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The aim of this review was to rapidly synthesize the available evidence regarding the expected impacts of piped water chlorination, drainage, and sewerage on individuals living in low- and middle-income urban settings. A systematic search was conducted in bibliographic databases and library catalogs. Impact evaluations that included a comparator and one of the three interventions of interest, attempted to control for confounding and selection bias, and took place in urban settings in a low- or middle-income country were considered. Outcomes related to health, well-being, economic growth, and the bacterial content of water were considered. A total of 1,483 articles were identified, with 18 included after final screening. Most studies were case-control and took place in Brazil, the Pacific Islands, or south-western Asia. Fifteen studies considered sewerage, five considered chlorination, and two studies considered drainage with some studies considering multiple interventions. All primary outcomes were related to health. When implemented alone, the sewerage and chlorination interventions were largely successful. The evidence regarding the effects of chlorination, drainage, and sewerage interventions is limited and generally has a high risk of bias. When properly implemented, sewerage and chlorination are likely to have positive health impacts. However, when implemented poorly, all three interventions can have negative health impacts. HIGHLIGHTS Most studies focused on sewerage interventions.; Chlorination and sewerage interventions were successful in reducing disease burden.; Contamination sources included lack of improved WaSH, sources in the nearby environment, and household hygiene practices.; Infrastructure maintenance issues affected the interventions’ impacts.; Proper household hygiene practices should be included for effective interventions.

BackgroundHypertension is a major contributor to global morbidity and mortality. In South Africa, the government has employed a whole systems approach to address the growing burden of non-communicable diseases. We used a novel incident care cascade approach to measure changes in the South African health system’s ability to manage hypertension between 2008 and 2017.MethodsWe used data from Waves 1-5 of the National Income Dynamics Study (NIDS) to estimate trends in the hypertension care cascade and unmet treatment need across four successive cohorts with incident hypertension. We used a negative binomial regression to identify factors that may predict higher rates of hypertension control, controlling for socio-demographic and healthcare factors. The largest cascade attrition occurred prior to diagnosis.ResultsIn 2011, 19·6% (95%CI 14·2, 26·2) of individuals with incident hypertension were diagnosed, 15·4% (95%CI 10·8, 21·4) were on treatment and 7.1% had controlled blood pressure. By 2017, the proportion of individuals with diagnosed incident hypertension had increased to 24·4% (95%CI 15·9, 35·4) with increases in treatment (23·3%, 95%CI 15·0, 34·3) and control (22·1%, 95%CI 14·1, 33·.0) were also observed, translating to a decrease in unmet need from 92·9% in 2011 to 77·9% in 2017. Multivariable regression showed that participants with incident hypertension in 2017 were 3·01 (95%CI 1·77, 5·13) times more likely to have a controlled blood pressure compared to those in 2011.ConclusionsThe proportion of people with incident hypertension who successfully progressed to controlled blood pressure tripled between 2011 and 2017 in South Africa. Despite these improvements, a low absolute proportion of the population were able to control their blood pressure and a high burden of unmet need remains.Summary BoxWhat is already knownPrevalent cascades provide insight to where losses in care cascades occur.While mostly used in the management of HIV, recently they have also been adopted in studying the management of non-communicable diseases on a population level.Prevalent hypertension cascades in South Africa showed a high burden of unmet need, with the biggest losses where lost between disease development and diagnosis.What are the new findingsIncident hypertension cascades improved from 2008 to 2017 in South Africa.What do the new findings implyIncident cascades provide an improved means to measure changes in management cascades as this allows us to distinguish between historical and current health system performance.Our data show that while substantial improvements in the care cascade occurred between 2008 and 2017, a large burden of unmet need remains.

Background: Exposure to toxic metals (TMs) such as lead can cause lifelong neurodevelopmental impairment and other adverse outcomes. TMs enter drinking water from human activity, geogenic contamination, and corrosion of water system components. Several studies report TM contamination in piped systems and private wells in high-income countries (HICs). However, few robust studies report on TM contamination in low- and middle-income countries (LMICs). Objectives: We characterized the occurrence and investigated sources of TM contamination in 261 rural water systems in three West African LMICs to inform prevention and management. Methods: Water samples were collected from 261 community water systems (handpumps and public taps) across rural Ghana, Mali, and Niger. Scrapings were collected from accessible components of a subset of these systems using a drill with acid-washed diamond-tipped bits. Samples were analyzed by inductively coupled plasma (ICP) mass spectrometry or ICP optical emission spectroscopy. Results: Of the TMs studied, lead most frequently occurred at levels of concern in sampled water system components and water samples. Lead mass fractions exceeded International Plumbing Code (IPC) recommended limits (0.25% wt/wt) for components in 82% (107/130) of systems tested; brass components proved most problematic, with 72% (26/36) exceeding IPC limits. Presence of a brass component in a water system increased expected lead concentrations in drinking-water samples by 3.8 times. Overall, lead exceeded World Health Organization (WHO) guideline values in 9% (24/261) of drinking-water samples across countries; these results are broadly comparable to results observed in many HICs. Results did not vary significantly by geography or system type. Discussion: Ensuring use of lead-free (