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Tanasescu R, Tench CR, Constantinescu CS, Telford G, Singh S, Frakich N, Onion D, Auer DP, Gran B, Evangelou N, Falah Y, Ranshaw C, Cantacessi C, Jenkins TP, Pritchard DI. Hookworm Treatment for Relapsing Multiple Sclerosis: A Randomized Double-Blinded Placebo-Controlled Trial. JAMA Neurol 2021; 77:1089-1098. [PMID: 32539079 DOI: 10.1001/jamaneurol.2020.1118] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Importance Studies suggest gut worms induce immune responses that can protect against multiple sclerosis (MS). To our knowledge, there are no controlled treatment trials with helminth in MS. Objective To determine whether hookworm treatment has effects on magnetic resonance imaging (MRI) activity and T regulatory cells in relapsing MS. Design, Setting, and Participants This 9-month double-blind, randomized, placebo-controlled trial was conducted between September 2012 and March 2016 in a modified intention-to-treat population (the data were analyzed June 2018) at the University of Nottingham, Queen's Medical Centre, a single tertiary referral center. Patients aged 18 to 61 years with relapsing MS without disease-modifying treatment were recruited from the MS clinic. Seventy-three patients were screened; of these, 71 were recruited (2 ineligible/declined). Interventions Patients were randomized (1:1) to receive either 25 Necator americanus larvae transcutaneously or placebo. The MRI scans were performed monthly during months 3 to 9 and 3 months posttreatment. Main Outcomes and Measures The primary end point was the cumulative number of new/enlarging T2/new enhancing T1 lesions at month 9. The secondary end point was the percentage of cluster of differentiation (CD) 4+CD25highCD127negT regulatory cells in peripheral blood. Results Patients (mean [SD] age, 45 [9.5] years; 50 women [71%]) were randomized to receive hookworm (35 [49.3%]) or placebo (36 [50.7%]). Sixty-six patients (93.0%) completed the trial. The median cumulative numbers of new/enlarging/enhancing lesions were not significantly different between the groups by preplanned Mann-Whitney U tests, which lose power with tied data (high number of zeroactivity MRIs in the hookworm group, 18/35 [51.4%] vs 10/36 [27.8%] in the placebo group). The percentage of CD4+CD25highCD127negT cells increased at month 9 in the hookworm group (hookworm, 32 [4.4%]; placebo, 34 [3.9%]; P = .01). No patients withdrew because of adverse effects. There were no differences in adverse events between groups except more application-site skin discomfort in the hookworm group (82% vs 28%). There were 5 relapses (14.3%) in the hookworm group vs 11 (30.6%) receiving placebo. Conclusions and Relevance Treatment with hookworm was safe and well tolerated. The primary outcome did not reach significance, likely because of a low level of disease activity. Hookworm infection increased T regulatory cells, suggesting an immunobiological effect of hookworm. It appears that a living organism can precipitate immunoregulatory changes that may affect MS disease activity. Trial Registration ClinicalTrials.gov Identifier: NCT01470521.
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Affiliation(s)
- Radu Tanasescu
- Division of Clinical Neuroscience, University of Nottingham, Nottingham, England.,Department of Neurology, Nottingham University Hospitals National Health Service Trust, Nottingham, England.,Division of Clinical Neurosciences, University of Medicine and Pharmacy Carol Davila Bucharest, Bucharest, Romania.,Department of Neurology, Colentina Hospital, Bucharest, Romania
| | - Christopher R Tench
- Division of Clinical Neuroscience, University of Nottingham, Nottingham, England.,National Institute of Health Research Nottingham BRC, Nottingham, England
| | - Cris S Constantinescu
- Division of Clinical Neuroscience, University of Nottingham, Nottingham, England.,Department of Neurology, Nottingham University Hospitals National Health Service Trust, Nottingham, England
| | - Gary Telford
- Immune Regulation Research Group, University of Nottingham, Nottingham, England
| | - Sonika Singh
- Division of Clinical Neuroscience, University of Nottingham, Nottingham, England
| | - Nanci Frakich
- Division of Clinical Neuroscience, University of Nottingham, Nottingham, England
| | - David Onion
- Flow Cytometry Facilities, School of Life Sciences, University of Nottingham, Nottingham, England
| | - Dorothee P Auer
- Division of Clinical Neuroscience, University of Nottingham, Nottingham, England.,National Institute of Health Research Nottingham BRC, Nottingham, England.,Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, England
| | - Bruno Gran
- Division of Clinical Neuroscience, University of Nottingham, Nottingham, England.,Department of Neurology, Nottingham University Hospitals National Health Service Trust, Nottingham, England
| | - Nikos Evangelou
- Division of Clinical Neuroscience, University of Nottingham, Nottingham, England.,Department of Neurology, Nottingham University Hospitals National Health Service Trust, Nottingham, England
| | - Yasser Falah
- Division of Clinical Neuroscience, University of Nottingham, Nottingham, England.,Department of Neurology, Nottingham University Hospitals National Health Service Trust, Nottingham, England
| | - Colin Ranshaw
- Immune Regulation Research Group, University of Nottingham, Nottingham, England
| | - Cinzia Cantacessi
- Department of Veterinary Medicine, University of Cambridge, Cambridge, England
| | - Timothy P Jenkins
- Department of Veterinary Medicine, University of Cambridge, Cambridge, England
| | - David I Pritchard
- Immune Regulation Research Group, University of Nottingham, Nottingham, England
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Essa T, Birhane Y, Endris M, Moges A, Moges F. Current Status of Schistosoma mansoni Infections and Associated Risk Factors among Students in Gorgora Town, Northwest Ethiopia. ACTA ACUST UNITED AC 2013. [DOI: 10.5402/2013/636103] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Background and Objective. Schistosomiasis is highly prevalent in tropics and causes morbidity and mortality in developing countries including Ethiopia. This study is aimed to assess the current status of S. mansoni infections and associated risk factors among students in Gorgora town, Northwest Ethiopia. Method. A cross-sectional study was conducted from October 2010 to November 2010 at Gorgora, Northwest Ethiopia. All students (579) present during the study period were enrolled. Pretested questionnaires were used to collect sociodemographic data and predisposing factors. Stool examination was performed using wet mount and Kato-Katz techniques. Data were entered and analysed using SPSS version 20.0 statistical software. Result. Among 579 students enrolled, 291 (50.3%) were positive for one or more intestinal parasites. Prevalence of S. mansoni was found to be 20.6% with mean intensity of infection (125 eggs per gram of feces). Lack of awareness and water contact habits such as frequent swimming in the open water source, agricultural activities on bare foot, and washing clothes were also associated with high risk of S. mansoni infection. Conclusion. Even though there seems to be a decline in the prevalence of S. mansoni infections in the study area, the problem still persists and affects students significantly. Therefore, therapeutic intervention and health education are needed.
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Affiliation(s)
- Tarko Essa
- Pathfinder International, Addis Ababa, Ethiopia
| | - Yemane Birhane
- Addis Continental Institute of Public Health, Addis Ababa, Ethiopia
| | - Mengistu Endris
- Department of Medical Microbiology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, P.O. Box 196, Gondar, Ethiopia
| | - Asmeret Moges
- Addis Continental Institute of Public Health, Addis Ababa, Ethiopia
| | - Feleke Moges
- Department of Medical Microbiology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, P.O. Box 196, Gondar, Ethiopia
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Abou-Zeid AH, Abkar TA, Mohamed RO. Schistosomiasis infection among primary school students in a war zone, Southern Kordofan State, Sudan: a cross-sectional study. BMC Public Health 2013; 13:643. [PMID: 23845226 PMCID: PMC3729662 DOI: 10.1186/1471-2458-13-643] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 07/10/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Schistosomiasis is a major health problem adversely affecting the health of vulnerable populations in Sudan. METHODS We conducted a school-based survey to estimate the prevalence of schistosomiasis in 36 villages in Southern Kordofan (SK) State. A total of 2,302 primary school students were recruited. Each student completed a questionnaire and submitted one urine and one stool sample. RESULTS The prevalence of schistosomiasis haematobium was 23.7%, while schistosomiasis mansoni was not detected among the study participants. S. haematobium infection was identified in all areas, with the highest prevalence in the western locality of SK State. The infection was associated with the distance between home/school and open water sources. In addition, S. haematobium infection was associated with the existence of and distance to open water sources, higher frequency of contact with open water, absence of a health advocacy group in the school and history of schistosomiasis treatment. CONCLUSIONS This study highlights schistosomiasis as a public health problem in SK State. The findings will guide the schistosomiasis Control Program of the State Ministry of Health in developing and applying treatment plans for schistosomiasis in SK State.
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Affiliation(s)
- Alaa H Abou-Zeid
- Public Health Department, Faculty of Medicine, Cairo University, Kasr Al Ainy St., Cairo, Egypt.
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Chipeta MG, Ngwira B, Kazembe LN. Analysis of Schistosomiasis haematobium infection prevalence and intensity in Chikhwawa, Malawi: an application of a two part model. PLoS Negl Trop Dis 2013; 7:e2131. [PMID: 23556017 PMCID: PMC3605235 DOI: 10.1371/journal.pntd.0002131] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Accepted: 02/10/2013] [Indexed: 11/18/2022] Open
Abstract
Background Urinary Schistosomiasis infection, a common cause of morbidity especially among children in less developed countries, is measured by the number of eggs per urine. Typically a large proportion of individuals are non-egg excretors, leading to a large number of zeros. Control strategies require better understanding of its epidemiology, hence appropriate methods to model infection prevalence and intensity are crucial, particularly if such methods add value to targeted implementation of interventions. Methods We consider data that were collected in a cluster randomized study in 2004 in Chikhwawa district, Malawi, where eighteen (18) villages were selected and randomised to intervention and control arms. We developed a two-part model, with one part for analysis of infection prevalence and the other to model infection intensity. In both parts of the model we adjusted for age, sex, education level, treatment arm, occupation, and poly-parasitism. We also assessed for spatial correlation in the model residual using variogram analysis and mapped the spatial variation in risk. The model was fitted using maximum likelihood estimation. Results and discussion The study had a total of 1642 participants with mean age of 32.4 (Standard deviation: 22.8), of which 55.4 % were female. Schistosomiasis prevalence was 14.2 %, with a large proportion of individuals (85.8 %) being non-egg excretors, hence zero-inflated data. Our findings showed that S. haematobium was highly localized even after adjusting for risk factors. Prevalence of infection was low in males as compared to females across all the age ranges. S. haematobium infection increased with presence of co-infection with other parasite infection. Infection intensity was highly associated with age; with highest intensity in school-aged children (6 to 15 years). Fishing and working in gardens along the Shire River were potential risk factors for S. haematobium infection intensity. Intervention reduced both infection intensity and prevalence in the intervention arm as compared to control arm. Farmers had high infection intensity as compared to non farmers, despite the fact that being a farmer did not show any significant association with probability of infection. These results evidently indicate that infection prevalence and intensity are associated with risk factors differently, suggesting a non-singular epidemiological setting. The dominance of agricultural, socio-economic and demographic factors in determining S. haematobium infection and intensity suggest that disease transmission and control strategies should continue centring on improving socio-economic status, environmental modifications to control S. haematobium intermediate host snails and mass drug administration, which may be more promising approaches to disease control in high intensity and prevalence settings. Schistosomiasis is one of the great causes of morbidity among school aged children in the tropical region and Sub Saharan Africa in particular. It's mainly transmitted through contact with water infested with intermediate host snail Cercariae. Currently, over 200 million people are estimated to be infected in SSA alone. Here, we used robust and contemporary statistical methods in a two part application to analyse risk factors for S. haematobium infection intensity and prevalence. We found that S. haematobium was more common in younger children as compared to older children, thus making the infection and prevalence age dependent. We also found that mass chemotherapy reduced both infection prevalence and intensity. We found that dominance of agricultural, socio-economic and demographic factors in determining S. haematobium infection risk in the villages carries important implications for disease surveillance and control strategies. Therefore disease transmission and control strategies centered on improving strategies involving socio-economic status, environmental modifications to control S. haematobium intermediate host snails and mass drug administration may be more promising approaches to disease control in high intensity and prevalence settings.
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Affiliation(s)
- Michael G Chipeta
- Malawi Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.
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Geiger SM, Jardim-Botelho A, Williams W, Alexander N, Diemert DJ, Bethony JM. Serum CCL11 (eotaxin-1) and CCL17 (TARC) are serological indicators of multiple helminth infections and are driven by Schistosoma mansoni infection in humans. Trop Med Int Health 2013; 18:750-60. [PMID: 23496801 DOI: 10.1111/tmi.12095] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To evaluate systemic serum cytokine and chemokine markers for inflammation and Th1/Th2 responses in relation to multiple helminth infections, parasite burden and/or nutritional status of individuals. METHODS In a longitudinal study, stool samples from 210 individuals from an area highly endemic for Ascaris lumbricoides, Necator americanus and Schistosoma mansoni were examined before and 12 months after clearance of parasites by chemotherapy. On both occasions, the presence of mono- or multiple infections and intensities of infection were compared with nutritional parameters and with serum cytokines or chemokines as markers for inflammatory, regulatory or Th1- or Th2-type immune responses. RESULTS Before treatment, we were not able to associate any altered nutritional parameters with increased inflammatory responses, and highest intensities of infection were found in eutrophic participants with multiple infections. In contrast, major changes in serum Th2-type chemokine levels were measured in individuals infected with intestinal helminths and/or S. mansoni, and resulted in significantly higher CCL11 and CCL17 concentrations, both before treatment and after reinfection. CONCLUSIONS The driving force for these elevated type 2 serum chemokine concentrations was an S. mansoni infection and faecal egg counts significantly correlated with serum IL-10 concentrations.
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Affiliation(s)
- Stefan M Geiger
- Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Belo Horizonte, Brazil.
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Abou-Zeid AHA, Abkar TA, Mohamed RO. Schistosomiasis and soil-transmitted helminths among an adult population in a war affected area, Southern Kordofan state, Sudan. Parasit Vectors 2012; 5:133. [PMID: 22759923 PMCID: PMC3481353 DOI: 10.1186/1756-3305-5-133] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Accepted: 07/03/2012] [Indexed: 12/03/2022] Open
Abstract
Background Schistosomiasis remains a major health problem at global and national levels, contributing to the vulnerability of the poor people in Sudan. Southern Kordofan is affected by Schistosomiasis but the disease prevalence was unknown. Methods 1826 adults were recruited in a community-based survey. Each recruited subject submitted at least 10 ml urine and one stool sample; they were also interviewed and filled in a questionnaire. Results 1826 adults were recruited in a community-based survey. Each recruited subject submitted at least 10 ml urine and one stool sample; they were also interviewed and filled in a questionnaire. The prevalence of S. haematobium was 6.9 % among the adult population. We estimated S. mansoni prevalence as 0.0 %. S. haematobium infection was focally distributed at the village level. The infection was associated with non preference of latrine use – if available, use of open water source for household affairs such as cleaning and also with the history of schistosomiasis treatment. The prevalence of soil transmitted helminths (STH) was also reported as high at 7.8 %, and two species were identified; Hymenolepis nana and Giardia lamblia. Conclusion Schistosomiasis is a significant health problem among the adult population in Southern Kordofan. The estimated prevalence will serve as a guide in developing a Schistosomiasis Control Program and applying treatment plans.
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Affiliation(s)
- Alaa Hammad Ali Abou-Zeid
- Public Health Department, Faculty of Medicine, Cairo University, Kasr Al Ainy St, Manial, Cairo, Egypt.
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Oliveira RR, Figueiredo JP, Cardoso LS, Jabar RL, Souza RP, Wells MT, Carvalho EM, Fitzgerald DW, Barnes KC, Araújo MI, Glesby MJ. Factors associated with resistance to Schistosoma mansoni infection in an endemic area of Bahia, Brazil. Am J Trop Med Hyg 2012; 86:296-305. [PMID: 22302866 DOI: 10.4269/ajtmh.2012.11-0204] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Detailed knowledge of factors associated with resistance to Schistosoma mansoni infection in endemic areas might facilitate more effective schistosomiasis control. We conducted a cross-sectional study of persons resistant to schistosomiasis and found no association between socioeconomic status and resistance to infection. Mononuclear cells of resistant subjects produced higher levels of interleukin-5 (IL-5), IL-13 and interferon-γ upon stimulation with soluble egg antigen (SEA) compared with infected persons. When stimulated with Sm21.6 or Sm22.6, levels of IL-10 were higher in cell culture of resistant persons. Levels of IgE against soluble adult worm antigen (SWAP) and against interleukin-4-inducing principle from S. mansoni eggs (IPSE) and levels of IgG4 against SWAP, SEA, and Sm22.6 were lower in the resistant group compared with the susceptible group. Our data suggest that socioeconomic status could not fully explain resistance to S. mansoni infection observed in the studied area. However, a mixture of Th1 and Th2 immune responses and low levels of specific IgG4 against parasite antigens could be mediating resistance to infection.
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Affiliation(s)
- Ricardo R Oliveira
- Serviço de Imunologia, Hospital Universitário Professor Edgard Santos, Universidade Federal da Bahia, Salvador, Bahia, Brazil.
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Tarafder MR, Carabin H, McGarvey ST, Joseph L, Balolong E, Olveda R. Assessing the impact of misclassification error on an epidemiological association between two helminthic infections. PLoS Negl Trop Dis 2011; 5:e995. [PMID: 21468317 PMCID: PMC3066162 DOI: 10.1371/journal.pntd.0000995] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Accepted: 03/03/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Polyparasitism can lead to severe disability in endemic populations. Yet, the association between soil-transmitted helminth (STH) and the cumulative incidence of Schistosoma japonicum infection has not been described. The aim of this work was to quantify the effect of misclassification error, which occurs when less than 100% accurate tests are used, in STH and S. japonicum infection status on the estimation of this association. METHODOLOGY/PRINCIPAL FINDINGS Longitudinal data from 2276 participants in 50 villages in Samar province, Philippines treated at baseline for S. japonicum infection and followed for one year, served as the basis for this analysis. Participants provided 1-3 stool samples at baseline and 12 months later (2004-2005) to detect infections with STH and S. japonicum using the Kato-Katz technique. Variation from day-to-day in the excretion of eggs in feces introduces individual variations in the sensitivity and specificity of the Kato-Katz to detect infection. Bayesian logit models were used to take this variation into account and to investigate the impact of misclassification error on the association between these infections. Uniform priors for sensitivity and specificity of the diagnostic test to detect the three STH and S. japonicum were used. All results were adjusted for age, sex, occupation, and village-level clustering. Without correction for misclassification error, the odds ratios (ORs) between hookworm, Ascaris lumbricoides, and Trichuris trichiura, and S. japonicum infections were 1.28 (95% Bayesian credible intervals: 0.93, 1.76), 0.91 (95% BCI: 0.66, 1.26), and 1.11 (95% BCI: 0.80, 1.55), respectively, and 2.13 (95% BCI: 1.16, 4.08), 0.74 (95% BCI: 0.43, 1.25), and 1.32 (95% BCI: 0.80, 2.27), respectively, after correction for misclassification error for both exposure and outcome. CONCLUSIONS/SIGNIFICANCE The misclassification bias increased with decreasing test accuracy. Hookworm infection was found to be associated with increased 12-month cumulative incidence of S. japonicum infection after correction for misclassification error. Such important associations might be missed in analyses which do not adjust for misclassification errors.
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Affiliation(s)
- Mushfiqur R Tarafder
- Department of Biostatistics and Epidemiology, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America.
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Reis DCD, Kloos H, King C, Quites HFO, Matoso LF, Coelho KR, Gazzinelli A. Accessibility to and utilisation of schistosomiasis-related health services in a rural area of state of Minas Gerais, Brazil. Mem Inst Oswaldo Cruz 2010; 105:587-97. [DOI: 10.1590/s0074-02762010000400039] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2008] [Accepted: 10/16/2009] [Indexed: 11/22/2022] Open
Affiliation(s)
- Dener Carlos dos Reis
- Universidade Federal de Minas Gerais, Brasil; Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais, Brasil
| | | | | | | | - Leonardo Ferreira Matoso
- Universidade Federal de Minas Gerais, Brasil; Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais, Brasil
| | - Kellen Rosa Coelho
- Universidade Federal de Minas Gerais, Brasil; Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais, Brasil
| | - Andrea Gazzinelli
- Universidade Federal de Minas Gerais, Brasil; Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais, Brasil
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Mupfasoni D, Karibushi B, Koukounari A, Ruberanziza E, Kaberuka T, Kramer MH, Mukabayire O, Kabera M, Nizeyimana V, Deville MA, Ruxin J, Webster JP, Fenwick A. Polyparasite helminth infections and their association to anaemia and undernutrition in Northern Rwanda. PLoS Negl Trop Dis 2009; 3:e517. [PMID: 19753110 PMCID: PMC2737105 DOI: 10.1371/journal.pntd.0000517] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Accepted: 08/20/2009] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Intestinal schistosomiasis and soil-transmitted helminth (STH) infections constitute major public health problems in many parts of sub-Saharan Africa. In this study we examined the functional significance of such polyparasite infections in anemia and undernutrition in Rwandan individuals. METHODS Three polyparasite infection profiles were defined, in addition to a reference profile that consisted of either no infections or low-intensity infection with only one of the focal parasite species. Logistic regression models were applied to data of 1,605 individuals from 6 schools in 2 districts of the Northern Province before chemotherapeutic treatment in order to correctly identify individuals who were at higher odds of being anaemic and/or undernourished. FINDINGS Stunted relative to nonstunted, and males compared to females, were found to be at higher odds of being anaemic independently of polyparasite infection profile. The odds of being wasted were 2-fold greater for children with concurrent infection of at least 2 parasites at M+ intensity compared to those children with the reference profile. Males compared to females and anaemic compared to nonanaemic children were significantly more likely to be stunted. None of the three polyparasite infection profiles were found to have significant effects on stunting. CONCLUSION The present data suggest that the levels of polyparasitism, and infection intensities in the Rwandan individuals examined here may be lower as compared to other recent similar epidemiological studies in different regions across sub-Saharan Africa. Neither the odds of anaemia nor the odds of stunting were found to be significantly different in the three-polyparasite infection profiles. However, the odds of wasting were higher in those children with at least two parasites at M+ intensity compared to those children with the reference profile. Nevertheless, despite the low morbidity levels indicated in the population under study here, we recommend sustainable efforts for the deworming of affected populations to be continued in order to support the economic development of the country.
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Affiliation(s)
| | | | - Artemis Koukounari
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
- * E-mail:
| | | | | | - Michael H. Kramer
- TRAC Plus - Center for Treatment and Research on AIDS, Malaria, Tuberculosis and Other Epidemics, Kigali, Rwanda
| | | | | | - Vianney Nizeyimana
- TRAC Plus - Center for Treatment and Research on AIDS, Malaria, Tuberculosis and Other Epidemics, Kigali, Rwanda
| | - Marie-Alice Deville
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Josh Ruxin
- Access Project, Kigali, Rwanda
- The Earth Institute, Columbia University, New York, New York, United States of America
| | - Joanne P. Webster
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Alan Fenwick
- Schistosomiasis Control Initiative, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
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Kapito-Tembo AP, Mwapasa V, Meshnick SR, Samanyika Y, Banda D, Bowie C, Radke S. Prevalence distribution and risk factors for Schistosoma hematobium infection among school children in Blantyre, Malawi. PLoS Negl Trop Dis 2009; 3:e361. [PMID: 19156193 PMCID: PMC2614474 DOI: 10.1371/journal.pntd.0000361] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2008] [Accepted: 12/16/2008] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Schistosomiasis is a public health problem in Malawi but estimates of its prevalence vary widely. There is need for updated information on the extent of disease burden, communities at risk and factors associated with infection at the district and sub-district level to facilitate effective prioritization and monitoring while ensuring ownership and sustainability of prevention and control programs at the local level. METHODS AND FINDINGS We conducted a cross-sectional study between May and July 2006 among pupils in Blantyre district from a stratified random sample of 23 primary schools. Information on socio-demographic factors, schistosomiasis symptoms and other risk factors was obtained using questionnaires. Urine samples were examined for Schistosoma hematobium ova using filtration method. Bivariate and multiple logistic regressions with robust estimates were used to assess risk factors for S. hematobium. One thousand one hundred and fifty (1,150) pupils were enrolled with a mean age of 10.5 years and 51.5% of them were boys. One thousand one hundred and thirty-nine (1,139) pupils submitted urine and S. hematobium ova were detected in 10.4% (95%CI 5.43-15.41%). Male gender (OR 1.81; 95% CI 1.06-3.07), child's knowledge of an existing open water source (includes river, dam, springs, lake, etc.) in the area (OR 1.90; 95% CI 1.14-3.46), history of urinary schistosomiasis in the past month (OR 3.65; 95% CI 2.22-6.00), distance of less than 1 km from school to the nearest open water source (OR 5.39; 95% CI 1.67-17.42) and age 8-10 years (OR 4.55; 95% CI 1.53-13.50) compared to those 14 years or older were associated with infection. Using urine microscopy as a gold standard, the sensitivity and specificity of self-reported hematuria was 68.3% and 73.6%, respectively. However, the positive predictive value was low at 23.9% and was associated with age. CONCLUSION The study provides an important update on the status of infection in this part of sub-Saharan Africa and exemplifies the success of deliberate national efforts to advance active participation in schistosomiasis prevention and control activities at the sub-national or sub-district levels. In this population, children who attend schools close to open water sources are at an increased risk of infection and self-reported hematuria may still be useful in older children in this region.
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Affiliation(s)
- Atupele P Kapito-Tembo
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA.
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