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Graeff-Teixeira C, Marcolongo-Pereira C, Kersanach BB, Geiger SM, Negrão-Correa D. Descriptive study on risk of increased morbidity of schistosomiasis and graft loss after liver transplantation. Rev Soc Bras Med Trop 2024; 57:e00201. [PMID: 39082515 PMCID: PMC11290851 DOI: 10.1590/0037-8682-0097-2024] [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: 03/13/2024] [Accepted: 05/29/2024] [Indexed: 08/02/2024] Open
Abstract
Solid-organ transplantation procedures have witnessed a surge in frequency. Consequently, increased attention to associated infections and their impact on graft success is warranted. The liver is the principal target for infection by the flatworm Schistosoma mansoni. Hence, rigorous screening protocols for this parasite should be implemented for liver transplantation donors and recipients. This study investigated the risks posed by schistosomiasis-infected liver tissues for successful liver transplantation (LT), considering donors and recipients, by analyzing reported cases. Among the 43 patients undergoing LT (donors = 19; recipients = 24), 32 were infected with S. mansoni, five were infected with other Schistosoma species, and no identification was made in four patients. Reported follow-up periods ranged from 1 to 132 months, and all patients achieved successful recovery. As these helminths do not replicate in their vertebrate hosts, immunosuppressive treatment is not expected to promote increased morbidity or reactivation. Moreover, suspected or confirmed schistosomiasis infections often have a benign course, and generally, should not prevent LT. The available literature was reviewed and a provisional screening protocol has been proposed.
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Affiliation(s)
- Carlos Graeff-Teixeira
- Universidade Federal do Espírito Santo, Centro de Ciências da Saúde, Departamento de Patologia e Núcleo de Doenças Infecciosas, Vitória, ES, Brasil
| | - Clairton Marcolongo-Pereira
- Universidade Federal do Espírito Santo, Centro de Ciências da Saúde, Departamento de Patologia e Núcleo de Doenças Infecciosas, Vitória, ES, Brasil
- Centro Universitário do Espírito Santo, Faculdade de Medicina, Colatina, ES, Brasil
| | - Betina Bolina Kersanach
- Universidade Federal do Espírito Santo, Centro de Ciências da Saúde, Departamento de Patologia e Núcleo de Doenças Infecciosas, Vitória, ES, Brasil
| | - Stefan Michael Geiger
- Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Departamento de Parasitologia, Belo Horizonte, MG, Brasil
| | - Deborah Negrão-Correa
- Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Laboratório de Esquistossomose e Imuno-helmintologia - Departamento de Parasitologia, Belo Horizonte, MG, Brasil
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Coffeng LE, Graham M, Browning R, Kura K, Diggle PJ, Denwood M, Medley GF, Anderson RM, de Vlas SJ. Improving the Cost-efficiency of Preventive Chemotherapy: Impact of New Diagnostics on Stopping Decisions for Control of Schistosomiasis. Clin Infect Dis 2024; 78:S153-S159. [PMID: 38662699 PMCID: PMC11045014 DOI: 10.1093/cid/ciae020] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2024] Open
Abstract
BACKGROUND Control of schistosomiasis (SCH) relies on the regular distribution of preventive chemotherapy (PC) over many years. For the sake of sustainable SCH control, a decision must be made at some stage to scale down or stop PC. These "stopping decisions" are based on population surveys that assess whether infection levels are sufficiently low. However, the limited sensitivity of the currently used diagnostic (Kato-Katz [KK]) to detect low-intensity infections is a concern. Therefore, the use of new, more sensitive, molecular diagnostics has been proposed. METHODS Through statistical analysis of Schistosoma mansoni egg counts collected from Burundi and a simulation study using an established transmission model for schistosomiasis, we investigated the extent to which more sensitive diagnostics can improve decision making regarding stopping or continuing PC for the control of S. mansoni. RESULTS We found that KK-based strategies perform reasonably well for determining when to stop PC at a local scale. Use of more sensitive diagnostics leads to a marginally improved health impact (person-years lived with heavy infection) and comes at a cost of continuing PC for longer (up to around 3 years), unless the decision threshold for stopping PC is adapted upward. However, if this threshold is set too high, PC may be stopped prematurely, resulting in a rebound of infection levels and disease burden (+45% person-years of heavy infection). CONCLUSIONS We conclude that the potential value of more sensitive diagnostics lies more in the reduction of survey-related costs than in the direct health impact of improved parasite control.
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Affiliation(s)
- Luc E Coffeng
- Department of Public Health, Erasmus Medical Center, University Medical Center Rotterdam, The Netherlands
| | - Matthew Graham
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford
| | | | - Klodeta Kura
- London Centre for Neglected Tropical Disease Research, School of Public Health, Imperial College London
- Medical Research Council Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London
| | - Peter J Diggle
- Centre for Health Informatics, Computing, and Statistics, Lancaster University Medical School, United Kingdom
| | - Matthew Denwood
- Department of Veterinary and Animal Sciences, University of Copenhagen, Denmark
| | - Graham F Medley
- Department of Global Health and Development, Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Roy M Anderson
- London Centre for Neglected Tropical Disease Research, School of Public Health, Imperial College London
- Medical Research Council Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London
| | - Sake J de Vlas
- Department of Public Health, Erasmus Medical Center, University Medical Center Rotterdam, The Netherlands
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Magalhães FDC, Moreira JMP, de Rezende MC, Favero V, Graeff-Teixeira C, Coelho PMZ, Carneiro M, Geiger SM, Negrão-Corrêa D. Evaluation of isotype-based serology for diagnosis of Schistosoma mansoni infection in individuals living in endemic areas with low parasite burden. Acta Trop 2023; 248:107017. [PMID: 37774894 DOI: 10.1016/j.actatropica.2023.107017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 08/31/2023] [Accepted: 09/01/2023] [Indexed: 10/01/2023]
Abstract
Intestinal schistosomiasis is a chronic and debilitating disease that affects public health systems worldwide. Control interventions to reduce morbidity primarily involve the diagnosis and treatment of infected individuals. However, the recommended Kato-Katz (KK) parasitological method shows low sensitivity in individuals with low parasite loads and is not useful for monitoring elimination of parasite transmission at later stages. In the current study, we evaluated the accuracy of serum reactivity levels of different immunoglobulin isotypes in an enzyme-linked immunosorbent assay (ELISA), utilizing Schistosoma mansoni crude extracts, with the aim to improve the diagnosis of infected individuals with low parasite loads. The serum reactivity of IgM and IgG subclass antibodies (IgG1, IgG3, and IgG4) against soluble adult worm and egg antigen preparations was evaluated in residents from a schistosomiasis-endemic area in northern Minas Gerais, Brazil. The parasitological status of the study population was determined through fecal examination with multiple parasitological tests to create a consolidated reference standard (CRS) plus a fecal DNA detection test (q-PCR). Twelve months after praziquantel treatment, a second serum sample was obtained from the population for reexamination. A two-graph receiver operating characteristic curve (TG-ROC) analysis was performed using the serum reactivity of non-infected endemic controls and egg-positive individuals, and the cut-off value was established based on the intersection point of the sensibility and specificity curves in TG-ROC analyses. The diagnostic accuracy of each serological test was evaluated in relation to the parasitological CRS and to the combination of CRS plus qPCR results. The data revealed that serum reactivity of IgM and IgG3 against S. mansoni antigens did not allow identification of infected individuals from the endemic area. In contrast, serum IgG1 and IgG4-reactivity against schistosome antigens could distinguish between infected and non-infected individuals, with AUC values ranging between 0.728-0.925. The reactivity of IgG4 anti-soluble egg antigen - SEA (sensitivity 79 %, specificity 69 %, kappa = 0.49) had the best diagnostic accuracy, showing positive reactivity in more than 75 % of the infected individuals who eliminated less than 12 eggs per gram of feces. Moreover, serum IgG4 reactivity against SEA and against soluble worm antigen preparation (SWAP) was significantly reduced in the serum of infected individuals after 12 months of confirmed parasitological cure and in the absence of re-infection. These results reinforce that the described IgG4 anti-SEA ELISA assay is a sensitive alternative for the diagnosis of active intestinal schistosomiasis in individuals from endemic areas, including in those with a very low parasite load.
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Affiliation(s)
- Fernanda do Carmo Magalhães
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - João Marcelo Peixoto Moreira
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Michelle Carvalho de Rezende
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Vivian Favero
- Laboratório de Biologia Parasitária, Escola de Ciências, Pontifícia Universidade Católica do Rio Grande do Sul, Brazil
| | - Carlos Graeff-Teixeira
- Centro de Ciências da Saúde, Núcleo de Doenças Infecciosas, Universidade Federal do Espírito Santo, Brazil
| | - Paulo Marcos Zech Coelho
- Laboratório de Esquistossomose, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Brazil
| | - Mariângela Carneiro
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Stefan Michael Geiger
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Deborah Negrão-Corrêa
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
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Umbelino-Walker I, Wong F, Cassolato M, Pantelias A, Jacobson J, Kalume C. Integration of female genital schistosomiasis into HIV/sexual and reproductive health and rights and neglected tropical diseases programmes and services: a scoping review. Sex Reprod Health Matters 2023; 31:2262882. [PMID: 37850814 PMCID: PMC10586082 DOI: 10.1080/26410397.2023.2262882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2023] Open
Abstract
Female genital schistosomiasis (FGS) affects approximately 56 million women and girls across sub-Saharan Africa and is associated with up to a threefold increased prevalence of HIV. Integrating FGS with HIV programmes as part of comprehensive sexual and reproductive health (SRH) services may be one of the most significant missed opportunities for preventing HIV incidence among girls and women. A search of studies published until October 2021 via Scopus and ProQuest was conducted using PRISMA guidelines to assess how FGS can be integrated into HIV/SRH and neglected tropical diseases (NTDs) programmes and services. Data extraction included studies that integrated interventions and described the opportunities and challenges. A total of 334 studies were identified, with 22 eligible for analysis and summarised conducting a descriptive numerical analysis and qualitative review. We adapted a framework for integrated implementation of FGS, HIV, and HPV/cervical cancer to thematically organise the results, classifying them into five themes: awareness and community engagement, diagnosis, treatment, burden assessment, and economic evaluation. Most activities pertained to awareness and community engagement (n = 9), diagnosis (n = 9) and were primarily connected to HIV/AIDS (n = 8) and school-based services and programming (n = 8). The studies mainly described the opportunities and challenges for integration, rather than presenting results from implemented integration interventions, highlighting an evidence gap on FGS integration into HIV/SRH and NTD programmes. Investments are needed to realise the potential of FGS integration to address the burden of this neglected disease and improve HIV and SRH outcomes for millions of women and girls at risk.
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Affiliation(s)
| | - Felicia Wong
- Independent Consultant, Frontline AIDS, Worthing, UK
| | | | | | - Julie Jacobson
- Managing Partner, Co-Founder, Bridges to Development, Seattle, WA, USA
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Chala B. Advances in Diagnosis of Schistosomiasis: Focus on Challenges and Future Approaches. Int J Gen Med 2023; 16:983-995. [PMID: 36967838 PMCID: PMC10032164 DOI: 10.2147/ijgm.s391017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 03/07/2023] [Indexed: 03/20/2023] Open
Abstract
Schistosomiasis is the second most devastating parasite prevalent in the tropical region of the world, posing significant public health impacts in endemic areas. Presently, several disease mitigation measures have shown a decline in transmission of the infection rate in risk localities using mass drug administration (MDA) of school-based or community-wide treatments. Despite all the endeavors made, the decline in transmission of infection rate has not been attained in the entire medicated segment of the population. Perhaps the current challenges of control of the disease appear to be strongly associated with a lack of appropriate diagnostic tools. It's well known that the current diagnosis of schistosomiasis greatly relies on conventional methods. On the other hand, minor symptoms of schistosomiasis and low sensitivity and specificity of diagnostic methods are still unresolved diagnostic challenges to clinicians. Numerous scholars have reviewed various diagnostic methods of schistosomiasis and attempted to identify their strengths and weaknesses, currently on function. As a result of the known limitations of the existing diagnostic tools, the need to develop new and feasible diagnostic methods and diagnostic markers is unquestionable for more precise detection of the infection. Hence, advances in diagnostic methods have been considered part of the solution for the control and eventual elimination strategy of the disease in endemic areas. As of today, easy, cheap, and accurate diagnostics for schistosomiasis are difficult to get, and this limits the concerted efforts towards full control of schistosomiasis. While looking for new diagnostic methods and markers, it is important to simultaneously work on improving the existing diagnostic methods for better results. This review tries to give new insights to the status of the existing diagnostic methods of schistosomiasis from conventional to modern via summarizing the strengths and limitations of the methods. It also tries to recommend new, sensitive and feasible diagnostic methods for future approaches.
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Affiliation(s)
- Bayissa Chala
- Department of Applied Biology, School of Applied Natural Science, Adama Science and Technology University, Adama, Ethiopia
- Correspondence: Bayissa Chala, Email ;
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Makia CM, Fesuh NB, Amabo EN, Gamba VA, Oluwole AS, Stothard R. Urogenital schistosomiasis (UGS) and female genital schistosomiasis (FGS) in Cameroon: an observational assessment of key reproductive health determinants of girls and women in the Matta Health Area. BMJ Open 2023; 13:e063392. [PMID: 36787976 PMCID: PMC9930553 DOI: 10.1136/bmjopen-2022-063392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 02/05/2023] [Indexed: 02/16/2023] Open
Abstract
OBJECTIVES AND SETTING Across sub-Saharan Africa, urogenital schistosomiasis (UGS), in particular female genital schistosomiasis (FGS), is a significant waterborne parasitic disease, with its direct burden on the sexual and reproductive health (SRH) of sufferers infrequently measured. UGS has an established control plan, which in most endemic regions as in Cameroon, still excludes FGS considerations. Highlighting existent associations between UGS and FGS could increase the management of FGS within UGS interventions. This study seeks to identify current associations among FGS and UGS with some reproductive health indicators, to provide formative information for better integrated control. PARTICIPANTS 304 females aged 5-69 years were all examined for UGS by urine filtration and microscopy. Among these, 193 women and girls were eligible for clinical FGS assessment based on age (>13). After selective questioning for FGS symptoms, a subgroup of 67 women and girls consented for clinical examination for FGS using portable colposcopy, with observed sequelae classified according to the WHO FGS pocket atlas. OUTCOME Overall UGS and FGS prevalence was measured, with FGS-related/UGS-related reproductive health symptoms recorded. Associations between FGS and UGS were investigated by univariate and multivariate logistic regression analyses. RESULTS Overall UGS prevalence was 63.8% (194/304), where FGS prevalence (subgroup) was 50.7% (34/67). FGS manifestation increased significantly with increasing age, while a significant decrease with ascending age was observed for UGS. Lower abdominal pain (LAP) vaginal itches (VI) and coital pain (CP) were identified as the main significant shared symptoms of both FGS and UGS, while LAP with menstrual irregularity (MI) appeared a strong symptomatic indicator for FGS. CONCLUSION LAP, MI, CP and VI are the potential SRH indicators that could be exploited in future for targeting of praziquantel provision to FGS sufferers within primary care, complementary with existing praziquantel distribution for UGS sufferers in Schistosoma haematobium endemic areas.
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Affiliation(s)
- Christine Masong Makia
- Social Sciences and Management, Catholic University of Central Africa, Yaounde, Centre, Cameroon
| | - Nono Betrand Fesuh
- Department of Mathematics and Physical Sciences, National Advanced School of Engineering, University of Yaoundé 1, Yaoundé, Centre, Cameroon
| | | | - Victoria A Gamba
- Department of Obstetrics and Gynecology, University of Nairobi, Nairobi, Nairobi, Kenya
| | - Akinola Stephen Oluwole
- Department of Pure and Applied Zoology, Federal University of Agriculture Abeokuta, Abeokuta, Ogun, Nigeria
| | - Russell Stothard
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, UK
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Hoekstra PT, Madinga J, Lutumba P, van Grootveld R, Brienen EAT, Corstjens PLAM, van Dam GJ, Polman K, van Lieshout L. Diagnosis of Schistosomiasis without a Microscope: Evaluating Circulating Antigen (CCA, CAA) and DNA Detection Methods on Banked Samples of a Community-Based Survey from DR Congo. Trop Med Infect Dis 2022; 7:315. [PMID: 36288056 PMCID: PMC9608707 DOI: 10.3390/tropicalmed7100315] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 10/13/2022] [Accepted: 10/17/2022] [Indexed: 11/16/2022] Open
Abstract
Detection of Schistosoma eggs in stool or urine is known for its low sensitivity in diagnosing light infections. Alternative diagnostics with better sensitivity while remaining highly specific, such as real-time PCR and circulating antigen detection, are progressively used as complementary diagnostic procedures but have not yet replaced microscopy. This study evaluates these alternative methods for the detection of Schistosoma infections in the absence of microscopy. Schistosomiasis presence was determined retrospectively in 314 banked stool and urine samples, available from a previous survey on the prevalence of taeniasis in a community in the Democratic Republic of the Congo, using real-time PCR, the point-of-care circulating cathodic antigen (POC-CCA) test, as well as the up-converting particle lateral flow circulating anodic antigen (UCP-LF CAA) test. Schistosoma DNA was present in urine (3%) and stool (28%) samples, while CCA (28%) and CAA (69%) were detected in urine. Further analysis of the generated data indicated stool-based PCR and the POC-CCA test to be suitable diagnostics for screening of S. mansoni infections, even in the absence of microscopy. A substantial proportion (60%) of the 215 CAA-positive cases showed low antigen concentrations, suggesting that even PCR and POC-CCA underestimated the "true" number of schistosome positives.
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Affiliation(s)
- Pytsje T. Hoekstra
- Department of Parasitology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | - Joule Madinga
- Institute of Health and Society, Université Catholique de Louvain, 1348 Brussels, Belgium
- Department of Biomedical Sciences, Institute of Tropical Medicine, 2000 Antwerp, Belgium
| | - Pascal Lutumba
- Institut National de Recherche Biomédicale, Kinshasa 1197, Democratic Republic of the Congo
- Department of Tropical Medicine, University of Kinshasa, Kinshasa 7948, Democratic Republic of the Congo
| | - Rebecca van Grootveld
- Department of Clinical Microbiology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | - Eric A. T. Brienen
- Department of Parasitology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | - Paul L. A. M. Corstjens
- Department of Cell and Chemical Biology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | - Govert J. van Dam
- Department of Parasitology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | - Katja Polman
- Department of Biomedical Sciences, Institute of Tropical Medicine, 2000 Antwerp, Belgium
- Department of Health Sciences, VU University Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Lisette van Lieshout
- Department of Parasitology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
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Degarege A, Animut A, Negash Y, Erko B. Performance of Urine Reagent Strips in Detecting the Presence and Estimating the Prevalence and Intensity of Schistosoma haematobium Infection. Microorganisms 2022; 10:2062. [PMID: 36296338 PMCID: PMC9611304 DOI: 10.3390/microorganisms10102062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 10/16/2022] [Accepted: 10/17/2022] [Indexed: 08/27/2023] Open
Abstract
The performance of the urine reagent strips (URS) in detecting the presence and estimating the intensity of Schistosoma haematobium infection was evaluated using urine filtration microscopy as a reference standard. Urine samples collected from 1288 school-age children living in five villages of the Afar and one village in the Gambella Regional States of Ethiopia between October 2021 and April 2022 were examined using urine filtration and URS. The prevalence of S. haematobium infection was 31.6% based on urine filtration and 32.1% using URS. Using results of the urine filtration as a reference, the sensitivity, specificity, negative predictive values, and accuracy of the URS in detecting S. haematobium egg-positive urine specimens were 73.7%, 87.8%, 87.1%, and 82.8%, respectively. Sensitivity increased significantly with an increase in the urine egg count. Specificity was greater in low prevalence settings and among children aged 5-9 years. The level of hematuria detected was trace (19.1%), weak (30.2%), moderate (36.0%), or high (14.7%). The log odds of showing higher-level hematuria significantly increased as the number of egg counts in urine increased. In conclusion, URS remains good in rapidly screening individuals for S. haematobium infection, but the sensitivity of the test could be lower, particularly when the intensity of the infection is light.
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Affiliation(s)
- Abraham Degarege
- Department of Epidemiology, College of Public Health, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Abebe Animut
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa P.O. Box 1176, Ethiopia
| | - Yohannes Negash
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa P.O. Box 1176, Ethiopia
| | - Berhanu Erko
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa P.O. Box 1176, Ethiopia
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Liang S, Ponpetch K, Zhou YB, Guo J, Erko B, Stothard JR, Murad MH, Zhou XN, Satrija F, Webster JP, Remais JV, Utzinger J, Garba A. Diagnosis of Schistosoma infection in non-human animal hosts: A systematic review and meta-analysis. PLoS Negl Trop Dis 2022; 16:e0010389. [PMID: 35522699 PMCID: PMC9116658 DOI: 10.1371/journal.pntd.0010389] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 05/18/2022] [Accepted: 04/03/2022] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Reliable and field-applicable diagnosis of schistosome infections in non-human animals is important for surveillance, control, and verification of interruption of human schistosomiasis transmission. This study aimed to summarize uses of available diagnostic techniques through a systematic review and meta-analysis. METHODOLOGY AND PRINCIPAL FINDINGS We systematically searched the literature and reports comparing two or more diagnostic tests in non-human animals for schistosome infection. Out of 4,909 articles and reports screened, 19 met our inclusion criteria, four of which were considered in the meta-analysis. A total of 14 techniques (parasitologic, immunologic, and molecular) and nine types of non-human animals were involved in the studies. Notably, four studies compared parasitologic tests (miracidium hatching test (MHT), Kato-Katz (KK), the Danish Bilharziasis Laboratory technique (DBL), and formalin-ethyl acetate sedimentation-digestion (FEA-SD)) with quantitative polymerase chain reaction (qPCR), and sensitivity estimates (using qPCR as the reference) were extracted and included in the meta-analyses, showing significant heterogeneity across studies and animal hosts. The pooled estimate of sensitivity was 0.21 (95% confidence interval (CI): 0.03-0.48) with FEA-SD showing highest sensitivity (0.89, 95% CI: 0.65-1.00). CONCLUSIONS/SIGNIFICANCE Our findings suggest that the parasitologic technique FEA-SD and the molecular technique qPCR are the most promising techniques for schistosome diagnosis in non-human animal hosts. Future studies are needed for validation and standardization of the techniques for real-world field applications.
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Affiliation(s)
- Song Liang
- Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
| | - Keerati Ponpetch
- Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
- Sirindhorn College of Public Health Trang, Faculty of Public Health and Allied Health Sciences, Praboromarajchanok Institute, Trang, Thailand
| | - Yi-Biao Zhou
- School of Public Health, Fudan University, Shanghai, People’s Republic of China
| | - Jiagang Guo
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
| | - Berhanu Erko
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - J. Russell Stothard
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Merseyside, United Kingdom
| | - M. Hassan Murad
- Division of Public Health, Infectious Diseases and Occupational Medicine, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, People’s Republic of China
| | - Fadjar Satrija
- Department of Animal Infectious Diseases and Veterinary Public Health, Faculty of Veterinary Medicine, IPB University, Bogor, Indonesia
| | - Joanne P. Webster
- Department of Pathobiology and Population Sciences, Royal Veterinary College, Hertfordshire, United Kingdom
| | - Justin V. Remais
- School of Public Health, University of California, Berkeley, Berkeley, California, United States of America
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Amadou Garba
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
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10
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Grolimund CM, Bärenbold O, Hatz CF, Vennervald BJ, Mayombana C, Mshinda H, Utzinger J, Vounatsou P. Infection intensity-dependent accuracy of reagent strip for the diagnosis of Schistosoma haematobium and estimation of treatment prevalence thresholds. PLoS Negl Trop Dis 2022; 16:e0010332. [PMID: 35468129 PMCID: PMC9071146 DOI: 10.1371/journal.pntd.0010332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 05/05/2022] [Accepted: 03/15/2022] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Reagent strip to detect microhematuria as a proxy for Schistosoma haematobium infections has been considered an alternative to urine filtration for individual diagnosis and community-based estimates of treatment needs for preventive chemotherapy. However, the diagnostic accuracy of reagent strip needs further investigation, particularly at low infection intensity levels. METHODS We used existing data from a study conducted in Tanzania that employed urine filtration and reagent strip testing for S. haematobium in two villages, including a baseline and six follow-up surveys after praziquantel treatment representing a wide range of infection prevalence. We developed a Bayesian model linking individual S. haematobium egg count data based on urine filtration to reagent strip binary test results available on multiple days and estimated the relation between infection intensity and sensitivity of reagent strip. Furthermore, we simulated data from 3,000 hypothetical populations with varying mean infection intensity to infer on the relation between prevalence observed by urine filtration and the interpretation of reagent strip readings. PRINCIPAL FINDINGS Reagent strip showed excellent sensitivity even for single measurement reaching 100% at around 15 eggs of S. haematobium per 10 ml of urine when traces on reagent strip were considered positive. The corresponding specificity was 97%. When traces were considered negative, the diagnostic accuracy of the reagent strip was equivalent to urine filtration data obtained on a single day. A 10% and 50% urine filtration prevalence based on a single day sampling corresponds to 11.2% and 48.6% prevalence by reagent strip, respectively, when traces were considered negative, and 17.6% and 57.7%, respectively, when traces were considered positive. CONCLUSIONS/SIGNIFICANCE Trace results should be included in reagent strip readings when high sensitivity is required, but excluded when high specificity is needed. The observed prevalence of reagent strip results, when traces are considered negative, is a good proxy for prevalence estimates of S. haematobium infection by urine filtration on a single day.
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Affiliation(s)
- Carla M. Grolimund
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Oliver Bärenbold
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Christoph F. Hatz
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Birgitte J. Vennervald
- Department of Veterinary and Animal Science, University of Copenhagen, Copenhagen, Denmark
| | | | | | - 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
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11
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Molecular Techniques as Alternatives of Diagnostic Tools in China as Schistosomiasis Moving towards Elimination. Pathogens 2022; 11:pathogens11030287. [PMID: 35335611 PMCID: PMC8951378 DOI: 10.3390/pathogens11030287] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 02/13/2022] [Accepted: 02/21/2022] [Indexed: 12/15/2022] Open
Abstract
Schistosomiasis japonica caused by the trematode flukes of Schistosoma japonicum was one of the most grievous infectious diseases in China in the mid-20th century, while its elimination has been placed on the agenda of the national strategic plan of healthy China 2030 after 70 years of continuous control campaigns. Diagnostic tools play a pivotal role in warfare against schistosomiasis but must adapt to the endemic status and objectives of activities. With the decrease of prevalence and infection intensity of schistosomiasis in human beings and livestock, optimal methodologies with high sensitivity and absolute specificity are needed for the detection of asymptomatic cases or light infections, as well as disease surveillance to verify elimination. In comparison with the parasitological methods with relatively low sensitivity and serological techniques lacking specificity, which both had been widely used in previous control stages, the molecular detection methods based on the amplification of promising genes of the schistosome genome may pick up the baton to assist the eventual aim of elimination. In this article, we reviewed the developed molecular methods for detecting S. japonicum infection and their application in schistosomiasis japonica diagnosis. Concurrently, we also analyzed the chances and challenges of molecular tools to the field application process in China.
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12
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Rogers MJ, McManus DP, Muhi S, Gordon CA. Membrane Technology for Rapid Point-of-Care Diagnostics for Parasitic Neglected Tropical Diseases. Clin Microbiol Rev 2021; 34:e0032920. [PMID: 34378956 PMCID: PMC8404699 DOI: 10.1128/cmr.00329-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Parasitic neglected tropical diseases (NTDs) affect over one billion people worldwide, with individuals from communities in low-socioeconomic areas being most at risk and suffering the most. Disease management programs are hindered by the lack of infrastructure and resources for clinical sample collection, storage, and transport and a dearth of sensitive diagnostic methods that are inexpensive as well as accurate. Many diagnostic tests and tools have been developed for the parasitic NTDs, but the collection and storage of clinical samples for molecular and immunological diagnosis can be expensive due to storage, transport, and reagent costs, making these procedures untenable in most areas of endemicity. The application of membrane technology, which involves the use of specific membranes for either sample collection and storage or diagnostic procedures, can streamline this process, allowing for long-term sample storage at room temperature. Membrane technology can be used in serology-based diagnostic assays and for nucleic acid purification prior to molecular analysis. This facilitates the development of relatively simple and rapid procedures, although some of these methods, mainly due to costs, lack accessibility in low-socioeconomic regions of endemicity. New immunological procedures and nucleic acid storage, purification, and diagnostics protocols that are simple, rapid, accurate, and cost-effective must be developed as countries progress control efforts toward the elimination of the parasitic NTDs.
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Affiliation(s)
- Madeleine J. Rogers
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Donald P. McManus
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Stephen Muhi
- Victorian Infectious Diseases Service, The Royal Melbourne Hospital, Parkville, Victoria, Australia
| | - Catherine A. Gordon
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
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13
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Mewamba EM, Tiofack AAZ, Kamdem CN, Ngassam RIK, Mbagnia MCT, Nyangiri O, Noyes H, Womeni HM, Njiokou F, Simo G. Field assessment in Cameroon of a reader of POC-CCA lateral flow strips for the quantification of Schistosoma mansoni circulating cathodic antigen in urine. PLoS Negl Trop Dis 2021; 15:e0009569. [PMID: 34260610 PMCID: PMC8312929 DOI: 10.1371/journal.pntd.0009569] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 07/26/2021] [Accepted: 06/16/2021] [Indexed: 11/23/2022] Open
Abstract
Background Determining Schistosoma mansoni infection rate and intensity is challenging due to the low sensitivity of the Kato-Katz (KK) test that underestimates the true disease prevalence. Circulating cathodic antigen (CCA) excreted in urine is constantly produced by adult worms and has been used as the basis of a simple, non-invasive point of care test (POC-CCA) for Schistosoma mansoni infections. Although the abundance of CCA in urine is proportional to worm burden, the POC-CCA test is marketed as a qualitative test, making it difficult to investigate the wide range of infection intensities. This study was designed to compare the prevalence and intensity of S. mansoni by KK and POC-CCA and quantify, on fresh and frozen (<-20°C) urine samples, CCA using the visual scores and the ESEquant LR3 reader. Methodology Stool and urine samples were collected from 759 school-aged children. The prevalence and intensity of S. mansoni were determined using KK and POC-CCA. The degree of the positivity of POC-CCA was estimated by quantifying CCA on fresh and frozen urine samples using visual scores and strip reader. The prevalence, the infection intensity as well the relative amounts of CCA were compared. Results The S. mansoni infection rates inferred from POC-CCA and KK were 40.7% and 9.4% respectively. Good correlations were observed between infection intensities recorded by; i) the reader and visual scoring system on fresh (Rho = 0.89) and frozen samples (Rho = 0.97), ii) the reader on fresh urine samples and KK (epg) (Rho = 0.44). Nevertheless, 238 POC-CCA positive children were negative for KK, and sixteen of them had high levels of CCA. The correlation between results from the reader on fresh and frozen samples was good (Rho = 0.85). On frozen samples, CCA was not detected in 55 samples that were positive in fresh urine samples. Conclusion This study confirmed the low sensitivity of KK and the high capacity of POC-CCA to provide reliable data on the prevalence and intensity of S. mansoni infections. The lateral flow reader enabled accurate quantification of CCA under field conditions on fresh and frozen urine samples with less time and effort than KK. Diagnosis of schistosomiasis has relied on the Kato-Katz technique which remains challenging due to its low sensitivity. To overcome this limitation, the Point-of-care-Circulating Cathodic Antigen (POC-CCA) test has been developed to detect CCA produced by adult living worm. However, this test is sold for qualitative use only because it is difficult to estimate the intensity of the positive band by eye. This study was designed with the aim of comparing the prevalence and intensity of S. mansoni infections by KK and POC-CCA and quantifying under field conditions on fresh and frozen (<-20°C) urine samples, CCA using the visual scores and the ESEquant LR3 reader. We conducted the KK and POC-CCA tests on stool and urine samples collected from SAC (5 to 4 years) in Makenene, Cameroon. Our results showed discrepancies between results from KK and POC-CCA test. The numerical values generated by the reader made it possible to avoid subjective visual interpretation of POC-CCA results. This study also identified children with high levels of CCA in their urine but without schistosome eggs in their stools. The good correlation observed between results obtained on fresh and frozen urine samples confirmed that POC-CCA test can be used on samples stored for one year at -20° C.
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Affiliation(s)
- Estelle Mezajou Mewamba
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Arnol Auvaker Zebaze Tiofack
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | - Cyrille Nguemnang Kamdem
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
| | | | - Mureille Carole Tchami Mbagnia
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
| | - Oscar Nyangiri
- College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Harry Noyes
- Centre for Genomic Research, University of Liverpool, Liverpool, United Kingdom
| | - Hilaire Marcaire Womeni
- Unité de Recherche de Biochimie, des plantes Médicinales, des Sciences alimentaires et Nutrition, University of Dschang, Dschang, Cameroon
| | - Flobert Njiokou
- Parasitology and Ecology Laboratory, Department of Animal Biology and Physiology, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
- Centre for Research in Infectious Diseases, Yaoundé, Cameroon
| | - Gustave Simo
- Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
- * E-mail: ,
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14
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Stothard JR, Webster BL. Acute Schistosomiasis: Which Molecular Diagnostic Test Is Best and Why. Clin Infect Dis 2021; 72:1699-1700. [PMID: 32215645 DOI: 10.1093/cid/ciaa319] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 03/24/2020] [Indexed: 11/14/2022] Open
Affiliation(s)
- J Russell Stothard
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Bonnie L Webster
- Department of Life Sciences, Natural History Museum, London, United Kingdom
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15
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Ponpetch K, Erko B, Bekana T, Richards L, Liang S. Biogeographical characteristics of Schistosoma mansoni endemic areas in Ethiopia: a systematic review and meta analysis. Infect Dis Poverty 2021; 10:83. [PMID: 34099066 PMCID: PMC8185935 DOI: 10.1186/s40249-021-00864-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 05/19/2021] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND In Ethiopia, schistosomiasis is caused by Schistosoma mansoni and S. haematobium with the former being widespread and more than 4 million people are estimated to be infected by S. mansoni annually with 35 million at risk of infection. Although many school- and community-based epidemiological surveys were conducted over the past decades, the national distribution of schistosomiasis endemic areas and associated socio-environmental determinants remain less well understood. In this paper, we review S. mansoni prevalence of infections and describe key biogeographical characteristics in the endemic areas in Ethiopia. METHODS We developed a database of S. mansoni infection surveys in Ethiopia through a systematic review by searching articles published between 1975 and 2019 on electronic online databases including PubMed, ScienceDirect, and Web of Science. A total of 62 studies involving 95 survey locations were included in the analysis. We estimated adjusted prevalence of infection from each survey by considering sensitivity and specificity of diagnostic tests using Bayesian approach. All survey locations were georeferenced and associated environmental and geographical characteristics (e.g. elevation, normalized difference vegetation index, soil properties, wealth index, and climatic data) were described using descriptive statistics and meta-analysis. RESULTS The results showed that the surveys exhibited a wide range of adjusted prevalence of infections from 0.5% to 99.5%, and 36.8% of the survey sites had adjusted prevalence of infection higher than 50%. S. mansoni endemic areas were distributed in six regional states with the majority of surveys being in Amhara and Oromia. Endemic sites were found at altitudes from 847.6 to 3141.8 m above sea level, annual mean temperatures between 17.9 and 29.8 ℃, annual cumulative precipitation between 1400 and 1898 mm, normalized difference vegetation index between 0.03 and 0.8, wealth index score between -68 857 and 179 756; and sand, silt, and clay fraction in soil between 19.1-47.2, 23.0-36.7, and 20.0-52.8 g/100 g, respectively. CONCLUSIONS The distribution of S. mansoni endemic areas and prevalence of infections exhibit remarked environmental and ecological heterogeneities. Future research is needed to understand how much these heterogeneities drive the parasite distribution and transmission in the region.
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Affiliation(s)
- Keerati Ponpetch
- Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, FL, 32610, USA.
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, 32610, USA.
- Faculty of Public Health and Allied Health Sciences, Ministry of Public Health, Sirindhorn College of Public Health Trang, Praboromarajchanok Institute, Nonthaburi, Thailand.
| | - Berhanu Erko
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Teshome Bekana
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Lindsay Richards
- University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Song Liang
- Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, FL, 32610, USA
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, 32610, USA
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16
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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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Vilches TN, Graeff-Teixeira C, Yang HM. Assessing the effects of diagnostic sensitivity on schistosomiasis dynamics. J Theor Biol 2021; 523:110727. [PMID: 33887298 DOI: 10.1016/j.jtbi.2021.110727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 03/29/2021] [Accepted: 04/12/2021] [Indexed: 11/26/2022]
Abstract
Schistosomiasis is a parasite infection that affects millions of people around the world. It is endemic in 13 different states in Brazil and responsible for increasing morbidity in the population. One of its main characteristics is a heterogeneous distribution of worm burden in the human population, which makes the diagnosis difficult. We aimed to investigate how the sensitivity of the diagnostic method may contribute to successful control interventions against infections in a population. In order to do that, we present an ordinary differential equations model that considers three levels of worm burden in the human population, a snail population, and a miracidium reservoir. Through a steady-state analysis and its local stability, we show how this worm-burden heterogeneity can be responsible for the persistence of infection, especially due to reinfection in the highest level of worm burden. The analysis highlights sensitive diagnosis, besides treatment and sanitary improvements, as a key factor for schistosomiasis transmission control.
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Evaluation of a real-time recombinase polymerase amplification assay for rapid detection of Schistosoma haematobium infection in resource-limited setting. Acta Trop 2021; 216:105847. [PMID: 33497617 DOI: 10.1016/j.actatropica.2021.105847] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 01/12/2021] [Accepted: 01/19/2021] [Indexed: 12/27/2022]
Abstract
Accurate diagnosis of urogenital schistosomiasis is vital for surveillance/control programs as well as achieving the WHO 2012-2020 road map for the total eradication of schistosomiasis. Recombinase polymerase amplification (RPA) has emerged as a rapid and simple molecular tool adaptable for fewer resources with diagnostic accuracy similar to polymerase chain reaction (PCR). This rapid molecular assay employs the use of enzymes for the amplification of nucleic acid taget at a constant temperature. The aim of this study was to validate a real-time RPA assay targeting the Dra 1 repittitive sequence of Schistosoma (S.) haematobium and evaluate its use in urogenital schistosomiasis diagnosis. S. haematobium Dra 1 molecular DNA standard was applied to determine the assay's analytical sensitivity. DNA extracts of S. haematobium, other Schistosoma species, protozoa and bacteria species were used to determine the specificity of the RPA assay. Clinical performance of the assay was validated with a panel of 135 urine samples from volunteers of schistosomiasis endemic communities. The developed assay was evaluated with urine samples extracted by just boiling and with SpeedXtract® DNA extraction kit. A specific fragment of S. haematobium Dra 1 repetitive sequence was amplified within 15 minutes at a constant 42˚C using the developed S. haematobium RPA assay. The detection limit was 15 copies of Dra1 molecular DNA standard per reaction. There was no cross-reaction with other protozoan and bacterial species except Schistosoma species, S. mansoni and S. japonicum. Using 135 urine samples, Schistosoma RPA assay had a clinical sensitivity and specificity of 98.4% (95% CI, 91.6-100) and 100% (95% CI, 94.9-99) respectively when compared to S. haematobium Dra 1 qPCR assay. The diagnostic performance of S. haematobium real-time RPA assay was not affected by the use of crude DNA extracted samples. The S. haematobium RPA assay can serve as an alternative to PCR, especially in low resource settings.
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Graeff-Teixeira C, Favero V, de Souza RP, Pascoal VF, Bittencourt HR, Fukushige M, Geiger SM, Negrão-Corrêa D. Use of Schistosoma mansoni soluble egg antigen (SEA) for antibody detection and diagnosis of schistosomiasis: The need for improved accuracy evaluations of diagnostic tools. Acta Trop 2021; 215:105800. [PMID: 33352167 DOI: 10.1016/j.actatropica.2020.105800] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 11/25/2020] [Accepted: 12/14/2020] [Indexed: 02/08/2023]
Abstract
Many antigens for use in antibody-detection systems for schistosomiasis have been investigated over the past 40 years. In particular, soluble egg antigens (SEA) are still widely used in enzyme-linked immunosorbent assays (ELISAs) for detection of immunoglobulin classes and subclasses. Here, we conducted a literature review to examine accuracy evaluations of SEA-Immunoglobulin G (IgG)-ELISAs performed to detect Schistosoma mansoni infections and published between 1979 and 2019. S. mansoni is the main causative agent for intestinal schistosomiasis in many countries in Africa and Central and South America. After retrieving 214 relevant abstracts from the PubMed database, we selected 15 publications to undergo a full review. Sensitivity and specificity values varied from 71 to 99%, and from 6 to 100%, respectively. In addition, 11/15 studies did not state confidence intervals. Therefore, the findings from this review indicate that after four decades, we still do not have consistent evaluation estimates of SEA-IgG-ELISAs. Antigen mass per well and dilution of test sera in these articles varied from 0.018 µg to 1.5 µg, and from 1:50 to 1:500, respectively. Most of the reported accuracy evaluations used control sera which were selected based on parasitological examinations for egg detection, although ill-defined criteria were also noted. The number and composition of control serum panels was considered not adequate in approximately half of the studies. It is also noteworthy that among more than 30 diagnostic antigen preparations under development since the 1970s, most were not validated in the field and they failed to reach populations in need. Thus, attention to guidelines for standardization, estimations of accuracy, and reporting of results is needed to facilitate coordinated efforts aimed at schistosomiasis control and elimination.
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20
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Ramírez ADP, Favero V, Lindholz CG, Veríssimo CDM, Pascoal VF, Candido RRF, Morassutti AL, Graeff-Teixeira C. Schistosomiasis: an epidemiological update on Brazil's southernmost low endemic area in Esteio. Rev Soc Bras Med Trop 2020; 53:e20200411. [PMID: 33027417 PMCID: PMC7534964 DOI: 10.1590/0037-8682-0411-2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 07/31/2020] [Indexed: 12/31/2022] Open
Abstract
INTRODUCTION Brazil's southernmost state, Rio Grande do Sul (RGS), was considered schistosomiasis-free until 1998 when a low endemic focus was identified in Esteio, a city located next to the capital of RGS. In the last two decades, the control interventions applied in the region have been apparently successful, and the absence of new cases indicated the possibility of interrupted schistosomiasis transmission. The objective of this study was to update the clinical and epidemiological data of schistosomiasis in Esteio. METHODS We reviewed all 28 individuals diagnosed with the infection since 1997 and a survey was applied to a group of 29 school-aged children residing in Vila Pedreira, one of the most affected neighborhoods. RESULTS No eggs were detected in fecal samples using the Helmintex method, and all samples were negative for serum antibodies on examination by the western blot technique using the Schistosoma mansoni microsomal antigen (MAMA- WB). In contrast, 23 individuals (79%) tested positive for the cathodic circulating antigen with the point-of-care immunochromatographic test (POC-CCA) on urine samples. Of the 28 formerly infected individuals, only eight were located, of which four tested positive, and four tested negative for serum antibodies using the MAMA-WB technique. CONCLUSIONS Current adverse conditions for S. mansoni transmission in Esteio and the absence of a confirmed diagnosis suggests that there is (i) a lack of specificity of the POC-CCA test in low endemic settings, and (ii) a high probability that interruption of schistosomiasis has been achieved in Esteio.
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Affiliation(s)
- Angélica da Paz Ramírez
- Pontifícia Universidade Católica do Rio Grande do Sul, Escola de Ciências, Departamento de Ecologia e Biodiversidade, Porto Alegre, RS, Brasil
| | - Vivian Favero
- Pontifícia Universidade Católica do Rio Grande do Sul, Escola de Ciências, Departamento de Ecologia e Biodiversidade, Porto Alegre, RS, Brasil
| | - Catieli Gobetti Lindholz
- Pontifícia Universidade Católica do Rio Grande do Sul, Escola de Ciências, Departamento de Ecologia e Biodiversidade, Porto Alegre, RS, Brasil
| | - Carolina de Marco Veríssimo
- Pontifícia Universidade Católica do Rio Grande do Sul, Escola de Ciências, Departamento de Ecologia e Biodiversidade, Porto Alegre, RS, Brasil
| | - Vanessa Fey Pascoal
- Pontifícia Universidade Católica do Rio Grande do Sul, Escola de Ciências, Departamento de Ecologia e Biodiversidade, Porto Alegre, RS, Brasil
| | - Renata Russo Frasca Candido
- Pontifícia Universidade Católica do Rio Grande do Sul, Escola de Ciências, Departamento de Ecologia e Biodiversidade, Porto Alegre, RS, Brasil.,University of Western Australia, Department of Physics, Perth, Australia
| | - Alessandra Loureiro Morassutti
- Pontifícia Universidade Católica do Rio Grande do Sul, Escola de Ciências, Departamento de Ecologia e Biodiversidade, Porto Alegre, RS, Brasil
| | - Carlos Graeff-Teixeira
- Pontifícia Universidade Católica do Rio Grande do Sul, Escola de Ciências, Departamento de Ecologia e Biodiversidade, Porto Alegre, RS, Brasil.,Universidade Federal do Espírito Santo, Centro de Ciências da Saúde, Departamento de Patologia e Núcleo de Doenças Infecciosas, Vitória, ES, Brasil
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21
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Kayuni SA, O'Ferrall AM, Baxter H, Hesketh J, Mainga B, Lally D, Al-Harbi MH, LaCourse EJ, Juziwelo L, Musaya J, Makaula P, Stothard JR. An outbreak of intestinal schistosomiasis, alongside increasing urogenital schistosomiasis prevalence, in primary school children on the shoreline of Lake Malawi, Mangochi District, Malawi. Infect Dis Poverty 2020; 9:121. [PMID: 32867849 PMCID: PMC7456765 DOI: 10.1186/s40249-020-00736-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 08/07/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Intestinal schistosomiasis was not considered endemic in Lake Malawi until November 2017 when populations of Biomphalaria pfeifferi were first reported; in May 2018, emergence of intestinal schistosomiasis was confirmed. This emergence was in spite of ongoing control of urogenital schistosomiasis by preventive chemotherapy. Our current study sought to ascertain whether intestinal schistosomiasis is transitioning from emergence to outbreak, to judge if stepped-up control interventions are needed. METHODS During late-May 2019, three cross-sectional surveys of primary school children for schistosomiasis were conducted using a combination of rapid diagnostic tests, parasitological examinations and applied morbidity-markers; 1) schistosomiasis dynamics were assessed at Samama (n = 80) and Mchoka (n = 80) schools, where Schistosoma mansoni was first reported, 2) occurrence of S. mansoni was investigated at two non-sampled schools, Mangochi Orphan Education and Training (MOET) (n = 60) and Koche (n = 60) schools, where B. pfeifferi was nearby, and 3) rapid mapping of schistosomiasis, and B. pfeifferi, conducted across a further 8 shoreline schools (n = 240). After data collection, univariate analyses and Chi-square testing were performed, followed by binary logistic regression using generalized linear models, to investigate epidemiological associations. RESULTS In total, 520 children from 12 lakeshore primary schools were examined, mean prevalence of S. mansoni by 'positive' urine circulating cathodic antigen (CCA)-dipsticks was 31.5% (95% confidence interval [CI]: 27.5-35.5). Upon comparisons of infection prevalence in May 2018, significant increases at Samama (relative risk [RR] = 1.7, 95% CI: 1.4-2.2) and Mchoka (RR = 2.7, 95% CI: 1.7-4.3) schools were observed. Intestinal schistosomiasis was confirmed at MOET (18.3%) and Koche (35.0%) schools, and in all rapid mapping schools, ranging from 10.0 to 56.7%. Several populations of B. pfeifferi were confirmed, with two new eastern shoreline locations noted. Mean prevalence of urogenital schistosomiasis was 24.0% (95% CI: 20.3-27.7). CONCLUSIONS We notify that intestinal schistosomiasis, once considered non-endemic in Lake Malawi, is now transitioning from emergence to outbreak. Once control interventions can resume after coronavirus disease 2019 (COVID-19) suspensions, we recommend stepped-up preventive chemotherapy, with increased community-access to treatments, alongside renewed efforts in appropriate environmental control.
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Affiliation(s)
- Sekeleghe A Kayuni
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, L3 5QA, Liverpool, UK.,Medi Clinic Limited, Medical Aid Society of Malawi (MASM), 22 Lower Sclatter Road, P.O. Box 1254, Blantyre, Malawi
| | - Angus M O'Ferrall
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, L3 5QA, Liverpool, UK
| | - Hamish Baxter
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, L3 5QA, Liverpool, UK
| | - Josie Hesketh
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, L3 5QA, Liverpool, UK
| | - Bright Mainga
- Laboratory Department, Mangochi District Hospital, P.O. Box 42, Mangochi, Malawi
| | - David Lally
- Malawi Liverpool Wellcome Trust Programme of Clinical Tropical Research, Queen Elizabeth Central Hospital, College of Medicine, P.O. Box 30096, Blantyre, Malawi
| | | | - E James LaCourse
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, L3 5QA, Liverpool, UK
| | - Lazarus Juziwelo
- National Schistosomiasis and STH Control Programme, Ministry of Health, Lilongwe, Malawi
| | - Janelisa Musaya
- Malawi Liverpool Wellcome Trust Programme of Clinical Tropical Research, Queen Elizabeth Central Hospital, College of Medicine, P.O. Box 30096, Blantyre, Malawi.,Department of Basic Medical Sciences, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Peter Makaula
- Research for Health Environment and Development, P.O. Box 345, Mangochi, Malawi
| | - J Russell Stothard
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, L3 5QA, Liverpool, UK.
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22
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Sturt AS, Webb EL, Phiri CR, Mweene T, Chola N, van Dam GJ, Corstjens PLAM, Wessels E, Stothard JR, Hayes R, Ayles H, Hansingo I, van Lieshout L, Bustinduy AL. Genital self-sampling compared with cervicovaginal lavage for the diagnosis of female genital schistosomiasis in Zambian women: The BILHIV study. PLoS Negl Trop Dis 2020; 14:e0008337. [PMID: 32663222 PMCID: PMC7360036 DOI: 10.1371/journal.pntd.0008337] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 04/29/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Given the potentially causal association of female genital schistosomiasis (FGS) with HIV-1 infection, improved diagnostics are urgently needed to scale-up FGS surveillance. The BILHIV (bilharzia and HIV) study assessed the performance of home-based self-collection methods (cervical and vaginal swabs) compared to cervicovaginal lavage (CVL) for the detection of Schistosoma DNA by real-time polymerase chain reaction (PCR). METHODS Between January and August 2018, a consecutive series of female participants from the Population-Cohort of the previous HIV prevention trial HPTN 071 (PopART), resident in Livingstone, Zambia were invited to take part in BILHIV if they were 18-31 years old, non-pregnant and sexually active. Genital self-collected swabs and a urine specimen were obtained and a questionnaire completed at home visits. CVL was obtained at clinic follow-up. RESULTS 603 women self-collected genital swabs. Of these, 527 women had CVL performed by a mid-wife during clinic follow-up. Schistosoma DNA was more frequently detected in genital self-collected specimens (24/603, 4.0%) compared to CVL (14/527, 2.7%). Overall, 5.0% (30/603) women had female genital schistosomiasis, defined as a positive PCR by any genital sampling method (cervical swab PCR, vaginal swab PCR, or CVL PCR) and 95% (573/603) did not have a positive genital PCR. The sensitivity of any positive genital self-collected swab against CVL was 57.1% (95% CI 28.9-82.3%), specificity 97.3% (95.5-98.5%). In a subset of participants with active schistosome infection, determined by detectable urine Circulating Anodic Antigen (CAA) (15.1%, 91/601), positive PCR (4.3%, 26/601), or positive microscopy (5.5%, 33/603), the sensitivity of any positive self-collected specimen against CVL was 88.9% (51.8-99.7%). CONCLUSIONS Genital self-sampling increased the overall number of PCR-based FGS diagnoses in a field setting, compared with CVL. Home-based sampling may represent a scalable alternative method for FGS community-based diagnosis in endemic resource limited settings.
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Affiliation(s)
- Amy S. Sturt
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Emily L. Webb
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | | | | | - Govert J. van Dam
- 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
| | - Els Wessels
- Department of Medical Microbiology, Leiden University Medical Center, Leiden, The Netherlands
| | - J. Russell Stothard
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Richard Hayes
- MRC Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Helen Ayles
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Zambart, Lusaka, Zambia
| | - Isaiah Hansingo
- Department of Obstetrics and Gynaecology, Livingstone Central Hospital, Livingstone, Zambia
| | - Lisette van Lieshout
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Amaya L. Bustinduy
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom
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23
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Taylor EM. NTD Diagnostics for Disease Elimination: A Review. Diagnostics (Basel) 2020; 10:E375. [PMID: 32517108 PMCID: PMC7344624 DOI: 10.3390/diagnostics10060375] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/07/2020] [Accepted: 06/02/2020] [Indexed: 11/16/2022] Open
Abstract
Neglected Tropical Diseases (NTDs) marked out for disease elimination provide a lens through which to explore the changing status of diagnosis in global health. This paper reports on the findings of a scoping review, which set out to explore the main debates around diagnosis for the elimination of NTDs, including the multiple roles diagnostic technologies are being ascribed and the ideal characteristics of tests. It also attempts to summarise the state of diagnosis for three NTDs with elimination goals. The review places special emphasis on point-of-care testing in acknowledgement of the remote and underserved areas where NTDs proliferate. Early NTD campaigns were largely focused on attack phase planning, whereby a similar set of interventions could be transplanted anywhere. Now, with elimination goals in sight, strategies must be tailored to local settings if they are to attain and sustain success. Diagnostic data helps with local adaptation and is increasingly used for programmatic decision-making. The review finds that elimination goals reframe whom diagnosis is for and the myriad roles diagnostics can play. The exigencies of elimination also serve to highlight deficiencies in the current diagnostic arsenal and development pipeline for many NTDs. Moving forward, a guiding framework is needed to drive research and stimulate investment in diagnosis to support NTD goals.
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Affiliation(s)
- Emma Michelle Taylor
- Department of Social Anthropology, University of Edinburgh, Edinburgh EH8 9LD, UK
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24
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Detecting Schistosoma mansoni infections among pre-school-aged children in southern Ghana: a diagnostic comparison of urine-CCA, real-time PCR and Kato-Katz assays. BMC Infect Dis 2020; 20:301. [PMID: 32321418 PMCID: PMC7178570 DOI: 10.1186/s12879-020-05034-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 04/15/2020] [Indexed: 11/16/2022] Open
Abstract
Background In Ghana, pre-school-aged children (PSAC) are at risk of intestinal schistosomiasis and are living in need of praziquantel treatment. To better assess the infection burden within this vulnerable demographic group, we have provided a comparative assessment of the prevalence of Schistosoma mansoni in pre-school-aged children by urine circulating cathodic antigen (CCA) dipsticks, real-time PCR Taqman® faecal assays and Kato-Katz coproscopy. Methods In all, 190 pre-school-aged children were sampled from three endemic communities (viz. Tomefa, Torgahkope/Adakope, and Manheam) around Weija dam, Southern Ghana. Fresh stool and urine samples were collected from all participants for diagnosis. Results Among all the three communities, the urine-CCA assay recorded the highest prevalence values of 90.5% (95% CI 80.4–96.4), 87.9% (95% CI 76.7–95), and 81.2% (95% CI 69.9–89.6) in Tomefa, Torgahkope/Adakope, and Manheam respectively. Prevalence by real-time PCR was 50% (95% CI 35.5–64.5), 8% (95% CI 2.2–19.2) and 16.7% (95% CI 8.3–28.5), while by Kato-Katz was 55.6% (95% CI 42.5–68.1), 8.6% (95% CI 2.9–19) and 11.6% (95% CI 5.1–21.6) respectively. Children aged 1 year and over were found to be positive with the urine-CCA assay; by the ages of 3–4, over 50% were urine-CCA patent. The sensitivity and specificity of the POC-CCA dipsticks, when compared against the combined results of Kato-Katz/TaqMan results was found to be 84.1% (95% CI = 72.7–92.1) and 12.9% (95% CI = 6.6–22) respectively. Conclusions We propose that the urine-CCA dipstick may be a useful rapid diagnostic tool to estimate the prevalence of intestinal schistosomiasis in PSAC, particularly in rapid identification of at-risk areas. However, our assessment has shown that it possible to record false positives when compared to combined Kato-Katz and qPCR results. To guide PSAC praziquantel treatment needs, we propose the urine CCA assay should be included in routine surveillance of intestinal schistosomiasis alongside other diagnostics such as Kato-Katz and urine filtration.
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25
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An update on non-invasive urine diagnostics for human-infecting parasitic helminths: what more could be done and how? Parasitology 2019; 147:873-888. [PMID: 31831084 PMCID: PMC7284843 DOI: 10.1017/s0031182019001732] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Reliable diagnosis of human helminth infection(s) is essential for ongoing disease surveillance and disease elimination. Current WHO-recommended diagnostic assays are unreliable in low-endemic near-elimination settings and typically involve the invasive, onerous and potentially hazardous sampling of bodily fluids such as stool and blood, as well as tissue via biopsy. In contrast, diagnosis by use of non-invasive urine sampling is generally painless, more convenient and low risk. It negates the need for specialist staff, can usually be obtained immediately upon request and is better accepted by patients. In some instances, urine-based diagnostic assays have also been shown to provide a more reliable diagnosis of infection when compared to traditional methods that require alternative and more invasive bodily samples, particularly in low-endemicity settings. Given these relative benefits, we identify and review current research literature to evaluate whether non-invasive urine sampling is currently exploited to its full potential in the development of diagnostic tools for human helminthiases. Though further development, assessment and validation are needed before their routine use in control programmes, low-cost, rapid and reliable assays capable of detecting transrenal helminth-derived antigens and cell-free DNA show excellent promise for future use at the point-of-care in high-, medium- and even low-endemicity elimination settings.
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26
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Rostron P, Pennance T, Bakar F, Rollinson D, Knopp S, Allan F, Kabole F, Ali SM, Ame SM, Webster BL. Development of a recombinase polymerase amplification (RPA) fluorescence assay for the detection of Schistosoma haematobium. Parasit Vectors 2019; 12:514. [PMID: 31685024 PMCID: PMC6827214 DOI: 10.1186/s13071-019-3755-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Accepted: 10/19/2019] [Indexed: 01/20/2023] Open
Abstract
Background Accurate diagnosis of urogenital schistosomiasis is vital for surveillance and control programmes. While a number of diagnostic techniques are available there is a need for simple, rapid and highly sensitive point-of-need (PON) tests in areas where infection prevalence and intensity are low. Recombinase Polymerase Amplification (RPA) is a sensitive isothermal molecular diagnostic technology that is rapid, portable and has been used at the PON for several pathogens. Results A real time fluorescence RPA assay (RT-ShDra1-RPA) targeting the Schistosoma haematobium Dra1 genomic repeat region was developed and was able to detect 1 fg of S. haematobium gDNA. Results were obtained within 10 minutes using a small portable battery powered tube scanner device that incubated reactions at 40 °C, whilst detecting DNA amplification and fluorescence over time. The assay’s performance was evaluated using 20 urine samples, with varying S. haematobium egg counts, from school children from Pemba Island, Zanzibar Archipelago, Tanzania. Prior to RPA analysis, samples were prepared using a quick crude field DNA extraction method, the Speed Extract Kit (Qiagen, Manchester, UK). Positive assay results were obtained from urine samples with egg counts of 1–926 eggs/10 ml, except for two samples, which had inconclusive results. These two samples had egg counts of two and three eggs/10 ml of urine. Conclusions The RT-ShDra1-RPA assay proved robust for S. haematobium gDNA detection and was able to amplify and detect S. haematobium DNA in urine samples from infected patients. The assay’s speed and portability, together with the use of crude sample preparation methods, could advance the rapid molecular diagnosis of urogenital schistosomiasis at the PON within endemic countries.
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Affiliation(s)
- Penelope Rostron
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Tom Pennance
- Department of Life Sciences, Natural History Museum, London, UK.,London Centre for Neglected Tropical Disease Research (LCNTDR), London, UK.,Cardiff University, Cardiff, UK
| | - Faki Bakar
- Public Health Laboratory - Ivo de Carneri, P.O. Box 122, Chake-Chake, Pemba, United Republic of Tanzania
| | - David Rollinson
- Department of Life Sciences, Natural History Museum, London, UK.,London Centre for Neglected Tropical Disease Research (LCNTDR), London, UK
| | - Stefanie Knopp
- Department of Life Sciences, Natural History Museum, London, UK.,London Centre for Neglected Tropical Disease Research (LCNTDR), London, UK.,Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland.,University of Basel, Petersplatz 1, 4003, Basel, Switzerland
| | - Fiona Allan
- Department of Life Sciences, Natural History Museum, London, UK.,London Centre for Neglected Tropical Disease Research (LCNTDR), London, UK
| | - Fatma Kabole
- Zanzibar Neglected Diseases Programme, Ministry of Health, P.O. Box 236, Zanzibar Town, Unguja, United Republic of Tanzania
| | - Said M Ali
- Public Health Laboratory - Ivo de Carneri, P.O. Box 122, Chake-Chake, Pemba, United Republic of Tanzania
| | - Shaali M Ame
- Public Health Laboratory - Ivo de Carneri, P.O. Box 122, Chake-Chake, Pemba, United Republic of Tanzania
| | - Bonnie L Webster
- Department of Life Sciences, Natural History Museum, London, UK. .,London Centre for Neglected Tropical Disease Research (LCNTDR), London, UK.
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27
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How can schistosome circulating antigen assays be best applied for diagnosing male genital schistosomiasis (MGS): an appraisal using exemplar MGS cases from a longitudinal cohort study among fishermen on the south shoreline of Lake Malawi. Parasitology 2019; 146:1785-1795. [PMID: 31452477 PMCID: PMC6939168 DOI: 10.1017/s0031182019000969] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We provide an update on diagnostic methods for the detection of urogenital schistosomiasis (UGS) in men and highlight that satisfactory urine-antigen diagnostics for UGS lag much behind that for intestinal schistosomiasis, where application of a urine-based point-of-care strip assay, the circulating cathodic antigen (CCA) test, is now advocated. Making specific reference to male genital schistosomiasis (MGS), we place greater emphasis on parasitological detection methods and clinical assessment of internal genitalia with ultrasonography. Unlike the advances made in defining a clinical standard protocol for female genital schistosomiasis, MGS remains inadequately defined. Whilst urine filtration with microscopic examination for ova of Schistosoma haematobium is a convenient but error-prone proxy of MGS, we describe a novel low-cost sampling and direct visualization method for the enumeration of ova in semen. Using exemplar clinical cases of MGS from our longitudinal cohort study among fishermen along the shoreline of Lake Malawi, the portfolio of diagnostic needs is appraised including: the use of symptomatology questionnaires, urine analysis (egg count and CCA measurement), semen analysis (egg count, circulating anodic antigen measurement and real-time polymerase chain reaction analysis) alongside clinical assessment with portable ultrasonography.
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28
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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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29
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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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Developing a real-time PCR assay based on multiplex high-resolution melt-curve analysis: a pilot study in detection and discrimination of soil-transmitted helminth and schistosome species. Parasitology 2018; 145:1733-1738. [PMID: 30152296 DOI: 10.1017/s0031182018001361] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
With the push towards control and elimination of soil-transmitted helminthiasis and schistosomiasis in low- and middle-income countries, there is a need to develop alternative diagnostic assays that complement the current in-country resources, preferably at a lower cost. Here, we describe a novel high-resolution melt (HRM) curve assay with six PCR primer pairs, designed to sub-regions of the nuclear ribosomal locus. Used within a single reaction and dye detection channel, they are able to discriminate Ancylostoma duodenale, Necator americanus, Strongyloides stercoralis, Ascaris lumbricoides, Trichuris trichiuria and Schistosoma spp. by HRM curve analysis. Here we describe the primers and the results of a pilot assessment whereby the HRM assay was tested against a selection of archived fecal samples from Ghanaian children as characterized by Kato-Katz and real-time PCR analysis with species-specific TaqMan hydrolysis probes. The resulting sensitivity and specificity of the HRM was 80 and 98.6% respectively. We judge the assay to be appropriate in modestly equipped and resourced laboratories. This method provides a potentially cheaper alternative to the TaqMan method for laboratories in lower resource settings. However, the assay requires a more extensive assessment as the samples used were not representative of all target organisms.
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Comparison of sensitivity and specificity of three diagnostic tests to detect Schistosoma mansoni infections in school children in Mwanza region, Tanzania. PLoS One 2018; 13:e0202499. [PMID: 30133490 PMCID: PMC6105001 DOI: 10.1371/journal.pone.0202499] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 08/04/2018] [Indexed: 12/31/2022] Open
Abstract
Background Schistosomiasis remains one of the most prevalent parasitic infections in the world and has significant economic and public health consequences, particularly in poor communities. Reliable and accurate diagnosis plays a key role in surveillance, prevention and control of schistosomiasis. Currently, the microscopic Kato Katz (KK) stool thick smear technique is the most commonly used method to diagnose Schistosoma mansoni infections in epidemiological surveys. It is well-known that the sensitivity of this parasitological method decreases when infection intensities are moderate to low, however. The urine-based Point-of Care Circulating Cathodic Antigen (POC-CCA) test has been extensively evaluated as a further diagnostic tool. Several studies have shown that the POC-CCA test is more sensitive but less specific than the KK method. However, to clarify the meaning of inconsistent results between KK and POC-CCA tests in clinical routine, this study compares the accuracy of microscopy and POC-CCA versus real-time polymerase chain reaction (real-time PCR) results of urine and faecal samples from African school children participants. Methodology This was a school-based cross-sectional study conducted in 2015 among 305 school children aged 7–16 years from two primary schools located in Ilemela and Magu Districts, north-western Tanzania. Single stool and urine samples were collected from each participant and examined for the presence of Schistosoma mansoni eggs, parasite antigen, and parasite DNA using KK thick smears, POC-CCA tests, and real-time PCR, respectively. Principal findings The prevalence of S. mansoni infection, calculated by KK was 85.2%, by real-time PCR 92.9% and by POC-CCA 94.9%. In comparison to KK, the POC-CCA and real-time PCR tests had sensitivities of 89.7% and 99.5% and specificities of 22.73% and 29.55%, respectively. However, due to the known limitations of the KK assay, we also used latent class analysis (LCA) that included POC-CCA, KK, and schistosome-specific real-time PCR results to determine their sensitivities and specificities. The POC-CCA test had the highest sensitivity (99.5%) and a specificity of 63.4% by LCA and the real-time PCR test had a sensitivity of 98.7% and the highest specificity (81.2%). Conclusion In moderate and high prevalence areas, the POC-CCA cassette test is more sensitive than the KK method and can be used for screening and geographical mapping of S. mansoni infections. Real-time PCR is highly sensitive and also shows the highest specificity among the 3 investigated diagnostic procedures. It can offer added value in diagnosing schistosomiasis.
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Weerakoon KG, Gordon CA, McManus DP. DNA Diagnostics for Schistosomiasis Control. Trop Med Infect Dis 2018; 3:tropicalmed3030081. [PMID: 30274477 PMCID: PMC6160968 DOI: 10.3390/tropicalmed3030081] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Revised: 07/25/2018] [Accepted: 07/30/2018] [Indexed: 02/07/2023] Open
Abstract
Despite extensive efforts over the last few decades, the global disease burden of schistosomiasis still remains unacceptably high. This could partly be attributed to the lack of accurate diagnostic tools for detecting human and animal schistosome infections in endemic areas. In low transmission and low prevalence areas where schistosomiasis elimination is targeted, case detection requires a test that is highly sensitive. Diagnostic tests with low sensitivity will miss individuals with low infection intensity and these will continue to contribute to transmission, thereby interfering with the efficacy of the control measures operating. Of the many diagnostic approaches undertaken to date, the detection of schistosome DNA using DNA amplification techniques including polymerase chain reaction (PCR) provide valuable adjuncts to more conventional microscopic and serological methods, due their accuracy, high sensitivity, and the capacity to detect early pre-patent infections. Furthermore, DNA-based methods represent important screening tools, particularly in those endemic areas with ongoing control where infection prevalence and intensity have been reduced to very low levels. Here we review the role of DNA diagnostics in the path towards the control and elimination of schistosomiasis.
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Affiliation(s)
- Kosala G Weerakoon
- Molecular Parasitology Laboratory, Infectious Diseases Division, QIMR Berghofer Medical Research Institute, Brisbane 4006, Australia.
- School of Public Health, University of Queensland, Brisbane 4006, Australia.
- Department of Parasitology, Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura 50008, Sri Lanka.
| | - Catherine A Gordon
- Molecular Parasitology Laboratory, Infectious Diseases Division, QIMR Berghofer Medical Research Institute, Brisbane 4006, Australia.
| | - Donald P McManus
- Molecular Parasitology Laboratory, Infectious Diseases Division, QIMR Berghofer Medical Research Institute, Brisbane 4006, Australia.
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Ajibola O, Gulumbe BH, Eze AA, Obishakin E. Tools for Detection of Schistosomiasis in Resource Limited Settings. Med Sci (Basel) 2018; 6:medsci6020039. [PMID: 29789498 PMCID: PMC6024580 DOI: 10.3390/medsci6020039] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 05/15/2018] [Accepted: 05/16/2018] [Indexed: 12/20/2022] Open
Abstract
Schistosomiasis is a debilitating disease affecting over 200 million people, with the highest burden of morbidity and mortality in African countries. Despite its huge impact on the health and socio-economic burden of the society, it remains a neglected tropical disease, with limited attention from governments and stakeholders in healthcare. One of the critical areas that is hugely under-developed is the development of accurate diagnostics for both intestinal and urogenital schistosomiasis. Diagnosis of schistosomiasis is important for the detection and treatment of disease in endemic and non-endemic settings. A conclusive detection method is also an indispensable part of treatment, both in the clinic and during mass drug administration (MDA), for the monitoring efficacy of treatment. Here, we review the available diagnostic methods and discuss the challenges encountered in diagnosis in resource limited settings. We also present the available diagnostics and cost implications for deployment in resource limited settings. Lastly, we emphasize the need for more funding directed towards the development of affordable diagnostic tools that is affordable for endemic countries as we work towards the elimination of the disease.
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Affiliation(s)
- Olumide Ajibola
- Department of Microbiology, Federal University Birnin Kebbi, P.M.B. 1157 Kalgo Road, Birnin Kebbi 860222, Kebbi State, Nigeria.
| | - Bashar Haruna Gulumbe
- Department of Microbiology, Federal University Birnin Kebbi, P.M.B. 1157 Kalgo Road, Birnin Kebbi 860222, Kebbi State, Nigeria.
| | - Anthonius Anayochukwu Eze
- Department of Medical Biochemistry, University of Nigeria, Enugu Campus, Enugu 400241, Enugu State, Nigeria.
| | - Emmanuel Obishakin
- Biotechnology Division, National Veterinary Research Institute, P.M.B. 001, Vom, Jos, 930281, Plateau State, Nigeria.
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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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Evaluation of diagnostic methods for the detection of intestinal schistosomiasis in endemic areas with low parasite loads: Saline gradient, Helmintex, Kato-Katz and rapid urine test. PLoS Negl Trop Dis 2018; 12:e0006232. [PMID: 29470516 PMCID: PMC5823366 DOI: 10.1371/journal.pntd.0006232] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 01/11/2018] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND In some tropical countries, such as Brazil, schistosomiasis control programs have led to a significant reduction in the prevalence and parasite burden of endemic populations. In this setting, the Kato-Katz technique, as the standard diagnostic method for the diagnosis of Schistosoma mansoni infections, which involves the analysis of two slides from one fecal sample, loses its sensitivity. As a result, a significant number of infected individuals are not detected. The objective of this study was to perform extensive parasitological testing of up to three fecal samples and include a rapid urine test (POC-CCA) in a moderate prevalence area in Northern Minas Gerais, Brazil, and evaluate the performance of each test separately and in combination. METHODS AND FINDINGS A total of 254 individuals were examined with variants of the standard Kato-Katz technique (up to18 Kato-Katz slides prepared from three fecal samples), a modified Helmintex (30 g of feces), the saline gradient (500 mg of feces), and the POC-CCA methods. We established a reference standard taking into consideration all the positive results in any of the parasitological exams. Evaluation of the parasite burden by two Kato-Katz slides confirmed that most of the individuals harbored a light infection. When additional slides and different parasitological methods were included, the estimated prevalence rose 2.3 times, from 20.4% to 45.9%. The best sensitivity was obtained with the Helmintex method (84%). All parasitological methods readily detected a high or moderate intensity of infection; however, all lost their high sensitivity in the case of low or very low intensity infections. The overall sensitivity of POC-CCA (64.9%) was similar to the six Kato-Katz slides from three fecal samples. However, POC-CCA showed low concordance (κ = 0.34) when compared with the reference standard. CONCLUSIONS The recommended Kato-Katz method largely underestimated the prevalence of S. mansoni infection. Because the best performance was achieved with a modified Helmintex method, this technique might serve as a more precise reference standard. An extended number of Kato-Katz slides in combination with other parasitological methods or with POC-CCA was able to detect more than 80% of egg-positive individuals; however, the rapid urine test (POC-CCA) produced a considerable percentage of false positive results.
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Poulton K, Webster B. Development of a lateral flow recombinase polymerase assay for the diagnosis of Schistosoma mansoni infections. Anal Biochem 2018; 546:65-71. [PMID: 29425749 DOI: 10.1016/j.ab.2018.01.031] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 01/25/2018] [Accepted: 01/30/2018] [Indexed: 12/14/2022]
Abstract
Infection with Schistosoma mansoni causes intestinal schistosomiasis, a major health problem across Africa. The accurate diagnosis of intestinal schistosomiasis is vital to inform surveillance/control programs. Diagnosis mainly relies on microscopic detection of eggs in faecal samples but many factors affect sensitivity. Molecular diagnostics are sensitive and specific but application is limited as necessary infrastructure, financial resources and skilled personnel are often lacking in endemic settings. Recombinase Polymerase Amplification (RPA) is an isothermal DNA amplification/detection technology that is practical in nearly any setting. Here we developed a RPA lateral flow (LF) assay targeting the 28S rDNA region of S. mansoni. The 28S LF-RPA assay's lower limit of detection was 10pg DNA with the lower test parameters permitting sufficient amplification being 6 min and 25°C. Optimal assay parameters were 40-45°C and 10 min with an analytical sensitivity of 102 copies of DNA. Additionally the PCRD3 lateral flow detection cassettes proved more robust and sensitive compared to the Milenia HybriDetect strips. This 28S LF-RPA assay produces quick reproducible results that are easy to interpret, require little infrastructure and is a promising PON test for the field molecular diagnosis of intestinal schistosomiasis.
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Affiliation(s)
- Kate Poulton
- The London School of Hygiene and Tropical Medicine, Keppel Street, London, UK; The Natural History Museum, Cromwell Road, London, UK
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Candido RRF, Morassutti AL, Graeff-Teixeira C, St Pierre TG, Jones MK. Exploring Structural and Physical Properties of Schistosome Eggs: Potential Pathways for Novel Diagnostics? ADVANCES IN PARASITOLOGY 2018; 100:209-237. [PMID: 29753339 DOI: 10.1016/bs.apar.2018.03.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In this era of increasing demand for sensitive techniques to diagnose schistosomiasis, there is a need for an increased focus on the properties of the parasite eggs. The eggs are not only directly linked to the morbidity of chronic infection but are also potential key targets for accurate diagnostics. Eggs were the primary target of diagnostic tools in the past and we argue they could be the target of highly sensitive tools in the future if we focus on characteristics of their structure and shell surface that could be exploited for enhanced detection. In this review, we discuss the current state of knowledge of the physical structures of schistosome eggs and eggshells with a view to identifying pathways to a comprehensive understanding of their role in the host-parasite relationship and pathogenesis of infection, and pathways to new strategies for development of diagnostics.
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Affiliation(s)
- Renata R F Candido
- School of Physics, The University of Western Australia, Crawley, WA, Australia.
| | - Alessandra L Morassutti
- School of Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Carlos Graeff-Teixeira
- School of Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Timothy G St Pierre
- School of Physics, The University of Western Australia, Crawley, WA, Australia
| | - Malcolm K Jones
- School of Veterinary Sciences, The University of Queensland, Brisbane, QLD, Australia
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Bakuza JS, Gillespie R, Nkwengulila G, Adam A, Kilbride E, Mable BK. Assessing S. mansoni prevalence in Biomphalaria snails in the Gombe ecosystem of western Tanzania: the importance of DNA sequence data for clarifying species identification. Parasit Vectors 2017; 10:584. [PMID: 29169384 PMCID: PMC5701381 DOI: 10.1186/s13071-017-2525-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Accepted: 11/06/2017] [Indexed: 01/10/2023] Open
Abstract
Background Snails are essential for the transmission and maintenance of schistosomiasis in endemic areas, as they serve as intermediate hosts for schistosome parasites. A clear understanding of the snail species present, their local distribution and infection status is therefore a prerequisite for effective control of schistosomiasis. The purpose of this study was to establish the infection status and distribution of Schistosoma mansoni in snails in the Gombe area along the shores of Lake Tanganyika in western Tanzania, using both detection of cercarial shedding and molecular approaches. Methods Snails were collected from streams located close to human settlements in Gombe National Park, as well as from nearby villages (Kiziba, Mtanga, Mwamgongo and Bugamba) and the largest town in the region (Kigoma). Snails were individually exposed to light to induce shedding of schistosome larvae, which were examined using a compound light microscope. Additionally, the internal transcribed spacer (ITS) region of the ribosomal RNA gene cluster was simultaneously amplified in both snails and their trematodes using a single polymerase chain reaction (PCR) and sequenced to confirm species identification. Results Snails morphologically identified as Biomphalaria pfeifferi were present in all streams except at Mtanga but their distribution was patchy in both time and space. Sequencing of PCR products indicated that not all snails were B. pfeifferi. None of the snails from Gombe or Bugamba shed schistosome larvae, while larvae were shed at all other sites. Overall, an infection prevalence of only 12% was observed in snails based on cercarial shedding. While 47% of the snails were PCR-positive for the 500 bp ITS fragment, which was predicted to indicate infection with S. mansoni, sequence data demonstrated that these bands are not species-specific and can be amplified from other trematode infections. In addition, a 1000 bp band was amplified in 14% of samples, which was identified as a trematode in the family Derogenidae. Conclusions The results support the previous assumption that B. pfeifferi snails may be involved in transmitting schistosomiasis in the area but suggest that the community structure of both snails and trematodes may be more complicated than previously thought. This emphasises the importance of confirming species identifications using sequencing, rather than relying only on PCR-based diagnostics or cercarial shedding. Electronic supplementary material The online version of this article (10.1186/s13071-017-2525-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jared S Bakuza
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK. .,Department of Biological Sciences, Dar es Salaam University College of Education, Dar es Salaam, Tanzania.
| | - Robert Gillespie
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Gamba Nkwengulila
- Department of Zoology and Wildlife Conservation, University of Dar es Salaam, Dar es Salaam, Tanzania
| | - Aileen Adam
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Elizabeth Kilbride
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Barbara K Mable
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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Corstjens PLAM, Hoekstra PT, de Dood CJ, van Dam GJ. Utilizing the ultrasensitive Schistosoma up-converting phosphor lateral flow circulating anodic antigen (UCP-LF CAA) assay for sample pooling-strategies. Infect Dis Poverty 2017; 6:155. [PMID: 29089064 PMCID: PMC5664425 DOI: 10.1186/s40249-017-0368-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 10/09/2017] [Indexed: 01/08/2023] Open
Abstract
Background Methodological applications of the high sensitivity genus-specific Schistosoma CAA strip test, allowing detection of single worm active infections (ultimate sensitivity), are discussed for efficient utilization in sample pooling strategies. Besides relevant cost reduction, pooling of samples rather than individual testing can provide valuable data for large scale mapping, surveillance, and monitoring. Method The laboratory-based CAA strip test utilizes luminescent quantitative up-converting phosphor (UCP) reporter particles and a rapid user-friendly lateral flow (LF) assay format. The test includes a sample preparation step that permits virtually unlimited sample concentration with urine, reaching ultimate sensitivity (single worm detection) at 100% specificity. This facilitates testing large urine pools from many individuals with minimal loss of sensitivity and specificity. The test determines the average CAA level of the individuals in the pool thus indicating overall worm burden and prevalence. When requiring test results at the individual level, smaller pools need to be analysed with the pool-size based on expected prevalence or when unknown, on the average CAA level of a larger group; CAA negative pools do not require individual test results and thus reduce the number of tests. Results Straightforward pooling strategies indicate that at sub-population level the CAA strip test is an efficient assay for general mapping, identification of hotspots, determination of stratified infection levels, and accurate monitoring of mass drug administrations (MDA). At the individual level, the number of tests can be reduced i.e. in low endemic settings as the pool size can be increased as opposed to prevalence decrease. Conclusions At the sub-population level, average CAA concentrations determined in urine pools can be an appropriate measure indicating worm burden. Pooling strategies allowing this type of large scale testing are feasible with the various CAA strip test formats and do not affect sensitivity and specificity. It allows cost efficient stratified testing and monitoring of worm burden at the sub-population level, ideally for large-scale surveillance generating hard data for performance of MDA programs and strategic planning when moving towards transmission-stop and elimination.
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Affiliation(s)
- Paul L A M Corstjens
- Department of Molecular Cell Biology, Leiden University Medical Center, P.O. Box 9600, 2300, RC, Leiden, The Netherlands.
| | - Pytsje T Hoekstra
- Department of Parasitology, Leiden University Medical Center, P.O. Box 9600, 2300, RC, Leiden, The Netherlands
| | - Claudia J de Dood
- Department of Molecular Cell Biology, Leiden University Medical Center, P.O. Box 9600, 2300, RC, Leiden, The Netherlands
| | - Govert J van Dam
- Department of Parasitology, Leiden University Medical Center, P.O. Box 9600, 2300, RC, Leiden, The Netherlands
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Inocencio da Luz R, Linsuke S, Lutumba P, Hasker E, Boelaert M. Assessment of schistosomiasis and soil-transmitted helminths prevalence in school-aged children and opportunities for integration of control in local health services in Kwilu Province, the Democratic Republic of the Congo. Trop Med Int Health 2017; 22:1442-1450. [PMID: 28853206 DOI: 10.1111/tmi.12965] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To determine the prevalence of schistosomiasis (SCH) and soil-transmitted helminths (STH) in the Democratic Republic of Congo, and to assess the capacity of the local health centres for diagnosis and treatment. METHODS Cross-sectional school-based survey in two health districts in the Province of Kwilu. We collected a stool and a urine sample for parasitological examination. Urine filtration and duplicate Kato-Katz thick smears were used for the diagnosis of SCH. Health centres were evaluated using a structured questionnaire. RESULTS In total, 526 children participated in the study and the overall prevalence of Schistosoma mansoni infection was 8.9% (95% CI: 3.5-13.2) in both districts. The prevalence was higher in Mosango (11.7%; 95% CI: 8.9-14.8) than Yasa Bonga district (6.2%; 95% CI: 1.1-11.4). Urine filtration showed that Schistosoma haematobium infection was not present. The combined STH infection prevalence was 58.1% in both districts; hookworm infection was the most common STH found in 52.9% (95% CI: 29.3-62.4) of subjects, followed by Ascaris lumbricoides 9.3% (95% CI: 5.8-15.5) and Trichuris trichiura 2.1% (95% CI: 0.9-4.9). Mixed STH infections were observed as well as SCH-STH coinfection. CONCLUSION Further mapping of both SCH and STH burden is needed, and coverage of preventive chemotherapy in school-aged children should be increased.
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Affiliation(s)
- R Inocencio da Luz
- Department of Public Health, Institute of Tropical Medicine Antwerp, Antwerp, Belgium
| | - S Linsuke
- Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of the Congo
| | - P Lutumba
- Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of the Congo
| | - E Hasker
- Department of Public Health, Institute of Tropical Medicine Antwerp, Antwerp, Belgium
| | - M Boelaert
- Department of Public Health, Institute of Tropical Medicine Antwerp, Antwerp, Belgium
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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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Vonghachack Y, Sayasone S, Khieu V, Bergquist R, van Dam GJ, Hoekstra PT, Corstjens PLAM, Nickel B, Marti H, Utzinger J, Muth S, Odermatt P. Comparison of novel and standard diagnostic tools for the detection of Schistosoma mekongi infection in Lao People's Democratic Republic and Cambodia. Infect Dis Poverty 2017; 6:127. [PMID: 28793922 PMCID: PMC5550959 DOI: 10.1186/s40249-017-0335-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 07/12/2017] [Indexed: 12/29/2022] Open
Abstract
Background Given the restricted distribution of Schistosoma mekongi in one province in Lao People’s Democratic Republic (Lao PDR) and two provinces in Cambodia, together with progress of the national control programmes aimed at reducing morbidity and infection prevalence, the elimination of schistosomiasis mekongi seems feasible. However, sensitive diagnostic tools will be required to determine whether elimination has been achieved. We compared several standard and novel diagnostic tools in S. mekongi-endemic areas. Methods The prevalence and infection intensity of S. mekongi were evaluated in 377 study participants from four villages in the endemic areas in Lao PDR and Cambodia using Kato-Katz stool examination, antibody detection based on an enzyme-linked immunosorbent assay (ELISA) and schistosome circulating antigen detection by lateral-flow tests. Two highly sensitive test systems for the detection of cathodic and anodic circulating antigens (CCA, CAA) in urine and serum were utilized. Results Stool microscopy revealed an overall prevalence of S. mekongi of 6.4% (one case in Cambodia and 23 cases in Lao PDR), while that of Opisthorchis viverrini, hookworm, Trichuris trichiura, Ascaris lumbricoides and Taenia spp. were 50.4%, 28.1%, 3.5%, 0.3% and 1.9%, respectively. In the urine samples, the tests for CCA and CAA detected S. mekongi infections in 21.0% and 38.7% of the study participants, respectively. In the serum samples, the CAA assay revealed a prevalence of 32.4%, while a combination of the CAA assay in serum and in urine revealed a prevalence of 43.2%. There was a difference between the two study locations with a higher prevalence reached in the samples from Lao PDR. Conclusions The CCA, CAA and ELISA results showed substantially higher prevalence estimates for S. mekongi compared to Kato-Katz thick smears. Active schistosomiasis mekongi in Lao PDR and Cambodia might thus have been considerably underestimated previously. Hence, sustained control efforts are still needed to break transmission of S. mekongi. The pivotal role of highly sensitive diagnostic assays in areas targeting elimination cannot be overemphasised. Electronic supplementary material The online version of this article (doi:10.1186/s40249-017-0335-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Youthanavanh Vonghachack
- Faculty of Basic Sciences, University of Health Sciences, Ministry of Health, Vientiane, Lao People's Democratic Republic.,Swiss Tropical and Public Health Institute, P.O. Box, CH-4002, Basel, Switzerland.,University of Basel, P.O. Box, CH-4003, Basel, Switzerland
| | - Somphou Sayasone
- National Institute of Public Health, Ministry of Health, Vientiane, Lao People's Democratic Republic
| | - Virak Khieu
- National Centre for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia
| | | | - Govert J van Dam
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Pytsje T Hoekstra
- Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Paul L A M Corstjens
- Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Beatrice Nickel
- Swiss Tropical and Public Health Institute, P.O. Box, CH-4002, Basel, Switzerland.,University of Basel, P.O. Box, CH-4003, Basel, Switzerland
| | - Hanspeter Marti
- Swiss Tropical and Public Health Institute, P.O. Box, CH-4002, Basel, Switzerland.,University of Basel, P.O. Box, CH-4003, Basel, Switzerland
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, P.O. Box, CH-4002, Basel, Switzerland.,University of Basel, P.O. Box, CH-4003, Basel, Switzerland
| | - Sinuon Muth
- National Centre for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia
| | - Peter Odermatt
- Swiss Tropical and Public Health Institute, P.O. Box, CH-4002, Basel, Switzerland. .,University of Basel, P.O. Box, CH-4003, Basel, Switzerland.
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Turner HC, Bettis AA, Dunn JC, Whitton JM, Hollingsworth TD, Fleming FM, Anderson RM. Economic Considerations for Moving beyond the Kato-Katz Technique for Diagnosing Intestinal Parasites As We Move Towards Elimination. Trends Parasitol 2017; 33:435-443. [PMID: 28187989 PMCID: PMC5446322 DOI: 10.1016/j.pt.2017.01.007] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 12/29/2016] [Accepted: 01/09/2017] [Indexed: 12/30/2022]
Abstract
While the need for more sensitive diagnostics for intestinal helminths is well known, the cost of developing and implementing new tests is considered relatively high compared to the Kato-Katz technique. Here, we review the reported costs of performing the Kato-Katz technique. We also outline several economic arguments we believe highlight the need for further investment in alternative diagnostics, and considerations that should be made when comparing their costs. In our opinion, we highlight that, without new diagnostic methods, it will be difficult for policy makers to make the most cost-effective decisions and that the potentially higher unit costs of new methods can be outweighed by the long-term programmatic benefits they have (such as the ability to detect the interruption of transmission).
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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.
| | - 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
| | - Julia C Dunn
- 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
| | - 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
| | - T Déirdre Hollingsworth
- Mathematics Institute, University of Warwick, Coventry CV4 7AL, UK; School of Life Sciences, University of Warwick, Coventry CV4 7AL, 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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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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Tchuem Tchuenté LA, Rollinson D, Stothard JR, Molyneux D. Moving from control to elimination of schistosomiasis in sub-Saharan Africa: time to change and adapt strategies. Infect Dis Poverty 2017; 6:42. [PMID: 28219412 PMCID: PMC5319063 DOI: 10.1186/s40249-017-0256-8] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Accepted: 02/08/2017] [Indexed: 11/17/2022] Open
Abstract
Schistosomiasis is a water borne parasitic disease of global importance and with ongoing control the disease endemic landscape is changing. In sub-Saharan Africa, for example, the landscape is becoming ever more heterogeneous as there are several species of Schistosoma that respond in different ways to ongoing preventive chemotherapy and the inter-sectoral interventions currently applied. The major focus of preventive chemotherapy is delivery of praziquantel by mass drug administration to those shown to be, or presumed to be, at-risk of infection and disease. In some countries, regional progress may be uneven but in certain locations there are very real prospects to transition from control into interruption of transmission, and ultimately elimination. To manage this transition requires reconsideration of some of the currently deployed diagnostic tools used in surveillance and downward realignment of existing prevalence thresholds to trigger mass treatment. A key challenge will be maintaining and if possible, expanding the current donation of praziquantel to currently overlooked groups, then judging when appropriate to move from mass drug administration to selective treatment. In so doing, this will ensure the health system is adapted, primed and shown to be cost-effective to respond to these changing disease dynamics as we move forward to 2020 targets and beyond.
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Affiliation(s)
- Louis-Albert Tchuem Tchuenté
- National Programme for the Control of Schistosomiasis and STH, Ministry of Public Health, Yaoundé, Cameroon. .,Centre for Schistosomiasis and Parasitology, University of Yaoundé I, Yaoundé, Cameroon.
| | - David Rollinson
- Department of Life Sciences, The Natural History Museum, London, SW7 5BD, UK
| | - J Russell Stothard
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - David Molyneux
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
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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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Stothard JR, Campbell SJ, Osei-Atweneboana MY, Durant T, Stanton MC, Biritwum NK, Rollinson D, Ombede DRE, Tchuem-Tchuenté LA. Towards interruption of schistosomiasis transmission in sub-Saharan Africa: developing an appropriate environmental surveillance framework to guide and to support 'end game' interventions. Infect Dis Poverty 2017; 6:10. [PMID: 28088239 PMCID: PMC5237522 DOI: 10.1186/s40249-016-0215-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 12/12/2016] [Indexed: 01/03/2023] Open
Abstract
Schistosomiasis is a waterborne parasitic disease in sub-Saharan Africa, particularly common in rural populations living in impoverished conditions. With the scale-up of preventive chemotherapy, national campaigns will transition from morbidity- to transmission-focused interventions thus formal investigation of actual or expected declines in environmental transmission is needed as 'end game' scenarios arise. Surprisingly, there are no international or national guidelines to do so in sub-Saharan Africa. Our article therefore provides an introduction to key practicalities and pitfalls in the development of an appropriate environmental surveillance framework. In this context, we discuss how strategies need to be adapted and tailored to the local level to better guide and support future interventions through this transition. As detection of egg-patent infection in people becomes rare, careful sampling of schistosome larvae in freshwater and in aquatic snails with robust species-specific DNA assays will be required. Appropriate metrics, derived from observed prevalence(s) as compared with predetermined thresholds, could each provide a clearer insight into contamination- and exposure-related dynamics. Application could be twofold, first to certify areas currently free from schistosomiasis transmission or second to red-flag recalcitrant locations where extra effort or alternative interventions are needed.
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Affiliation(s)
- J. Russell Stothard
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA UK
| | - Suzy J. Campbell
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA UK
| | - Mike Y. Osei-Atweneboana
- Department of Environmental Biology and Health, Council for Scientific and Industrial Research-Water Research Insitute, P.O. Box M 32, Accra, Ghana
| | - Timothy Durant
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA UK
| | - Michelle C. Stanton
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA UK
| | | | - David Rollinson
- Department of Life Sciences; Natural History Museum, Cromwell Road, London, SW7 5BD UK
| | - Dieudonné R. Eloundou Ombede
- Centre for Schistosomiasis and Parasitology, Yaoundé, Cameroon
- Laboratory of Parasitology and Ecology, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon
| | - Louis-Albert Tchuem-Tchuenté
- Centre for Schistosomiasis and Parasitology, Yaoundé, Cameroon
- Laboratory of Parasitology and Ecology, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon
- National Programme for the Control of Schistosomiasis and Intestinal Helminthiasis, Ministry of Public Health, Yaoundé, Cameroon
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A preface on advances in diagnostics for infectious and parasitic diseases: detecting parasites of medical and veterinary importance. Parasitology 2017; 141:1781-8. [PMID: 25415359 DOI: 10.1017/s0031182014001309] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
There are many reasons why detection of parasites of medical and veterinary importance is vital and where novel diagnostic and surveillance tools are required. From a medical perspective alone, these originate from a desire for better clinical management and rational use of medications. Diagnosis can be at the individual-level, at close to patient settings in testing a clinical suspicion or at the community-level, perhaps in front of a computer screen, in classification of endemic areas and devising appropriate control interventions. Thus diagnostics for parasitic diseases has a broad remit as parasites are not only tied with their definitive hosts but also in some cases with their vectors/intermediate hosts. Application of current diagnostic tools and decision algorithms in sustaining control programmes, or in elimination settings, can be problematic and even ill-fitting. For example in resource-limited settings, are current diagnostic tools sufficiently robust for operational use at scale or are they confounded by on-the-ground realities; are the diagnostic algorithms underlying public health interventions always understood and well-received within communities which are targeted for control? Within this Special Issue (SI) covering a variety of diseases and diagnostic settings some answers are forthcoming. An important theme, however, throughout the SI is to acknowledge that cross-talk and continuous feedback between development and application of diagnostic tests is crucial if they are to be used effectively and appropriately.
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49
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Stanton MC. The Role of Spatial Statistics in the Control and Elimination of Neglected Tropical Diseases in Sub-Saharan Africa: A Focus on Human African Trypanosomiasis, Schistosomiasis and Lymphatic Filariasis. ADVANCES IN PARASITOLOGY 2017; 97:187-241. [PMID: 28325371 DOI: 10.1016/bs.apar.2017.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Disease control and elimination programmes can benefit greatly from accurate information on the spatial variability of disease risk, particularly when risk is highly spatially heterogeneous. Due to advances in statistical methodology, coupled with the increased availability of geospatial technology, this information is becoming increasingly accessible. In this chapter we describe recent advancements in spatial methods associated with the analysis of disease data measured at the point-level and demonstrate their application to the control and elimination of neglected tropical diseases (NTDs). We further provide information on spatially referenced data sources and software that can be used to create NTD risk maps, concentrating on those that can be freely obtained. Examples relating to three NTDs affecting populations in sub-Saharan Africa are presented throughout the chapter, i.e., human African trypanosomiasis, schistosomiasis and lymphatic filariasis. These three diseases, with differing routes of transmission, control methods and level of spatial heterogeneity, demonstrate the flexibility and applicability of the methods described.
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Affiliation(s)
- M C Stanton
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom.
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Hawkins KR, Cantera JL, Storey HL, Leader BT, de los Santos T. Diagnostic Tests to Support Late-Stage Control Programs for Schistosomiasis and Soil-Transmitted Helminthiases. PLoS Negl Trop Dis 2016; 10:e0004985. [PMID: 28005900 PMCID: PMC5179049 DOI: 10.1371/journal.pntd.0004985] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Global efforts to address schistosomiasis and soil-transmitted helminthiases (STH) include deworming programs for school-aged children that are made possible by large-scale drug donations. Decisions on these mass drug administration (MDA) programs currently rely on microscopic examination of clinical specimens to determine the presence of parasite eggs. However, microscopy-based methods are not sensitive to the low-intensity infections that characterize populations that have undergone MDA. Thus, there has been increasing recognition within the schistosomiasis and STH communities of the need for improved diagnostic tools to support late-stage control program decisions, such as when to stop or reduce MDA. Failure to adequately address the need for new diagnostics could jeopardize achievement of the 2020 London Declaration goals. In this report, we assess diagnostic needs and landscape potential solutions and determine appropriate strategies to improve diagnostic testing to support control and elimination programs. Based upon literature reviews and previous input from experts in the schistosomiasis and STH communities, we prioritized two diagnostic use cases for further exploration: to inform MDA-stopping decisions and post-MDA surveillance. To this end, PATH has refined target product profiles (TPPs) for schistosomiasis and STH diagnostics that are applicable to these use cases. We evaluated the limitations of current diagnostic methods with regards to these use cases and identified candidate biomarkers and diagnostics with potential application as new tools. Based on this analysis, there is a need to develop antigen-detecting rapid diagnostic tests (RDTs) with simplified, field-deployable sample preparation for schistosomiasis. Additionally, there is a need for diagnostic tests that are more sensitive than the current methods for STH, which may include either a field-deployable molecular test or a simple, low-cost, rapid antigen-detecting test.
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Affiliation(s)
- Kenneth R. Hawkins
- Diagnostics Program, PATH, Seattle, Washington, United States of America
- * E-mail:
| | - Jason L. Cantera
- Diagnostics Program, PATH, Seattle, Washington, United States of America
| | - Helen L. Storey
- Diagnostics Program, PATH, Seattle, Washington, United States of America
| | - Brandon T. Leader
- Diagnostics Program, PATH, Seattle, Washington, United States of America
| | - Tala de los Santos
- Diagnostics Program, PATH, Seattle, Washington, United States of America
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