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Vaillant MT, Philippy F, Neven A, Barré J, Bulaev D, Olliaro PL, Utzinger J, Keiser J, Garba AT. Diagnostic tests for human Schistosoma mansoni and Schistosoma haematobium infection: a systematic review and meta-analysis. THE LANCET. MICROBE 2024; 5:e366-e378. [PMID: 38467130 PMCID: PMC10990967 DOI: 10.1016/s2666-5247(23)00377-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 10/22/2023] [Accepted: 11/16/2023] [Indexed: 03/13/2024]
Abstract
BACKGROUND Accurate diagnosis is pivotal for implementing strategies for surveillance, control, and elimination of schistosomiasis. Despite their low sensitivity in low-endemicity areas, microscopy-based urine filtration and the Kato-Katz technique are considered as reference diagnostic tests for Schistosoma haematobium and Schistosoma mansoni infections, respectively. We aimed to collate all available evidence on the accuracy of other proposed diagnostic techniques. METHODS In this systematic review and meta-analysis, we searched PubMed, Embase, the Cochrane Library, and LILACS for studies published from database inception to Dec 31, 2022, investigating the sensitivity and specificity of diagnostic tests for S haematobium and S mansoni infections against Kato-Katz thick smears or urine microscopy (reference tests) involving adults (aged ≥18 years), school-aged children (aged 7 to 18 years), or preschool-aged children (aged 1 month to 7 years). We extracted raw data on true positives, true negatives, false positives, and false negatives for the diagnostic tests and data on the number of participants, study authors, publication year, journal, study design, participants' age and sex, prevalence of Schistosoma infection, and treatment status. To account for imperfect reference tests, we used a hierarchical Bayesian latent class meta-analysis to model test accuracy. FINDINGS Overall, we included 121 studies, assessing 28 different diagnostic techniques. Most studies (103 [85%] of 121) were done in Africa, 14 (12%) in South America, one (1%) in Asia, and one (1%) in an unknown country. Compared with the reference test, Kato-Katz thick smears, circulating cathodic antigen urine cassette assay version 1 (CCA1, 36 test comparisons) had excellent sensitivity (95% [95% credible interval 88-99]) and reasonable specificity (74% [63-83]) for S mansoni. ELISA-based tests had a performance comparable to circulating cathodic antigen, but there were few available test comparisons. For S haematobium, proteinuria (42 test comparisons, sensitivity 73% [62-82]; specificity 94% [89-98]) and haematuria (75 test comparisons, sensitivity 85% [80-90]; specificity 96% [92-99]) reagent strips showed high specificity, with haematuria reagent strips having better sensitivity. Despite limited data, nucleic acid amplification tests (NAATs; eg, PCR or loop-mediated isothermal amplification [LAMP]) showed promising results with sensitivity estimates above 90%. We found an unclear risk of bias of about 70% in the use of the reference or index tests and of 50% in patient selection. All analyses showed substantial heterogeneity (I2>80%). INTERPRETATION Although NAATs and immunological diagnostics show promise, the limited information available precludes drawing definitive conclusions. Additional research on diagnostic accuracy and cost-effectiveness is needed before the replacement of conventional tests can be considered. FUNDING WHO and Luxembourg Institute of Health.
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Affiliation(s)
- Michel T Vaillant
- Competence Center for Methodology and Statistics, Luxembourg Institute of Health, Strassen, Luxembourg.
| | - Fred Philippy
- Competence Center for Methodology and Statistics, Luxembourg Institute of Health, Strassen, Luxembourg; Zortify, Luxembourg City, Luxembourg
| | - Anouk Neven
- Competence Center for Methodology and Statistics, Luxembourg Institute of Health, Strassen, Luxembourg
| | - Jessica Barré
- Competence Center for Methodology and Statistics, Luxembourg Institute of Health, Strassen, Luxembourg; Luxembourg National Office of Health, Luxembourg City, Luxembourg
| | - Dmitry Bulaev
- Competence Center for Methodology and Statistics, Luxembourg Institute of Health, Strassen, Luxembourg
| | - Piero L Olliaro
- International Severe Acute Respiratory and Emerging Infection Consortium, Pandemic Sciences Institute, University of Oxford, Oxford, UK
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute and Medical Parasitology and Infection Biology Department, University of Basel, Basel, Switzerland
| | - Amadou T Garba
- Department of Control of Neglected Tropical Diseases, WHO, Geneva, Switzerland
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Gender-related differences in prevalence, intensity and associated risk factors of Schistosoma infections in Africa: A systematic review and meta-analysis. PLoS Negl Trop Dis 2021; 15:e0009083. [PMID: 34788280 PMCID: PMC8635327 DOI: 10.1371/journal.pntd.0009083] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 12/01/2021] [Accepted: 09/29/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Schistosomiasis remains a global-health problem with over 90% of its burden concentrated in Africa. Field studies reflect the complex ways in which socio-cultural and socio-economic variables, affect the distribution of Schistosoma infections across different populations. This review set out to systematically investigate and quantify the differences in Schistosoma infection burdens between males and females in Africa for two of the most prevalent Schistosoma species-Schistosoma mansoni and Schistosoma haematobium. METHODOLOGY We searched (from inception to 11th March 2020) Embase, MEDLINE, PubMed, and Web of Science for relevant studies on schistosomiasis. We included studies that report S. mansoni and/or S. haematobium prevalence and/or intensity data distributed between males and females. We conducted meta-analyses on the male to female (M:F) prevalence of infection ratios. Subgroup analyses were performed according to study baseline prevalence, sample size and the lower and upper age limit of study participants. We also present a descriptive analysis of differential risk and intensity of infection across males and females. Evidence for differences in the prevalence of schistosomiasis infection between males and females is presented, stratified by Schistosoma species. RESULT We identified 128 relevant studies, with over 200,000 participants across 23 countries. Of all the reported differences in the prevalence of infection between males and females, only 41% and 34% were statistically significant for S. mansoni and S. haematobium, respectively. Similar proportions of studies (27% and 34% for for S. haematobium and S. mansoni, respectively) of the reported differences in intensity of infection between males and females were statistically significant. The meta-analyses summarized a higher prevalence of infection in males; pooled random-effects weighted M:F prevalence of infection ratios were 1.20 (95% CI 1.11-1.29) for S. haematobium and 1.15 (95% CI 1.08-1.22) for S. mansoni. However, females are underrespresented in some of the studies. Additionally, there was significant heterogeneity across studies (Higgins I2 statistic (p-values < 0.001, I2values>95%)). Results of the subgroup analysis showed that the baseline prevalence influenced the M:F prevalence ratios for S. haematobium and S. mansoni, with higher M:F prevalence of infection ratios in settings with a lower baseline prevalence of infection. Across the studies, we identified four major risk factors associated with infection rates: occupational and recreational water contact, knowledge, socio-economic factors and demographic factors. The effect of these risk factors on the burden of infection in males and females varied across studies. CONCLUSIONS We find evidence of differences in prevalence of infection between males and females which may reflect differences in gender norms and water contact activities, suggesting that policy changes at the regional level may help ameliorate gender-related disparities in schistosomiasis infection burden. Collecting, robustly analysing, and reporting, sex-disaggregated epidemiological data, is currently lacking, but would be highly informative for planning effective treatment programmes and establishing those most at risk of schistosomiasis infections.
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Fenwick A. Schistosomiasis research and control since the retirement of Sir Patrick Manson in 1914. Trans R Soc Trop Med Hyg 2018; 111:191-198. [PMID: 28957468 PMCID: PMC5914372 DOI: 10.1093/trstmh/trx036] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 06/13/2017] [Indexed: 11/13/2022] Open
Abstract
On 14 December 2016, Professor Alan Fenwick OBE delivered the prestigious 'Manson Lecture' to the Royal Society for Tropical Medicine and Hygiene at the Royal Society in London. This paper, based on the Manson Lecture, presents the research carried out to study the epidemiology of schistosomiasis in Africa and test the various control tools as they were proposed from 1914 to date. Subsequently the development of national control programmes against schistosomiasis in Africa from 2000 towards the full national coverage now being delivered in many countries is discussed. In 2000 only Egypt in Africa was offering treatment to the infected and at-risk populations. By 2016 the World Health Assembly resolutions and the WHO NTD targets for 2020 are close to being achieved in some countries where schistosomiasis appears no longer to be 'a public health problem'. However, in some areas in sub-Saharan Africa, continuous annual treatment is still needed because of remaining 'hotspots' where transmission seems to be stubbornly continuing. The author therefore questions whether the timescales to reach eliminations are realistic and whether the tools are available to reach those targets.
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Affiliation(s)
- Alan Fenwick
- Professor of Tropical Parasitology, School of Public Health, Imperial College, St Mary's Campus.,Norfolk Place, London W2 1PG, UK
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Towards elimination of schistosomiasis after 5000 years of endemicity in Egypt. Acta Trop 2018; 181:112-121. [PMID: 29453950 DOI: 10.1016/j.actatropica.2018.02.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 01/29/2018] [Accepted: 02/11/2018] [Indexed: 11/21/2022]
Abstract
Schistosomiasis is a snail-transmitted infectious disease caused by a long lasting infection with a blood fluke of the genus Schistosoma. S. haematobium and S. mansoni are the species endemic in Egypt. The country has been plagued and seriously suffered from schistosomiasis over the past 5000 years. Great strides had been done in controlling the disease since 1922. The history, epidemiology and the different control approaches were reviewed. Currently, Egypt is preparing towards schistosomiasis elimination by 2020. The new strategy depends on four main axes; large scale treatment in all areas of residual transmission by targeting entire populations with PZQ, intensified snail control, heath education and behavioral changes and expansion of the complementary public health interventions. While on the road towards elimination, we addressed here the important challenges, lessons and the key issues from the different control strategies to help the achievement of our goal. Notably, frangibility of the drug based control, emergence of resistance against PZQ, persistence of some hot spots areas, the need of further control efforts to the high risk individuals and community involvement in the control programs, reconsideration of diagnostic tests used in surveillance, and continous monitoring of the field to detect changes in the snail intermediate host. Importantly, the adaptation between the parasite and its intermediate snail host throughout water bodies in Egypt merits attention as Schistosoma infection can be introduced to the new reclaimed areas. This review may help supplying information for the policy makers to tailor control measures suitable to the local context that could help in the transfer from control to elimination.
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Donohue RE, Mashoto KO, Mubyazi GM, Madon S, Malecela MN, Michael E. Biosocial Determinants of Persistent Schistosomiasis among Schoolchildren in Tanzania despite Repeated Treatment. Trop Med Infect Dis 2017; 2:E61. [PMID: 30270918 PMCID: PMC6082061 DOI: 10.3390/tropicalmed2040061] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 11/21/2017] [Accepted: 11/23/2017] [Indexed: 01/19/2023] Open
Abstract
Schistosomiasis is a parasitic disease endemic to Tanzania and other countries of the global south, which is currently being addressed through preventive chemotherapy campaigns. However, there is growing recognition that chemotherapy strategies will need to be supplemented to sustainably control and eventually eliminate the disease. There remains a need to understand the factors contributing to continued transmission in order to ensure the effective configuration and implementation of supplemented programs. We conducted a cross-sectional questionnaire, to evaluate the biosocial determinants facilitating the persistence of schistosomiasis, among 1704 Tanzanian schoolchildren residing in two districts undergoing a preventive chemotherapeutic program: Rufiji and Mkuranga. A meta-analysis was carried out to select the diagnostic questions that provided a likelihood for predicting infection status. We found that self-reported schistosomiasis continues to persist among the schoolchildren, despite multiple rounds of drug administration.Using mixed effects logistic regression modeling, we found biosocial factors, including gender, socio-economic status, and water, sanitation, and hygiene (WASH)-related variables, were associated with this continued schistosomiasis presence. These findings highlight the significant role that social factors may play in the persistence of disease transmission despite multiple treatments, and support the need not only for including integrated technical measures, such as WASH, but also addressing issues of poverty and gender when designing effective and sustainable schistosomiasis control programs.
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Affiliation(s)
- Rose E Donohue
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA.
| | - Kijakazi O Mashoto
- National Institute for Medical Research, P.O. Box 9653, 3 Barack Obama Drive, 11101 Dar es Salaam, Tanzania.
| | - Godfrey M Mubyazi
- National Institute for Medical Research, P.O. Box 9653, 3 Barack Obama Drive, 11101 Dar es Salaam, Tanzania.
| | - Shirin Madon
- Department of International Development, London School of Economics & Political Science, Houghton Street, London WC2A 2AE, UK.
- Department of Management, London School of Economics & Political Science, Houghton Street, London WC2A 2AE, UK.
| | - Mwele N Malecela
- Tanzania Commission for Science and Technology (COSTECH), P.O. Box 4302, Ali Hassan Mwinyi Road, Kijitonyama, 14113 Dar es Salaam, Tanzania.
| | - Edwin Michael
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA.
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Helmy YA, El-Adawy H, Abdelwhab EM. A Comprehensive Review of Common Bacterial, Parasitic and Viral Zoonoses at the Human-Animal Interface in Egypt. Pathogens 2017; 6:pathogens6030033. [PMID: 28754024 PMCID: PMC5617990 DOI: 10.3390/pathogens6030033] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 07/17/2017] [Accepted: 07/19/2017] [Indexed: 12/25/2022] Open
Abstract
Egypt has a unique geographical location connecting the three old-world continents Africa, Asia and Europe. It is the country with the highest population density in the Middle East, Northern Africa and the Mediterranean basin. This review summarizes the prevalence, reservoirs, sources of human infection and control regimes of common bacterial, parasitic and viral zoonoses in animals and humans in Egypt. There is a gap of knowledge conerning the epidemiology of zoonotic diseases at the human-animal interface in different localities in Egypt. Some zoonotic agents are “exotic” for Egypt (e.g., MERS-CoV and Crimean-Congo hemorrhagic fever virus), others are endemic (e.g., Brucellosis, Schistosomiasis and Avian influenza). Transboundary transmission of emerging pathogens from and to Egypt occurred via different routes, mainly importation/exportation of apparently healthy animals or migratory birds. Control of the infectious agents and multidrug resistant bacteria in the veterinary sector is on the frontline for infection control in humans. The implementation of control programs significantly decreased the prevalence of some zoonoses, such as schistosomiasis and fascioliasis, in some localities within the country. Sustainable awareness, education and training targeting groups at high risk (veterinarians, farmers, abattoir workers, nurses, etc.) are important to lessen the burden of zoonotic diseases among Egyptians. There is an urgent need for collaborative surveillance and intervention plans for the control of these diseases in Egypt.
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Affiliation(s)
- Yosra A Helmy
- Food Animal Health Research Program, Department of Veterinary Preventive Medicine, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691, USA.
- Department of Animal Hygiene, Zoonoses and Animal Ethology, Faculty of Veterinary Medicine, Suez Canal University, 41511 Ismailia, Egypt.
| | - Hosny El-Adawy
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Bacterial Infections and Zoonoses, Naumburger Str. 96a, 07743 Jena, Germany.
- Faculty of Veterinary Medicine, Kafrelsheikh University, 335516 Kafrelsheikh, Egypt.
| | - Elsayed M Abdelwhab
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Molecular Virology and Cell Biology, Suedufer 10, 17493 Greifswald-Insel Riems, Germany.
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Prophylactic effect of artemether on human schistosomiasis mansoni among Egyptian children: A randomized controlled trial. Acta Trop 2016; 158:52-58. [PMID: 26921676 DOI: 10.1016/j.actatropica.2016.02.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Revised: 02/15/2016] [Accepted: 02/21/2016] [Indexed: 11/23/2022]
Abstract
A double-blind, randomized controlled trial was conducted in an endemic focus for Schistosoma mansoni in Kafr El-Sheikh Governorate, Northern Nile Delta, Egypt, to evaluate the prophylactic effect of artemether (ART) given in conjunction with praziquantel (PZQ). The study encompassed 913 primary school children randomly assigned to two treatment groups PZQ/ART and PZQ/ART-placebo. At baseline, both groups received 40 mg/kg body weight of PZQ twice four weeks apart, after which one group received 6 mg/kg body weight of ART every 3 weeks in 5 cycles during the transmission season and the other group received ART-placebo. At the end of the study, prevalence of infection among the PZQ/ART was approximately half that of the PZQ/ART-placebo group, i.e. 6.7% versus 11.6%, and incidence of new infections for the PZQ/ART was 2.7% versus 6.5% for the PZQ/ART-placebo. In conclusion, PZQ/ART combined therapy might be considered as an adjunct measure against human schistosomiasis, by specifically reducing transmission and therefore contribute to disease elimination.
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Ochodo EA, Gopalakrishna G, Spek B, Reitsma JB, van Lieshout L, Polman K, Lamberton P, Bossuyt PMM, Leeflang MMG. Circulating antigen tests and urine reagent strips for diagnosis of active schistosomiasis in endemic areas. Cochrane Database Syst Rev 2015; 2015:CD009579. [PMID: 25758180 PMCID: PMC4455231 DOI: 10.1002/14651858.cd009579.pub2] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Point-of-care (POC) tests for diagnosing schistosomiasis include tests based on circulating antigen detection and urine reagent strip tests. If they had sufficient diagnostic accuracy they could replace conventional microscopy as they provide a quicker answer and are easier to use. OBJECTIVES To summarise the diagnostic accuracy of: a) urine reagent strip tests in detecting active Schistosoma haematobium infection, with microscopy as the reference standard; and b) circulating antigen tests for detecting active Schistosoma infection in geographical regions endemic for Schistosoma mansoni or S. haematobium or both, with microscopy as the reference standard. SEARCH METHODS We searched the electronic databases MEDLINE, EMBASE, BIOSIS, MEDION, and Health Technology Assessment (HTA) without language restriction up to 30 June 2014. SELECTION CRITERIA We included studies that used microscopy as the reference standard: for S. haematobium, microscopy of urine prepared by filtration, centrifugation, or sedimentation methods; and for S. mansoni, microscopy of stool by Kato-Katz thick smear. We included studies on participants residing in endemic areas only. DATA COLLECTION AND ANALYSIS Two review authors independently extracted data, assessed quality of the data using QUADAS-2, and performed meta-analysis where appropriate. Using the variability of test thresholds, we used the hierarchical summary receiver operating characteristic (HSROC) model for all eligible tests (except the circulating cathodic antigen (CCA) POC for S. mansoni, where the bivariate random-effects model was more appropriate). We investigated heterogeneity, and carried out indirect comparisons where data were sufficient. Results for sensitivity and specificity are presented as percentages with 95% confidence intervals (CI). MAIN RESULTS We included 90 studies; 88 from field settings in Africa. The median S. haematobium infection prevalence was 41% (range 1% to 89%) and 36% for S. mansoni (range 8% to 95%). Study design and conduct were poorly reported against current standards. Tests for S. haematobium Urine reagent test strips versus microscopyCompared to microscopy, the detection of microhaematuria on test strips had the highest sensitivity and specificity (sensitivity 75%, 95% CI 71% to 79%; specificity 87%, 95% CI 84% to 90%; 74 studies, 102,447 participants). For proteinuria, sensitivity was 61% and specificity was 82% (82,113 participants); and for leukocyturia, sensitivity was 58% and specificity 61% (1532 participants). However, the difference in overall test accuracy between the urine reagent strips for microhaematuria and proteinuria was not found to be different when we compared separate populations (P = 0.25), or when direct comparisons within the same individuals were performed (paired studies; P = 0.21).When tests were evaluated against the higher quality reference standard (when multiple samples were analysed), sensitivity was marginally lower for microhaematuria (71% vs 75%) and for proteinuria (49% vs 61%). The specificity of these tests was comparable. Antigen assayCompared to microscopy, the CCA test showed considerable heterogeneity; meta-analytic sensitivity estimate was 39%, 95% CI 6% to 73%; specificity 78%, 95% CI 55% to 100% (four studies, 901 participants). Tests for S. mansoni Compared to microscopy, the CCA test meta-analytic estimates for detecting S. mansoni at a single threshold of trace positive were: sensitivity 89% (95% CI 86% to 92%); and specificity 55% (95% CI 46% to 65%; 15 studies, 6091 participants) Against a higher quality reference standard, the sensitivity results were comparable (89% vs 88%) but specificity was higher (66% vs 55%). For the CAA test, sensitivity ranged from 47% to 94%, and specificity from 8% to 100% (4 studies, 1583 participants). AUTHORS' CONCLUSIONS Among the evaluated tests for S. haematobium infection, microhaematuria correctly detected the largest proportions of infections and non-infections identified by microscopy.The CCA POC test for S. mansoni detects a very large proportion of infections identified by microscopy, but it misclassifies a large proportion of microscopy negatives as positives in endemic areas with a moderate to high prevalence of infection, possibly because the test is potentially more sensitive than microscopy.
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Affiliation(s)
- Eleanor A Ochodo
- Academic Medical Center, University of AmsterdamDepartment of Clinical Epidemiology, Biostatistics and BioinformaticsAmsterdamNetherlands1100 DD
- Stellenbosch UniversityCentre for Evidence‐based Health Care, Faculty of Medicine and Health SciencesCape TownSouth Africa
| | - Gowri Gopalakrishna
- Academic Medical Center, University of AmsterdamDepartment of Clinical Epidemiology, Biostatistics and BioinformaticsAmsterdamNetherlands1100 DD
| | - Bea Spek
- Academic Medical Center, University of AmsterdamDepartment of Clinical Epidemiology, Biostatistics and BioinformaticsAmsterdamNetherlands1100 DD
- Hanze University GroningenDepartment of Speech and Language PathologyEyssoniuspleinGroningenNetherlands
| | - Johannes B Reitsma
- University Medical Center UtrechtJulius Center for Health Sciences and Primary CarePO Box 85500UtrechtNetherlands3508 GA Utrecht
| | - Lisette van Lieshout
- Leiden University Medical CenterDepartment of ParasitologyPO Box 9600LeidenNetherlands2300 RC
| | - Katja Polman
- Institute of Tropical MedicineDepartment of Biomedical SciencesNationalestraat 155AntwerpBelgium2000
| | - Poppy Lamberton
- Imperial College LondonDepartment of Infectious Disease EpidemiologySt. Mary's Campus, Norfolk PlaceLondonUKW2 1PG
| | - Patrick MM Bossuyt
- Academic Medical Center, University of AmsterdamDepartment of Clinical Epidemiology, Biostatistics and BioinformaticsAmsterdamNetherlands1100 DD
| | - Mariska MG Leeflang
- Academic Medical Center, University of AmsterdamDepartment of Clinical Epidemiology, Biostatistics and BioinformaticsAmsterdamNetherlands1100 DD
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Schistosoma mansoni infection in a fishermen community, the Lake Manzala region-Egypt. ASIAN PACIFIC JOURNAL OF TROPICAL DISEASE 2014. [DOI: 10.1016/s2222-1808(14)60607-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Kiran S, D M. Epidemiology of schistosomiasis in school aged children in some riverine areas of Sokoto, Nigeria. ACTA ACUST UNITED AC 2014. [DOI: 10.5897/jphe2013.0580] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Value of Polymerase Chain Reaction Amplified From Human Urine Samples for Diagnosis and Epidemiology of Urinary Schistosomiasis. INFECTIOUS DISEASES IN CLINICAL PRACTICE 2014. [DOI: 10.1097/ipc.0000000000000110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Hibbs AC, Secor WE, Van Gerven D, Armelagos G. Irrigation and infection: The immunoepidemiology of schistosomiasis in ancient Nubia. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2011; 145:290-8. [DOI: 10.1002/ajpa.21493] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Revised: 12/22/2010] [Indexed: 11/11/2022]
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Abou-El-Naga IF, El-Nassery SMF, Allam SR, Shaat EA, Mady RFM. Biomphalaria species in Alexandria water channels. Parasitol Int 2011; 60:247-54. [PMID: 21458594 DOI: 10.1016/j.parint.2011.03.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 02/27/2011] [Accepted: 03/23/2011] [Indexed: 11/15/2022]
Abstract
Of the several species of Biomphalaria snails worldwide that serve as the intermediate host for Schistosoma mansoni, Biomphalaria alexandrina is a species that is indigenous to Egypt. Recently, there has been much debate concerning the presence of Biomphalaria glabrata and the hybrid of the species with Biomphalaria alexandrina. Due to this debate, the absence of a clear explanation for the presence of B. glabrata in Egyptian water channels and the probability that they may be reintroduced, we conducted this field study to identify Biomphalaria species present in Alexandria water channels. Laboratory-adapted susceptible snails to Schistosoma mansoni of the following species were used as a reference; Biomphalaria alexandrina, Biomphalaria glabrata and their hybrid. These snails were used to perpetuate the Schistosoma life cycle at the Theodor Bilharz Research Institute (TBRI), Cairo, Egypt. Morphological and molecular studies were conducted on these reference snails as well as on the first generation of Biomphalaria snails from two areas in the Alexandria governorate. The morphological study included both external shell morphology and internal anatomy of the renal ridge. The molecular study used a species-specific PCR technique. The results demonstrated that there was an absence of Biomphalaria glabrata and the hybrid from Alexandria water channels. Moreover, the susceptibility patterns of these reference snails were studied by measuring the different parasitological parameters. It was found that Biomphalaria glabrata and the hybrid were significantly more susceptible than Biomphalaria alexandrina to the Egyptian strain of Schistosoma mansoni. The results demonstrated that if Biomphalaria glabrata was reintroduced and adapted to the local environment in Egypt, it would have important epidemiologic impacts that would have a serious effect on the health of Egyptian people.
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Affiliation(s)
- Iman F Abou-El-Naga
- Medical Parasitology Department, Faculty of Medicine, University of Alexandria, Alexandria, Egypt.
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El Naga IFA, Eissa MM, Mossallam SF, El-Halim SIA. Inheritance of Schistosoma mansoni infection incompatibility in Biomphalaria alexandrina snails. Mem Inst Oswaldo Cruz 2010; 105:149-54. [DOI: 10.1590/s0074-02762010000200007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Accepted: 02/25/2010] [Indexed: 11/21/2022] Open
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Strickland GT. Liver disease in Egypt: hepatitis C superseded schistosomiasis as a result of iatrogenic and biological factors. Hepatology 2006; 43:915-22. [PMID: 16628669 DOI: 10.1002/hep.21173] [Citation(s) in RCA: 186] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
In Egypt, schistosomiasis was traditionally the most important public health problem and infection with Schistosoma mansoni the major cause of liver disease. From the 1950s until the 1980s, the Egyptian Ministry of Health (MOH) undertook large control campaigns using intravenous tartar emetic, the standard treatment for schistosomiasis, as community-wide therapy. This commendable effort to control a major health problem unfortunately established a very large reservoir of hepatitis C virus (HCV) in the country. By the mid-1980s, the effective oral drug, praziquantel, replaced tartar emetic a s treatment f o r schistosomiasis in the entire country. This both reduced schistosomal transmission and disease and interrupted the "occult" HCV epidemic. It was evident when diagnostic serology became available in the 1990s that HCV had replaced schistosomiasis as the predominant cause of chronic liver disease. Epidemiological studies reported a high prevalence and incidence of HCV, particutarly within families in rural areas endemic for schistosomiasis. Clinical studies showed 70% to 90% of patients with chronic hepatitis, cirrhosis, or hepatocellular carcinoma had HCV infections. Co-infections with schistosomiasis caused more severe liver disease than infection with HCV alone. Schistosomiasis was reported to cause an imbalance in HCV-specific T-cell responses leading to increased viral load, a higher probability of HCV chronicity, and more rapid progression of complications in co-infected persons. As complications of HCV usually occur after 20 years of infection, the peak impact of the Egyptian outbreak has not yet occurred. Efforts have been initiated by the Egyptian MOH to prevent new infections and complications of HCV in the estimated 6 million infected persons.
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Affiliation(s)
- G Thomas Strickland
- Department of Epidemiology and Preventive Medicine, University of Maryland School of Medicine, Baltimore 21201, USA.
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Kishk FM, Gaber HM, Abd-Allah SM. Towards Enhancing Community Health in El-Fayoum, Egypt, Using Ecosystem Approaches. ECOHEALTH 2004; 1:SU84-SU96. [DOI: 10.1007/s10393-004-0058-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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van der Werf MJ, de Vlas SJ, Brooker S, Looman CWN, Nagelkerke NJD, Habbema JDF, Engels D. Quantification of clinical morbidity associated with schistosome infection in sub-Saharan Africa. Acta Trop 2003; 86:125-39. [PMID: 12745133 DOI: 10.1016/s0001-706x(03)00029-9] [Citation(s) in RCA: 640] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Health policy making in developing countries requires estimates of the (global) burden of disease. At present, most of the available data on schistosomiasis is limited to numbers of individuals harbouring the infection. We explored the relationship between the presence of schistosome infection and clinical morbidity, in order to estimate numbers of individuals with disease-specific morbidity for Schistosoma haematobium and Schistosoma mansoni infection in sub-Saharan Africa. We searched the literature for cross-sectional data from field studies reporting both schistosome infection and morbidity. This was used to derive a functional relationship between morbidity and infection. After standardisation for diagnostic method, the number of individuals with specific types of clinical morbidity or pathology was predicted. As only aggregated prevalences of infection were available for countries or areas, we adjusted for heterogeneity in infection levels within communities in those countries. In total, 70 million individuals out of 682 million (2000 estimate) in sub-Saharan Africa were estimated to experience haematuria in the last 2 weeks associated with S. haematobium infection, and 32 million dysuria. Ultrasound detected serious consequences of S. haematobium, major bladder wall pathology and major hydronephrosis, were predicted at 18 and 10 million, respectively. Infection with S. mansoni was estimated to cause diarrhoea in 0.78 million individuals, blood in stool in 4.4 million and hepatomegaly in 8.5 million. As the associations between prevalence of S. mansoni infection and prevalence of diarrhoea and blood in stool were not very clear, the resulting estimates may be underestimations. Using the very limited data available, we estimated the mortality rates due to non-functioning kidney (from S. haematobium) and haematemesis (from S. mansoni) at 150000 and 130000 per year. Given the overall high number of cases with schistosomiasis-related disease and associated death, we conclude that schistosomiasis remains an important public health problem in sub-Saharan Africa.
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Affiliation(s)
- Marieke J van der Werf
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, PO Box 1738, 3000 DR, Rotterdam, The Netherlands.
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van der Werf MJ, de Vlas SJ, Looman CWN, Nagelkerke NJD, Habbema JDF, Engels D. Associating community prevalence of Schistosoma mansoni infection with prevalence of signs and symptoms. Acta Trop 2002; 82:127-37. [PMID: 12020885 DOI: 10.1016/s0001-706x(02)00007-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Information on the prevalence of morbidity is needed for re-calculation of the Global Burden of Disease (WHO) due to Schistosoma mansoni. This study presents a statistical association which can be used to predict the prevalence of morbidity from the prevalence of S. mansoni in a community. We collected data from field studies reporting prevalence of infection and prevalence of morbidity. Data on infection prevalence were standardised to a default diagnostic sensitivity (i.e. Kato-Katz technique 41.7 mg). The data were described by an expression related to logistic regression. We determined associations between prevalence of infection and prevalence of early morbidity (diarrhoea, blood in stool and abdominal pain), hepatosplenic morbidity and late morbidity (haematemesis and ascitis). Diarrhoea and blood in stool due to S. mansoni infection mainly occurs in communities with a high prevalence of infection. An influence on hepatosplenic morbidity is already present at low community prevalence of infection. For the aspecific symptom abdominal pain we did not find an association.
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Affiliation(s)
- Marieke J van der Werf
- Department of Public Health, Erasmus University Rotterdam, P.O. Box 1738, 3000 DR, Rotterdam, The Netherlands.
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Hassan MM, Zaghloul AS, El-Serag HB, Soliman O, Patt YZ, Chappell CL, Beasley RP, Hwang LY. The role of hepatitis C in hepatocellular carcinoma: a case control study among Egyptian patients. J Clin Gastroenterol 2001; 33:123-6. [PMID: 11468438 DOI: 10.1097/00004836-200108000-00006] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Egypt has one of the highest prevalence rates of hepatitis C virus (HCV) infection in the world; however, the risk and attribution related to HCV in Egyptian patients with hepatocellular carcinoma (HCC) remains unknown. GOALS The current study was undertaken to estimate the risk of HCC in relation to HCV in Egypt. STUDY Thirty-three patients with HCC and 35 healthy controls who had a similar socioeconomic status were prospectively enrolled at the University of Cairo National Cancer Institute. RESULTS Anti-HCV antibodies were present in 75.8% of the patients and in 42.9% of the controls (p = 0.01); hepatitis B surface antigen (HBsAg) was present in 15.2% of the patients and in 2.9% of the controls (p = 0.03). In addition, the sex-and age-adjusted odds ratio (OR) for anti-HCV antibodies was 5.1 (95% CI = 1.5-17.4) and for HBsAg was 13.2 (95% CI = 1.2-148.2). Concurrent Schistosoma mansoni and anti-HCV was associated with an OR of 10.3 (95% CI = 1.3-79.8), which was higher than that for anti-HCV (6.5; 95% CI = 1.6-26.6) and S. mansoni infection (0.2; 95% CI = 0.1-6.2) alone. Finally, we estimated the attributable fraction of HCC to HCV to be 64% in this study population and 48% in the general Egyptian population. CONCLUSIONS Both HCV and hepatitis B virus infection increase the risk of HCC in Egyptian patients, whereas isolated Schistosoma infection does not. Because of the very high prevalence rate of HCV in the general Egyptian population, it accounts for most HCC cases in Egypt.
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Affiliation(s)
- M M Hassan
- Department of Gastrointestinal Oncology and Digestive Diseases, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, USA.
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