Interventions to improve water quality for preventing diarrhoea

Seasonal Variability Influence on the Prevalence of Diarrhoea among Under-Five-Year-old Children in Kersa District, Eastern Ethiopia: A Community-Based Longitudinal Study

BACKGROUND

The health effects of climate change have been found to be a global concern for the last 2 centuries. However, the effect of climate variability on diarrhoea among under-five-year-old children is perhaps undocumented or otherwise unknown. The aim of the present study was to determine the effect of climate variability on diarrhoea among children under 5 years of age.

METHODS

A community-based longitudinal study was conducted over 8 repeated visits from June 2016 to May 2018 at the Kersa Demographic Surveillance and Health Research Center. A total of 500 randomly selected households and their 48 improved water sources were included in the survey from 3 agro-ecological zones, the rural and urban areas of the study area. Data was collected on household characteristics, diarrhoea, WASH practices, water quality and quantity in households, and improved water sources. A structured pre-tested questionnaire, an observational check list and laboratory tests were used for data collection. The data was entered into Epi Data Version 3.01 and transferred to Stata Version 12 for analysis. Multilevel mixed-effect Poisson regression was used to determine the relationship between predictors and outcome variables. A P-value of less than .05 was the cut-off point for statistically significant.

RESULTS

The prevalence of diarrhoea in 2 weeks among children under 5 years of age was 17.2% (95% CI: 15.8-19.71). Rainfall, E. coli contamination of drinking water at the source and in the home, 20 L of water consumption per capita per day, sharing water sources with animals and home water treatment by residents of the mid- and lowlands were all predictors of diarrhoea. The space-time scan statistic confirmed that child diarrhoea had random variation in both space and time.

CONCLUSION

Climate variability has influenced the prevalence of diarrhoea among under-five-year-old children. Climate-resilient measures should be taken to reduce the burden of diarrhoea in the community.

Sustainable nano-sodium silicate and silver nitrate impregnated locally made ceramic filters for point-of-use water treatments in sub-Sahara African households

The poor access to water quality for Nigerians has pushed for the designing of new trend silver nitrate impregnated locally made Point-Of-Use (POU) ceramic filters to enhance water purification efficiency for household use. This study utilized silver nitrate-molded ceramic filters prepared with Kaolin from Owode, silt soil, sodium silicate, sawdust, and distilled water in three varying proportions to ascertain pollution removal efficiencies. Heating was carried out by firing the filters at 900 °C and further preheating at 400 °C after dipping in silver nitrate solution. Silver nanoparticle and dissociated particle discharge from filter pot painted with 0.03 mg/g casein-covered nAg or AgNO₃ were estimated as an element of pH (5–9), ionic strength (1–50mM), and cation species (Na+, Ca2+, Mg2+). Silver delivery was constrained by disintegration as Ag+ and resulting cation exchange measures, paying little heed to silver structure applied. Water analysis for both heavy metals (Pb and Cd) and microbial load (E. coli) evaluated, corroborate the maximum removal efficiency. It was observed that kaolin-sawdust with the Silver nitrate filters showed a constant and effective removal of both heavy metals and disinfection of microbial loads. The minimum flow rates observed were 4.97 mL/min for batch filter used for Iju River water sample one (AF1) and 4.98 mL/min for batch filter used for Iju River water sample two (AF2) having porosity 49.05% and 50.00%, whereas the 5 mL/min higher flow rate was used for batch filter from borehole water sample one (BF1) and batch filter used for well water sample two (CF2) with porosity of 50.00%. Significantly, the results obtained show that the filters are suitable for point-of-use application in both the urban and rural areas of developing countries such as Nigeria

Determinants of Childhood Diarrhea in Households with Improved Water, Sanitation, and Hygiene (WASH) in Ethiopia: Evidence from a Repeated Cross-Sectional Study

BACKGROUND

Determinants of childhood diarrhea in households with improved WASH (ie, households with improved drinking water sources, improved sanitation facilities, and those who practiced safe child stool disposal) are limited. This study aimed to identify the determinants of diarrhea among under-five children exclusively in households with improved Water, Sanitation, and Hygiene (WASH).

METHODS

A repeated cross-sectional study design was followed, and data from the Demographic and Health Survey (DHS) conducted between 2005 and 2016 in Ethiopia was used. A total of 1,975 child-mother pairs (257 children with diarrhea and 1718 children without diarrhea) in households with improved WASH were included in this study. Hierarchical conditional logistic regression models were used. Adjusted odds ratios (AOR) with corresponding 95% confidence intervals (CI) were estimated to determine the strength of association.

RESULTS

Children aged 13 to 24 months (Adjusted Odds Ratio [AOR] = 2.70, 95%CI: 1.69-4.32), children who did not receive the measles vaccine (AOR = 2.33, 95%CI: 1.60-3.39), and those residing in the agrarian region (AOR = 1.66, 95%CI: 1.10-2.49) were significantly more likely to develop diarrheal morbidity. The size of the child at birth was also found to be significantly associated with diarrheal morbidity.

CONCLUSION

In this study, child factors (age of the child, vaccinated for measles, and the size of a child at birth), and household-related factors (contextual region) had a significant effect on the risk of childhood diarrheal morbidity in households with improved WASH in Ethiopia.

PROTOCOL: Water, sanitation and hygiene for reducing childhood mortality in low- and middle-income countries

Respiratory tract infections and diarrhoea are the two biggest killers of children in low income contexts. They are closely related to access to, and use of improved water, sanitation and hygiene (WASH). However, there is no high quality systematic review that quantifies the effect of WASH improvements on childhood mortality. Existing systematic reviews of WASH improvements measure effects on morbidity, under the (often implicit) assumption that morbidity is closely correlated with mortality. This is at least partly because the impact evaluations on which they are based are only designed to detect changes in morbidity with statistical precision, whereas mortality is a relatively rare outcome. The proposed review will address this evidence synthesis gap, using the greater statistical power of meta-analysis to pool findings across studies.

Ruminant Fecal Contamination of Drinking Water Introduced Post-Collection in Rural Kenyan Households

In sub-Saharan Africa, many families travel to collect water and store it in their homes for daily use, presenting an opportunity for the introduction of fecal contamination. One stored and one source water sample were each collected from 45 households in rural Kenya. All 90 samples were analyzed for fecal indicator bacteria (E. coli and enterococci) and species-specific contamination using molecular microbial source tracking assays. Human (HF183), avian (GFD), and ruminant (BacR) contamination were detected in 52, two, and four samples, respectively. Stored water samples had elevated enterococci concentrations (p < 0.01, Wilcoxon matched pairs test) and more frequent BacR detection (89% versus 27%, p < 0.01, McNemar's exact test) relative to source water samples. fsQCA (fuzzy set qualitative comparative analysis) was conducted on the subset of households with no source water BacR contamination to highlight combinations of factors associated with the introduction of BacR contamination to stored water supplies. Three combinations were identified: (i) ruminants in the compound, safe water extraction methods, and long storage time, (ii) ruminants, unsafe water extraction methods, and no soap at the household handwashing station, and (iii) long storage time and no soap. This suggests that multiple pathways contribute to the transmission of ruminant fecal contamination in this context, which would have been missed if data were analyzed using standard regression techniques.

Drinking Water Safety: Role of Hand Hygiene, Sanitation Facility, and Water System in Semi-Urban Areas of India

Poor drinking water quality is one of the main causes of acute diarrheal disease in developing countries. The study investigated the relationship between fecal contamination of hands, stored drinking water, and source waters in India. We further evaluated the environmental and behavioral factors associated with recontamination of water between collection and consumption. The bacterial contamination, that is, Escherichia coli (log₁₀ most probable number per two hands), found on mothers' hands (mean = 1.11, standard deviation [SD] = 1.2, N = 152) was substantially higher than that on their children younger than 5 years (mean = 0.64, SD = 1.0, and N = 152). We found a low level of E. coli (< 1 per 100 mL) in the source water samples; however, E. coli contamination in stored drinking water was above the recommended guidelines of the World Health Organization. The study also found that E. coli on hands was significantly associated with E. coli in the stored drinking water (P < 0.001). Moreover, E. coli was positively associated with gastrointestinal symptoms (odds ratio 1.42, P < 0.05). In the households with elevated levels (> 100 E. coli/100 mL) of fecal contamination, we found that 43.5% had unimproved sanitation facilities, poor water handling practices, and higher diarrheal incidences. The water quality deterioration from the source to the point of consumption is significant. This necessitates effective interventions in collection, transport, storage, and extraction practices when hand-water contact is likely to occur. These findings support the role of hands in the contamination of stored drinking water and suggest that clean source water does not guarantee safe water at the point of consumption.

The Impact of Social Disparities on Microbiological Quality of Drinking Water Supply in Ugu District Municipality of Kwazulu-Natal Province, South Africa

This study was undertaken to highlight the social disparity between rural and urban areas in terms of housing patterns, provision of safe drinking water, access to sanitation facilities, education, employment rate and health-related to diarrhoeal episodes in Ugu District Municipality of KwaZulu-Natal Province of South Africa. To achieve this aim, a survey was conducted using a structured questionnaire. Drinking water samples were collected from the point of supply and the storage containers to assess the microbiological quality of drinking water in both rural and urban areas. Results of this study revealed prominent residential segregation between rural and urban communities, whereby the houses in the rural areas were generally constructed with corrugated iron sheets, or mud brick and mortar whereas conventional brick-and-mortar construction was used to build those in the urban areas. All of the urban households had flush toilets in their houses (100%), while 98.2% of the rural households were relying on pit latrines and 1.8% were reported to defecate in an open field. The District unemployment rate was at 58.1% in rural areas and none among the urban community. Results also showed that only 13.6% of the rural dwellers completed their secondary education compared to 70.4% of the urban areas. The diarrhoeal episodes were high in rural areas (34.1%) while none of these episodes was reported in urban areas. Great disparity in the water supply persists between rural and urban communities. For the former, the standpipes located outside their homes (90.9%) remain the sole mode of access to drinking water, while in the urban area, all households had pipes/taps inside their houses. Assessment of the drinking water quality revealed only the stored drinking water used by the rural community of Ugu District was contaminated. High prevalence of E. coli ranging from 63.3 % to 66.7% was recorded only in stored water after the sequencing of 16S rRNA genes. Species-specific PCR primers exposed the presence of enteropathogenic Escherichia coli at a rate ranging between 1.4% and 3.7% in this water Overall, this study has been able to highlight the disparity left by the legacy of racial segregation in the Ugu Municipality District. Therefore, the local government must intervene in educating homeowners on safe water storage practices.

The seasonality of diarrheal pathogens: A retrospective study of seven sites over three years

BACKGROUND

Pediatric diarrhea can be caused by a wide variety of pathogens, from bacteria to viruses to protozoa. Pathogen prevalence is often described as seasonal, peaking annually and associated with specific weather conditions. Although many studies have described the seasonality of diarrheal disease, these studies have occurred predominantly in temperate regions. In tropical and resource-constrained settings, where nearly all diarrhea-associated mortality occurs, the seasonality of many diarrheal pathogens has not been well characterized. As a retrospective study, we analyze the seasonal prevalence of diarrheal pathogens among children with moderate-to-severe diarrhea (MSD) over three years from the seven sites of the Global Enteric Multicenter Study (GEMS), a case-control study. Using data from this expansive study on diarrheal disease, we characterize the seasonality of different pathogens, their association with site-specific weather patterns, and consistency across study sites.

METHODOLOGY/PRINCIPAL FINDINGS

Using traditional methodologies from signal processing, we found that certain pathogens peaked at the same time every year, but not at all sites. We also found associations between pathogen prevalence and weather or "seasons," which are defined by applying modern machine-learning methodologies to site-specific weather data. In general, rotavirus was most prevalent during the drier "winter" months and out of phase with bacterial pathogens, which peaked during hotter and rainier times of year corresponding to "monsoon," "rainy," or "summer" seasons.

CONCLUSIONS/SIGNIFICANCE

Identifying the seasonally-dependent prevalence for diarrheal pathogens helps characterize the local epidemiology and inform the clinical diagnosis of symptomatic children. Our multi-site, multi-continent study indicates a complex epidemiology of pathogens that does not reveal an easy generalization that is consistent across all sites. Instead, our study indicates the necessity of local data to characterizing the epidemiology of diarrheal disease. Recognition of the local associations between weather conditions and pathogen prevalence suggests transmission pathways and could inform control strategies in these settings.

Multiplex PCR assay for simultaneous detection and differentiation of Entamoeba histolytica, Giardia lamblia, and Salmonella spp. in the municipality-supplied drinking water

BACKGROUND

The contamination with Entamoeba histolytica, Giardia lamblia, and Salmonella spp. in drinking water is the most prevalent in Indian subcontinent, but often difficult to detect all these pathogens from the drinking water.

MATERIALS AND METHODS

A multiplex polymerase chain reaction (mPCR) method was developed to detect contamination of municipality-supplied drinking water with E. histolytica, G. lamblia, and Salmonella spp. The primers were designed to target small subunit of 16S rRNA type gene of E. histolytica and G. lamblia, and invasive A gene of Salmonella typhimurium. The optimized mPCR assay was applied on 158 municipality-supplied drinking water samples collected from Delhi.

RESULTS

Out of total 158 water samples, 89 (56.32%) were found positive for the targeted pathogens by mPCR while conventional methods could be detected only in 11 (6.96%) samples. The mPCR assay showed 100% sensitivity and specificity for these pathogens in comparison with culture and microscopic detection. Of the 89 mPCR-positive samples, G. lamblia, E. histolytica, and Salmonella spp. were present in 35 (22.15%), 26 (16.45%), and 28 (17.72%), respectively. Nine (5.69%) samples were positive for both E. histolytica and G. lamblia, 10 (6.32%) were positive for G. lamblia and Salmonella spp., and 8 (5.06%) had Salmonella spp. and E. histolytica. Nonetheless, 3 (1.89%) samples were positive for all three pathogens.

CONCLUSIONS

The present assay is an alternative to conventional methods to serve as highly sensitive, specific, and economical means for water quality surveillance to detect the outbreak caused by E. histolytica, G. lamblia, and Salmonella spp. pathogens.

Silver nanoparticles as an effective disinfectant: A review

The paradigm modifications in the metallic crystals from bulky to micro-size to nano-scale have resulted in excellent and amazing properties; which have been the remarkable interests in a wider range of applications. Particularly, Ag NPs have much attention owing to their distinctive optical, chemical, electrical and catalytic properties that can be tuned with surface nature, size, shapes, etc. and hence these crystals have been used in various fields such as catalysis, sensor, electronic components, antimicrobial agents in the health industry etc. Among them, Ag NPs based disinfectants have paid attention due to the practical applications in our daily life. Therefore the Ag NPs have been used in different sectors such as silver-based air/water filters, textile, animal husbandry, biomedical and food packaging etc. In this review, the Ag NPs as a disinfectant in different sectors have been included in detail.

Cost of Caregivers for Treating Hospitalized Diarrheal Patients in Bangladesh

INTRODUCTION

Diarrheal diseases are a global public health problem and one of the leading causes of mortality, morbidity and economic loss. The objective of the study is to estimate the economic cost of caregivers and cost distribution per diarrheal episodes in Bangladesh.

METHODS

This was a cross-sectional hospital-based study conducted in public hospitals in Bangladesh. A total of 801 diarrheal patients were randomly selected and interviewed during January to December 2015. Simple descriptive statistics including frequencies, percentage, mean with 95% CI and median are presented.

RESULTS

The overall average cost of caregivers was BDT 2243 (US$ 28.58) while only BDT 259 (US$ 3.29) was spent as out of pocket payments. Caregivers mostly spent money (US$ 1.63) for food, lodging, utility bills, and other lump sum costs followed by the transportation costs (US$ 1.57). The caregivers spent more (US$ 44.45) when they accompanied the patients who were admitted in inpatients care and almost 3.6 times higher than for out-patients care (US$ 12.42).

CONCLUSIONS

The study delivers an empirical evidence to the health-care programmers and policy makers about the economic cost of caregivers during diarrheal treatment care, which should be accounted for in designing future diarrheal prevention programme.

The association between domestic animal presence and ownership and household drinking water contamination among peri-urban communities of Kisumu, Kenya

INTRODUCTION

Household drinking water can be contaminated by diarrheagenic enteropathogens at numerous points between the source and actual consumption. Interventions to prevent this contamination have focused on preventing exposure to human waste through interventions to improve drinking water, sanitation and hygiene (WASH). In many cases though, the infectious agent may be of zoonotic rather than human origin suggesting that unsafely managed animal waste may contribute to the contamination of household drinking water and the associated diarrheal disease burden.

METHODS

A cross-sectional household survey of 800 households was conducted across three informal peri-urban neighborhoods of Kisumu, Kenya, collecting stored drinking water samples, administering a household survey including water, sanitation and hygiene infrastructure and behaviors, and recording domestic animal presence and ownership. We used multivariate logistic regression to assess the association of traditional WASH factors and domestic animal presence and ownership on microbial contamination of household drinking water.

RESULTS

The majority of households sampled had fecally contaminated drinking water (67%), defined by the presence of any colony forming units of the fecal indicator bacteria enterococci. After adjustment for potential confounders, including socio-economic status and water and sanitation access, both household animal ownership (aOR 1.31; CI 1.00-1.73, p = 0.05) and the presence of animal waste in the household compound (aOR 1.38; CI 1.01, 1.89, p = 0.04) were found to be significantly associated with household drinking water contamination. None of the conventional WASH variables were found to be significantly associated with household drinking water contamination in the study population.

CONCLUSIONS

Water, sanitation, and hygiene strategies to reduce diarrheal disease should consider the promotion of safe animal contact alongside more traditional interventions focusing on the management of human waste. Future research on fecal contamination of unsafe household drinking water should utilize host-specific markers to determine whether the source is human or animal to prepare targeted public health messages.

Effectiveness of a Household Water, Sanitation and Hygiene Package on an Outpatient Program for Severe Acute Malnutrition: A Pragmatic Cluster-Randomized Controlled Trial in Chad

Water, sanitation and hygiene (WASH) interventions have a small but measurable benefit on stunting, but not on wasting. Our objective was to assess the effectiveness of a household WASH package on the performance of an Outpatient Therapeutic feeding Program (OTP) for severe acute malnutrition (SAM). We conducted a cluster-randomized controlled trial embedded in a routine OTP. The study population included 20 health centers (clusters) from Mao and Mondo districts in Chad. Both arms received the OTP. The intervention arm received an additional household WASH package (chlorine, soap, water storage container, and promotion on its use). The primary objective measures were the relapse rates to SAM at 2 and 6 months post-recovery. The secondary objectives included the recovery rate from SAM, the time-to-recovery, the weight gain, and the diarrhea longitudinal prevalence in OTP. The study lasted from April 2015 to May 2016. Among the 1,603 recruited children, 845 were in the intervention arm and 758 in the control arm. No differences in the relapse rates were noticed at 2 (-0.4%; P = 0.911) and 6 (-1.0%; P = 0.532) months. The intervention decreased the time-to-recovery (-4.4 days; P = 0.038), improved the recovery rate (10.5%; P = 0.034), and the absolute weight gain (3.0 g/d; P = 0.014). No statistical differences were noticed for the diarrhea longitudinal prevalence (-1.7%; P = 0.223) and the weight gain velocity (0.4 g/kg/d; P = 0.086). Our results showed that adding a household WASH package did not decrease post-recovery relapse rates but increased the recovery rate among children admitted in OTP. We recommend further robust trials in other settings to confirm our results.

Investigating a community wide outbreak of hepatitis A in Kerala, India

Background:

There was an outbreak of acute hepatitis in Nellikuzhy panchayat of Kothamangalam taluk, Ernakulam district, Kerala, during November and early December 2016. Objective of this study is to describe the epidemiological features of the outbreak and to identify the probable source.

Materials and Methods:

The outbreak was defined in terms of time, place, and person. A hypothesis was generated and tested using a case–control study. Cases were selected by simple random sampling from the line list and controls were age-matched neighborhood individuals without any history of jaundice. Chi-square test, univariate analysis, and multi-variate logistic regression analyses were done to identify the probable risk factors.

Results:

Around 223 hepatitis A cases were identified. Attack rate was found to be highest among the age group of 16-30 years at 1.44% and was eight times higher among males. Epidemic curve suggested a point source outbreak possibly from exposure to food or water from a newly opened hotel in the area. The case–control study confirmed the hypothesis with a statistically significant association between cases and history of exposure to food from the hotel [OR 120; 95% CI 14.6–996.2; P value < 0.001].

Conclusion:

Observations and results of the case–control study revealed that the probable source of the Hepatitis A outbreak at Nellikuzhy panchayat was a hotel. The study findings also add evidences to the changing epidemiological pattern of hepatitis A in Kerala, and warrant the necessity to enforce food safety rules in the State.

A New Method for the Deposition of Metallic Silver on Porous Ceramic Water Filters

A new method of silver application to a porous ceramic water filter used for point-of-use water treatment is developed. We evaluated filter performance for filters manufactured by the conventional method of painting an aqueous suspension of silver nanoparticles onto the filter and filters manufactured with a new method that applies silver nitrate to the clay-water-sawdust mixture prior to pressing and firing the filter. Filters were evaluated using miscible displacement flow-through experiments with pulse and continuous-feed injections of E. coli. Flow characteristics were quantified by tracer experiments using [3H]H2O. Experiments using pulse injections of E. coli showed similar performance in breakthrough curves between the two application methods. Long-term challenge tests performed with a continuous feed of E. coli and growth medium resulted in similar log removal rates, but the removal rate by nanosilver filters decreased over time. Silver nitrate filters provided consistent removal with lower silver levels in the effluent and effective bacterial disinfection. Results from continued use with synthetic groundwater over 4 weeks, with a pulse injection of E. coli at 2 and 4 weeks, support similar conclusions—nanosilver filters perform better initially, but after 4 weeks of use, nanosilver filters suffer larger decreases in performance. Results show that including silver nitrate in the mixing step may effectively reduce costs, improve silver retention in the filter, increase effective lifespan, and maintain effective pathogen removal while also eliminating the risk of exposure to inhalation of silver nanoparticles by workers in developing-world filter production facilities.

Use of Serologic Responses against Enteropathogens to Assess the Impact of a Point-of-Use Water Filter: A Randomized Controlled Trial in Western Province, Rwanda

Diarrhea is a leading contributor to childhood morbidity and mortality in sub-Saharan Africa. Given the challenge of blinding most water, sanitation, and hygiene (WASH) interventions, diarrheal disease outcome measures in WASH intervention trials are subject to potential bias and misclassification. Using the platform of a cluster-randomized controlled trial of a household-based drinking water filter in western province, Rwanda, we assessed the impact of the drinking water filter on enteric seroconversion in young children as a health outcome and examined the association between serologic responses and caregiver-reported diarrhea. Among the 2,179 children enrolled in the trial, 189 children 6-12 months of age were enrolled in a nested serology study. These children had their blood drawn at baseline and 6-12 months after the intervention was distributed. Multiplex serologic assays for Giardia, Cryptosporidium, Entamoeba histolytica, norovirus, Campylobacter, enterotoxigenic Escherichia coli and Vibrio cholerae were performed. Despite imperfect uptake, receipt of the water filter was associated with a significant decrease in seroprevalence of IgG directed against Cryptosporidium parvum Cp17 and Cp23 (relative risk [RR]: 0.62, 95% confidence interval [CI]: 0.44-0.89). Serologic responses were positively associated with reported diarrhea in the previous 7 days for both Giardia intestinalis (RR: 1.94, 95% CI: 1.04-3.63) and C. parvum (RR: 2.21, 95% CI: 1.09-4.50). Serologic responses for all antigens generally increased in the follow-up round, rising sharply after 12 months of age. The water filter is associated with reduced serologic responses against C. parvum, a proxy for exposure and infection; therefore, serologic responses against protozoa may be a suitable health outcome measure for WASH trials among children with diarrhea.

Affordable house designs to improve health in rural Africa: a field study from northeastern Tanzania

BACKGROUND

The population of sub-Saharan Africa is currently estimated to be 1245 million and is expected to quadruple by the end of the century, necessitating the building of millions of homes. Malaria remains a substantial problem in this region and efforts to minimise transmission should be considered in future house planning. We studied how building elements, which have been successfully employed in southeast Asia to prevent mosquitos from entering and cooling the house, could be integrated in a more sustainable house design in rural northeastern Tanzania, Africa, to decrease mosquito density and regulate indoor climate.

METHODS

In this field study, six prototype houses of southeast Asian design were built in in the village of Magoda in Muheza District, Tanga Region, Tanzania, and compared with modified and unmodified, traditional, sub-Saharan African houses. Prototype houses were built with walls made of lightweight permeable materials (bamboo, shade net, or timber) with bedrooms elevated from the ground and with screened windows. Modified and unmodified traditional African houses, wattle-daub or mud-block constructions, built on the ground with poor ventilation served as controls. In the modified houses, major structural problems such as leaking roofs were repaired, windows screened, open eaves blocked with bricks and mortar, cement floors repaired or constructed, and rain gutters and a tank for water storage added. Prototype houses were randomly allocated to village households through a free, fair, and transparent lottery. The lottery tickets were deposited in a bucket made of transparent plastic. Each participant could draw one ticket. Hourly measurements of indoor temperature and humidity were recorded in all study houses with data loggers and mosquitoes were collected indoors and outdoors using Furvela tent traps and were identified with standard taxonomic keys. Mosquitoes of the Anopheles gambiae complex were identified to species using PCR. Attitudes towards the new house design were assessed 6-9 months after the residents moved into their new or modified homes through 15 in-depth interviews with household heads of the new houses and five focus group discussions including neighbours of each group of prototype housing.

FINDINGS

Between July, 2014, and July, 2015, six prototype houses were constructed; one single and one double storey building with each of the following claddings: bamboo, shade net, and timber. The overall reduction of all mosquitoes caught was highest in the double-storey buildings (96%; 95% CI 92-98) followed closely by the reduction found in single-storey buildings (77%; 72-82) and lowest in the modified reference houses (43%; 36-50) and unmodified reference houses (23%; 18-29). The indoor temperature in the new design houses was 2·3°C (95% CI 2·2-2·4) cooler than in the reference houses. While both single and two-storey buildings provided a cooler indoor climate than did traditional housing, two-story buildings provided the biggest reduction in mosquito densities (96%, 95% CI 89-100). Seven people who moved into the prototype houses and seven of their neighbours (three of whom had their houses modified) participated in in-depth interviews. After living in their new prototype houses for 6-9 months, residents expressed satisfaction with the new design, especially the second-storey sleeping area because of the privacy and security of upstairs bedrooms.

INTERPRETATION

The new design houses had fewer mosquitoes and were cooler than modified and unmodified traditional homes. New house designs are an underused intervention and hold promise to reduce malaria transmission in sub-Saharan Africa and keep areas malaria-free after elimination.

FUNDING

Ruth W Jensens Foundation, Copenhagen and Hanako Foundation, Singapore.

Optimizing Household Chlorination Marketing Strategies: A Randomized Controlled Trial on the Effect of Price and Promotion on Adoption in Haiti

Household water treatment can reduce diarrheal morbidity and mortality in developing countries, but adoption remains low and supply is often unreliable. To test effects of marketing strategies on consumers and suppliers, we randomized 1,798 households in rural Haiti and collected data on purchases of a household chlorination product for 4 months. Households received randomly selected prices ($0.11-$0.56 per chlorine bottle), and half received monthly visits from sales agents. Each $0.22 drop in price increased purchases by 0.10 bottles per household per month (P < 0.001). At the mean price, each 1% drop in price increased purchases by 0.45% (elasticity = 0.45). There is suggestive evidence that household visits by some sales agents increased purchases at mid-range prices; however, the additional revenue did not offset visit cost. Choosing the lowest price and conducting visits maximizes chlorine purchase, whereas slightly raising the retail price and not conducting visits maximizes cost recovery. For the equivalent cost, price discounts increase purchases 4.2 times as much as adding visits at the current retail price. In this context, price subsidies may be a more cost-effective use of resources than household visits, though all marketing strategies tested offer cost-effective ways to achieve incremental health impact. Decisions about pricing and promotion for health products in developing countries affect health impact, cost recovery, and cost-effectiveness, and tradeoffs between these goals should be made explicit in program design.

Assessing the environmental context of hand washing among school children in Limpopo, South Africa

Despite its simplicity and efficacy, the promotion of hand washing for disease prevention remains a challenge particularly in resource-limited settings. Here we report on a quasi-experimental school-based study that aimed to improve habitual hand washing. Significant increases in hand washing occurred following improvements in hygiene and sanitation facilities (School A: t=13.86, p=0.0052). Smaller increases in hand washing occurred following education (School A: t=2.63; p=0.012; School B, no infrastructure improvements: t=1.66, p=0.239). Health policy and programming need to pay greater attention to the interplay of the structural, social, and individual dimensions of unique contextual environments that influence habitual behaviours.

Study design of a cluster-randomized controlled trial to evaluate a large-scale distribution of cook stoves and water filters in Western Province, Rwanda

Background

In Rwanda, pneumonia and diarrhea are the first and second leading causes of death, respectively, among children under five. Household air pollution (HAP) resultant from cooking indoors with biomass fuels on traditional stoves is a significant risk factor for pneumonia, while consumption of contaminated drinking water is a primary cause of diarrheal disease. To date, there have been no large-scale effectiveness trials of programmatic efforts to provide either improved cookstoves or household water filters at scale in a low-income country. In this paper we describe the design of a cluster-randomized trial to evaluate the impact of a national-level program to distribute and promote the use of improved cookstoves and advanced water filters to the poorest quarter of households in Rwanda.

Methods/Design

We randomly allocated 72 sectors (administratively defined units) in Western Province to the intervention, with the remaining 24 sectors in the province serving as controls. In the intervention sectors, roughly 100,000 households received improved cookstoves and household water filters through a government-sponsored program targeting the poorest quarter of households nationally. The primary outcome measures are the incidence of acute respiratory infection (ARI) and diarrhea among children under five years of age. Over a one-year surveillance period, all cases of acute respiratory infection (ARI) and diarrhea identified by health workers in the study area will be extracted from records maintained at health facilities and by community health workers (CHW). In addition, we are conducting intensive, longitudinal data collection among a random sample of households in the study area for in-depth assessment of coverage, use, environmental exposures, and additional health measures.

Discussion

Although previous research has examined the impact of providing household water treatment and improved cookstoves on child health, there have been no studies of national-level programs to deliver these interventions at scale in a developing country. The results of this study, the first RCT of a large-scale programmatic cookstove or household water filter intervention, will inform global efforts to reduce childhood morbidity and mortality from diarrheal disease and pneumonia.

Trial registration

This trial is registered at Clinicaltrials.gov (NCT02239250).

The effects of improved sanitation on diarrheal prevalence, incidence, and duration in children under five in the SNNPR State, Ethiopia: study protocol for a randomized controlled trial

Background

Diarrhea is one of the leading causes of death, killing 1.3 million in 2013 across the globe, of whom, 0.59 million were children under 5 years of age. Globally, about 1 billion people practice open defecation, and an estimated 2.4 billion people were living without improved sanitation facilities in 2015. Much of the previous research investigating the effect of improved sanitation has been based on observational studies. Recent studies have executed a cluster-randomized controlled trial to investigate the effect of improved sanitation. However, none of these recent studies achieved a sufficient level of latrine coverage. Without universal or at least a sufficient level of latrine coverage, a determination of the effect of improved latrines on the prevention of diarrheal disease is difficult.

This cluster-randomized trial aims to explore the net effect of improved latrines on diarrheal prevalence and incidence in children under five and to investigate the effect on the diarrheal duration.

Method/design

A phase-in and factorial design will be used for the study. The intervention for improving latrines will be implemented in an intervention arm during the first phase, and the comparable intervention will be performed in the control arm during the second phase. During the second phase, a water pipe will be connected to the gotts (villages) in the intervention arm. After the second phase is completed, the control group will undergo the intervention of receiving a water pipe connection. For diarrheal prevalence, five rounds of surveying will be conducted at the household level. The first four rounds will be carried out in the first phase to explore the effect of improved latrines, and the last one, in the second phase to examine the combined effects of improved water and sanitation. For documentation of diarrheal incidence and duration, the mother or caregiver will record the diarrheal episodes of her youngest child on the “Sanitation Calendar” every day. Of 212 gotts in the project area, 48 gotts were selected for the trial, and 1200 households with a child under 5 will be registered for the intervention or control arm. Informed consent from 1200 households will be obtained from the mother or caregiver in written form.

Discussion

To our knowledge, this is the second study to assess the effects of improved latrines on child diarrheal reduction through the application of Community-Led Total Sanitation.

Trial registration

Current Controlled Trials, ISRCTN82492848

Household Water Treatment and Safe Storage to Prevent Diarrheal Disease in Developing Countries

Household water treatment and safe storage (HWTS), such as boiling, filtering, or chlorinating water at home, have been shown to be effective in improving the microbiological quality of drinking water. However, estimates of their protective effect against diarrhea, a major killer, have varied widely. While results may be exaggerated because of reporting bias, this heterogeneity is consistent with other environmental interventions that are implemented with varying levels of coverage and uptake in settings where the source of exposure represents one of many transmission pathways. Evidence suggests that the effectiveness of HWTS can be optimized by ensuring that the method is microbiologically effective; (2) making it accessible to an exposed population; and (3) securing their consistent and long-term use.

Consistency of Use and Effectiveness of Household Water Treatment Practices Among Urban and Rural Populations Claiming to Treat Their Drinking Water at Home: A Case Study in Zambia

Household water treatment (HWT) can improve drinking water quality and prevent disease, if used correctly and consistently. While international monitoring suggests that 1.8 billion people practice HWT, these estimates are based on household surveys that may overstate the level of consistent use and do not address microbiological effectiveness. We sought to examine how HWT is practiced among households identified as HWT users according to international monitoring standards. Case studies were conducted in urban and rural Zambia. After a baseline survey (urban: 203 households, rural: 276 households) to identify HWT users, 95 urban and 82 rural households were followed up for 6 weeks. Consistency of HWT reporting was low; only 72.6% of urban and 50.0% of rural households reported to be HWT users in the subsequent visit. Similarly, availability of treated water was low, only 23.3% and 4.2% of urban and rural households, respectively, had treated water on all visits. Drinking water was significantly worse than source water in both settings. Only 19.6% of urban and 2.4% of rural households had drinking water free of thermotolerant coliforms on all visits. Our findings raise questions about the value of the data gathered through the international monitoring of HWT practices as predictors of water quality in the home.

Interventions to improve water quality for preventing diarrhoea

BACKGROUND

Diarrhoea is a major cause of death and disease, especially among young children in low-income countries. In these settings, many infectious agents associated with diarrhoea are spread through water contaminated with faeces.In remote and low-income settings, source-based water quality improvement includes providing protected groundwater (springs, wells, and bore holes), or harvested rainwater as an alternative to surface sources (rivers and lakes). Point-of-use water quality improvement interventions include boiling, chlorination, flocculation, filtration, or solar disinfection, mainly conducted at home.

OBJECTIVES

To assess the effectiveness of interventions to improve water quality for preventing diarrhoea.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register (11 November 2014), CENTRAL (the Cochrane Library, 7 November 2014), MEDLINE (1966 to 10 November 2014), EMBASE (1974 to 10 November 2014), and LILACS (1982 to 7 November 2014). We also handsearched relevant conference proceedings, contacted researchers and organizations working in the field, and checked references from identified studies through 11 November 2014.

SELECTION CRITERIA

Randomized controlled trials (RCTs), quasi-RCTs, and controlled before-and-after studies (CBA) comparing interventions aimed at improving the microbiological quality of drinking water with no intervention in children and adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We used meta-analyses to estimate pooled measures of effect, where appropriate, and investigated potential sources of heterogeneity using subgroup analyses. We assessed the quality of evidence using the GRADE approach.

MAIN RESULTS

Forty-five cluster-RCTs, two quasi-RCTs, and eight CBA studies, including over 84,000 participants, met the inclusion criteria. Most included studies were conducted in low- or middle-income countries (LMICs) (50 studies) with unimproved water sources (30 studies) and unimproved or unclear sanitation (34 studies). The primary outcome in most studies was self-reported diarrhoea, which is at high risk of bias due to the lack of blinding in over 80% of the included studies. Source-based water quality improvementsThere is currently insufficient evidence to know if source-based improvements such as protected wells, communal tap stands, or chlorination/filtration of community sources consistently reduce diarrhoea (one cluster-RCT, five CBA studies, very low quality evidence). We found no studies evaluating reliable piped-in water supplies delivered to households. Point-of-use water quality interventionsOn average, distributing water disinfection products for use at the household level may reduce diarrhoea by around one quarter (Home chlorination products: RR 0.77, 95% CI 0.65 to 0.91; 14 trials, 30,746 participants, low quality evidence; flocculation and disinfection sachets: RR 0.69, 95% CI 0.58 to 0.82, four trials, 11,788 participants, moderate quality evidence). However, there was substantial heterogeneity in the size of the effect estimates between individual studies.Point-of-use filtration systems probably reduce diarrhoea by around a half (RR 0.48, 95% CI 0.38 to 0.59, 18 trials, 15,582 participants, moderate quality evidence). Important reductions in diarrhoea episodes were shown with ceramic filters, biosand systems and LifeStraw® filters; (Ceramic: RR 0.39, 95% CI 0.28 to 0.53; eight trials, 5763 participants, moderate quality evidence; Biosand: RR 0.47, 95% CI 0.39 to 0.57; four trials, 5504 participants, moderate quality evidence; LifeStraw®: RR 0.69, 95% CI 0.51 to 0.93; three trials, 3259 participants, low quality evidence). Plumbed in filters have only been evaluated in high-income settings (RR 0.81, 95% CI 0.71 to 0.94, three trials, 1056 participants, fixed effects model).In low-income settings, solar water disinfection (SODIS) by distribution of plastic bottles with instructions to leave filled bottles in direct sunlight for at least six hours before drinking probably reduces diarrhoea by around a third (RR 0.62, 95% CI 0.42 to 0.94; four trials, 3460 participants, moderate quality evidence).In subgroup analyses, larger effects were seen in trials with higher adherence, and trials that provided a safe storage container. In most cases, the reduction in diarrhoea shown in the studies was evident in settings with improved and unimproved water sources and sanitation.

AUTHORS' CONCLUSIONS

Interventions that address the microbial contamination of water at the point-of-use may be important interim measures to improve drinking water quality until homes can be reached with safe, reliable, piped-in water connections. The average estimates of effect for each individual point-of-use intervention generally show important effects. Comparisons between these estimates do not provide evidence of superiority of one intervention over another, as such comparisons are confounded by the study setting, design, and population.Further studies assessing the effects of household connections and chlorination at the point of delivery will help improve our knowledge base. As evidence suggests effectiveness improves with adherence, studies assessing programmatic approaches to optimising coverage and long-term utilization of these interventions among vulnerable populations could also help strategies to improve health outcomes.

Evidence on the Effectiveness of Water, Sanitation, and Hygiene (WASH) Interventions on Health Outcomes in Humanitarian Crises: A Systematic Review

Background

Water, sanitation, and hygiene (WASH) interventions are amongst the most crucial in humanitarian crises, although the impact of the different WASH interventions on health outcomes remains unclear.

Aim

To examine the quantity and quality of evidence on WASH interventions on health outcomes in humanitarian crises, as well as evaluate current evidence on their effectiveness against health outcomes in these contexts.

Methods

A systematic literature review was conducted of primary and grey quantitative literature on WASH interventions measured against health outcomes in humanitarian crises occurring from 1980–2014. Populations of interest were those in resident in humanitarian settings, with a focus on acute crisis and early recovery stages of humanitarian crises in low and middle-income countries. Interventions of interest were WASH-related, while outcomes of interest were health-related. Study quality was assessed via STROBE/CONSORT criteria. Results were analyzed descriptively, and PRISMA reporting was followed.

Results

Of 3963 studies initially retrieved, only 6 published studies measured a statistically significant change in health outcome as a result of a WASH intervention. All 6 studies employed point-of-use (POU) water quality interventions, with 50% using safe water storage (SWS) and 35% using household water treatment (HWT). All 6 studies used self-reported diarrhea outcomes, 2 studies also reported laboratory confirmed outcomes, and 2 studies reported health treatment outcomes (e.g. clinical admissions). 1 study measured WASH intervention success in relation to both health and water quality outcomes; 1 study recorded uptake (use of soap) as well as health outcomes. 2 studies were unblinded randomized-controlled trials, while 4 were uncontrolled longitudinal studies. 2 studies were graded as providing high quality evidence; 3 studies provided moderate and 1 study low quality evidence.

Conclusion

The current evidence base on the impact of WASH interventions on health outcomes in humanitarian crises is extremely limited, and numerous methodological limitations limit the ability to determine associative, let alone causal, relationships.

Effect of sanitation and water treatment on intestinal protozoa infection: a systematic review and meta-analysis

BACKGROUND

Pathogenic intestinal protozoa infections are responsible for substantial mortality and morbidity, particularly in settings where people lack improved sanitation and safe drinking water. We assessed the relation between access to, and use of, sanitation facilities and water treatment and infection with intestinal protozoa.

METHODS

We did a systematic review and searched PubMed, ISI Web of Science, and Embase from inception to June 30, 2014, without restrictions on language. All publications were examined by two independent reviewers and were included if they presented data at the individual level about access or use of sanitation facilities or water treatment, in combination with individual-level data on human intestinal protozoa infections. Meta-analyses using random effects models were used to calculate overall estimates.

FINDINGS

54 studies were included and odds ratios (ORs) extracted or calculated from 2 × 2 contingency tables. The availability or use of sanitation facilities was associated with significantly lower odds of infection with Entamoeba histolytica or Entamoeba dispar (OR 0·56, 95% CI 0·42-0·74) and Giardia intestinalis (0·64, 0·51-0·81), but not for Blastocystis hominis (1·03, 0·87-1·23), and Cryptosporidium spp (0·68, 0·17-2·68). Water treatment was associated with significantly lower odds of B hominis (0·52, 0·34-0·78), E histolytica or E dispar (0·61, 0·38-0·99), G intestinalis (0·63, 0·50-0·80), and Cryptosporidium spp infections (0·83, 0·70-0·98).

INTERPRETATION

Availability and use of sanitation facilities and water treatment is associated with lower odds of intestinal protozoa infections. Interventions that focus on water and sanitation, coupled with hygiene behaviour, should be emphasised to sustain the control of intestinal protozoa infections.

FUNDING

Swiss National Science Foundation (project numbers PBBSP3-146869 and P300P3-154634), Medicor Foundation, European Research Council (614739-A_HERO).

Are long-lasting insecticide-treated bednets and water filters cost-effective tools for delaying HIV disease progression in Kenya?

BACKGROUND

Co-infection with malaria and other infectious diseases has been shown to increase viral load and accelerate HIV disease progression. A recent study in Kenya demonstrated that providing long-lasting insecticide-treated bednets (LLIN) and water filters (WF) to HIV-positive adults with CD4 >350 cells/mm(3) significantly reduced HIV progression.

DESIGN

We conducted a cost analysis to estimate the potential net financial savings gained by delaying HIV progression and increasing the time to antiretroviral therapy (ART) eligibility through delivering LLIN and WF to 10% of HIV-positive adults with CD4 >350 cells/mm(3) in Kenya.

RESULTS

Given a 3-year duration of intervention benefit, intervention unit cost of US$32 and patient-year ART cost of US$757 (2011 US$), over the lifetime of ART patients, in Kenya, we estimated the intervention could yield a return on investment (ROI) of 11 (95% uncertainty range [UR]: 5-23), based on a cost of about US$2 million and savings in ART costs of about US$26 million (95% UR: 8-50) (discounted at 3%). Our findings were subjected to a number of sensitivity analyses. Of note, deferral of time to ART eligibility could potentially result in 3,000 new HIV infections not averted by ART and thus decrease ART cost savings to US$14 million, decreasing the ROI to 6.

CONCLUSIONS

Provision of LLIN and WF could be a cost-saving and practical method to defer time to ART eligibility in the context of highly resource-constrained environments experiencing donor fatigue for HIV/AIDS programs.

Household water quantity and health: a systematic review

While the quantity of water used in the home is thought to be an important determinant of health, much of the evidence relies on using water access as a proxy for quantity. This review examines the health effects of household water quantity using studies that directly measured water quantity. We searched MEDLINE, EMBASE, the Cochrane Library, Web of Science, and article reference lists. Eligible studies included experimental and observational studies that measured a difference in water quantity and quantified an association between water quantity and health outcomes. 21 studies, divided into six of the many possible water-quantity associated outcomes, met the eligibility criteria. Due to heterogeneity in designs, settings, methods, and outcomes, a meta-analysis was inappropriate. Overall results showed a positive association between water quantity and health outcomes, but the effect depended on how the water was used. Increased water usage for personal hygiene was generally associated with improved trachoma outcomes, while increased water consumption was generally associated with reduced gastrointestinal infection and diarrheal disease and improved growth outcomes. In high-income countries, increased water consumption was associated with higher rates of renal cell carcinoma and bladder cancer but not associated with type II diabetes, cardiac-related mortality, or all-cause mortality.

Explaining low rates of sustained use of siphon water filter: evidence from follow-up of a randomised controlled trial in Bangladesh

OBJECTIVE

To assess sustained siphon filter usage among a low-income population in Bangladesh and study relevant motivators and barriers.

METHODS

After a randomised control trial in Bangladesh during 2009, 191 households received a siphon water filter along with educational messages. Researchers revisited households after 3 and 6 months to assess filter usage and determine relevant motivators and barriers. Regular users were defined as those who reported using the filter most of the time and were observed to be using the filter at follow-up visits. Integrated behavioural model for water, sanitation and hygiene (IBM-WASH) was used to explain factors associated with regular filter use.

RESULTS

Regular filter usage was 28% at the 3-month follow-up and 21% at the 6-month follow-up. Regular filter users had better quality water at the 6-month, but not at the 3-month visit. Positive predictors of regular filter usage explained through IBM-WASH at both times were willingness to pay >US$1 for filters, and positive attitude towards filter use (technology dimension at individual level); reporting boiling drinking water at baseline (psychosocial dimension at habitual level); and Bengali ethnicity (contextual dimension at individual level). Frequently reported barriers to regular filter use were as follows: considering filter use an additional task, filter breakage and time required for water filtering (technology dimension at individual level).

CONCLUSION

The technological, psychosocial and contextual dimensions of IBM-WASH contributed to understanding the factors related to sustained use of siphon filter. Given the low regular usage rate and the hardware-related problems reported, the contribution of siphon filters to improving water quality in low-income urban communities in Bangladesh is likely to be minimal.

Assessing the consistency and microbiological effectiveness of household water treatment practices by urban and rural populations claiming to treat their water at home: a case study in Peru

BACKGROUND

Household water treatment (HWT) can improve drinking water quality and prevent disease if used correctly and consistently by vulnerable populations. Over 1.1 billion people report treating their water prior to drinking it. These estimates, however, are based on responses to household surveys that may exaggerate the consistency and microbiological performance of the practice-key factors for reducing pathogen exposure and achieving health benefits. The objective of this study was to examine how HWT practices are actually performed by households identified as HWT users, according to international monitoring standards.

METHODS AND FINDINGS

We conducted a 6-month case study in urban (n = 117 households) and rural (n = 115 households) Peru, a country in which 82.8% of households report treating their water at home. We used direct observation, in-depth interviews, surveys, spot-checks, and water sampling to assess water treatment practices among households that claimed to treat their drinking water at home. While consistency of reported practices was high in both urban (94.8%) and rural (85.3%) settings, availability of treated water (based on self-report) at time of collection was low, with 67.1% and 23.0% of urban and rural households having treated water at all three sampling visits. Self-reported consumption of untreated water in the home among adults and children <5 was common and this was corroborated during home observations. Drinking water of self-reported users was significantly better than source water in the urban setting and negligible but significantly better in the rural setting. However, only 46.3% and 31.6% of households had drinking water <1 CFU/100 mL at all follow-up visits.

CONCLUSIONS

Our results raise questions about the usefulness of current international monitoring of HWT practices and their usefulness as a proxy indicator for drinking water quality. The lack of consistency and sub-optimal microbiological effectiveness also raises questions about the potential of HWT to prevent waterborne diseases.

Water filter provision and home-based filter reinforcement reduce diarrhea in Kenyan HIV-infected adults and their household members

Among human immunodeficiency virus (HIV)-infected adults and children in Africa, diarrheal disease remains a major cause of morbidity and mortality. We evaluated the effectiveness of provision and home-based reinforcement of a point-of-use water filtration device to reduce diarrhea among 361 HIV-infected adults in western Kenya by comparing prevalence of self-reported diarrhea before and after these interventions. After provision of the filter, 8.7% of participants reported diarrhea compared with 17.2% in the 3 months before filter provision (odds ratio [OR] = 0.39, 95% confidence interval [95% CI] = 0.23-0.66, P < 0.001). The association was similar among 231 participants who were already taking daily cotrimoxazole prophylaxis before being given a filter (OR = 0.47, 95% CI = 0.25-0.88, P = 0.019). Educational reinforcement was also associated with a modest reduction in self-reported diarrhea (OR = 0.50, 95% CI = 0.20-0.99, P = 0.047). Provision and reinforcement of water filters may confer significant benefit in reducing diarrhea among HIV-infected persons, even when cotrimoxazole prophylaxis is already being used.

Fecal contamination of drinking-water in low- and middle-income countries: a systematic review and meta-analysis

BACKGROUND

Access to safe drinking-water is a fundamental requirement for good health and is also a human right. Global access to safe drinking-water is monitored by WHO and UNICEF using as an indicator "use of an improved source," which does not account for water quality measurements. Our objectives were to determine whether water from "improved" sources is less likely to contain fecal contamination than "unimproved" sources and to assess the extent to which contamination varies by source type and setting.

METHODS AND FINDINGS

Studies in Chinese, English, French, Portuguese, and Spanish were identified from online databases, including PubMed and Web of Science, and grey literature. Studies in low- and middle-income countries published between 1990 and August 2013 that assessed drinking-water for the presence of Escherichia coli or thermotolerant coliforms (TTC) were included provided they associated results with a particular source type. In total 319 studies were included, reporting on 96,737 water samples. The odds of contamination within a given study were considerably lower for "improved" sources than "unimproved" sources (odds ratio [OR] = 0.15 [0.10-0.21], I2 = 80.3% [72.9-85.6]). However over a quarter of samples from improved sources contained fecal contamination in 38% of 191 studies. Water sources in low-income countries (OR = 2.37 [1.52-3.71]; p<0.001) and rural areas (OR = 2.37 [1.47-3.81] p<0.001) were more likely to be contaminated. Studies rarely reported stored water quality or sanitary risks and few achieved robust random selection. Safety may be overestimated due to infrequent water sampling and deterioration in quality prior to consumption.

CONCLUSION

Access to an "improved source" provides a measure of sanitary protection but does not ensure water is free of fecal contamination nor is it consistent between source types or settings. International estimates therefore greatly overstate use of safe drinking-water and do not fully reflect disparities in access. An enhanced monitoring strategy would combine indicators of sanitary protection with measures of water quality.

A review and perspective of existing research on the release of nanomaterials from solid nanocomposites

Advances in adding nanomaterials to various matrices have occurred in tandem with the identification of potential hazards associated with exposure to pure forms of nanomaterials. We searched multiple research publication databases and found that, relative to data generated on potential nanomaterial hazards or exposures, very little attention has focused on understanding the potential and conditions for release of nanomaterials from nanocomposites. However, as a prerequisite to exposure studying release is necessary to inform risk assessments. We identified fifty-four studies that specifically investigated the release of nanomaterials, and review them in the following release scenario groupings: machining, weathering, washing, contact and incineration. While all of the identified studies provided useful information, only half were controlled experiments. Based on these data, the debris released from solid, non-food nanocomposites contains in varying frequencies, a mixture of four types of debris. Most frequently identified are (1) particles of matrix alone, and slightly less often, the (2) matrix particles exhibit the nanomaterial partially or fully embedded; far less frequently is (3) the added nanomaterial entirely dissociated from the matrix identified: and most rare are (4) dissolved ionic forms of the added nanomaterial. The occurrence of specific debris types appeared to be dependent on the specific release scenario and environment. These data highlight that release from nanocomposites can take multiple forms and that additional research and guidance would be beneficial, allowing for more consistent characterization of the release potential of nanomaterials. In addition, these data support calls for method validation and standardization, as well as understanding how laboratory release scenarios relate to real-world conditions. Importantly, as risk is considered to be a function of the inherent hazards of a substance and the actual potential for exposure, data on nanomaterial release dynamics and debris composition from commercially relevant nanocomposites are a valuable starting point for consideration in fate and transport modeling, exposure assessment, and risk assessment frameworks for nanomaterials.

Water, sanitation, hygiene, and soil-transmitted helminth infection: a systematic review and meta-analysis

BACKGROUND

Preventive chemotherapy represents a powerful but short-term control strategy for soil-transmitted helminthiasis. Since humans are often re-infected rapidly, long-term solutions require improvements in water, sanitation, and hygiene (WASH). The purpose of this study was to quantitatively summarize the relationship between WASH access or practices and soil-transmitted helminth (STH) infection.

METHODS AND FINDINGS

We conducted a systematic review and meta-analysis to examine the associations of improved WASH on infection with STH (Ascaris lumbricoides, Trichuris trichiura, hookworm [Ancylostoma duodenale and Necator americanus], and Strongyloides stercoralis). PubMed, Embase, Web of Science, and LILACS were searched from inception to October 28, 2013 with no language restrictions. Studies were eligible for inclusion if they provided an estimate for the effect of WASH access or practices on STH infection. We assessed the quality of published studies with the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach. A total of 94 studies met our eligibility criteria; five were randomized controlled trials, whilst most others were cross-sectional studies. We used random-effects meta-analyses and analyzed only adjusted estimates to help account for heterogeneity and potential confounding respectively. Use of treated water was associated with lower odds of STH infection (odds ratio [OR] 0.46, 95% CI 0.36-0.60). Piped water access was associated with lower odds of A. lumbricoides (OR 0.40, 95% CI 0.39-0.41) and T. trichiura infection (OR 0.57, 95% CI 0.45-0.72), but not any STH infection (OR 0.93, 95% CI 0.28-3.11). Access to sanitation was associated with decreased likelihood of infection with any STH (OR 0.66, 95% CI 0.57-0.76), T. trichiura (OR 0.61, 95% CI 0.50-0.74), and A. lumbricoides (OR 0.62, 95% CI 0.44-0.88), but not with hookworm infection (OR 0.80, 95% CI 0.61-1.06). Wearing shoes was associated with reduced odds of hookworm infection (OR 0.29, 95% CI 0.18-0.47) and infection with any STH (OR 0.30, 95% CI 0.11-0.83). Handwashing, both before eating (OR 0.38, 95% CI 0.26-0.55) and after defecating (OR 0.45, 95% CI 0.35-0.58), was associated with lower odds of A. lumbricoides infection. Soap use or availability was significantly associated with lower infection with any STH (OR 0.53, 95% CI 0.29-0.98), as was handwashing after defecation (OR 0.47, 95% CI 0.24-0.90). Observational evidence constituted the majority of included literature, which limits any attempt to make causal inferences. Due to underlying heterogeneity across observational studies, the meta-analysis results reflect an average of many potentially distinct effects, not an average of one specific exposure-outcome relationship.

CONCLUSIONS

WASH access and practices are generally associated with reduced odds of STH infection. Pooled estimates from all meta-analyses, except for two, indicated at least a 33% reduction in odds of infection associated with individual WASH practices or access. Although most WASH interventions for STH have focused on sanitation, access to water and hygiene also appear to significantly reduce odds of infection. Overall quality of evidence was low due to the preponderance of observational studies, though recent randomized controlled trials have further underscored the benefit of handwashing interventions. Limited use of the Joint Monitoring Program's standardized water and sanitation definitions in the literature restricted efforts to generalize across studies. While further research is warranted to determine the magnitude of benefit from WASH interventions for STH control, these results call for multi-sectoral, integrated intervention packages that are tailored to social-ecological contexts.

Climate change and waterborne diarrhoea in northern India: impacts and adaptation strategies

Although several studies show the vulnerability of human health to climate change, a clear comprehensive quantification of the increased health risks attributable to climate change is lacking. Even more complicated are assessments of adaptation measures for this sector. We discuss the impact of climate change on diarrhoea as a representative of a waterborne infectious disease affecting human health in the Ganges basin of northern India. A conceptual framework is presented for climate exposure response relationships based on studies from different countries, as empirical studies and appropriate epidemiological data sets for India are lacking. Four climate variables are included: temperature, increased/extreme precipitation, decreased precipitation/droughts and relative humidity. Applying the conceptual framework to the latest regional climate projections for northern India shows increases between present and future (2040s), varying spatially from no change to an increase of 21% in diarrhoea incidences, with 13.1% increase on average for the Ganges basin. We discuss three types of measures against diarrhoeal disease: reactive actions, preventive actions and national policy options. Preventive actions have the potential to counterbalance this expected increase. However, given the limited progress in reducing incidences over the past decade consorted actions and effective implementation and integration of existing policies are needed.

Household water chlorination reduces incidence of diarrhea among under-five children in rural Ethiopia: a cluster randomized controlled trial

Background

Household water treatment has been advocated as a means of decreasing the burden of diarrheal diseases among young children in areas where piped and treated water is not available. However, its effect size, the target population that benefit from the intervention, and its acceptability especially in rural population is yet to be determined. The objective of the study was to assess the effectiveness of household water chlorination in reducing incidence of diarrhea among children under-five years of age.

Method

A cluster randomized community trial was conducted in 36 rural neighborhoods of Eastern Ethiopia. Households with at least one child under-five years of age were included in the study. The study compared diarrhea incidence among children who received sodium hypochlorite (liquid bleach) for household water treatment and children who did not receive the water treatment. Generalized Estimation Equation model was used to compute adjusted incidence rate ratio and the corresponding 95% confidence interval.

Result

In this study, the incidence of diarrhea was 4.5 episodes/100 person week observations in the intervention arm compared to 10.4 episodes/100 person week observations in the control arm. A statistically significant reduction in incidence of diarrhea was observed in the intervention group compared to the control (Adjusted IRR = 0.42, 95% CI 0.36–0.48).

Conclusion

Expanding access to household water chlorination can help to substantially reduce child morbidity and achieve millennium development goal until reliable access to safe water is achieved.

Trial Registration

ClinicalTrials.gov NCT01376440

Modeling the effect of water, sanitation, and hygiene and oral cholera vaccine implementation in Haiti

In 2010, toxigenic Vibrio cholerae was newly introduced to Haiti. Because resources are limited, decision-makers need to understand the effect of different preventive interventions. We built a static model to estimate the potential number of cholera cases averted through improvements in coverage in water, sanitation and hygiene (WASH) (i.e., latrines, point-of-use chlorination, and piped water), oral cholera vaccine (OCV), or a combination of both. We allowed indirect effects and non-linear relationships between effect and population coverage. Because there are limited incidence data for endemic cholera in Haiti, we estimated the incidence of cholera over 20 years in Haiti by using data from Malawi. Over the next two decades, scalable WASH interventions could avert 57,949-78,567 cholera cases, OCV could avert 38,569-77,636 cases, and interventions that combined WASH and OCV could avert 71,586-88,974 cases. Rate of implementation is the most influential variable, and combined approaches maximized the effect.

Modeling health impact of global health programs implemented by Population Services International

Background

Global health implementing organizations benefit most from health impact estimation models that isolate the individual effects of distributed products and services - a feature not typically found in intervention impact models, but which allow comparisons across interventions and intervention settings. Population Services International (PSI), a social marketing organization, has developed a set of impact models covering seven health program areas, which translate product/service distribution data into impact estimates. Each model's primary output is the number of disability-adjusted life-years (DALYs) averted by an intervention within a specific country and population context. This paper aims to describe the structure and inputs for two types of DALYs averted models, considering the benefits and limitations of this methodology.

Methods

PSI employs two modeling approaches for estimating health impact: a macro approach for most interventions and a micro approach for HIV, tuberculosis (TB), and behavior change communication (BCC) interventions. Within each intervention country context, the macro approach determines the coverage that one product/service unit provides a population in person-years, whereas the micro approach estimates an individual's risk of infection with and without the product/service unit. The models use these estimations to generate per unit DALYs averted coefficients for each intervention. When multiplied by program output data, these coefficients predict the total number of DALYs averted by an intervention in a country.

Results

Model outputs are presented by country for two examples: Water Chlorination DALYs Averted Model, a macro model, and the HIV Condom DALYs Averted Model for heterosexual transmission, a micro model. Health impact estimates measured in DALYs averted for PSI interventions on a global level are also presented.

Conclusions

The DALYs averted models offer implementing organizations practical measurement solutions for understanding an intervention's contribution to improving health. These models calculate health impact estimates that reflect the scale and diversity of program operations and intervention settings, and that enable comparisons across health areas and countries. Challenges remain in accounting for intervention synergies, attributing impact to a single organization, and sourcing and updating model inputs. Nevertheless, these models demonstrate how DALYs averted can be viably used by the global health community as a metric for predicting intervention impact using standard program output data.

Interventions to improve water quality and supply, sanitation and hygiene practices, and their effects on the nutritional status of children

BACKGROUND

Water, sanitation and hygiene (WASH) interventions are frequently implemented to reduce infectious diseases, and may be linked to improved nutrition outcomes in children.

OBJECTIVES

To evaluate the effect of interventions to improve water quality and supply (adequate quantity to maintain hygiene practices), provide adequate sanitation and promote handwashing with soap, on the nutritional status of children under the age of 18 years and to identify current research gaps.

SEARCH METHODS

We searched 10 English-language (including MEDLINE and CENTRAL) and three Chinese-language databases for published studies in June 2012. We searched grey literature databases, conference proceedings and websites, reviewed reference lists and contacted experts and authors.

SELECTION CRITERIA

Randomised (including cluster-randomised), quasi-randomised and non-randomised controlled trials, controlled cohort or cross-sectional studies and historically controlled studies, comparing WASH interventions among children aged under 18 years.

DATA COLLECTION AND ANALYSIS

Two review authors independently sought and extracted data on childhood anthropometry, biochemical measures of micronutrient status, and adherence, attrition and costs either from published reports or through contact with study investigators. We calculated mean difference (MD) with 95% confidence intervals (CI). We conducted study-level and individual-level meta-analyses to estimate pooled measures of effect for randomised controlled trials only.

MAIN RESULTS

Fourteen studies (five cluster-randomised controlled trials and nine non-randomised studies with comparison groups) from 10 low- and middle-income countries including 22,241 children at baseline and nutrition outcome data for 9,469 children provided relevant information. Study duration ranged from 6 to 60 months and all studies included children under five years of age at the time of the intervention. Studies included WASH interventions either singly or in combination. Measures of child anthropometry were collected in all 14 studies, and nine studies reported at least one of the following anthropometric indices: weight-for-height, weight-for-age or height-for-age. None of the included studies were of high methodological quality as none of the studies masked the nature of the intervention from participants.Weight-for-age, weight-for-height and height-for-age z-scores were available for five cluster-randomised controlled trials with a duration of between 9 and 12 months. Meta-analysis including 4,627 children identified no evidence of an effect of WASH interventions on weight-for-age z-score (MD 0.05; 95% CI -0.01 to 0.12). Meta-analysis including 4,622 children identified no evidence of an effect of WASH interventions on weight-for-height z-score (MD 0.02; 95% CI -0.07 to 0.11). Meta-analysis including 4,627 children identified a borderline statistically significant effect of WASH interventions on height-for-age z-score (MD 0.08; 95% CI 0.00 to 0.16). These findings were supported by individual participant data analysis including information on 5,375 to 5,386 children from five cluster-randomised controlled trials.No study reported adverse events. Adherence to study interventions was reported in only two studies (both cluster-randomised controlled trials) and ranged from low (< 35%) to high (> 90%). Study attrition was reported in seven studies and ranged from 4% to 16.5%. Intervention cost was reported in one study in which the total cost of the WASH interventions was USD 15/inhabitant. None of the studies reported differential impacts relevant to equity issues such as gender, socioeconomic status and religion.

AUTHORS' CONCLUSIONS

The available evidence from meta-analysis of data from cluster-randomised controlled trials with an intervention period of 9-12 months is suggestive of a small benefit of WASH interventions (specifically solar disinfection of water, provision of soap, and improvement of water quality) on length growth in children under five years of age. The duration of the intervention studies was relatively short and none of the included studies is of high methodological quality. Very few studies provided information on intervention adherence, attrition and costs. There are several ongoing trials in low-income country settings that may provide robust evidence to inform these findings.

Effect of household-based drinking water chlorination on diarrhoea among children under five in Orissa, India: a double-blind randomised placebo-controlled trial

BACKGROUND

Boiling, disinfecting, and filtering water within the home can improve the microbiological quality of drinking water among the hundreds of millions of people who rely on unsafe water supplies. However, the impact of these interventions on diarrhoea is unclear. Most studies using open trial designs have reported a protective effect on diarrhoea while blinded studies of household water treatment in low-income settings have found no such effect. However, none of those studies were powered to detect an impact among children under five and participants were followed-up over short periods of time. The aim of this study was to measure the effect of in-home water disinfection on diarrhoea among children under five.

METHODS AND FINDINGS

We conducted a double-blind randomised controlled trial between November 2010 and December 2011. The study included 2,163 households and 2,986 children under five in rural and urban communities of Orissa, India. The intervention consisted of an intensive promotion campaign and free distribution of sodium dichloroisocyanurate (NaDCC) tablets during bi-monthly households visits. An independent evaluation team visited households monthly for one year to collect health data and water samples. The primary outcome was the longitudinal prevalence of diarrhoea (3-day point prevalence) among children aged under five. Weight-for-age was also measured at each visit to assess its potential as a proxy marker for diarrhoea. Adherence was monitored each month through caregiver's reports and the presence of residual free chlorine in the child's drinking water at the time of visit. On 20% of the total household visits, children's drinking water was assayed for thermotolerant coliforms (TTC), an indicator of faecal contamination. The primary analysis was on an intention-to-treat basis. Binomial regression with a log link function and robust standard errors was used to compare prevalence of diarrhoea between arms. We used generalised estimating equations to account for clustering at the household level. The impact of the intervention on weight-for-age z scores (WAZ) was analysed using random effect linear regression. Over the follow-up period, 84,391 child-days of observations were recorded, representing 88% of total possible child-days of observation. The longitudinal prevalence of diarrhoea among intervention children was 1.69% compared to 1.74% among controls. After adjusting for clustering within household, the prevalence ratio of the intervention to control was 0.95 (95% CI 0.79-1.13). The mean WAZ was similar among children of the intervention and control groups (-1.586 versus -1.589, respectively). Among intervention households, 51% reported their child's drinking water to be treated with the tablets at the time of visit, though only 32% of water samples tested positive for residual chlorine. Faecal contamination of drinking water was lower among intervention households than controls (geometric mean TTC count of 50 [95% CI 44-57] per 100 ml compared to 122 [95% CI 107-139] per 100 ml among controls [p<0.001] [n = 4,546]).

CONCLUSIONS

Our study was designed to overcome the shortcomings of previous double-blinded trials of household water treatment in low-income settings. The sample size was larger, the follow-up period longer, both urban and rural populations were included, and adherence and water quality were monitored extensively over time. These results provide no evidence that the intervention was protective against diarrhoea. Low compliance and modest reduction in water contamination may have contributed to the lack of effect. However, our findings are consistent with other blinded studies of similar interventions and raise additional questions about the actual health impact of household water treatment under these conditions.

TRIAL REGISTRATION

ClinicalTrials.govNCT01202383 Please see later in the article for the Editors' Summary.

Examining the relationship between infectious diseases and flooding in Europe: A systematic literature review and summary of possible public health interventions

Introduction Many infectious diseases are sensitive to climatic changes; specifically, flooding. This systematic literature review aimed to strengthen the quality and completeness of evidence on infectious diseases following flooding, relevant to Europe. Methods A systematic literature review from 2004-2012 was performed. Focused searches of the following databases were conducted: Medline, Scopus, PubMed, Cochrane Library, and Evidence Aid. Personal communications with key informants were also reviewed. Results Thirty-eight studies met the inclusion criteria. Evidence suggested that water-borne, rodent-borne, and vector-borne diseases have been associated with flooding in Europe, although at a lower incidence than developing countries. Conclusion Disease surveillance and early warning systems, coupled with effective prevention and response capabilities, can reduce current and future vulnerability to infectious diseases following flooding.

Slum upgrading strategies involving physical environment and infrastructure interventions and their effects on health and socio-economic outcomes

BACKGROUND

Slums are densely populated, neglected parts of cities where housing and living conditions are exceptionally poor. In situ slum upgrading, at its basic level, involves improving the physical environment of the existing area, such as improving and installing basic infrastructure like water, sanitation, solid waste collection, electricity, storm water drainage, access roads and footpaths, and street lighting, as well as home improvements and securing land tenure.

OBJECTIVES

To explore the effects of slum upgrading strategies involving physical environment and infrastructure interventions on the health, quality of life and socio-economic wellbeing of urban slum dwellers in low and middle income countries (LMIC). Where reported, data were collected on the perspectives of slum dwellers regarding their needs, preferences for and satisfaction with interventions received.

SEARCH METHODS

We searched for published and unpublished studies in 28 bibliographic databases including multidisciplinary (for example Scopus) and specialist databases covering health, social science, urban planning, environment and LMIC topics. Snowballing techniques included searching websites, journal handsearching, contacting authors and reference list checking. Searches were not restricted by language or publication date.

SELECTION CRITERIA

We included studies examining the impact of slum upgrading strategies involving physical environment or infrastructure improvements (with or without additional co-interventions) on the health, quality of life and socio-economic wellbeing of LMIC urban slum dwellers. Randomised controlled trials (RCTs), controlled before and after studies (CBAs) and interrupted time series (ITS) were eligible for the main analysis. Controlled studies with only post-intervention data (CPI) and uncontrolled before and after (UBA) studies were included in a separate narrative to examine consistency of results and to supplement evidence gaps in the main analysis.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed risk of bias for each study. Differences between the included study interventions and outcomes precluded meta-analysis so the results were presented in a narrative summary with illustrative harvest plots. The body of evidence for outcomes within the main analysis was assessed according to GRADE as very low, low, moderate or high quality.

MAIN RESULTS

We identified 10,488 unique records, with 323 screened as full text. Five studies were included for the main analysis: one RCT with a low risk, two CBAs with a moderate risk and two CBAs with a high risk of bias. Three CBAs evaluated multicomponent slum upgrading strategies. Road paving only was evaluated in one RCT and water supply in one CBA. A total of 3453 households or observations were included within the four studies reporting sample sizes.Most health outcomes in the main studies related to communicable diseases, for which the body of evidence was judged to be low quality. One CBA with a moderate risk of bias found that diarrhoeal incidence was reduced in households which received water connections from a private water company (risk ratio (RR) 0.53; 95% confidence interval (CI) 0.27 to 1.04) and the severity of diarrhoeal episodes (RR 0.48; 95% CI 0.19 to 1.22). There was no effect for duration of diarrhoea. Road paving did not result in changes in parasitic infections or sickness in one RCT. After multicomponent slum upgrading, claims for a waterborne disease as opposed to a non-waterborne disease reduced (RR 0.64; 95% CI 0.27 to 0.98) in one CBA with a high risk of bias but there was no change in sanitation-related mortality in a CBA with a moderate risk of bias.The majority of socio-economic outcomes reported within the main studies related to financial poverty, for which the body of evidence was of very low quality. Results were mixed amongst the main studies; one RCT and two CBAs reported no effect on the income of slum dwellers following slum upgrading. One further CBA found significant reduction in monthly water expenditure (mean difference (MD) -17.11 pesos; 95% CI -32.6 to -1.62). One RCT also showed mixed results for employment variables, finding no effect on unemployment levels but increased weekly worked hours (MD 4.68; 95% CI -0.46 to 9.82) and lower risk of residents intending to migrate for work (RR 0.78; 95% CI 0.60 to 1.01).There was no evidence available to assess the impact of slum upgrading on non-communicable diseases or social capital. Maternal and perinatal conditions, infant mortality, nutritional deficiencies, injuries, self-reported quality of life, education and crime were evaluated in one study each.Nine supporting studies were included that measured varying outcomes (6794 households or observations within eight studies reporting sample sizes). One CPI evaluated cement flooring only while three UBAs and five CPIs evaluated multicomponent slum upgrading strategies. All studies but one had a high risk of bias.The studies reinforced main study findings for diarrhoea incidence and water-related expenditure. Findings for parasitic infections and financial poverty were inconsistent with the main studies. In addition, supporting studies reported a number of disparate outcomes that were not evaluated in the main studies.Five supporting studies included some limited information on slum dweller perspectives. They indicated the importance of appropriate siting of facilities, preference for private facilities, delivering synergistic interventions together, and ensuring that infrastructure was fit for purpose and systems were provided for cleaning, maintenance and repair.

AUTHORS' CONCLUSIONS

A high risk of bias within the included studies, heterogeneity and evidence gaps prevent firm conclusions on the effect of slum upgrading strategies on health and socio-economic wellbeing. The most common health and socio-economic outcomes reported were communicable diseases and indicators of financial poverty. There was a limited but consistent body of evidence to suggest that slum upgrading may reduce the incidence of diarrhoeal diseases and water-related expenditure. The information available on slum dwellers' perspectives provided some insight to barriers and facilitators for successful implementation and maintenance of interventions.The availability and use of reliable, comparable outcome measures to determine the effect of slum upgrading on health, quality of life and socio-economic wellbeing would make a useful contribution to new research in this important area. Given the complexity in delivering slum upgrading, evaluations should look to incorporate process and qualitative information alongside quantitative effectiveness data to determine which particular interventions work (or don't work) and for whom.

Health and environmental sanitation in India: Issues for prioritizing control strategies

Environmental sanitation is a major public health issue in India. Recent interventional studies on environmental sanitation in India highlighted the importance of prioritizing control strategies. Research related to the appropriate cost-effective intervention strategies and their implementation in Indian context is a big challenge. This paper discusses various intervention strategies related to environmental sanitation in India and emphasizes to prioritize it according to the need of country.

High adherence is necessary to realize health gains from water quality interventions

Background

Safe drinking water is critical for health. Household water treatment (HWT) has been recommended for improving access to potable water where existing sources are unsafe. Reports of low adherence to HWT may limit the usefulness of this approach, however.

Methods and Findings

We constructed a quantitative microbial risk model to predict gains in health attributable to water quality interventions based on a range of assumptions about pre-treatment water quality; treatment effectiveness in reducing bacteria, viruses, and protozoan parasites; adherence to treatment interventions; volume of water consumed per person per day; and other variables. According to mean estimates, greater than 500 DALYs may be averted per 100,000 person-years with increased access to safe water, assuming moderately poor pre-treatment water quality that is a source of risk and high treatment adherence (>90% of water consumed is treated). A decline in adherence from 100% to 90% reduces predicted health gains by up to 96%, with sharpest declines when pre-treatment water quality is of higher risk.

Conclusions

Results suggest that high adherence is essential in order to realize potential health gains from HWT.

Linking quantitative microbial risk assessment and epidemiological data: informing safe drinking water trials in developing countries

Intervention trials are used extensively to assess household water treatment (HWT) device efficacy against diarrheal disease in developing countries. Using these data for policy, however, requires addressing issues of generalizability (relevance of one trial in other contexts) and systematic bias associated with design and conduct of a study. To illustrate how quantitative microbial risk assessment (QMRA) can address water safety and health issues, we analyzed a published randomized controlled trial (RCT) of the LifeStraw Family Filter in the Congo. The model accounted for bias due to (1) incomplete compliance with filtration, (2) unexpected antimicrobial activity by the placebo device, and (3) incomplete recall of diarrheal disease. Effectiveness was measured using the longitudinal prevalence ratio (LPR) of reported diarrhea. The Congo RCT observed an LPR of 0.84 (95% CI: 0.61, 1.14). Our model predicted LPRs, assuming a perfect placebo, ranging from 0.50 (2.5-97.5 percentile: 0.33, 0.77) to 0.86 (2.5-97.5 percentile: 0.68, 1.09) for high (but not perfect) and low (but not zero) compliance, respectively. The calibration step provided estimates of the concentrations of three pathogen types (modeled as diarrheagenic E. coli, Giardia, and rotavirus) in drinking water, consistent with the longitudinal prevalence of reported diarrhea measured in the trial, and constrained by epidemiological data from the trial. Use of a QMRA model demonstrated the importance of compliance in HWT efficacy, the need for pathogen data from source waters, the effect of quantifying biases associated with epidemiological data, and the usefulness of generalizing the effectiveness of HWT trials to other contexts.

Vomiting, diarrhea, constipation, and gastroenteritis

Diseases that cause vomiting, diarrhea, constipation, and gastroenteritis are major problems for populations worldwide. Patients, particularly infants, elderly, and immunocompromised individuals, may present at any point in a wide spectrum of disease states, underscoring the need for the clinician to treat these ailments aggressively. Several promising new treatment modalities, from oral rehydration solutions to antiemetic therapies, have been introduced over the past decade. Future directions include the use of probiotic agents and better tolerated rehydration solutions. Gastrointestinal disease will continue to be a focus worldwide in the search for better ways to cure illnesses associated with vomiting and diarrhea.

Factors associated with compliance among users of solar water disinfection in rural Bolivia

BACKGROUND

Diarrhoea is the second leading cause of childhood mortality, with an estimated 1.3 million deaths per year. Promotion of Solar Water Disinfection (SODIS) has been suggested as a strategy for reducing the global burden of diarrhoea by improving the microbiological quality of drinking water. Despite increasing support for the large-scale dissemination of SODIS, there are few reports describing the effectiveness of its implementation. It is, therefore, important to identify and understand the mechanisms that lead to adoption and regular use of SODIS.

METHODS

We investigated the behaviours associated with SODIS adoption among households assigned to receive SODIS promotion during a cluster-randomized trial in rural Bolivia. Distinct groups of SODIS-users were identified on the basis of six compliance indicators using principal components and cluster analysis. The probability of adopting SODIS as a function of campaign exposure and household characteristics was evaluated using ordinal logistic regression models.

RESULTS

Standardised, community-level SODIS-implementation in a rural Bolivian setting was associated with a median SODIS use of 32% (IQR: 17-50). Households that were more likely to use SODIS were those that participated more frequently in SODIS promotional events (OR=1.07, 95%CI: 1.01-1.13), included women (OR=1.18, 95%CI: 1.07-1.30), owned latrines (OR=3.38, 95%CI: 1.07-10.70), and had severely wasted children living in the home (OR=2.17, 95%CI: 1.34-3.49).

CONCLUSIONS

Most of the observed household characteristics showed limited potential to predict compliance with a comprehensive, year-long SODIS-promotion campaign; this finding reflects the complexity of behaviour change in the context of household water treatment. However, our findings also suggest that the motivation to adopt new water treatment habits and to acquire new knowledge about drinking water treatment is associated with prior engagements in sanitary hygiene and with the experience of contemporary family health concerns.Household-level factors like the ownership of a latrine, a large proportion of females and the presence of a malnourished child living in a home are easily assessable indicators that SODIS-programme managers could use to identify early adopters in SODIS promotion campaigns.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00731497.