We conducted a controlled before-and-after trial to evaluate the impact of an onsite urban sanitation intervention on the prevalence of enteric infection, soil transmitted helminth re-infection, and diarrhea among children in Maputo, Mozambique. A non-governmental organization replaced existing poor-quality latrines with pour-flush toilets with septic tanks serving household clusters. We enrolled children aged 1-48 months at baseline and measured outcomes before and 12 and 24 months after the intervention, with concurrent measurement among children in a comparable control arm. Despite nearly exclusive use, we found no evidence that intervention affected the prevalence of any measured outcome after 12 or 24 months of exposure. Among children born into study sites after intervention, we observed a reduced prevalence of Trichuris and Shigella infection relative to the same age group at baseline (<2 years old). Protection from birth may be important to reduce exposure to and infection with enteric pathogens in this setting.

IntroductionAccess to safe sanitation in low-income, informal settlements of Sub-Saharan Africa has not significantly improved since 1990. The combination of a high faecal-related disease burden and inadequate infrastructure suggests that investment in expanding sanitation access in densely populated urban slums can yield important public health gains. No rigorous, controlled intervention studies have evaluated the health effects of decentralised (non-sewerage) sanitation in an informal urban setting, despite the role that such technologies will likely play in scaling up access.Methods and analysisWe have designed a controlled, before-and-after (CBA) trial to estimate the health impacts of an urban sanitation intervention in informal neighbourhoods of Maputo, Mozambique, including an assessment of whether exposures and health outcomes vary by localised population density. The intervention consists of private pour-flush latrines (to septic tank) shared by multiple households in compounds or household clusters. We will measure objective health outcomes in approximately 760 children (380 children with household access to interventions, 380 matched controls using existing shared private latrines in poor sanitary conditions), at 2 time points: immediately before the intervention and at follow-up after 12 months. The primary outcome is combined prevalence of selected enteric infections among children under 5 years of age. Secondary outcome measures include soil-transmitted helminth (STH) reinfection in children following baseline deworming and prevalence of reported diarrhoeal disease. We will use exposure assessment, faecal source tracking, and microbial transmission modelling to examine whether and how routes of exposure for diarrhoeagenic pathogens and STHs change following introduction of effective sanitation.EthicsStudy protocols have been reviewed and approved by human subjects review boards at the London School of Hygiene and Tropical Medicine, the Georgia Institute of Technology, the University of North Carolina at Chapel Hill, and the Ministry of Health, Republic of Mozambique.Trial registration numberNCT02362932.

Background. Onsite sanitation serves more than 740 million people in urban areas, primarily in low-income countries. Although this critical infrastructure may play an important role in controlling enteric infections in high-burden settings, its health impacts have never been evaluated in a controlled trial. Methods. We conducted a controlled before and after trial to evaluate the impact an onsite urban sanitation intervention on the prevalence of bacterial and protozoan infection (primary outcome), soil transmitted helminth (STH) re-infection, and seven-day period prevalence of diarrhoea among children living in informal neighborhoods of Maputo, Mozambique. A non-governmental organization replaced existing shared latrines in poor condition with engineered pour-flush toilets with septic tanks serving household clusters. We enrolled children aged 1-48 months at baseline and measured outcomes before the intervention and at 12 and 24 months following intervention. We measured outcomes concurrently among children served by the sanitation improvements and those in a comparable control arm served by existing poor sanitation. The trial was registered at ClinicalTrials.gov, number NCT02362932. Findings. At baseline, we enrolled 454 children from 208 intervention clusters and 533 children from 287 control clusters. We enrolled or re-visited 462 intervention and 477 control children 12 months 60 after intervention and 502 intervention and 499 control children 24 months after intervention. Despite nearly exclusive use of the intervention, we found no evidence that engineered onsite sanitation affected the overall prevalence of any measured bacterial or protozoan infection (12-month adjusted prevalence ratio 1.05, 95% CI [0.95-1.16]; 24-month adjusted prevalence ratio 0.99, 95% CI [0.91-1.09]), any STH re-infection (1.11 [0.89-1.38]; 0.95 [0.77-1.17]), or diarrhoea (1.69 [0.89-3.21]; 0.84 [0.47-1.51]) after 12 or 24 months of exposure. Among children born into study sites after the intervention and measured at the 24-month visit, we observed a reduced prevalence of any STH re-infection of 49% (adjusted prevalence ratio 0.51 [95% confidence interval 0.27 - 0.95]), Trichuris of 76% (0.24 [0.10 - 0.60]), and Shigella infection by 51% (0.49 [0.28-0.85]) relative to the same age group at baseline. Interpretation. The intervention did not reduce the overall prevalence of enteric infection and diarrhoea among all enrolled children but may have substantially reduced the prevalence of STHs and Shigella among children born into clusters with sanitary improvements.

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About 20% of the urban population in sub-Saharan Africa relies on resellers of utility water for their water supply, yet the practice has received little attention either in the academic literature or in sector policy. This study uses primary data collected from more than 200 resellers in Maputo, Mozambique, through in-person surveys, participant observation and focus group discussions. Despite the widely held assumption that all small-scale water providers are profit-maximizing entrepreneurs, this study suggests that this model does not characterize resale behavior in Maputo. Instead, three non-mutually exclusive motivations provide more persuasive explanations for why households resell utility water: (1) earning cash to meet daily subsistence needs; (2) obtaining a form of informal social insurance to deal with future needs; and (3) solidifying embeddedness in social relationships by satisfying the social norms of their communities. These findings suggest that programs and policies typically designed for small-scale providers may be inappropriate for water resellers.