Community-Academic Team Teaching in a CBPR Course: Lessons Learned about Course Instruction.

BACKGROUND: Community-based participatory research (CBPR) involves community and academic partners working collaboratively to understand and address local challenges. Undergraduates who engage in CBPR through a course can learn valuable research and professional skills, but we found no studies describing the experiences of community and academic partner instructors who have co-taught undergraduate CBPR courses. We describe lessons the instructors learned from collaboratively teaching one such course. LESSONS LEARNED: The lessons we include highlight how community-academic team teaching can 1) provide unique opportunities to teach and model partnership and collaboration, 2) incorporate nontraditional learning opportunities for students to practice skills and engage in content reflection, 3) be challenged by differing community and academic priorities, and 4) surface power dynamics in the classroom that should be explicitly discussed. CONCLUSIONS: Community and academic partners can successfully team teach in an undergraduate CBPR course and encourage the development of important skills that can be transferable to the real world. Focusing on offering traditional and nontraditional learning opportunities and modelling partnership and collaboration can also facilitate this. Beyond these benefits, instructors considering a model like this should be prepared to intentionally engage in discussions within and outside the classroom about respective priorities and the ways in which knowledge that is traditionally valued in academic settings can create power dynamics in the classroom. Ultimately, structural supports, such as institutional funding for community partners and consideration of benefits to community partners and organizations beyond the research itself can facilitate these types of collaborations.

Longitudinal borehole functionality in 15 rural Ghanaian towns from three groundwater quality clusters.

OBJECTIVE: In sub-Saharan Africa, 45% of the rural population uses boreholes (BHs). Despite recent gains in improved water access and coverage, parallel use of unimproved sources persists. Periodic infrastructure disrepair contributes to non-exclusive use of BHs. Our study describes functionality of BHs in 2014, 2015, and 2016 in 15 rural towns in the Eastern Region of Ghana sourced from three groundwater quality clusters (high iron, high salinity, and control). We also assess factors affecting cross-sectional and longitudinal functionality using logistic regression. RESULTS: BH functionality rates ranged between 81 and 87% and were similar across groundwater quality clusters. Of 51 BHs assessed in all three years, 34 (67%) were consistently functional and only 3 (6%) were consistently broken. There was a shift toward proactive payment for water over the course of the study in the control and high-salinity clusters. Payment mechanism, population served, presence of nearby alternative water sources, and groundwater quality cluster were not significant predictors of cross-sectional or longitudinal BH functionality. However, even in the high iron cluster, where water quality is poor and no structured payment mechanism for water exists, BHs are maintained, showing that they are important community resources.

Key correlates of exclusive breastfeeding at three timepoints: Evidence from Ethiopia.

Aim: To compare factors associated with exclusive breastfeeding (EBF) within 1 h of birth, within 3 days, and within the first 6 months post-birth. Methods: We used multivariate logistic regression models and data from "The Alive and Thrive Phase 2 Amhara Baseline Survey 2015" from Ethiopia (N = 3113). Results: Giving colostrum was strongly associated with EBF at all three time points, controlling for multiple confounders. Putting the baby to the breast before cleaning the baby and before cleaning the mother was significantly associated with EBF within 1 h and for the first 3 days. EBF within an hour of birth was more likely for girl babies than boy babies. Having a healthcare professional check whether the baby was sucking well was significantly associated with EBF 3 days post-birth. Conclusions: The World Health Organization recommends breastfeeding within 1 h of birth and exclusively thereafter for 6 months, which can improve health outcomes for infants and children. In Ethiopia, many factors influence breastfeeding practices, but little is known about how these factors differ at various key timepoints in the 6 months after birth. Our study provides important information on correlates of EBF at three timepoints and shows that factors that are significantly correlated with EBF vary over time. Future research should assess the potential causal links among statistically significant associations between EBF and risk factors at various times between birth and 6 months of age. Ultimately, these findings have the potential to inform areas of intervention related to promoting EBF.

Informal preparation and years of experience: Key correlates of dyslexia knowledge among Massachusetts early elementary teachers.

BACKGROUND: Dyslexia is a neurobiological condition affecting phonological processing and characterized by reading and phonological awareness difficulties. We assessed correlations between dyslexia knowledge and five independent variables among early elementary teachers in Massachusetts. METHODS: We designed a survey based on two published assessment tools and surveyed 92 early elementary teachers. Using univariate and multivariate linear regression models, we assessed the relationships among knowledge (dependent variable) and confidence, feelings of preparedness, years of teaching experience, informal education and professional development opportunities (independent variables). RESULTS: The mean knowledge score was 68 ± 14%; teachers performed best on questions about perceptions of dyslexia, classroom management/teaching strategies and some dyslexia characteristics. Informal education and years of teaching experience were consistently positively associated with knowledge. DISCUSSION AND CONCLUSIONS: Formal training and professional development opportunities may need to focus more specifically on learning disabilities and dyslexia. Teachers should also have input on professional development needs. Our findings suggest a need for additional studies on strategies to improve educator knowledge of dyslexia and assess outcomes.

"Collaboration Toward One Collective Goal": A Mixed-Methods Study of Short-Term Learning Outcomes and Long-Term Impacts Among Students Participating in an Undergraduate Community-Based Participatory Research (CBPR) Course.

Background: Research shows positive learning outcomes for students participating in service learning. However, the impacts of undergraduate student participation in Community-Based Participatory Research (CBPR) courses are minimally studied. Methods: We used a triangulation mixed-methods design approach to analyze short- and long-term (1-5 years post-course) data collected from 59 undergraduate students across 5 cohorts of a CBPR course (2014-19). Thematic analysis was used to analyze the qualitative data and descriptive statistics and frequencies were generated to analyze the quantitative data. Results: We developed five key themes based on short-term qualitative data: integration of CBPR and traditional research skills; importance of community engagement in research; identity; accountability; and collaboration. Themes from qualitative course evaluations aligned with these findings. Long-term qualitative data revealed that former students gained research knowledge, research skills, and professional skills and then applied these in other settings. This aligns with quantitative findings, where >79% of respondents reported that course participation "extensively" improved their research skills. Post-course, students still reflected on the importance of community engagement in research and reported a substantially enhanced likelihood of civic engagement. Discussion/Conclusions: Students gained critical knowledge and skills that positively impact their ability to engage in community-based work well after the end of course participation. Some students reported considering research-oriented careers and graduate programs for the first time after course participation. Collaborative learning experiences with community partners and members encouraged students to reflect on research designs that center community voices. We stress here that community partnerships require extensive cultivation, but they can create opportunities to translate findings directly back to communities and provide numerous benefits to undergraduate students. We hope that our findings provide the information needed to consider pilot testing practice-based CBPR courses in a variety of public health training contexts.

Rural Ghanaian households are more likely to use alternative unimproved water sources when water from boreholes has undesirable organoleptic characteristics.

Sustainable Development Goal (SDG) 6 aims to achieve universal access to safe drinking water sources. However, the health benefits of meeting this goal will only be fully realized if improved sources are used to the exclusion of unimproved sources. Very little is known about how rural African households balance the use of improved and unimproved water sources when multiple options are present. We assessed parallel use of untreated surface water and unimproved hand-dug wells (HDWs) in the presence of boreholes (BHs) using a semi-quantitative water use survey among 750 residents of 15 rural Ghanaian communities, distributed across three BH water quality clusters: control, high salinity, and high iron. Multivariate mixed effects logistic regression models were used to assess the impact of water quality cluster on the use of BHs, HDWs, and surface water, controlling for distance to the nearest source of each type. Reported surface water use was significantly higher in the high salinity and high iron clusters than in the control cluster, especially for water-intensive activities. Respondents in the non-control clusters had approximately eight times higher odds of clothes washing with surface water (p < 0.01) than in the control. Respondents in the high salinity cluster also had 4.3 times higher odds of drinking surface water (p < 0.05). BH use was high in all clusters, but decreased substantially when distance to the nearest BH exceeded 300 m (OR = 0.17-0.25, p < 0.001). Water use from all sources was inversely correlated with distance, with the largest effect observed on HDW use in multivariate models (OR = 0.02, p < 0.001). Surface water and HDW use will likely continue despite the presence of BHs when perceived groundwater quality is poor and other water sources are in close proximity. It is essential to account for naturally-occurring but undesirable groundwater quality parameters in rural water planning to ensure that SDG 6 is met and health benefits are realized.

HCV treatment access among Latinxs who inject drugs: qualitative findings from Boston, Massachusetts, 2016.

BACKGROUND: Compared with Caucasians, Latinxs with the hepatitis C virus (HCV) tend to initiate treatment less often, discontinue treatment, become infected younger, and have higher reinfection rates post-treatment. Little is known about HCV treatment experiences among Latinxs who inject drugs in the Northeastern USA. We assessed knowledge, attitudes, and perceptions tied to HCV, as well as HCV treatment readiness, and explored the overall HCV treatment experience of Latinx people who inject drugs (PWID) in Boston. METHODS: We conducted qualitative interviews with monolingual and bilingual Spanish-speaking Latinx PWID (n = 15) in Boston, Massachusetts, between 2015 and 2016. We used a thematic content analysis approach to code and analyze data to identify knowledge, attitudes, and experiences related to HCV treatment. RESULTS: We identified barriers and facilitators to HCV treatment. Six salient themes emerged from the data. For participants who had not initiated HCV treatment, lack of referral, fear of quitting drugs, and fear of relapse were perceived barriers. Trust in medical providers and a willingness to quit drugs were primary facilitators. Most participants had positive HCV treatment experiences, and several emphasized the need for outreach to Latinxs about the advantages of newer treatment options. Concerns about HCV reinfection were also notable. CONCLUSIONS: We identified a range of experiences tied to HCV treatment among Latinx PWID. HCV care providers play a key role in determining treatment uptake, and more treatment information should be disseminated to Latinx PWID. Healthcare providers should capitalize on treatment facilitators by ensuring referrals to treatment and should continue to address perceived barriers.

The use of remotely sensed environmental parameters for spatial and temporal schistosomiasis prediction across climate zones in Ghana.

Schistosomiasis control in sub-Saharan Africa is enacted primarily through preventive chemotherapy. Predictive models can play an important role in filling knowledge gaps in the distribution of the disease and help guide the allocation of limited resources. Previous modeling approaches have used localized cross-sectional survey data and environmental data typically collected at a discrete point in time. In this analysis, 8 years (2008-2015) of monthly schistosomiasis cases reported into Ghana's national surveillance system were used to assess temporal and spatial relationships between disease rates and three remotely sensed environmental variables: land surface temperature (LST), normalized difference vegetation index (NDVI), and accumulated precipitation (AP). Furthermore, the analysis was stratified by three major and nine minor climate zones, defined using a new climate classification method. Results showed a downward trend in reported disease rates (~ 1% per month) for all climate zones. Seasonality was present in the north with two peaks (March and September), and in the middle of the country with a single peak (July). Lowest disease rates were observed in December/January across climate zones. Seasonal patterns in the environmental variables and their associations with reported schistosomiasis infection rates varied across climate zones. Precipitation consistently demonstrated a positive association with disease outcome, with a 1-cm increase in rainfall contributing a 0.3-1.6% increase in monthly reported schistosomiasis infection rates. Generally, surveillance of neglected tropical diseases (NTDs) in low-income countries continues to suffer from data quality issues. However, with systematic improvements, our approach demonstrates a way for health departments to use routine surveillance data in combination with publicly available remote sensing data to analyze disease patterns with wide geographic coverage and varying levels of spatial and temporal aggregation.

Assessment of urogenital schistosomiasis knowledge among primary and junior high school students in the Eastern Region of Ghana: A cross-sectional study.

BACKGROUND: Knowledge of urogenital schistosomiasis can empower individuals to limit surface water contact and participate in mass drug administration campaigns, but nothing is currently known about the schistosomiasis knowledge that schoolchildren have in Ghana. We developed and implemented a survey tool aiming to assess the knowledge of urogenital schistosomiasis (treatment, transmission, prevention, symptoms) among science teaches and primary and junior high school students in the Eastern Region of Ghana. METHODS: We developed a 22-question knowledge survey tool and administered it to 875 primary and 938 junior high school students from 74 schools in 37 communities in the Eastern Region of Ghana. Teachers (n = 57) answered 20 questions matched to student questions. We compared knowledge scores (as percent of correct answers) across topics, gender, and class year and assessed associations with teacher's knowledge scores using t-tests, chi-squared tests, univariate, and multivariate linear regression, respectively. RESULTS: Students performed best when asked about symptoms (mean±SD: 76±21% correct) and prevention (mean±SD: 69±25% correct) compared with transmission (mean±SD: 50±15% correct) and treatment (mean±SD: 44±23% correct) (p<0.0005). Teachers performed best on prevention (mean±SD: 93±12% correct, p<0.0005) and poorest on treatment (mean±SD: 69±16% correct, p<0.001). When listing five facts about urogenital schistosomiasis, teachers averaged 2.9±1.2 correct. Multiple regression models suggest that gender, class year, teacher score, and town of residency explain ~27% of variability in student scores. On average, junior high school students outperformed primary school students by 10.2 percentage points (CI95%: 8.6-11.8); boys outperformed girls by 3.5 percentage points (CI95%: 2.3-4.7). CONCLUSIONS: Our survey parsed four components of student and teacher knowledge. We found strong knowledge in several realms, as well as knowledge gaps, especially on transmission and treatment. Addressing relevant gaps among students and science teachers in UGS-endemic areas may help high-risk groups recognize risky water contact activities, improve participation in mass drug administration, and spark interest in science by making it practical.

Contextualizing Schistosoma haematobium transmission in Ghana: Assessment of diagnostic techniques and individual and community water-related risk factors.

OBJECTIVES: The study assessed associations between Schistosoma haematobium infection (presence of parasite eggs in urine or hematuria) and self-reported metrics (macrohematuria, fetching surface water, or swimming) to evaluate their performance as proxies of infection in presence of regular preventive chemotherapy. It also examined community water characteristics (safe water access, surface water access, and groundwater quality) to provide context for schistosomiasis transmission in different types of communities and propose interventions. METHODS: Logistic regression was used to assess the associations between the various measured and self-reported metrics in a sample of 897 primary school children in 30 rural Ghanaian communities. Logistic regression was also used to assess associations between community water characteristics, self-reported water-related behaviors and S. haematobium infection. Communities were subsequently categorized as candidates for three types of interventions: provision of additional safe water sources, provision of groundwater treatment, and health education about water-related disease risk, depending on their water profile. RESULTS: Microhematuria presence measured with a reagent strip was a good proxy of eggs in urine at individual (Kendall's τb = 0.88, p < 0.001) and at school-aggregated (Spearman's rs = 0.96, p < 0.001) levels. Self-reported macrohematuria and swimming were significantly associated (p < 0.05) with egg presence, but self-reported fetching was not. Of the community water characteristics, greater surface water access and presence of groundwater quality problems were significantly associated with increased likelihood of fetching, swimming, and S. haematobium infection. Access to improved water sources did not exhibit an association with any of these outcomes. CONCLUSIONS: The study illustrates that in presence of regular school-based treatment with praziquantel, microhematuria assessed via reagent strips remains an adequate proxy for S. haematobium infection in primary schoolchildren. Community water profiles, in combination with self-reported water-related behaviors, can help elucidate reasons for some endemic communities continuing to experience ongoing transmission and tailor interventions to these local contexts to achieve sustainable control.

Physicochemical parameters affecting the perception of borehole water quality in Ghana.

Rural Ghanaian communities continue using microbiologically contaminated surface water sources due in part to undesirable organoleptic characteristics of groundwater from boreholes. Our objective was to identify thresholds of physical and chemical parameters associated with consumer complaints related to groundwater. Water samples from 94 boreholes in the dry season and 68 boreholes in the rainy season were analyzed for 18 parameters. Interviews of consumers were conducted at each borehole regarding five commonly expressed water quality problems (salty taste, presence of particles, unfavorable scent, oily sheen formation on the water surface, and staining of starchy foods during cooking). Threshold levels of water quality parameters predictive of complaints were determined using the Youden index maximizing the sum of sensitivity and specificity. The probability of complaints at various parameter concentrations was estimated using logistic regression. Exceedances of WHO guidelines were detected for pH, turbidity, chloride, iron, and manganese. Concentrations of total dissolved solids (TDS) above 172mg/L were associated with salty taste complaints. Although the WHO guideline is 1000mg/L, even at half the guideline, the likelihood of salty taste complaint was 75%. Iron concentrations above 0.11, 0.14 and 0.43mg/L (WHO guideline value 0.3mg/L) were associated with complaints of unfavorable scent, oily sheen, and food staining, respectively. Iron and TDS concentrations exhibited strong spatial clustering associated with specific geological formations. Improved groundwater sources in rural African communities that technically meet WHO water quality guidelines may be underutilized in preference of unimproved sources for drinking and domestic uses, compromising human health and sustainability of improved water infrastructure.

Indicators of improved water access in the context of schistosomiasis transmission in rural Eastern Region, Ghana.

Populations with poor access to water, sanitation and hygiene (WASH) infrastructure are disproportionately affected by the neglected tropical diseases (NTDs). As a result, WASH has gained increasing prominence in integrated control and elimination of NTDs, including schistosomiasis. In order to identify underserved populations, relevant measures of access to WASH infrastructure at sub-national or local levels are needed. We conducted a field survey of all public water sources in 74 rural communities in the Eastern Region of Ghana and computed indicators of water access using two methods: one based on the design capacity and another on the spatial distribution of water sources. The spatial method was applied to improved and surface water sources. According to the spatial method, improved water sources in the study area were well-distributed within communities with 95% (CI95%: 91, 98) of the population having access within 500m when all, and 87% (CI95%: 81, 93) when only functional water sources were considered. According to the design capacity-based method, indicator values were lower: 63% (CI95%: 57, 69) for all and 49% (CI95%: 43, 55) for only functional sources. Surface water access was substantial with 62% (CI95%: 54, 71) of the population located within 500m of a perennial surface water source. A negative relationship was observed between functional improved water access and surface water access within 300m. In this context, perceived water quality of the improved sources was also important, with a 17% increase in surface water access in towns with one reported water quality problem as compared to towns with no problems. Our study offers a potential methodology to use water point mapping data to identify communities in need of improved water access to achieve schistosomiasis risk reduction.

A mixed-methods approach to understanding water use and water infrastructure in a schistosomiasis-endemic community: case study of Asamama, Ghana.

BACKGROUND: Surface water contaminated with human waste may transmit urogenital schistosomiasis (UGS). Water-related activities that allow skin exposure place people at risk, but public health practitioners know little about why some communities with access to improved water infrastructure have substantial surface water contact with infectious water bodies. Community-based mixed-methods research can provide critical information about water use and water infrastructure improvements. METHODS: Our mixed-methods study assessed the context of water use in a rural community endemic for schistosomiasis. RESULTS: Eighty-seven (35.2 %) households reported using river water but not borehole water; 26 (10.5 %) reported using borehole water but not river water; and 133 (53.8 %) households reported using both water sources. All households are within 1 km of borehole wells, but tested water quality was poor in most wells. Schistosomiasis is perceived by study households (89.3 %) to be a widespread problem in the community, but perceived schistosomiasis risk fails to deter households from river water usage. Hematuria prevalence among schoolchildren does not differ by household water use preference. Focus group data provides context for water preferences. Demand for improvements to water infrastructure was a persistent theme; however, roles and responsibilities with respect to addressing community water and health concerns are ill-defined. CONCLUSIONS: Collectively, our study illustrates how complex attitudes towards water resources can affect which methods will be appropriate to address schistosomiasis.

Piped water consumption in Ghana: A case study of temporal and spatial patterns of clean water demand relative to alternative water sources in rural small towns.

Continuous access to adequate quantities of safe water is essential for human health and socioeconomic development. Piped water systems (PWSs) are an increasingly common type of water supply in rural African small towns. We assessed temporal and spatial patterns in water consumption from public standpipes of four PWSs in Ghana in order to assess clean water demand relative to other available water sources. Low water consumption was evident in all study towns, which manifested temporally and spatially. Temporal variability in water consumption that is negatively correlated with rainfall is an indicator of rainwater preference when it is available. Furthermore, our findings show that standpipes in close proximity to alternative water sources such as streams and hand-dug wells suffer further reductions in water consumption. Qualitative data suggest that consumer demand in the study towns appears to be driven more by water quantity, accessibility, and perceived aesthetic water quality, as compared to microbiological water quality or price. In settings with chronic under-utilization of improved water sources, increasing water demand through household connections, improving water quality with respect to taste and appropriateness for laundry, and educating residents about health benefits of using piped water should be prioritized. Continued consumer demand and sufficient revenue generation are important attributes of a water service that ensure its function over time. Our findings suggest that analyzing water consumption of existing metered PWSs in combination with qualitative approaches may enable more efficient planning of community-based water supplies and support sustainable development.

Agreement among Four Prevalence Metrics for Urogenital Schistosomiasis in the Eastern Region of Ghana.

Few studies assess agreement among Schistosoma haematobium eggs, measured hematuria, and self-reported metrics. We assessed agreement among four metrics at a single time point and analyzed the stability of infection across two time points with a single metric. We used data from the Eastern Region of Ghana and constructed logistic regression models. Girls reporting macrohematuria were 4.1 times more likely to have measured hematuria than girls not reporting macrohematuria (CI95%: 2.1-7.9); girls who swim were 3.6 times more likely to have measured hematuria than nonswimmers (CI95%: 1.6-7.9). For boys, neither self-reported metric was predictive. Girls with measured hematuria in 2010 were 3.3 times more likely to be positive in 2012 (CI95%: 1.01-10.5), but boys showed no association. Boys with measured hematuria in 2008 were 6.0 times more likely to have measured hematuria in 2009 (CI95%: 1.5-23.9) and those with eggs in urine in 2008 were 4.8 times more likely to have eggs in urine in 2009 (CI95%: 1.2-18.8). For girls, measured hematuria in 2008 predicted a positive test in 2009 (OR = 2.8; CI95%: 1.1-6.8), but egg status did not. Agreement between dipstick results and eggs suggests continued dipstick used is appropriate. Self-reported swimming should be further examined. For effective disease monitoring, we recommend annual dipstick testing.

Effective control of Schistosoma haematobium infection in a Ghanaian community following installation of a water recreation area.

BACKGROUND: Urogenital schistosomiasis caused by Schistosoma haematobium was endemic in Adasawase, Ghana in 2007. Transmission was reported to be primarily through recreational water contact. METHODS: We designed a water recreation area (WRA) to prevent transmission to school-aged children. The WRA features a concrete pool supplied by a borehole well and a gravity-driven rainwater collection system; it is 30 m(2) and is split into shallow and deep sections to accommodate a variety of age groups. The WRA opened in 2009 and children were encouraged to use it for recreation as opposed to the local river. We screened children annually for S. haematobium eggs in their urine in 2008, 2009, and 2010 and established differences in infection rates before (2008-09) and after (2009-10) installation of the WRA. After each annual screening, children were treated with praziquantel and rescreened to confirm parasite clearance. PRINCIPAL FINDINGS: Initial baseline testing in 2008 established that 105 of 247 (42.5%) children were egg-positive. In 2009, with drug treatment alone, the pre-WRA annual cumulative incidence of infection was 29 of 216 (13.4%). In 2010, this incidence rate fell significantly (p<0.001, chi-squared) to 9 of 245 (3.7%) children after installation of the WRA. Logistic regression analysis was used to determine correlates of infection among the variables age, sex, distance between home and river, minutes observed at the river, low height-for-age, low weight-for-age, low Body Mass Index (BMI)-for-age, and previous infection status. CONCLUSION/SIGNIFICANCE: The installation and use of a WRA is a feasible and highly effective means to reduce the incidence of schistosomiasis in school-aged children in a rural Ghanaian community. In conjunction with drug treatment and education, such an intervention can represent a significant step towards the control of schistosomiasis. The WRA should be tested in other water-rich endemic areas to determine whether infection prevalence can be substantially reduced.

Diagnostic accuracy of urine filtration and dipstick tests for Schistosoma haematobium infection in a lightly infected population of Ghanaian schoolchildren.

Two screening methods, reagent dipsticks for hematuria and urine filtration for Schistosoma haematobium eggs, were evaluated for their sensitivity and specificity in diagnosing infection with S. haematobium in lightly infected Ghanaian children. Schoolchildren aged 8-18 years (n=255) provided urine samples on three occasions. Overall, 36.4% of girls and 50.7% of boys presented with eggs at least once; 3.3% of girls and 7.5% of boys presented with both eggs and hematuria three times. Many children presented with eggs but without hematuria, or with hematuria but without eggs. When each child was screened three times, the sensitivity of each test method improved by at least 22.9% as compared with single screening, but previously unidentified infections were detected at the third screening, indicating that even three screenings is insufficient. Nearly half of lightly infected children (<50 eggs/10 ml urine, by maximum egg count) were egg-positive during only one of three screenings. Thus, data presented here indicate that when individuals are screened repeatedly, infection status can be assessed more accurately, control programs can be properly evaluated, and population estimates of S. haematobium infection may be made with increased confidence, as compared with single screening.