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Background: The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) focus is on randomized trials of different approaches to mass drug administration (MDA) in endemic countries in Africa. Because their studies provided an opportunity to evaluate the effects of mass treatment on Schistosoma-associated morbidity, nested cohort studies were developed within SCORE's intervention trials to monitor changes in a suite of schistosomiasis disease outcomes. This paper describes the process SCORE used to select markers for prospective monitoring and the baseline prevalence of these morbidities in four parallel cohort studies.Methods: In July 2009, SCORE hosted a discussion of the potential impact of MDA on morbidities due to Schistosoma infection that might be measured in the context of multi-year control. Candidate markers were reviewed and selected for study implementation. Baseline data were then collected from cohorts of children in four country studies: two in high endemic S. mansoni sites (Kenya and Tanzania), and two in high endemic S. haematobium sites (Niger and Mozambique), these cohorts to be followed prospectively over 5 years.Results: At baseline, 62% of children in the S. mansoni sites had detectable eggs in their stool, and 10% had heavy infections (≥ 400 eggs/g feces). Heavy S. mansoni infections were found to be associated with increased baseline risk of anemia, although children with moderate or heavy intensity infections had lower risk of physical wasting. Prevalence of egg-positive infection in the combined S. haematobium cohorts was 27%, with 5% of individuals having heavy infection (≥50 eggs/10 mL urine). At baseline, light intensity S. haematobium infection was associated with anemia and with lower scores in the social domain of health-related quality-of-life (HRQoL) assessed by Pediatric Quality of Life Inventory.Conclusions: Our consensus on practical markers of Schistosoma-associated morbidity indicated that height, weight, hemoglobin, exercise tolerance, HRQoL, and ultrasound abnormalities could be used as reference points for gauging treatment impact. Data collected over five years of program implementation will provide guidance for future evaluation of morbidity control in areas endemic for schistosomiasis.Trial Registration: These cohort studies are registered and performed in conjunction with the International Standard Randomised Controlled Trial Registry trials ISRCTN16755535 , ISRCTN14117624 , ISRCTN95819193 , and ISRCTN32045736 . [ABSTRACT FROM AUTHOR]

Background: Gaining and sustaining control of schistosomiasis and, whenever feasible, achieving local elimination are the year 2020 targets set by the World Health Organization. In Zanzibar, various institutions and stakeholders have joined forces to eliminate urogenital schistosomiasis within 5 years. We report baseline findings before the onset of a randomized intervention trial designed to assess the differential impact of community-based praziquantel administration, snail control, and behavior change interventions. Methodology: In early 2012, a baseline parasitological survey was conducted in ∼20,000 people from 90 communities in Unguja and Pemba. Risk factors for schistosomiasis were assessed by administering a questionnaire to adults. In selected communities, local knowledge about schistosomiasis transmission and prevention was determined in focus group discussions and in-depths interviews. Intermediate host snails were collected and examined for shedding of cercariae. Principal Findings: The baseline Schistosoma haematobium prevalence in school children and adults was 4.3% (range: 0–19.7%) and 2.7% (range: 0–26.5%) in Unguja, and 8.9% (range: 0–31.8%) and 5.5% (range: 0–23.4%) in Pemba, respectively. Heavy infections were detected in 15.1% and 35.6% of the positive school children in Unguja and Pemba, respectively. Males were at higher risk than females (odds ratio (OR): 1.45; 95% confidence interval (CI): 1.03–2.03). Decreasing adult age (OR: 1.04; CI: 1.02–1.06), being born in Pemba (OR: 1.48; CI: 1.02–2.13) or Tanzania (OR: 2.36; CI: 1.16–4.78), and use of freshwater (OR: 2.15; CI: 1.53–3.03) showed higher odds of infection. Community knowledge about schistosomiasis was low. Only few infected Bulinus snails were found. Conclusions/Significance: The relatively low S. haematobium prevalence in Zanzibar is a promising starting point for elimination. However, there is a need to improve community knowledge about disease transmission and prevention. Control measures tailored to the local context, placing particular attention to hot-spot areas, high-risk groups, and individuals, will be necessary if elimination is to be achieved. Author Summary: Schistosomiasis is a chronic and debilitating disease caused by parasitic worms. It negatively impacts on the health and wellbeing of mainly rural dwellers in tropical and sub-tropical countries. The World Health Organization recently put forward an ambitious goal for the year 2020: to control schistosomiasis globally. Interruption of transmission and elimination of schistosomiasis are encouraged whenever resources allow. After careful consideration, the Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) selected the Zanzibar archipelago to learn how best to eliminate schistosomiasis. We report the baseline findings of a 5-year program. Parasitological examination of about 20,000 people on Unguja and Pemba islands revealed a low overall prevalence of Schistosoma haematobium (7%). Nevertheless, hot-spots with high prevalence (>20%) and high-risk groups (males, young adults, people born in Pemba or mainland Tanzania, and people using natural freshwater) were identified. The community knowledge about schistosomiasis transmission and prevention was poor. Few of the collected intermediate host snails shed S. haematobium cercariae. A multi-arm randomized trial is now being implemented to determine the differential impact of mass deworming, snail control, and behavior change interventions. Lessons learned from this schistosomiasis elimination program will be important for other settings. [ABSTRACT FROM AUTHOR]

This paper examines how socio-economic changes in Tanzania have impacted on parent-child relationships, in particular parental behavioural control over their children and parental influence on young people's sexual behaviour. Data came from participant observation, focus group discussions and in-depth interviews with young people (14-24 years) and their parents. Socio-economic changes (education, changes in values, material needs provision) affected parent-young person relationships. Young people contributed to the economic needs of their families and parents receiving or expecting more support from their children exercised less behavioural control (in sexual and non-sexual matters of their children). Parents and young people spent less time together than in earlier generations. Parents reported that they thought their children were more knowledgeable about sexual and reproductive health than they were. As young people received more education and contributed more to their families' economic well being. they emerged as decision-makers in their own right and parental influence waned. Policy interventions addressing sexual and reproductive health among young people should consider family influence on young people as well as the influence of young people on their families and parental authority. Families, and particularly parents, should be supported to respond to the emerging challenges and changes in their families and the wider society. [ABSTRACT FROM AUTHOR]

Although transactional sex has been linked to undesirable sexual health outcomes, there is a lack of clarity as to the meaning of the practice, which appears to extend beyond behaviors related to women's economic circumstances. This article explored the perspectives of parents and unmarried young people on motivations for, and beliefs about, transactional sex in rural Tanzania using an ethnographic research design. Data collection involved 17 focus groups and 46 in-depth interviews with young people aged 14-24 years and parents/caregivers. Transactional sex was widely accepted by both parents and young people. Male parents equated sexual exchange to buying meat from a butcher and interpreted women's demand for exchange before sex with personal power. Young men referred to transactional sex as the easiest way to get a woman to satisfy their sexual desires while also proving their masculinity. Young women perceived themselves as lucky to be created women as they could exploit their sexuality for pleasure and material gain. They felt men were stupid for paying for "goods" (vagina) they could not take away. Mothers were in agreement with their daughters. Although young women saw exploitation of the female body in positive terms, they were also aware of the health risks but ascribed these to bad luck. Interventions aimed at tackling transactional sex in the interests of women's empowerment and as a strategy for HIV prevention need to understand the cultural beliefs associated with the practice that may make it thrive despite the known risks. [ABSTRACT FROM AUTHOR]

Background: Parenting through control and monitoring has been found to have an effect on young people's sexual behaviour. There is a dearth of literature from sub-Saharan Africa on this subject. This paper examines parental control and monitoring and the implications of this on young people's sexual decision making in a rural setting in North-Western Tanzania. Methods: This study employed an ethnographic research design. Data collection involved 17 focus group discussions and 46 in-depth interviews conducted with young people aged 14-24 years and parents/carers of young people within this age-group. Thematic analysis was conducted with the aid of NVIVO 7 software. Results: Parents were motivated to control and monitor their children's behaviour for reasons such as social respectability and protecting them from undesirable sexual and reproductive health (SRH) outcomes. Parental control and monitoring varied by family structure, gender, schooling status, a young person's contribution to the economic running of the family and previous experience of a SRH outcome such as unplanned pregnancy. Children from single parent families reported that they received less control compared to those from both parent families. While a father's presence in the family seemed important in controlling the activities of young people, a mother's did not have a similar effect. Girls especially those still schooling received more supervision compared to boys. Young women who had already had unplanned pregnancy were not supervised as closely as those who hadn't. Parents employed various techniques to control and monitor their children's sexual activities. Conclusions: Despite parents making efforts to control and monitor their young people's sexual behaviour, they are faced with several challenges (e.g. little time spent with their children) which make it difficult for them to effectively monitor them. There is a need for interventions such as parenting skills building that might enable parents to improve their relationships with children. This would equip parents with the appropriate skills for positive guidance and monitoring of their children and avoid inappropriate parenting behaviour. As much as parents focus their attention on their school going daughters, there is a need to also remember the out-of-school young people as they are also vulnerable to adverse SRH outcomes. [ABSTRACT FROM AUTHOR]

Background: Many programmes on young people and HIV/AIDS prevention have focused on the in-school and channeled sexual and reproductive health messages through schools with limited activities for the young people's families. The assumption has been that parents in African families do not talk about sexual and reproductive health (SRH) with their children. These approach has had limited success because of failure to factor in the young person's family context, and the influence of parents. This paper explores parent-child communication about SRH in families, content, timing and reasons for their communication with their children aged 14-24 years in rural Tanzania. Methods: This study employed an ethnographic research design. Data collection involved eight weeks of participant observation, 17 focus group discussions and 46 in-depth interviews conducted with young people aged 14-24 years and parents of young people in this age group. Thematic analysis was conducted with the aid of NVIVO 7 software. Results: Parent-child communication about SRH happened in most families. The communication was mainly on same sex basis (mother-daughter and rarely father-son or father-daughter) and took the form of warnings, threats and physical discipline. Communication was triggered by seeing or hearing something a parent perceived negative and would not like their child to experience (such as a death attributable to HIV and unmarried young person's pregnancy). Although most young people were relaxed with their mothers than fathers, there is lack of trust as to what they can tell their parents for fear of punishment. Parents were limited as to what they could communicate about SRH because of lack of appropriate knowledge and cultural norms that restricted interactions between opposite sex. Conclusions: Due to the consequences of the HIV pandemic, parents are making attempts to communicate with their children about SRH. They are however, limited by cultural barriers, and lack of appropriate knowledge. With some skills training on communication and SRH, parents may be a natural avenue for channeling and reinforcing HIV/AIDS prevention messages to their children. [ABSTRACT FROM AUTHOR]

Objective: To predict the spatial distributions of Schistosoma haematobium and S. mansoni infections to assist planning the implementation of mass distribution of praziquantel as part of an on-going national control programme in Tanzania.Methods: Bayesian geostatistical models were developed using parasitological data from 143 schools.Results: In the S. haematobium models, although land surface temperature and rainfall were significant predictors of prevalence, they became non-significant when spatial correlation was taken into account. In the S. mansoni models, distance to water bodies and annual minimum temperature were significant predictors, even when adjusting for spatial correlation. Spatial correlation occurred over greater distances for S. haematobium than for S. mansoni. Uncertainties in predictions were examined to identify areas requiring further data collection before programme implementation.Conclusion: Bayesian geostatistical analysis is a powerful and statistically robust tool for identifying high prevalence areas in a heterogeneous and imperfectly known environment. [ABSTRACT FROM AUTHOR]

Background: Schistosomiasis is a parasitic infection that continues to be a major public health problem in many developing countries being responsible for an estimated burden of at least 1.4 million disability-adjusted life years (DALYs) in Africa alone. Importantly, morbidity due to schistosomiasis has been greatly reduced in some parts of the world, including Zanzibar. The Zanzibar government is now committed to eliminate urogenital schistosomiasis. Over the next 3-5 years, the whole at-risk population will be administered praziquantel (40 mg/kg) biannually. Additionally, snail control and behaviour change interventions will be implemented in selected communities and the outcomes and impact measured in a randomized intervention trial., Methods/design: In this 5-year research study, on both Unguja and Pemba islands, urogenital schistosomiasis will be assessed in 45 communities with urine filtration and reagent strips in 4,500 schoolchildren aged 9-12 years annually, and in 4,500 first-year schoolchildren and 2,250 adults in years 1 and 5. Additionally, from first-year schoolchildren, a finger-prick blood sample will be collected and examined for Schistosoma haematobium infection biomarkers. Changes in prevalence and infection intensity will be assessed annually. Among the 45 communities, 15 were randomized for biannual snail control with niclosamide, in concordance with preventive chemotherapy campaigns. The reduction of Bulinus globosus snail populations and S. haematobium-infected snails will be investigated. In 15 other communities, interventions triggering behaviour change have been designed and will be implemented in collaboration with the community. A change in knowledge, attitudes and practices will be assessed annually through focus group discussions and in-depth interviews with schoolchildren, teachers, parents and community leaders. In all 45 communities, changes in the health system, water and sanitation infrastructure will be annually tracked by standardized questionnaire-interviews with community leaders. Additional issues potentially impacting on study outcomes and all incurring costs will be recordedand monitored longitudinally., Discussion: Elimination of schistosomiasis has become a priority on the agenda of the Zanzibar government and the international community. Our study will contribute to identifying what, in addition to preventive chemotherapy, needs to be done to prevent, control, and ultimately eliminate schistosomiasis, and to draw lessons for current and future schistosomiasis elimination programmes in Africa and elsewhere., Trial Registration: ISRCTN48837681.

Recent shifts in global health policy have led to the implementation of mass drug administration (MDA) for neglected tropical diseases. Here we show how population genetic analyses can provide vital insights into the impact of such MDA on endemic parasite populations. We show that even a single round of MDA produced a genetic bottleneck with reductions in a range of measures of genetic diversity of Schistosoma mansoni. Phylogenetic analyses and indices of population differentiation indicated that schistosomes collected in the same schools in different years were more dissimilar than those from different schools collected within either of the study's 2 years, in addition to distinguishing re-infection from non-clearance (that might indicate putatively resistant parasites) from within those children infected at both baseline and follow-up. Such unique results illustrate the importance of genetic monitoring and examination of long lived multi-cellular parasites such as these under novel or increased chemotherapeutic selective pressures.

Spatial modelling was applied to self-reported schistosomiasis data from over 2.5 million school students from 12,399 schools in all regions of mainland Tanzania. The aims were to derive statistically robust prevalence estimates in small geographical units (wards), to identify spatial clusters of high and low prevalence and to quantify uncertainty surrounding prevalence estimates. The objective was to permit informed decision-making for targeting of resources by the Tanzanian national schistosomiasis control programme. Bayesian logistic regression models were constructed to investigate the risk of schistosomiasis in each ward, based on the prevalence of self-reported schistosomiasis and blood in urine. Models contained covariates representing climatic and demographic effects and random effects for spatial clustering. Degree of urbanisation, median elevation of the ward and median normalised difference vegetation index (NDVI) were significantly and negatively associated with schistosomiasis prevalence. Most regions contained wards that had >95% certainty of schistosomiasis prevalence being >10%, the selected threshold for bi-annual mass chemotherapy of school-age children. Wards with >95% certainty of schistosomiasis prevalence being >30%, the selected threshold for annual mass chemotherapy of school-age children, were clustered in north-western, south-western and south-eastern regions. Large sample sizes in most wards meant raw prevalence estimates were robust. However, when uncertainties were investigated, intervention status was equivocal in 6.7-13.0% of wards depending on the criterion used. The resulting maps are being used to plan the distribution of praziquantel to participating districts; they will be applied to prioritising control in those wards where prevalence was unequivocally above thresholds for intervention and might direct decision-makers to obtain more information in wards where intervention status was uncertain.

An evaluation of a commercially available antigen capture dipstick that detects schistosome circulating cathodic antigen (CCA) in urine was conducted in representative endemic areas for intestinal and urinary schistosomiasis in Uganda and Zanzibar, respectively. Under field-based conditions, the sensitivity (SS) and specificity (SP) of the dipstick was 83 and 81% for detection of Schistosoma mansoni infections while positive predictive (PPV) and negative predictive values (NPV) were 84%. Light egg-positive infections were sometimes CCA-negative while CCA-positives included egg-negative children. A positive association between faecal egg output and intensity of CCA test band was observed. Estimating prevalence of intestinal schistosomiasis by school with dipsticks was highly correlated (r=0.95) with Kato-Katz stool examinations, typically within +/-8.5%. In Zanzibar, however, dipsticks totally failed to detect S. haematobium despite examining children with egg-patent schistosomiasis. This was also later corroborated by further surveys in Niger and Burkina Faso. Laboratory testing of dipsticks with aqueous adult worm lysates from several reference species showed correct functioning, however, dipsticks failed to detect CCA in urine from S. haematobium-infected hamsters. While CCA dipsticks are a good alternative, or complement, to stool microscopy for field diagnosis of intestinal schistosomiasis, they have no proven value for field diagnosis of urinary schistosomiasis. At approximately 2.6 US dollars per dipstick, they are presently too expensive to be cost-effective for wide scale use in disease mapping surveys unless Lot Quality Assurance Sampling (LQAS) strategies are developed.

Schistosomiasis among pregnant women has been inadequately investigated. In order to determine the importance of Schistosoma mansoni in this subgroup, we conducted a cross-sectional survey of 972 women in Tanzania and investigated the prevalence of Schistosoma mansoni, hookworm and malaria and their associations with anaemia. Overall, 63.5% of women were infected with S. mansoni, with prevalence highest among younger women and decreasing with increasing age. The prevalence of hookworm was 56.3%, and 16.4% of women had malaria parasitaemia. Overall, 66.4% of women were anaemic. Increased risk of anaemia was associated with heavy infection with S. mansoni but not hookworm or Plasmodium falciparum parasitaemia.

This paper records attempts to overcome the problems of using a powerful but non-ovicidal molluscicide (N-tritylmorpholine) in eradicating snails from a dam by treating the water twice in 14 days. The first treatment was aimed at the existing snail population and the second at snails hatched from eggs that survived the first application. At each treatment an over-all concentration of 0.25 ppm was applied by spraying a 16% emulsifiable concentrate of N-tritylmorpholine from shore and boat to the water surface. The snails, Biomphalaria pfeifferi and Lymnaea natalensis, were first seen again 8 weeks from the start of the application in the region of 2 inlet furrows. When pretreatment levels of snails were again reached, a second double treatment was applied, again at an over-all concentration of 0.25 ppm but using a 50% paste formulation applied over 3 days for 3 hours per day to the inlet furrows. The snail kill was again 100% as measured by the sampling technique used but again young snails appeared 9 weeks later. The author concludes that single treatments at 5-week intervals probably represent the best means of control with N-tritylmorpholine.

In an attempt to justify future snail control on an irrigated sugar estate in Tanzania, the effects of Schistosoma mansoni infection on the productivity of apparently healthy cane cutters were investigated. The bonus earnings of cane cutters who were found to be infected with S. mansoni were compared, retrospectively, with earnings of uninfected cane cutters during the years 1968-69. For one 6-month period a more detailed study was made to correlate bonus earnings with actual output in tons of cane cut. It was found that in the four 6-month periods the mean bonus earnings of the uninfected cane cutters exceeded the mean bonus earnings of the infected men by 11.0%, 11.4%, 6.0%, and 13.7%, respectively. In all except the third period these differences were statistically significant. After treatment for S. mansoni infection, the workers were able to improve their earnings relative to both infected and uninfected workers. In a more detailed study of some of the workers during the third 6-month period, it was discovered that a 4% difference in bonus earnings represented a 1% difference in output. Taking into account the variations of bonus earnings it was estimated that the overall difference in productivity between infected and uninfected workers was 3-5%.

On an irrigated sugar estate in northern Tanzania a control programme against Schistosoma mansoni was carried out during 1968-70. Through the routine use of molluscicides, the population of Biomphalaria pfeifferi snails was kept at a greatly reduced level. Concurrently a mass campaign was carried out to detect residents who were infected with S. mansoni so that they might be treated. The effect of these measures on the overall prevalence of the disease was measured by random studies before and after the mass diagnosis and treatment. The techniques used for mass diagnosis, for treatment, and for the prevalence studies are described, and the results of the control programme are presented and discussed. In the mass diagnosis campaign over 90% of the population were examined and 2 286 courses of treatment were administered to 1 922 persons. The combination of chemotherapy and snail control led to a significant reduction in the number of S. mansoni. infections. In field workers the prevalence was reduced from 59% in early 1969 to 31% in late 1970. In nonfield workers the reduction was from 36% to 15% and in the wives of employees from 28% to 14%. The main reasons why the prevalence was not reduced further were considered to be the failure of the drugs used to effect a complete parasitological cure and the inability of the mass diagnosis campaign to detect light infections. It was estimated that the overall reduction in the number of eggs released into the community as a result of the control programme was about 85%.

On a sugar estate in northern Tanzania, an integrated control programme against Schistosoma mansoni was carried out during the three years 1968-70 inclusive. The costs of that programme are defined, the costs of future snail control in the same area are estimated, and an attempt is made to evaluate the cost-benefit ratio of schistosomiasis control in the estate. The total expenditure on snail control was US $23 538, of which US $17 371 was spent on molluscicides and US $5 135 on labour. This represents an annual expenditure of approximately US $1.31 per estate resident. In the mass diagnosis and treatment campaign the main items in the total expenditure of US $37 043 were labour (US $13 724), drugs (US $4 218), hospital charges (US $8 262), and lost working days (US $8 760). It is estimated that the recurrent annual expenditure necessary to keep S. mansoni at a low level in the future would be US $7 714 on snail control and US $1 832 on detecting and treating new cases; however, the institution of a snail control programme would reduce the need for chemotherapy and would result in recurrent annual savings of US $7 448. In addition, it was estimated from a productivity study that savings of about US $14 000 per year could result if treatment of infected workers raised productivity by 5%. The goodwill that resulted from the protection of wives and children against schistosomiasis would be a further benefit. When all factors are taken into account, snail control appears to be a feasible economic proposition.

In an attempt to prevent the transmission of Schistosoma mansoni on an irrigated sugar-cane estate, molluscicide experiments were carried out to find the optimum methods for controlling the intermediate-host snails, Biomphalaria pfeifferi. The ease of application of N-tritylmorpholine led to its adoption as the molluscicide of choice for the two separate irrigation systems on the estate. Experiments on the frequency and duration of molluscicide treatments were carried out, and from these it was concluded that 5-day applications of N-tritylmorpholine at 0.025 ppm every 7 weeks might lead to a break in transmission by control of the snails.In another set of trials, drainage ditches were treated alternately with N-tritylmorpholine and niclosamide ethanolamine salt, and although the chemicals differed only slightly in their effect, the latter-being ovicidal-was chosen to be applied at approximately 4 ppm by knapsack sprayer every 8 weeks. Extra treatment of small pools with the same compound was carried out during the long rains when irrigation was unnecessary and most of the canals were dry.It is pointed out that the effect of the control methods on S. mansoni transmission will need to be evaluated by studying the incidence of the disease in the population.

Three methods were used to measure the level of transmission of infections of Schistosoma mansoni on an irrigated sugar estate in northern Tanzania. The studies were carried out over a period of 3 years, during a programme for the control of the host snail Biomphalaria pfeifferi. During the second and third years a mass diagnosis and treatment campaign against the infection was also carried out. Examinations for infection were made in newly employed subjects on arrival and after 6 and 12 months. Two studies were made in young children at an interval of 18 months, to determine age prevalence curves. In the third method, subjects were examined for infection 18 months after being found free from infection in a previous survey. Results are compared with data recorded in a previous study, made before snail control was commenced. The results suggest that the control programme has led to a great reduction in the incidence of S. mansoni on the estate.