RESUMO
Schistosomiasis and soil-transmitted helminth (STH) control programs require target population engagement, assessed through knowledge, attitudes and practices (KAP) surveys. We report the results of a KAP survey of Angolan schoolchildren supported by a school preventive chemotherapy (PC) programme, without or with a school water, sanitation and hygiene (WASH) programme (PC+/WASH- and PC+/WASH+, respectively); and schoolchildren without a school PC or WASH program (PC-/WASH-). Schoolchildren from PC+/WASH- (N = 218), PC+/WASH+ (N = 250) and PC-/WASH- (N = 254) schools were interviewed. Descriptive statistics were used to report demographics and survey responses. Chi-square or Fisher's exact test was used to compare PC+/WASH- schoolchildren with (i) PC+/WASH+ and (ii) PC-/WASH- schoolchildren. A lower proportion of PC+/WASH- schoolchildren used latrines and a higher proportion practised open defecation at school compared with PC+/WASH+ schoolchildren. A lower proportion of PC+/WASH- schoolchildren always washed their hands after toileting and before meals at school compared with PC+/WASH+ schoolchildren. However, the PC+/WASH- schoolchildren reported better toileting and handwashing practices at school compared to PC-/WASH- schoolchildren. Over 90% of PC+ schoolchildren agreed with schistosomiasis and STH control and accepted schoolteacher PC delivery. Expanding the integration of both school PC and WASH programs will improve health behaviours relevant to reduce the risk of schistosomiasis and STHs in schoolchildren. This article is part of the theme issue 'Challenges and opportunities in the fight against neglected tropical diseases: a decade from the London Declaration on NTDs'.
Assuntos
Helmintos , Esquistossomose , Animais , Angola , Conhecimentos, Atitudes e Prática em Saúde , Esquistossomose/epidemiologia , Esquistossomose/prevenção & controle , Doenças Negligenciadas , Instituições Acadêmicas , SoloRESUMO
BACKGROUND: A school preventive chemotherapy (PC) program for soil-transmitted helminths (STHs) and schistosomiasis has operated in Huambo, Uige and Zaire provinces, Angola, since 2013 and 2014, respectively; complemented by a school water, sanitation and hygiene (WASH) program in a subset of schools from 2016. Conducted in 2021, this is the first impact assessment of the school program for the control of schistosomiasis and STHs. METHODOLOGY/PRINCIPAL FINDINGS: A two-stage cluster design was used to select schools and schoolchildren for parasitological and WASH surveys. The rapid diagnostic tests (RDTs), point of care circulating cathodic antigen (POC-CCA) and Hemastix, were used to estimate Schistosoma mansoni and Schistosoma haematobium prevalence, respectively. Kato Katz was used to detect STHs, and quantify STH and S. mansoni infections. Urine filtration was used to quantify S. haematobium infections. Prevalence, infection intensity, relative prevalence reduction and egg reduction rates were calculated for schistosomiasis and STHs. Cohen's Kappa co-efficient was used to assess agreement between RDTs and microscopy. Chi-square or Fisher's exact test was used to compare WASH indicators in WASH-supported and WASH-unsupported schools. Overall, 17,880 schoolchildren (599 schools) and 6,461 schoolchildren (214 schools) participated in the schistosomiasis and STH surveys, respectively. Prevalence of any schistosomiasis in Huambo was 29.6%, Uige 35.4%, and Zaire 28.2%. Relative reduction in schistosomiasis prevalence from 2014 for Huambo was 18.8% (95% confidence interval (CI) 8.6, 29.0), Uige -92.3% (95%CI -162.2, -58.3), and Zaire -14.0% (95%CI -48.6, 20.6). Prevalence of any STH in Huambo was 16.3%, Uige 65.1%, and Zaire 28.2%. Relative reduction in STH prevalence for Huambo was -28.4% (95%CI -92.1, 35.2), Uige -10.7% (95%CI -30.2, 8.8), and Zaire -20.9% (95%CI -79.5, 37.8). A higher proportion of WASH-supported schools had improved water sources, and toilet and handwashing facilities compared to WASH-unsupported schools. CONCLUSIONS/SIGNIFICANCE: The limited impact this school program has had in controlling schistosomiasis and STHs identifies the need for a comprehensive understanding of individual, community, and environmental factors associated with transmission, and consideration for a community-wide control program.
Assuntos
Helmintíase , Helmintos , Esquistossomose mansoni , Esquistossomose , Animais , Humanos , Criança , Helmintíase/tratamento farmacológico , Helmintíase/epidemiologia , Helmintíase/prevenção & controle , Solo/parasitologia , Angola/epidemiologia , Esquistossomose/epidemiologia , Esquistossomose/prevenção & controle , Esquistossomose/tratamento farmacológico , Água , Prevalência , Fezes/parasitologia , Esquistossomose mansoni/tratamento farmacológico , Esquistossomose mansoni/epidemiologia , Esquistossomose mansoni/prevenção & controleRESUMO
Few B cells express CD27, the primary marker for memory B cells, in pediatric schistosomiasis, suggesting B cell malfunction. This study further demonstrates unexpected high expression of CD117 on circulating B cells in children highly exposed to Schistosoma mansoni infectious larvae. CD117 is expressed by immature or lymphoma B cells, but not by mature, circulating cells. We therefore sought to define the significance of CD117 on blood B cells. We found that CD117-positive (CD117+) B cells increased with the intensity of schistosome infection. In addition, CD117 expression was reduced on CD23+ B cells previously shown to correlate with resistance to infection. Stimulation with a panel of cytokines demonstrated that CD117 levels were upregulated in response to a combination of interleukin 4 (IL-4) and stem cell factor (SCF), the ligand for CD117, whereas IL-2 led to a reduction. In addition, stimulation with SCF generally reduced B cell activation levels. Upon further investigation, it was established that multiple circulating cells expressed increased levels of CD117, including monocytes, neutrophils, and eosinophils, and expression levels correlated with that of B cells. Finally, we identified a population of large circulating cells with features of reticulocytes. Overall, our results suggest that hyperexposure to intravascular parasitic worms elicits immature cells from the bone marrow. Levels of SCF were shown to reduce as children began to transition through puberty. The study results pose an explanation for the inability of children to develop significant immunity to infection until after puberty.
Assuntos
Proteínas Proto-Oncogênicas c-kit , Esquistossomose mansoni , Linfócitos B , Medula Óssea/metabolismo , Humanos , Ativação LinfocitáriaRESUMO
BACKGROUND: Female genital schistosomiasis (FGS) constitutes four different lesions known to be caused by Schistosoma haematobium ova deposited in the genital tract. Schistosoma mansoni ova may also be found in the genital tract. However, it is not known if S. mansoni causes lower genital tract lesions characteristic of FGS. METHODOLOGY: This study was conducted in 8 villages along the shores of Lake Victoria, western Kenya. Stool and urine samples, collected from women of reproductive age on three consecutive days, were analysed for S. mansoni and S. haematobium infection. S. mansoni positive and S. haematobium negative willing participants, aged 18-50 years were invited to answer a questionnaire (demographics, symptoms), undergo a gynaecological examination and cytology specimen collection by an FGS expert. PRINCIPAL FINDINGS: Gynaecologic investigations were conducted in 147 S. mansoni-positive women who had a mean infection intensity of 253.3 epg (95% CI: 194.8-311.9 epg). Nearly 90% of them used Lake Victoria as their main water source. None were found to have cervicovaginal grainy sandy patches or rubbery papules. Homogenous yellow patches were found in 12/147 (8.2%) women. Women with homogenous yellow patches were significantly older (47 years) than the rest (34 years, p = 0.001). No association was found between intensity of S. mansoni infection and homogenous yellow patches (p = 0.70) or abnormal blood vessels (p = 0.14). S. mansoni infection intensity was not associated with genital itch, bloody or malodorous vaginal discharge. CONCLUSION: S. mansoni infection was neither associated with lower genital tract lesions nor symptoms typically found in women with FGS.
Assuntos
Esquistossomose Urinária , Esquistossomose mansoni , Animais , Colposcópios , Estudos Transversais , Feminino , Genitália , Humanos , Quênia/epidemiologia , Masculino , Prevalência , Schistosoma haematobium , Schistosoma mansoni , Esquistossomose Urinária/diagnóstico , Esquistossomose mansoni/complicações , Esquistossomose mansoni/epidemiologiaRESUMO
Introduction: Current diagnostic tools for schistosomiasis are limited, and new tests are necessary to enhance disease diagnosis and surveillance. Identification of novel disease-specific biomarkers may facilitate the development of such tests. We evaluated a panel of biomarkers used in sepsis and parasitic diseases for their potential suitability in the diagnosis of schistosomiasis. Objective: The study evaluated the levels of systemic plasma biomarkers in relation to Schistosoma mansoni infection and parasite burden. Methods: Six biomarkers were measured in the plasma of children from schistosomiasis-endemic regions using ELISA. The concentration of soluble CD23 (sCD23) and lipopolysaccharide (LPS) was tested in 199 and 124 plasma samples, respectively, while interleukin-6 (IL-6), soluble triggering receptor expressed on myeloid (sTREM) cells, eotaxin-1, and fatty acid-binding protein (FABP) concentrations were tested in 30 plasma samples. Results: The concentration of IL-6, eotaxin-1, FABP, and LPS was similar between schistosome-infected and uninfected children. The schistosome-infected children had higher median levels of sTREM and sCD23 as compared to uninfected children, 119.0 (29.9-208.9) versus 10.7 (0.0-73.4) (p = 0.046) and 2,549.0 (1,899.0-3,356.0) vs. 2,035.0 (1,448.0-2,939.0) (p = 0.05), respectively. In addition, sTREM was positively correlated with egg density (p = 0.017). Conclusion: Our data show that active schistosomiasis per se is associated with elevated levels of sTREM and sCD23. sTREM has potential diagnostic and prognostic values. However, these biomarkers did not distinguish between children with low egg burden and uninfected children.
Assuntos
Interleucina-6 , Esquistossomose , Biomarcadores , Quimiocina CCL11 , Criança , Humanos , Quênia , Lipopolissacarídeos , Receptor Gatilho 1 Expresso em Células MieloidesRESUMO
BACKGROUND: Over the past 20 years, schistosomiasis control has been scaled up. Preventive chemotherapy with praziquantel is the main intervention. We aimed to assess the effect of preventive chemotherapy on schistosomiasis prevalence in sub-Saharan Africa, comparing 2000-10 with 2011-14 and 2015-19. METHODS: In this spatiotemporal modelling study, we analysed survey data from school-aged children (aged 5-14 years) in 44 countries across sub-Saharan Africa. The data were extracted from the Global Neglected Tropical Diseases database and augmented by 2018 and 2019 survey data obtained from disease control programmes. Bayesian geostatistical models were fitted to Schistosoma haematobium and Schistosoma mansoni survey data. The models included data on climatic predictors obtained from satellites and other open-source environmental databases and socioeconomic predictors obtained from various household surveys. Temporal changes in Schistosoma species prevalence were estimated by a categorical variable with values corresponding to the three time periods (2000-10, 2011-14, and 2015-19) during which preventive chemotherapy interventions were scaled up. FINDINGS: We identified 781 references with relevant geolocated schistosomiasis survey data for 2000-19. There were 19 166 unique survey locations for S haematobium and 23 861 for S mansoni, of which 77% (14 757 locations for S haematobium and 18 372 locations for S mansoni) corresponded to 2011-19. Schistosomiasis prevalence among school-aged children in sub-Saharan Africa decreased from 23·0% (95% Bayesian credible interval 22·1-24·1) in 2000-10 to 9·6% (9·1-10·2) in 2015-19, an overall reduction of 58·3%. The reduction of S haematobium was 67·9% (64·6-71·1) and that of S mansoni 53·6% (45·2-58·3) when comparing 2000-10 with 2015-19. INTERPRETATION: Our model-based estimates suggest that schistosomiasis prevalence in sub-Saharan Africa has decreased considerably, most likely explained by the scale-up of preventive chemotherapy. There is a need to consolidate gains in the control of schistosomiasis by means of preventive chemotherapy, coupled with other interventions to interrupt disease transmission. FUNDING: European Research Council and WHO.
Assuntos
Anti-Helmínticos/uso terapêutico , Praziquantel/uso terapêutico , Schistosoma haematobium/efeitos dos fármacos , Schistosoma mansoni/efeitos dos fármacos , Esquistossomose/tratamento farmacológico , Análise Espaço-Temporal , Adolescente , África Subsaariana/epidemiologia , Animais , Quimioprevenção , Criança , Pré-Escolar , Estudos Transversais , Bases de Dados Factuais , Humanos , Praziquantel/administração & dosagem , Prevalência , Esquistossomose/classificação , Esquistossomose/epidemiologia , Instituições AcadêmicasRESUMO
BACKGROUND: Evidence indicates that whereas repeated rounds of mass drug administration (MDA) programs have reduced schistosomiasis prevalence to appreciable levels in some communities referred to here as responding villages (R). However, prevalence has remained high or less than anticipated in other areas referred to here as persistent hotspot villages (PHS). Using a cross-sectional quantitative approach, this study investigated the factors associated with sustained high Schistosoma mansoni prevalence in some villages despite repeated high annual treatment coverage in western Kenya. METHOD: Water contact sites selected based on observation of points where people consistently go to collect water, wash clothes, bathe, swim or play (young children), wash cars and harvest sand were mapped using hand-held smart phones on the Commcare platform. Quantitative cross-sectional surveys on behavioral characteristics were conducted using interviewer-based semi-structured questionnaires administered to assess water usage/contact patterns and open defecation. Questionnaires were administered to 15 households per village, 50 pupils per school and 1 head teacher per school. One stool and urine sample was collected from 50 school children aged 9-12 year old and 50 adults from both responding (R) and persistent hotspot (PHS) villages. Stool was analyzed by the Kato-Katz method for eggs of S. mansoni and soil-transmitted helminths. Urine samples were tested using the point-of-care circulating cathodic antigen (POC-CCA) test for detection of S. mansoni antigen. RESULTS: There was higher latrine coverage in R (n = 6) relative to PHS villages (n = 6) with only 33% of schools in the PHS villages meeting the WHO threshold for boy: latrine coverage ratio versus 83.3% in R, while no villages met the girl: latrine ratio requirement. A higher proportion of individuals accessed unprotected water sources for both bathing and drinking (68.5% for children and 89% for adults) in PHS relative to R villages. In addition, frequency of accessing water sources was higher in PHS villages, with swimming being the most frequent activity. As expected based upon selection criteria, both prevalence and intensity of S. mansoni were higher in the PHS relative to R villages (prevalence: 43.7% vs 20.2%; P < 0.001; intensity: 73.8 ± 200.6 vs 22.2 ± 96.0, P < 0.0001), respectively. CONCLUSION: Unprotected water sources and low latrine coverage are contributing factors to PHS for schistosomiasis in western Kenya. Efforts to increase provision of potable water and improvement in latrine infrastructure is recommended to augment control efforts in the PHS areas.
Assuntos
Aparelho Sanitário/parasitologia , Schistosoma mansoni/isolamento & purificação , Esquistossomose/epidemiologia , Solo/parasitologia , Adulto , Animais , Criança , Controle de Doenças Transmissíveis , Estudos Transversais , Fezes/parasitologia , Feminino , Humanos , Quênia/epidemiologia , Masculino , Prevalência , Saúde da População Rural , Esquistossomose/urina , Inquéritos e Questionários , Urina/parasitologiaRESUMO
BACKGROUND: Socioeconomic inequality including wealth distribution is a barrier to implementation of health policies. Wealth distribution can be measured effectively using household data on durable assets. Compared to other methods of analysing Socio-economic Status (SES) using durable assets, Multiple Correspondence Analysis (MCA) can create more reliable wealth quintiles. We therefore evaluated socioeconomic determinants of Schistosoma mansoni using MCA on household data among adult population in western Kenya. The hypothesis of this study was that MCA would be a useful predictor of S. mansoni prevalence and/or intensity. METHODOLOGY: Twelve villages, 6 villages that had showed the greatest decrease in S. mansoni prevalence (Responder villages) and 6 villages that showed relatively lower decrease (Hotspot villages) between the year 2011 and 2015 were randomly selected for this study. This was according to a previous Schistosomiasis Consortium for Operational Research and Elimination (SCORE) report from western Kenya. From each village, convenience sampling was used to identify 50 adults from 50 households for inclusion in this study. An interview with a questionnaire based upon MCA indicators was conducted. One stool sample from each of the 600 adults was examined based on four slides for S. mansoni eggs using Kato Katz technique. Mean Eggs per gram(EPG) was calculated by taking the average of the readings from the four slides. A log binomial regression model was used to identify the influence of the various age-groups(<30 years, 30-60 years and >60 years), household size, wealth class, occupation, education status, main water supply, sex and sub-county of residence on S. mansoni infection. EPG was then compared across variables that were significant based on multivariate log binomial model analysis using a mixed model. PRINCIPAL FINDINGS: Overall prevalence of S. mansoni was 41.3%. Significantly higher prevalence of S. mansoni were associated with males, those aged below 30 years, those who use unsafe water sources (unprotected wells, lakes and rivers), residents of Rachuonyo North, Hotspot villages and those earning livelihood from fishing. Only sex and household size were significant predictors in the multivariate model. Males were associated with significantly higher prevalence compared to the females (aPR = 1.37; 95% CI = 1.14-1.66). In addition, households with at least four persons had higher prevalence compared to those with less than four (aPR = 1.29; 95% CI = 1.03-1.61). However, there was no difference in prevalence between the wealth classes(broadly divided into poor and less poor categories). Intensity of infection (Mean EPG)was also significantly higher among males, younger age group, Rachuonyo North residents and Hotspot Villages. CONCLUSION: Socioeconomic status based on an MCA model was not a contributing factor to S. mansoni prevalence and/or intensity possibly because the study populations were not sufficiently dissimilar. The use of convenience sampling to identify participants could also have contributed to the lack of significant findings.
Assuntos
Fezes/parasitologia , População Rural/estatística & dados numéricos , Schistosoma mansoni/isolamento & purificação , Esquistossomose mansoni/economia , Esquistossomose mansoni/epidemiologia , Fatores Socioeconômicos , Adulto , Animais , Estudos Transversais , Características da Família , Feminino , Humanos , Quênia/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Esquistossomose mansoni/parasitologiaRESUMO
The Schistosomiasis Consortium for Operational Research (SCORE) was funded in 2008 to improve the evidence base for control and elimination of schistosomiasis-better understanding of the systemic morbidities experienced by children in schistosomiasis-endemic areas and the response of these morbidities to treatment, being essential for updating WHO guidelines for mass drug administration (MDA) in endemic areas. This article summarizes the SCORE studies that aimed to gauge the impact of MDA-based treatment on schistosomiasis-related morbidities. Morbidity cohort studies were embedded in the SCORE's larger field studies of gaining control of schistosomiasis in Kenya and Tanzania. Following MDA, cohort children had less undernutrition, less portal vein dilation, and increased quality of life in Year 5 compared with baseline. We also conducted a pilot study of the Behavioral Assessment System for Children (BASC-2) in conjunction with the Kenya gaining control study, which demonstrated beneficial effects of treatment on classroom behavior. In addition, the SCORE's Rapid Answers Project performed systematic reviews of previously available data, providing two meta-analyses related to morbidity. The first documented children's infection-related deficits in school attendance and achievement and in formal tests of learning and memory. The second showed that greater reductions in egg output following drug treatment correlates significantly with reduced odds of most morbidities. Overall, these SCORE morbidity studies provided convincing evidence to support the use of MDA to improve the health of school-aged children in endemic areas. However, study findings also support the need to use enhanced metrics to fully assess and better control schistosomiasis-associated morbidity.
Assuntos
Schistosoma/patogenicidade , Esquistossomose Urinária , Esquistossomose mansoni , Adolescente , Animais , Criança , Estudos de Coortes , Feminino , Humanos , Quênia/epidemiologia , Masculino , Administração Massiva de Medicamentos , Morbidade , Contagem de Ovos de Parasitas , Praziquantel/uso terapêutico , Prevalência , Schistosoma/efeitos dos fármacos , Schistosoma haematobium/efeitos dos fármacos , Schistosoma haematobium/patogenicidade , Schistosoma mansoni/efeitos dos fármacos , Schistosoma mansoni/patogenicidade , Esquistossomose Urinária/tratamento farmacológico , Esquistossomose Urinária/epidemiologia , Esquistossomose mansoni/tratamento farmacológico , Esquistossomose mansoni/epidemiologia , Instituições Acadêmicas , Tanzânia/epidemiologiaRESUMO
The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) was created to conduct research that could inform programmatic decision-making related to schistosomiasis. SCORE included several large cluster randomized field studies involving mass drug administration (MDA) with praziquantel. The largest of these were studies of gaining or sustaining control of schistosomiasis, which were conducted in five African countries. To enhance relevance for routine practice, the MDA in these studies was coordinated by or closely aligned with national neglected tropical disease (NTD) control programs. The study protocol set minimum targets of at least 90% for coverage among children enrolled in schools and 75% for all school-age children. Over the 4 years of intervention, an estimated 3.5 million treatments were administered to study communities. By year 4, the median village coverage was at or above targets in all studies except that in Mozambique. However, there was often a wide variation behind these summary statistics, and all studies had several villages with very low or high coverage. In studies where coverage was estimated by comparing the number of people treated with the number eligible for treatment, denominator estimation was often problematic. The SCORE experiences in conducting these studies provide lessons for future efforts that attempt to implement strong research designs in real-world contexts. They also have potential applicability to country MDA campaigns against schistosomiasis and other NTDs, most of which are conducted with less logistical and financial support than was available for the SCORE study efforts.
Assuntos
Anti-Helmínticos/uso terapêutico , Administração Massiva de Medicamentos , Esquistossomose/tratamento farmacológico , África , Animais , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Moçambique , Doenças Negligenciadas/tratamento farmacológico , Doenças Negligenciadas/prevenção & controle , Praziquantel/uso terapêutico , Prevalência , Saúde Pública , População Rural , Schistosoma , Esquistossomose/prevenção & controle , Instituições AcadêmicasRESUMO
This report summarizes the design and outcomes of randomized controlled operational research trials performed by the Bill & Melinda Gates Foundation-funded Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) from 2009 to 2019. Their goal was to define the effectiveness and test the limitations of current WHO-recommended schistosomiasis control protocols by performing large-scale pragmatic trials to compare the impact of different schedules and coverage regimens of praziquantel mass drug administration (MDA). Although there were limitations to study designs and performance, analysis of their primary outcomes confirmed that all tested regimens of praziquantel MDA significantly reduced local Schistosoma infection prevalence and intensity among school-age children. Secondary analysis suggested that outcomes in locations receiving four annual rounds of MDA were better than those in communities that had treatment holiday years, in which no praziquantel MDA was given. Statistical significance of differences was obscured by a wider-than-expected variation in community-level responses to MDA, defining a persistent hot spot obstacle to MDA success. No MDA schedule led to elimination of infection, even in those communities that started at low prevalence of infection, and it is likely that programs aiming for elimination of transmission will need to add supplemental interventions (e.g., snail control, improvement in water, sanitation and hygiene, and behavior change interventions) to achieve that next stage of control. Recommendations for future implementation research, including exploration of the value of earlier program impact assessment combined with intensification of intervention in hot spot locations, are discussed.
Assuntos
Administração Massiva de Medicamentos , Esquistossomose Urinária , Esquistossomose mansoni , África/epidemiologia , Animais , Anti-Helmínticos/uso terapêutico , Criança , Esquema de Medicação , Feminino , Humanos , Masculino , Praziquantel/uso terapêutico , Prevalência , Schistosoma haematobium/efeitos dos fármacos , Schistosoma mansoni/efeitos dos fármacos , Esquistossomose Urinária/tratamento farmacológico , Esquistossomose Urinária/epidemiologia , Esquistossomose Urinária/prevenção & controle , Esquistossomose Urinária/transmissão , Esquistossomose mansoni/tratamento farmacológico , Esquistossomose mansoni/epidemiologia , Esquistossomose mansoni/prevenção & controle , Esquistossomose mansoni/transmissão , Caramujos/parasitologia , Água/parasitologiaRESUMO
The WHO recommends mass treatment with praziquantel as the primary approach for Schistosoma mansoni-related morbidity control in endemic populations. The Schistosomiasis Consortium for Operational Research and Evaluation implemented multi-country, cluster-randomized trials to compare effectiveness of community-wide and school-based treatment (SBT) regimens on prevalence and intensity of schistosomiasis. To assess the impact of two different treatment schedules on S. mansoni-associated morbidity in children, cohort studies were nested within the randomized trials conducted in villages in Kenya and Tanzania having baseline prevalence ≥ 25%. Children aged 7-8 years were enrolled at baseline and followed to ages 11-12 years. Infection intensity and odds of infection were reduced both in villages receiving four years of annual community-wide treatment (CWT) and those who received biennial SBT over 4 years. These regimens were also associated with reduced odds of undernutrition and reduced odds of portal vein dilation at follow-up. However, neither hemoglobin levels nor the prevalence of the rare abnormal pattern C liver scores on ultrasound improved. For the combined cohorts, growth stunting worsened in the areas receiving biennial SBT, and maximal oxygen uptake as estimated by fitness testing scores declined under both regimens. After adjusting for imbalance in starting prevalence between study arms, children in villages receiving annual CWT had significantly greater decreases in infection prevalence and intensity than those villages receiving biennial SBT. Although health-related quality-of-life scores improved in both study arms, children in the CWT villages gained significantly more. We conclude that programs using annual CWT are likely to achieve better overall S. mansoni morbidity control than those implementing only biennial SBT.
Assuntos
Anti-Helmínticos/administração & dosagem , Administração Massiva de Medicamentos/estatística & dados numéricos , Esquistossomose mansoni/tratamento farmacológico , Esquistossomose mansoni/prevenção & controle , Criança , Estudos de Coortes , Esquema de Medicação , Fezes/parasitologia , Feminino , Geografia , Humanos , Quênia/epidemiologia , Masculino , Administração Massiva de Medicamentos/métodos , Praziquantel/administração & dosagem , Prevalência , Esquistossomose mansoni/epidemiologia , Instituições Acadêmicas/estatística & dados numéricos , Tanzânia/epidemiologiaRESUMO
Control of schistosomiasis presently relies largely on preventive chemotherapy with praziquantel through mass drug administration (MDA) programs. The Schistosomiasis Consortium for Operational Research and Evaluation has concluded five studies in four countries (Côte d'Ivoire, Kenya, Mozambique, and Tanzania) to evaluate alternative approaches to MDA. Studies involved four intervention years, with final evaluation in the fifth year. Mass drug administration given annually or twice over 4 years reduced average prevalence and intensity of schistosome infections, but not all villages that were treated in the same way responded similarly. There are multiple ways by which responsiveness to MDA, or the lack thereof, could be measured. In the analyses presented here, we defined persistent hotspots (PHS) as villages that achieved less than 35% reduction in prevalence and/or less than 50% reduction in infection intensity after 4 years of either school-based or community-wide MDA, either annually or twice in 4 years. By this definition, at least 30% of villages in each of the five studies were PHSs. We found no consistent relationship between PHSs and the type or frequency of intervention, adequacy of reported MDA coverage, and prevalence or intensity of infection at baseline. New research is warranted to identify PHSs after just one or a few rounds of MDA, and new adaptive strategies need to be advanced and validated for turning PHSs into responder villages.
Assuntos
Anti-Helmínticos/administração & dosagem , Administração Massiva de Medicamentos/estatística & dados numéricos , Praziquantel/administração & dosagem , Esquistossomose/epidemiologia , Esquistossomose/prevenção & controle , África/epidemiologia , Animais , Quimioprevenção , Criança , Estudos Transversais , Humanos , Prevalência , Schistosoma haematobium/efeitos dos fármacos , Esquistossomose/urinaRESUMO
BACKGROUND: Dissemination of research findings is acknowledged as an important component of any research process. Implementation of research findings into practice or policy is necessary for improving outcomes in the targeted community. Given the context and dynamic environment in which researchers operate, there is need to find out existing gaps in terms of disseminating research findings to key stakeholders. The objective of this study was to investigate the health research dissemination strategies used by Kenya Medical Research Institute (KEMRI) researchers. METHODS: This was a mixed-method study employing concurrent sequence (use of both qualitative and quantitative) methods of data collection. The study was conducted in KEMRI's 10 centres spread in 3 geographical areas: Kisumu, Kilifi, and Nairobi counties. Potential respondents were identified through purposive sampling. Three inter-related data collection methods were employed in this study. These methods included key informant interviews with: (a) MoH officials from county government; (b) KEMRI researchers; and (c) key KEMRI departments, namely Corporate Affairs and the library. Additionally, secondary sources of information, such as scientific reports, KEMRI annual reports, and financial statements, were also reviewed. RESULTS: Publication of papers in peer-reviewed journals was mentioned as the most common method of dissemination of research findings. Scientists published in 353 peer-reviewed journals (or publishing houses) between the years 2002 and 2015. Over 92.7% of these publications were in international peer-reviewed journals. Conferences and workshops were also mentioned. In the absence of a centralised electronic KEMRI publication database, the research team extracted and collated a publication lists from KEMRI annual reports and financial statements. This was limiting since it did not have an exhaustive list of all publications by KEMRI scientists. Only 3 respondents mentioned having written policy briefs or engaged the media as part of dissemination channels. The media representatives cited the use of social media (Facebook and Twitter) as another channel that KEMRI scientists could exploit. Challenges in dissemination included lack of knowledge on research translation leading to poor synthesis of research outputs as well as selective reporting by the media. CONCLUSION: Publications in peer-reviewed journals was the most preferred channel of communicating scientific outputs. Conferences and writing of policy briefs were the other sources of dissemination. We recommend that KEMRI dissemination channels should go well beyond simply making research available through the traditional vehicles of journal publications and scientific conference presentations but establish institutional mechanism which would facilitate extracting the main messages or key implications derived from research results and communicating them to stakeholders in attractive ways that would encourage them to factor the research implications into their work.
RESUMO
BACKGROUND: Among the different faces of immune reconstitution inflammatory syndrome (IRIS) developing in HIV-patients, no clinical definition has been reported for Schistosomiasis-IRIS (Schisto-IRIS). Although Schisto-IRIS remains largely uninvestigated, matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) have previously been associated with S. mansoni infection and tuberculosis-IRIS. Here, we aimed to investigate the relevance of these markers in Schisto-IRIS. METHODOLOGY: Patients were diagnosed with IRIS related to S. mansoni within a cohort of patients with Schistosomiasis-HIV co-infection, using a clinical working definition of Schisto-IRIS. We compared 9 patients who developed Schisto-IRIS to 9 Schisto+HIV+ controls who did not, and 9 Schisto-HIV+ controls. Plasma levels of MMP-1, MMP-7, MMP-10, TIMP-1, TIMP-2, sCD14, intestinal fatty-acid binding protein, C-reactive protein, and 8 anti-nuclear antibodies (ANA) were analyzed prior to and during 3 months of ART. PRINCIPAL FINDINGS: Although no differences were observed for MMP-1 and -7, MMP-10 levels decreased significantly in Schisto+HIV+ controls during 3 months of ART (p = 0.005) while persisting in Schisto-IRIS patients at significantly higher levels compared to Schisto-HIV+ controls (p≤0.030). In contrast TIMP-1 levels only decreased significantly in Schisto-IRIS patients (p = 0.012), while TIMP-2 levels were lower compared to Schisto+HIV+ controls at 2 weeks (p = 0.007), 1 month (p = 0.005) and 3 months (p = 0.031) of ART. Five out of 8 ANAs studied decreased significantly in Schisto-IRIS patients after 1 month of ART(p≤0.039), whereas only 1 ANA decreased for Schisto+HIV+ controls (p = 0.027). CONCLUSIONS/SIGNIFICANCE: In this study, we propose a working definition for the diagnosis of Schisto-IRIS in resource limited settings. We report persistent plasma levels of MMP-10, along with a more pronounced decrease in TIMP-1 and ANA-levels, and low levels of TIMP-2 during 3 months of ART. Corresponding to the clinical symptoms, these data suggest that Schisto-IRIS is marked by unbalanced MMP/TIMP dynamics which favor inflammation.
Assuntos
Síndrome Inflamatória da Reconstituição Imune/diagnóstico , Síndrome Inflamatória da Reconstituição Imune/etiologia , Metaloproteinases da Matriz/metabolismo , Esquistossomose mansoni/complicações , Inibidores Teciduais de Metaloproteinases/metabolismo , Adulto , Animais , Biomarcadores , Estudos de Casos e Controles , Estudos de Coortes , Coinfecção , Feminino , Infecções por HIV , Humanos , Quênia/epidemiologia , Masculino , Metaloproteinases da Matriz/sangue , Schistosoma mansoni , Esquistossomose mansoni/epidemiologia , Esquistossomose mansoni/imunologia , Inibidores Teciduais de Metaloproteinases/sangueRESUMO
Because anemia is one of the markers of morbidity associated with schistosomiasis, it has been proposed as a potential measure to evaluate the impact of control programs. However, anemia is also a common consequence of malaria, and schistosomiasis and malaria are often co-endemic. To estimate the attributable fraction of anemia due to Schistosoma mansoni and Plasmodium falciparum infections, we applied a log-binomial model to four studies measuring these parameters of a combined 5,849 children in western Kenya. In our studies, malaria contributed 23.3%, schistosomiasis contributed 6.6%, and co-infection contributed 27.6% of the anemia. We conclude that in areas where S. mansoni and P. falciparum are co-endemic, the contribution of schistosomiasis to anemia is masked by anemia resulting from malaria, thus limiting anemia as a useful measure for schistosomiasis control programs in these settings.
Assuntos
Anemia/etiologia , Coinfecção/complicações , Malária Falciparum/complicações , Esquistossomose mansoni/complicações , Adolescente , Anemia/epidemiologia , Criança , Pré-Escolar , Humanos , Lactente , Quênia/epidemiologia , Malária Falciparum/epidemiologia , Modelos Biológicos , Fatores de Risco , Esquistossomose mansoni/epidemiologiaRESUMO
Schistosomiasis control programs are designed to reduce morbidity by providing mass drug administration (MDA) of praziquantel to at-risk populations. We compared morbidity markers between two cohorts of Kenyan schoolchildren that initially had high prevalence of Schistosoma mansoni infections. One cohort (N = 416 at year 1) received four rounds of annual MDA in a community-wide treatment (CWT) strategy. The other cohort (N = 386 at year 1) received school-based treatment (SBT) every other year over the 4-year period. We measured infection with S. mansoni and soil-transmitted helminths (STH) as well as subtle morbidity markers at year 1, year 3, and year 5 and compared cohorts with mixed models after controlling for age and gender. At year 5, neither overall S. mansoni prevalence nor the prevalence of high infection-intensity S. mansoni infection was significantly reduced compared with baseline in either the CWT cohort (N = 277 remaining) or the SBT cohort (N = 235 remaining). Nevertheless, by year 5, children in both cohorts demonstrated significant decreases in wasting, ultrasound-detected organomegaly, and STH infection along with significantly improved pediatric quality-of-life scores compared with year 1. Stunting did not change over time, but children who were S. mansoni egg-positive at year 5 had significantly more stunting than children without schistosomiasis. The only significant difference between arms at year 5 was a lower prevalence of STH infections in the CWT group.
Assuntos
Administração Massiva de Medicamentos/estatística & dados numéricos , Schistosoma mansoni/efeitos dos fármacos , Esquistossomose mansoni/tratamento farmacológico , Esquistossomose mansoni/epidemiologia , Albendazol/uso terapêutico , Animais , Anti-Helmínticos/uso terapêutico , Criança , Estudos de Coortes , Estudos Transversais , Fezes/parasitologia , Feminino , Transtornos do Crescimento/epidemiologia , Transtornos do Crescimento/etiologia , Humanos , Quênia/epidemiologia , Masculino , Morbidade , Contagem de Ovos de Parasitas , Praziquantel/uso terapêutico , Prevalência , Solo/parasitologia , Fatores de TempoRESUMO
BACKGROUND: Since 2011, cohorts of schoolchildren in regions bordering Lake Victoria in Kenya and Tanzania have been investigated for morbidity caused by Schistosoma mansoni infection. Despite being neighbouring countries with similar lifestyles and ecological environments, Tanzanian schoolchildren had lower S. mansoni prevalence and intensity and they were taller and heavier, fewer were wasted and anaemic, and more were physical fit compared to their Kenyan peers. The aim of the present study was to evaluate whether diet and school-related markers of socioeconomic status (SES) could explain differences in morbidity beyond the effect of infection levels. METHODS AND PRINCIPAL FINDINGS: Parasitological and morbidity data from surveys in 2013-2014 were compared with information on diet and school-related markers of SES collected in 2015 using questionnaires. A total of 490 schoolchildren (163 Kenyans and 327 Tanzanians) aged 9-11 years provided data. A higher proportion of Tanzanian pupils (69.4%, 95% CI: 64.3-74.5) knew where to wash hands after toilet visits compared to Kenyan pupils (48.5%, 95% CI: 40.9-56.1; P<0.0005). Similar proportions of children in the two countries ate breakfast, lunch and dinner, but the content of the meals differed. At all three meals, a higher proportion (95% CI) of Tanzanian pupils consumed animal proteins (mostly fish proteins) compared to their Kenyan peers (35.0% (28.3-41.7) vs. 0%; P<0.0005 at breakfast; 69.0% (63.9-74.1) vs. 43.6% (35.8-51.4); P<0.0005 at lunch; and 67.2% (62.1-72.3) vs. 53.4% (45.8-61.0); P = 0.003 at dinner). Multivariable analyses investigating risk factors for important morbidity markers among individuals revealed that after controlling for schistosome and malaria infections, eating animal proteins (fish) and knowing where to wash hands after toilet visits were significant predictors for both haemoglobin levels and physical fitness (measured as VO2 max). CONCLUSIONS: These results suggest that the differences in morbidity may be affected by factors other than S. mansoni infection alone. Diet and hygiene practice differences were associated with health status of schoolchildren along Lake Victoria in Kenya and Tanzania. TRIAL REGISTRATION: Trials Registration numbers: ISRCT 16755535 (Kenya), ISRCT 95819193 (Tanzania).
Assuntos
Dieta , Higiene , Esquistossomose mansoni/epidemiologia , Animais , Antropometria , Criança , Estudos Transversais , Fezes/parasitologia , Feminino , Humanos , Quênia/epidemiologia , Lagos , Masculino , Morbidade , Aptidão Física , Prevalência , Fatores de Risco , Schistosoma mansoni/isolamento & purificação , Schistosoma mansoni/fisiologia , Esquistossomose mansoni/parasitologia , Instituições Acadêmicas , Classe Social , Inquéritos e Questionários , Tanzânia/epidemiologiaRESUMO
BACKGROUND: Mass drug administration (MDA) using praziquantel is the WHO-recommended approach for control of schistosomiasis. However, few studies have compared the impact of different schedules of MDA on the resultant infection levels. We wished to evaluate whether annual MDA was more effective than less frequent treatments for reducing community-level prevalence and intensity of Schistosoma mansoni infections. METHODS: We performed a cluster randomized trial (ISRCTN 14849830) of 3 different MDA frequencies over a 5 year period in 75 villages with moderate (10%-24%) initial prevalence of S. mansoni in school children in western Kenya. Praziquantel was distributed by school teachers to students either annually, the first 2 years, or every other year over a 4 year period. Prevalence and intensity of infection were measured by stool examination in 9-12 year old students using the Kato-Katz method at baseline, each treatment year, and for the final evaluation at year 5. S. mansoni prevalence and intensity were also measured in first year students at baseline and year 5. RESULTS: Twenty-five schools were randomly assigned to each arm. S. mansoni prevalence and infection intensity in 9-12 year old students significantly decreased within each arm from baseline to year 5 but there were no differences between arms. There were no differences in infection levels in first year students either within or between arms. CONCLUSIONS: Strategies employing 2 or 4 rounds of MDA had a similar impact in schools with moderate initial prevalence, suggesting that schistosomiasis control can be sustained by school-based MDA, even if provided only every other year.