wilcoxon signed-rank p < 0.05). In S. haematobium-infected individuals, these DNA methylation and immune phenotypic changes persisted at least 6 mo after successful deworming. This work demonstrates that helminth infection induces DNA methylation and immune perturbations that inhibit TB-specific immune control and that the duration of these changes are helminth specific.
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Affiliation(s)
- Andrew R DiNardo
- The Global Tuberculosis Program, Immigrant and Global Health, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030;
| | - Tomoki Nishiguchi
- The Global Tuberculosis Program, Immigrant and Global Health, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030
| | - Emily M Mace
- Department of Pathology, Baylor College of Medicine, Houston, TX 77030.,Texas Children's Hospital Center for Human Immunobiology, Department of Pediatrics, Texas Children's Hospital Center for Human Immunobiology, Baylor College of Medicine, Houston, TX 77030
| | - Kimal Rajapakshe
- Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030
| | - Godwin Mtetwa
- Baylor-Swaziland Children's Foundation, Mbabane H100, Swaziland
| | - Alexander Kay
- Baylor-Swaziland Children's Foundation, Mbabane H100, Swaziland
| | | | - W Evan Secor
- Parasitic Diseases Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA 30333
| | - Rojelio Mejia
- Department of Pediatrics, National School of Tropical Medicine, Texas Children's Hospital Center for Human Immunobiology, Houston, TX 77030
| | - Jordan S Orange
- Department of Pathology, Baylor College of Medicine, Houston, TX 77030.,Texas Children's Hospital Center for Human Immunobiology, Department of Pediatrics, Texas Children's Hospital Center for Human Immunobiology, Baylor College of Medicine, Houston, TX 77030
| | - Cristian Coarfa
- Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX 77030
| | - Kapil N Bhalla
- Department of Leukemia, MD Anderson Cancer Center, Houston, TX 77030; and
| | - Edward A Graviss
- Department of Pathology and Genomic Medicine, Houston Methodist Hospital Research Institute, Houston, TX 77030
| | - Anna M Mandalakas
- The Global Tuberculosis Program, Immigrant and Global Health, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030
| | - George Makedonas
- Department of Pathology, Baylor College of Medicine, Houston, TX 77030.,Texas Children's Hospital Center for Human Immunobiology, Department of Pediatrics, Texas Children's Hospital Center for Human Immunobiology, Baylor College of Medicine, Houston, TX 77030
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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.
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Clements MN, Corstjens PLAM, Binder S, Campbell CH, de Dood CJ, Fenwick A, Harrison W, Kayugi D, King CH, Kornelis D, Ndayishimiye O, Ortu G, Lamine MS, Zivieri A, Colley DG, van Dam GJ. Latent class analysis to evaluate performance of point-of-care CCA for low-intensity Schistosoma mansoni infections in Burundi. Parasit Vectors 2018; 11:111. [PMID: 29475457 PMCID: PMC5824563 DOI: 10.1186/s13071-018-2700-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 02/06/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Kato-Katz examination of stool smears is the field-standard method for detecting Schistosoma mansoni infection. However, Kato-Katz misses many active infections, especially of light intensity. Point-of-care circulating cathodic antigen (CCA) is an alternative field diagnostic that is more sensitive than Kato-Katz when intensity is low, but interpretation of CCA-trace results is unclear. To evaluate trace results, we tested urine and stool specimens from 398 pupils from eight schools in Burundi using four approaches: two in Burundi and two in a laboratory in Leiden, the Netherlands. In Burundi, we used Kato-Katz and point-of-care CCA (CCAB). In Leiden, we repeated the CCA (CCAL) and also used Up-Converting Phosphor Circulating Anodic Antigen (CAA). METHODS We applied Bayesian latent class analyses (LCA), first considering CCA traces as negative and then as positive. We used the LCA output to estimate validity of the prevalence estimates of each test in comparison to the population-level infection prevalence and estimated the proportion of trace results that were likely true positives. RESULTS Kato-Katz yielded the lowest prevalence (6.8%), and CCAB with trace considered positive yielded the highest (53.5%). There were many more trace results recorded by CCA in Burundi (32.4%) than in Leiden (2.3%). Estimated prevalence with CAA was 46.5%. LCA indicated that Kato-Katz had the lowest sensitivity: 15.9% [Bayesian Credible Interval (BCI): 9.2-23.5%] with CCA-trace considered negative and 15.0% with trace as positive (BCI: 9.6-21.4%), implying that Kato-Katz missed approximately 85% of infections. CCAB underestimated disease prevalence when trace was considered negative and overestimated disease prevalence when trace was considered positive, by approximately 12 percentage points each way, and CAA overestimated prevalence in both models. Our results suggest that approximately 52.2% (BCI: 37.8-5.8%) of the CCAB trace readings were true infections. CONCLUSIONS Whether measured in the laboratory or the field, CCA outperformed Kato-Katz at the low infection intensities in Burundi. CCA with trace as negative likely missed many infections, whereas CCA with trace as positive overestimated prevalence. In the absence of a field-friendly gold standard diagnostic, the use of a variety of diagnostics with differing properties will become increasingly important as programs move towards elimination of schistosomiasis. It is clear that CCA is a valuable tool for the detection and mapping of S. mansoni infection in the field and CAA may be a valuable field tool in the future.
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Affiliation(s)
- Michelle N. Clements
- Schistosomiasis Control Initiative (SCI), Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Paul L. A. M. Corstjens
- Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, the Netherlands
| | - Sue Binder
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA USA
| | - Carl H. Campbell
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA USA
| | - Claudia J. de Dood
- Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, the Netherlands
| | - Alan Fenwick
- Schistosomiasis Control Initiative (SCI), Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Wendy Harrison
- Schistosomiasis Control Initiative (SCI), Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Donatien Kayugi
- Programme National Intégré de lutte contre les Maladies Tropicales Négligées et la Cécité (PNIMTNC), Ministère de la Santé Publique et de la Lutte contre le SIDA, Bujumbura, Burundi
| | - Charles H. King
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH USA
| | - Dieuwke Kornelis
- Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, the Netherlands
| | - Onesime Ndayishimiye
- Programme National Intégré de lutte contre les Maladies Tropicales Négligées et la Cécité (PNIMTNC), Ministère de la Santé Publique et de la Lutte contre le SIDA, Bujumbura, Burundi
| | - Giuseppina Ortu
- Schistosomiasis Control Initiative (SCI), Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Mariama Sani Lamine
- Schistosomiasis Control Initiative (SCI), Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Antonio Zivieri
- Schistosomiasis Control Initiative (SCI), Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Daniel G. Colley
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA USA
| | - Govert J. van Dam
- Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, the Netherlands
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Impact and cost-effectiveness of snail control to achieve disease control targets for schistosomiasis. Proc Natl Acad Sci U S A 2018; 115:E584-E591. [PMID: 29301964 PMCID: PMC5789907 DOI: 10.1073/pnas.1708729114] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Schistosomiasis is an infectious disease that affects over 240 million people living in low- and middle-income countries, and is caused by parasitic worms that require snail hosts to complete its lifecycle. To improve public health control of this disease, there is growing interest in using chemical-based snail control that kills snail populations in environmental water sources, which will reduce infection rate in people. We modeled transmission of schistosomiasis and cost-effectiveness of various strategies with data from low- and high-prevalence rural Kenyan communities. Adding snail control alongside conventional mass treatment programs (instead of mass treatment programs alone) was found to be cost-effective, especially in settings with high disease burden and nonparticipation in mass treatment programs. Schistosomiasis is a parasitic disease that affects over 240 million people globally. To improve population-level disease control, there is growing interest in adding chemical-based snail control interventions to interrupt the lifecycle of Schistosoma in its snail host to reduce parasite transmission. However, this approach is not widely implemented, and given environmental concerns, the optimal conditions for when snail control is appropriate are unclear. We assessed the potential impact and cost-effectiveness of various snail control strategies. We extended previously published dynamic, age-structured transmission and cost-effectiveness models to simulate mass drug administration (MDA) and focal snail control interventions against Schistosoma haematobium across a range of low-prevalence (5–20%) and high-prevalence (25–50%) rural Kenyan communities. We simulated strategies over a 10-year period of MDA targeting school children or entire communities, snail control, and combined strategies. We measured incremental cost-effectiveness in 2016 US dollars per disability-adjusted life year and defined a strategy as optimally cost-effective when maximizing health gains (averted disability-adjusted life years) with an incremental cost-effectiveness below a Kenya-specific economic threshold. In both low- and high-prevalence settings, community-wide MDA with additional snail control reduced total disability by an additional 40% compared with school-based MDA alone. The optimally cost-effective scenario included the addition of snail control to MDA in over 95% of simulations. These results support inclusion of snail control in global guidelines and national schistosomiasis control strategies for optimal disease control, especially in settings with high prevalence, “hot spots” of transmission, and noncompliance to MDA.
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Clements MN, Donnelly CA, Fenwick A, Kabatereine NB, Knowles SCL, Meité A, N'Goran EK, Nalule Y, Nogaro S, Phillips AE, Tukahebwa EM, Fleming FM. Interpreting ambiguous 'trace' results in Schistosoma mansoni CCA Tests: Estimating sensitivity and specificity of ambiguous results with no gold standard. PLoS Negl Trop Dis 2017; 11:e0006102. [PMID: 29220354 PMCID: PMC5738141 DOI: 10.1371/journal.pntd.0006102] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 12/20/2017] [Accepted: 11/07/2017] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The development of new diagnostics is an important tool in the fight against disease. Latent Class Analysis (LCA) is used to estimate the sensitivity and specificity of tests in the absence of a gold standard. The main field diagnostic for Schistosoma mansoni infection, Kato-Katz (KK), is not very sensitive at low infection intensities. A point-of-care circulating cathodic antigen (CCA) test has been shown to be more sensitive than KK. However, CCA can return an ambiguous 'trace' result between 'positive' and 'negative', and much debate has focused on interpretation of traces results. METHODOLOGY/PRINCIPLE FINDINGS We show how LCA can be extended to include ambiguous trace results and analyse S. mansoni studies from both Côte d'Ivoire (CdI) and Uganda. We compare the diagnostic performance of KK and CCA and the observed results by each test to the estimated infection prevalence in the population. Prevalence by KK was higher in CdI (13.4%) than in Uganda (6.1%), but prevalence by CCA was similar between countries, both when trace was assumed to be negative (CCAtn: 11.7% in CdI and 9.7% in Uganda) and positive (CCAtp: 20.1% in CdI and 22.5% in Uganda). The estimated sensitivity of CCA was more consistent between countries than the estimated sensitivity of KK, and estimated infection prevalence did not significantly differ between CdI (20.5%) and Uganda (19.1%). The prevalence by CCA with trace as positive did not differ significantly from estimates of infection prevalence in either country, whereas both KK and CCA with trace as negative significantly underestimated infection prevalence in both countries. CONCLUSIONS Incorporation of ambiguous results into an LCA enables the effect of different treatment thresholds to be directly assessed and is applicable in many fields. Our results showed that CCA with trace as positive most accurately estimated infection prevalence.
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Affiliation(s)
| | - Christl A. Donnelly
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Alan Fenwick
- Schistosomiasis Control Initiative, Imperial College, London, United Kingdom
| | | | - Sarah C. L. Knowles
- Schistosomiasis Control Initiative, Imperial College, London, United Kingdom
- The Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, United Kingdom
| | - Aboulaye Meité
- Côte d'Ivoire Ministry of Health, National Program Against Filariasis, Schistosomiasis and Geohelminths, Abidjan, Côte d'Ivoire
| | - Eliézer K. N'Goran
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abijan, Côte d'Ivoire
| | - Yolisa Nalule
- Schistosomiasis Control Initiative, Imperial College, London, United Kingdom
| | - Sarah Nogaro
- Schistosomiasis Control Initiative, Imperial College, London, United Kingdom
| | - Anna E. Phillips
- Schistosomiasis Control Initiative, Imperial College, London, United Kingdom
| | | | - Fiona M. Fleming
- Schistosomiasis Control Initiative, Imperial College, London, United Kingdom
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Karanja DMS, Awino EK, Wiegand RE, Okoth E, Abudho BO, Mwinzi PNM, Montgomery SP, Secor WE. Cluster randomized trial comparing school-based mass drug administration schedules in areas of western Kenya with moderate initial prevalence of Schistosoma mansoni infections. PLoS Negl Trop Dis 2017; 11:e0006033. [PMID: 29059190 PMCID: PMC5667887 DOI: 10.1371/journal.pntd.0006033] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 11/02/2017] [Accepted: 10/11/2017] [Indexed: 11/18/2022] Open
Abstract
Background Mass drug administration (MDA) using praziquantel is the WHO-recommended approach for control of schistosomiasis. However, few studies have compared the impact of different schedules of MDA on the resultant infection levels. We wished to evaluate whether annual MDA was more effective than less frequent treatments for reducing community-level prevalence and intensity of Schistosoma mansoni infections. Methods We performed a cluster randomized trial (ISRCTN 14849830) of 3 different MDA frequencies over a 5 year period in 75 villages with moderate (10%-24%) initial prevalence of S. mansoni in school children in western Kenya. Praziquantel was distributed by school teachers to students either annually, the first 2 years, or every other year over a 4 year period. Prevalence and intensity of infection were measured by stool examination in 9–12 year old students using the Kato-Katz method at baseline, each treatment year, and for the final evaluation at year 5. S. mansoni prevalence and intensity were also measured in first year students at baseline and year 5. Results Twenty-five schools were randomly assigned to each arm. S. mansoni prevalence and infection intensity in 9–12 year old students significantly decreased within each arm from baseline to year 5 but there were no differences between arms. There were no differences in infection levels in first year students either within or between arms. Conclusions Strategies employing 2 or 4 rounds of MDA had a similar impact in schools with moderate initial prevalence, suggesting that schistosomiasis control can be sustained by school-based MDA, even if provided only every other year. The World Health Organization (WHO) guidelines recommend mass drug administration (MDA) of praziquantel for control of schistosomiasis. The target group for and the frequency of treatment are based on infections levels in school age children at the initiation of the control program. However, these guidelines have not been rigorously evaluated. Through the Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), we had the opportunity to compare the impact of school-based treatment in an area of western Kenya with moderate (10%-24%) initial prevalence of Schistosoma mansoni infections. We found that providing MDA every year or every other year over a 4 year period provided similar benefits for reducing prevalence and intensity of infection in the final evaluation at year 5. Annual or biennial MDA moved villages from the “moderate risk” to the “low risk category” prescribed in the WHO guidelines. The results from this study and parallel SCORE studies in other African countries should provide the evidence base necessary for improved WHO guidelines for schistosomiasis.
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Affiliation(s)
- Diana M. S. Karanja
- Neglected Tropical Diseases Branch, Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Emmy K. Awino
- Neglected Tropical Diseases Branch, Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Ryan E. Wiegand
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Edward Okoth
- Neglected Tropical Diseases Branch, Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Bernard O. Abudho
- Neglected Tropical Diseases Branch, Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Pauline N. M. Mwinzi
- Neglected Tropical Diseases Branch, Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Susan P. Montgomery
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - W. Evan Secor
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
- * E-mail:
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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.
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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
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Won KY, Kanyi HM, Mwende FM, Wiegand RE, Goodhew EB, Priest JW, Lee YM, Njenga SM, Secor WE, Lammie PJ, Odiere MR. Multiplex Serologic Assessment of Schistosomiasis in Western Kenya: Antibody Responses in Preschool Aged Children as a Measure of Reduced Transmission. Am J Trop Med Hyg 2017; 96:1460-1467. [PMID: 28719280 PMCID: PMC5462587 DOI: 10.4269/ajtmh.16-0665] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Currently, impact of schistosomiasis control programs in Schistosoma mansoni–endemic areas is monitored primarily by assessment of parasitologic indicators only. Our study was conducted to evaluate the use of antibody responses as a way to measure the impact of schistosomiasis control programs. A total of 3,612 serum samples collected at three time points from children 1–5 years of age were tested for antibody responses to two schistosome antigens (soluble egg antigen [SEA] and Sm25) by multiplex bead assay. The overall prevalence of antibody responses to SEA was high at baseline (50.0%). After one round of mass drug administration (MDA), there was minimal change in odds of SEA positivity (odds ratio [OR] = 1.02, confidence interval [CI] = 0.79–1.32, P = 0.89). However, after two rounds of treatment, there was a slight decrease in odds of SEA positivity (OR = 0.80, CI = 0.63–1.02, P = 0.08). In contrast to the SEA results, prevalence of antibody responses to Sm25 was lowest at baseline (14.1%) and higher in years 2 (19.8%) and 3 (18.4%). After one round of MDA, odds of Sm25 positivity increased significantly (OR = 1.51, CI = 1.14–2.02, P = 0.005) and remained significantly higher than baseline after two rounds of MDA (OR = 1.37, CI = 1.07–1.76, P = 0.01). There was a significant decrease in the proportion of 1-year-olds with positive SEA responses from 33.1% in year 1 to 13.2% in year 3 and a corresponding decrease in the odds (OR = 3.25, CI = 1.75–6.08, P < 0.001). These results provide preliminary evidence that schistosomiasis program impact can be monitored using serologic responses.
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Affiliation(s)
- Kimberly Y Won
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Henry M Kanyi
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
| | - Faith M Mwende
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
| | - Ryan E Wiegand
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - E Brook Goodhew
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Jeffrey W Priest
- Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Yeuk-Mui Lee
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Sammy M Njenga
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
| | - W Evan Secor
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Patrick J Lammie
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Maurice R Odiere
- Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
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Turner HC, Truscott JE, Bettis AA, Farrell SH, Deol AK, Whitton JM, Fleming FM, Anderson RM. Evaluating the variation in the projected benefit of community-wide mass treatment for schistosomiasis: Implications for future economic evaluations. Parasit Vectors 2017; 10:213. [PMID: 28454578 PMCID: PMC5410074 DOI: 10.1186/s13071-017-2141-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 04/18/2017] [Indexed: 12/14/2022] Open
Abstract
Background The majority of schistosomiasis control programmes focus on targeting school-aged children. Expanding the use of community-wide mass treatment to reach more adults is under consideration. However, it should be noted that this would require a further increase in programmatic resources, international aid, and commitment for the provision of praziquantel. Consequently, it is important to understand (i) where a change of strategy would have the greatest benefit, and (ii) how generalisable the conclusions of field trials and analytical studies based on mathematical models investigating the impact of community-wide mass treatment, are to a broad range of settings. Methods In this paper, we employ a previously described deterministic fully age-structured schistosomiasis transmission model and evaluate the benefit of community-wide mass treatment both in terms of controlling morbidity and eliminating transmission for Schistosoma mansoni, across a wide range of epidemiological settings and programmatic scenarios. This included variation in the baseline relative worm pre-control burden in adults, the overall level of transmission in defined settings, choice of effectiveness metric (basing morbidity calculations on prevalence or intensity), the level of school enrolment and treatment compliance. Results Community-wide mass treatment was found to be more effective for controlling the transmission of schistosome parasites than using a school-based programme only targeting school-aged children. However, in the context of morbidity control, the potential benefit of switching to community-wide mass treatment was highly variable across the different scenarios analysed. In contrast, for areas where the goal is to eliminate transmission, the projected benefit of community-wide mass treatment was more consistent. Conclusion Whether community-wide mass treatment is appropriate will depend on the local epidemiological setting (i.e. the relative pre-control burden in adults and transmission intensity), and whether the goal is morbidity control or eliminating transmission. This has important implications regarding the generalisability of cost-effectiveness analyses of schistosomiasis interventions. Our results indicate that areas with poor school-enrolment/coverage could benefit more from community-wide treatment of praziquantel and should potentially be prioritised for any change in strategy. This work highlights the importance of not over-generalising conclusions and policy in this area, but of basing decisions on high quality epidemiological data and quantitative analyses of the impact of interventions in a range of settings. Electronic supplementary material The online version of this article (doi:10.1186/s13071-017-2141-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hugo C Turner
- London Centre for Neglected Tropical Disease Research, London, UK. .,Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London, Norfolk Place, London, W2 1PG, UK. .,Oxford University Clinical Research Unit, Wellcome Trust Major Overseas Programme, Ho Chi Minh City, Vietnam. .,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - James E Truscott
- London Centre for Neglected Tropical Disease Research, London, UK.,Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - Alison A Bettis
- London Centre for Neglected Tropical Disease Research, London, UK.,Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - Sam H Farrell
- London Centre for Neglected Tropical Disease Research, London, UK.,Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - Arminder K Deol
- London Centre for Neglected Tropical Disease Research, London, UK.,Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - Jane M Whitton
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - Fiona M Fleming
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine (St. Mary's Campus), Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - Roy M Anderson
- London Centre for Neglected Tropical Disease Research, London, UK.,Department of Infectious Disease Epidemiology, School of Public Health, Faculty of Medicine, St Marys Campus, Imperial College London, Norfolk Place, London, W2 1PG, UK
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Colley DG, Andros TS, Campbell CH. Schistosomiasis is more prevalent than previously thought: what does it mean for public health goals, policies, strategies, guidelines and intervention programs? Infect Dis Poverty 2017; 6:63. [PMID: 28327187 PMCID: PMC5361841 DOI: 10.1186/s40249-017-0275-5] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 03/06/2017] [Indexed: 01/08/2023] Open
Abstract
Mapping and diagnosis of infections by the three major schistosome species (Schistosoma haematobium, S. mansoni and S. japonicum) has been done with assays that are known to be specific but increasingly insensitive as prevalence declines or in areas with already low prevalence of infection. This becomes a true challenge to achieving the goal of elimination of schistosomiasis because the multiplicative portion of the life-cycle of schistosomes, in the snail vector, favors continued transmission as long as even a few people maintain low numbers of worms that pass eggs in their excreta. New mapping tools based on detection of worm antigens (circulating cathodic antigen – CCA; circulating anodic antigen – CAA) in urine of those infected are highly sensitive and the CAA assay is reported to be highly specific. Using these tools in areas of low prevalence of all three of these species of schistosomes has demonstrated that more people harbor adult worms than are regularly excreting eggs at a level detectable by the usual stool assay (Kato-Katz) or by urine filtration. In very low prevalence areas this is sometimes 6- to10-fold more. Faced with what appears to be a sizable population of “egg-negative/worm-positive schistosomiasis” especially in areas of very low prevalence, national NTD programs are confounded about what guidelines and strategies they should enact if they are to proceed toward a goal of elimination. There is a critical need for continued evaluation of the assays involved and to understand the contribution of this “egg-negative/worm-positive schistosomiasis” condition to both individual morbidity and community transmission. There is also a critical need for new guidelines based on the use of these more sensitive assays for those national NTD programs that wish to move forward to strategies designed for elimination.
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Affiliation(s)
- Daniel G Colley
- Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), Center for Tropical and Emerging Global Diseases (CTEGD), University of Georgia, 500 DW Brooks Drive, Room 330B Coverdell Center, Athens, Georgia, 30602, USA. .,Department of Microbiology, University of Georgia, Athens, Georgia, 30602, USA.
| | - Tamara S Andros
- Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), Center for Tropical and Emerging Global Diseases (CTEGD), University of Georgia, 500 DW Brooks Drive, Room 330B Coverdell Center, Athens, Georgia, 30602, USA
| | - Carl H Campbell
- Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), Center for Tropical and Emerging Global Diseases (CTEGD), University of Georgia, 500 DW Brooks Drive, Room 330B Coverdell Center, Athens, Georgia, 30602, USA
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Abstract
Early in the history of schistosomiasis research, children under 5 years of age were known to be infected. Although this problem was recognized over 100 years ago, insufficient action has been taken to address this issue. Under current policy, such infected children only receive their first antiparasitic treatment (praziquantel - PZQ) upon entry into primary school as current mass drug administration programmes typically target school-aged children. For many infected children, they will wait up to 6 years before receiving their first medication and significant schistosomiasis-related morbidity may have already established. This inequity would not be accepted for other diseases. To unveil some of the reasons behind this neglect, it is paramount to understand the intricate historical relationship between schistosomiasis and British Imperial medicine, to underline its lasting influence on today's public health priorities. This review presents a perspective on the historical neglect of paediatric schistosomiasis, focusing on important gaps that persist from the early days after discovery of this parasite. Looking to end this inequity, we address several issues that need to be overcome to move forward towards the lasting success of schistosomiasis control and elimination efforts.
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Barda B, Coulibaly JT, Hatz C, Keiser J. Ultrasonographic evaluation of urinary tract morbidity in school-aged and preschool-aged children infected with Schistosoma haematobium and its evolution after praziquantel treatment: A randomized controlled trial. PLoS Negl Trop Dis 2017; 11:e0005400. [PMID: 28222149 PMCID: PMC5336295 DOI: 10.1371/journal.pntd.0005400] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 03/03/2017] [Accepted: 02/10/2017] [Indexed: 11/18/2022] Open
Abstract
Background Schistosoma haematobium infections are responsible for significant urinary tract (UT) complications. Schistosomiasis control programs aim to reduce morbidity, yet the extent of morbidity in preschool-aged children and the impact of treatment on morbidity reduction are not well studied. Methodology Our study was embedded in a randomized, placebo-controlled, single-blind trial in Côte d’Ivoire, which evaluated the efficacy and safety of three doses (20, 40 and 60 mg/kg) of praziquantel in school-aged (SAC) and preschool-aged (PSAC) children infected with S. haematobium. Enrolled children were invited to participate in an ultrasound examination prior and six months after treatment. At these time points 3 urine samples were collected for parasitological and clinical examinations. Principal findings 162 PSAC and 141 SAC participated in the ultrasound examination at baseline, of which 128 PSAC and 122 SAC were present at follow-up. At baseline 43% (70/162) of PSAC had UT morbidity, mostly at bladder level and 7% had hydronephrosis. 67% (94/141) of SAC revealed mainly moderate UT pathology, 4% presented pseudopolyps on the bladder wall, and 6% had pyelectasis. At follow up, 45% of PSAC and 58% of SAC were S. haematobium positive, mostly harboring light infection intensities (41% and 51%, respectively). Microhematuria was present in 33% of PSAC and 42% of SAC and leukocyturia in 53% and 40% of PSAC and SAC, respectively. 50% (64/128) of PSAC and 58% (71/122) of SAC presented urinary tract morbidity, which was mainly mild. A significant correlation (p<0.05) was observed between praziquantel treatment and reversal of S. haematobium induced morbidity. Progression of UT pathology decreased with increasing praziquantel dosages. A worsening of morbidity was observed among children in the placebo group. Conclusion/Significance Bladder morbidity is widespread among PSAC. Praziquantel treatment is significantly associated with the reversal of S. haematobium induced morbidity, which underscores the importance of preventive chemotherapy programs. These programs should be expanded to PSAC to prevent or decrease the prevalence of morbidity in young children. This trial is registered as an International Standard Randomized Controlled Trial, number ISRCTN15280205. Schistosoma haematobium is a parasite that infects the human genito-urinary tract. People get infected with the parasite through contact with fresh water and children are at major risk. The complications linked to this infection are due to an inflammation caused by accumulation of the eggs in peri-bladder veins. If not treated, infections can last years and different degrees of severity are observed. These range from thickening of the bladder wall and blurriness of the mucosa to more serious lesions such as pseudo polyps and masses in the bladder that can, with time, evolve in cancer of the bladder. We analyzed preschool-aged children (PSAC) and school-aged children (SAC) with ultrasound before and after praziquantel treatment. Children were randomly assigned to different doses of praziquantel (20, 40 or 60 mg/kg) or to placebo at baseline. Six months after treatment all children underwent another ultrasound of the urinary tract. We included 162 PSAC and 141 SAC at baseline, of which 128 PSAC and 122 SAC had a second ultrasound evaluation six months afterwards. In addition, urine was sampled at both time points for presence of blood, proteins and signs of infection (leukocytes and nitrates). Six months post-treatment 45% of PSAC and 58% of SAC were S. haematobium positive. Already at the first screening 43% of PSAC and 67% of SAC had bladder lesions. After treatment 50% of PSAC and 58% of SAC still had pathology linked to the infection. We found a correlation between the treatment dose and healing of bladder lesions. On the other hand, we experienced an aggravation of lesions in the placebo group. Praziquantel is given to SAC as preventive chemotherapy every year at national level, where this parasite is endemic. This program should be expanded and include PSAC as well in order to reduce the consequences of infection.
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Affiliation(s)
- Beatrice Barda
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, CH-4003 Basel, Switzerland
| | - Jean T. Coulibaly
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, CH-4003 Basel, Switzerland
- Unité de Formation et de Recherche Biosciences, Université Felix Houphouët-Boigny, Abidjan, Côte d’Ivoire
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
| | - Christoph Hatz
- University of Basel, CH-4003 Basel, Switzerland
- Medical Department, 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, CH-4003 Basel, Switzerland
- * E-mail:
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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.
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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.
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Sotillo J, Doolan D, Loukas A. Recent advances in proteomic applications for schistosomiasis research: potential clinical impact. Expert Rev Proteomics 2016; 14:171-183. [DOI: 10.1080/14789450.2017.1271327] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Javier Sotillo
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD, Australia
| | - Denise Doolan
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD, Australia
| | - Alex Loukas
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD, Australia
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Bustinduy AL, Friedman JF, Kjetland EF, Ezeamama AE, Kabatereine NB, Stothard JR, King CH. Expanding Praziquantel (PZQ) Access beyond Mass Drug Administration Programs: Paving a Way Forward for a Pediatric PZQ Formulation for Schistosomiasis. PLoS Negl Trop Dis 2016; 10:e0004946. [PMID: 27658198 PMCID: PMC5033572 DOI: 10.1371/journal.pntd.0004946] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Amaya L. Bustinduy
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom
- * E-mail:
| | - Jennifer F. Friedman
- Center for International Health Research, Rhode Island Hospital and Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Eyrun Floerecke Kjetland
- Norwegian Centre for Imported and Tropical Diseases, Department of Infectious Diseases Ullevaal, Oslo University Hospital, Oslo, Norway
- Discipline of Public Health Medicine, Nelson R. Mandela School of Medicine, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Amara E. Ezeamama
- Department of Epidemiology and Biostatistics University of Georgia, Athens, Georgia, United States of America
| | | | - J. Russell Stothard
- Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Charles H. King
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio, United States of America
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Parasitic helminth infections and the control of human allergic and autoimmune disorders. Clin Microbiol Infect 2016; 22:481-6. [PMID: 27172808 DOI: 10.1016/j.cmi.2016.04.024] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 04/26/2016] [Accepted: 04/30/2016] [Indexed: 02/06/2023]
Abstract
The profile of global health today presents a striking reciprocal distribution between parasitic diseases in many of the world's lower-income countries, and ever-increasing levels of inflammatory disorders such as allergy, autoimmunity and inflammatory bowel diseases in the more affluent societies. Attention is particularly focused on helminth worm parasites, which are associated with protection from allergy and inflammation in both epidemiologic and laboratory settings. One mechanistic explanation of this is that helminths drive the regulatory arm of the immune system, abrogating the ability of the host to expel the parasites, while also dampening reactivity to many bystander specificities. Interest has therefore heightened into whether helminth parasites, or their products, hold therapeutic potential for immunologic disorders of the developed world. In this narrative review, progress across a range of trials is discussed, together with prospects for isolating individual molecular mediators from helminths that may offer defined new therapies for inflammatory conditions.
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El Ridi R, Tallima H, Migliardo F. Biochemical and biophysical methodologies open the road for effective schistosomiasis therapy and vaccination. Biochim Biophys Acta Gen Subj 2016; 1861:3613-3620. [PMID: 27062905 DOI: 10.1016/j.bbagen.2016.03.036] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Revised: 03/19/2016] [Accepted: 03/22/2016] [Indexed: 12/27/2022]
Abstract
BACKGROUND Schistosomiasis caused by blood-dwelling flukes, namely Schistosoma mansoni and Schistosoma haematobium is a severe debilitating disease, widespread in sub-Saharan Africa, the Middle East, and South America. Developing and adult worms are unscathed by the surrounding immune effectors and antibodies because the parasite is protected by a double lipid bilayer armor which allows access of nutrients, while binding of specific antibodies is denied. SCOPE OF REVIEW Fluorescence recovery after bleaching, extraction of surface membrane cholesterol by methyl-β-cyclodextrin, inhibition and activation of sphingomyelin biosynthesis and hydrolysis, and elastic incoherent and quasi-elastic neutron scattering approaches have helped to clarify the basic mechanism of this immune evasion, and showed that sphingomyelin (SM) molecules in the worm apical lipid bilayer form with surrounding water molecules a tight hydrogen bond barrier. Viability of the parasite and permeability of the outer shield are controlled by equilibrium between SM biosynthesis and activity of a tegument-associated neutral sphingomyelinase (nSMase). MAJOR CONCLUSIONS Excessive nSMase activation by polyunsaturated fatty acids (PUFA), such as arachidonic acid (ARA) leads to disruption of the SM molecules and associated hydrogen bond network, with subsequent access of host antibodies and immune effectors to the outer membrane and eventual parasite death. GENERAL SIGNIFICANCE ARA was predicted and shown to be a potent schistosomicide in vitro and in vivo in experimental animals and in children. Additionally, it was advocated that schistosomiasis vaccine candidates should be selected uniquely among excretory-secretory products of developing worms, as contrary to cytosolic and surface membrane antigens, they are able to activate the effector functions of the host antibodies and toxic molecules. This article is part of a Special Issue entitled "Science for Life" Guest Editor: Dr. Austen Angell, Dr. Salvatore Magazù and Dr. Federica Migliardo".
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Affiliation(s)
- Rashika El Ridi
- Zoology Department, Faculty of Science, Cairo University, Cairo 12613, Egypt.
| | - Hatem Tallima
- Zoology Department, Faculty of Science, Cairo University, Cairo 12613, Egypt; Department of Chemistry, School of Science and Engineering, American University in Cairo, New Cairo, 11835 Cairo, Egypt
| | - Federica Migliardo
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, 98166 Messina, Italy
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