Evaluation of Microbial Water Quality Tests for Humanitarian Emergency and Development Settings

Effects of seasonality on access to improved water in Benue State, Nigeria

Many people switch sources of drinking water and sanitation between seasons, yet such shifts are not reflected in the reporting of access to improved water and sanitation services by the Joint Monitoring Programme (JMP). Drawing on quantitative and qualitative data collected from urban and rural sites in dry and rainy seasons in Benue state, Nigeria, this study highlights the importance of seasonal variations in water access and quality. Water testing showed that water sources had higher levels of contamination with coliforms, nitrate and chloride in the dry season than the wet season. The contamination of water from these pollutants is above WHO standards and believed to come mainly from pit latrines. Semi-structured interviews revealed that many people who use improved water and sanitation facilities in the rainy season sometimes switch to poorer quality unimproved sources in the dry season. Travel times for collecting water as well as waiting times also significantly increased in the dry season. It is recommended that this important seasonality element is factored into JMP data collection and reporting.

Bacteriological and physico-chemical quality of household drinking water in Kisii Town, Kisii County, Kenya

Water is a basic human need which is required in many operations especially in households. However, this essential commodity in most cases does not meet the generally accepted safety standards. The study was designed to investigate the physico-chemical and bacteriological quality of drinking water used in households in Kisii town, Kenya. Analytical cross-sectional study was conducted to obtain information concerning household drinking water quality and safety. Stratified random sampling was used to obtain 422 drinking water samples at the point of consumption from the 4 zones of Kisii town for analysis. From the study it was revealed that TDS and electrical conductivity of the analyzed water samples were within the recommended standards of less than 1000 ppm and 1500 μSCM-1 respectively. Further, it was found that 69.4% of the samples had pH range of between 6.5-8.5, 91.9% had turbidity of less than 5NTU, 3.8% had temperature below 15 °C and 31.2% of the chlorinated samples had chlorine residue above 0.2 ppm. In terms of bacteriological analysis, 39.3% of the samples were contaminated with total coliforms and 17.5% with E. coli. The main finding from the study was that the household water samples were contaminated with bacteria and unfit for human consumption because both total coliforms and E. coli exceeded the recommended Kenya Bureau of Standards (KEBS) and WHO standards. Therefore, public health officers should not only collect water samples from sources but also from households regularly to ascertain its quality and provide water safety promotion education to the general public. There was a strong relationship between bacterial contamination and temperature as well as chlorine residue. The study recommends Gusii Water and Sanitation Company (GWASCO) whose treatment and distribution capacity is expected to increase 4.5 times the current capacity to improve on their chlorine dosage at the treatment plant to ensure a minimum chlorine residue of 0.2 ppm at the household and community taps.

Fieldwork-based determination of design priorities for point-of-use drinking water quality sensors for use in resource-limited environments

Improved capabilities in microfluidics, electrochemistry, and portable assays have resulted in the development of a wide range of point-of-use sensors intended for environmental, medical, and agricultural applications in resource-limited environments of developing countries. However, these devices are frequently developed without direct interaction with their often-remote intended user base, creating the potential for a disconnect between users' actual needs and those perceived by sensor developers. As different analytical techniques have inherent strengths and limitations, effective measurement solution development requires determination of desired sensor attributes early in the development process. In this work, we present our findings on design priorities for point-of-use microbial water sensors based on fieldwork in rural India, as well as a guide to fieldwork methodologies for determining desired sensor attributes. We utilized group design workshops for initial identification of design priorities, and then conducted choice-based conjoint analysis interviews for quantification of user preferences among these priorities. We found the highest user preference for integrated reporting of contaminant concentration and recommended actions, as well as significant preferences for mostly reusable sensor architectures, same-day results, and combined ingredients. These findings serve as a framework for future microbial sensor development and a guide for fieldwork-based understanding of user needs.

Water source quality testing in Gezira State, Sudan, using the compartment bag test

Although poor water quality is recognized as a public health threat, it has been little investigated in Sudan. In this paper, water sources in Gezira State, Greater Wad Medani locality, have been categorized as safe, intermediate safe and high-risk unsafe sources using the compartment bag test (CBT) to detect E. coli, which is an indicator of fecal contamination of water. The CBT is simple, portable and self-contained, and it can be done in the field environment. A total of 122 samples were collected from different water sources and included rivers, water treatment plant, boreholes/tube wells, hand pumps, public water taps, public water coolers, public elevated water tanks and household elevated water tanks. It was found that 69% (84/122) of investigated water sources were safe to drink. The sources most likely to be contaminated were those close to industrial points and factories or open sources exposed to pollution. The result showed that the highest level of contamination of water sources (high risk and unsafe) was observed in rural area (9.1%) followed by urban (5.7%) and peri-urban (1.6%). Frequent and routine qualitative analysis of water sources using CBT is recommended to improve human health and hence the country's development.

Effects of improved drinking water quality on early childhood growth in rural Uttar Pradesh, India: A propensity-score analysis

Context

Recent randomised controlled trials in Bangladesh and Kenya concluded that household water treatment, alone or in combination with upgraded sanitation and handwashing, did not reduce linear growth faltering or improve other child growth outcomes. Whether these results are applicable in areas with distinct constellations of water, sanitation and hygiene (WaSH) risks is unknown. Analysis of observational data offers an efficient means to assess the external validity of trial findings. We studied whether a water quality intervention could improve child growth in a rural Indian setting with higher levels of circulating pathogens than the original trial sites.

Methods

We analysed a cross-sectional dataset including a microbiological measure of household water quality. All households accessed water from an improved source. We applied propensity score methods to emulate a randomised trial investigating the hypothesis that receipt of drinking water meeting Sustainable Development Goal (SDG) 6.1 quality standards for absence of faecal contamination leads to improved growth. Growth outcomes (stunting, underweight, wasting, and their corresponding Z-scores) were assessed in children 12–23 months of age. For each outcome, we estimated the mean and 95% confidence interval of the absolute risk difference between treatment groups.

Findings

Of 1088 households, 442 (40.62%) received drinking water meeting SDG 6.1 standards. The adjusted risk of child underweight was 7.4% (1.3% to 13.4%) lower among those drinking water satisfying SDG 6.1 norms than among controls. Evidence concerning the relationship of drinking water meeting SDG 6.1 norms to length-for-age and weight-for-age was inconclusive, and there was no apparent relationship with stunting or wasting.

Conclusions

In contexts characterised by high pathogen transmission, water quality improvements have the potential to reduce the proportion of underweight children, but are unlikely to impact stunting or wasting. Further research is required to assess how these modelled benefits can best be achieved in real world settings.

Locally produced hydrogen sulphide detecting water quality test kits increase household level monitoring in rural Tanzania

In developing countries, rural water sources have the highest levels of faecal contamination but are the least monitored. Affordable field-based water quality tests are needed. The presence of faecal indicator bacteria can be determined with hydrogen sulphide (H₂S) detecting tests, that are inexpensive and simple to make locally. In rural Tanzania, a non-governmental organisation (NGO) designed, produced and evaluated a new H₂S water quality test kit. The H₂S test results correlated with log₁₀ Escherichia coli densities from conventional water quality tests. The production cost was US$ 1.10 and the test retailed for US$ 1.37. In total, 433 tests were sold through local pharmacies and NGOs. Additionally, 165 WaSH education meetings, reaching 3,408 community members, were conducted with the H₂S test demonstrated in over half the meetings. Pre- and post-surveys of 294 meeting participants saw an increased reporting of household level water treatment by 24%. The H₂S test was widely accepted, with 94% of those surveyed willing to buy the test in the future. International and national guidelines for drinking water monitoring need to be amended to include locally produced H₂S water quality tests. This will enable households to monitor their own water sources and make informed choices about water safety and treatment.

The compartment bag test (CBT) for enumerating fecal indicator bacteria: Basis for design and interpretation of results

For the past several years, the compartment bag test (CBT) has been employed in water quality monitoring and public health protection around the world. To date, however, the statistical basis for the design and recommended procedures for enumerating fecal indicator bacteria (FIB) concentrations from CBT results have not been formally documented. Here, we provide that documentation following protocols for communicating the evolution of similar water quality testing procedures. We begin with an overview of the statistical theory behind the CBT, followed by a description of how that theory was applied to determine an optimal CBT design. We then provide recommendations for interpreting CBT results, including procedures for estimating quantiles of the FIB concentration probability distribution, and the confidence of compliance with recognized water quality guidelines. We synthesize these values in custom user-oriented 'look-up' tables similar to those developed for other FIB water quality testing methods. Modified versions of our tables are currently distributed commercially as part of the CBT testing kit.

Well water quality in rural Nicaragua using a low-cost bacterial test and microbial source tracking

Water-related diseases, particularly diarrhea, are major contributors to morbidity and mortality in developing countries. Monitoring water quality on a global scale is crucial to making progress in terms of population health. Traditional analytical methods are difficult to use in many regions of the world in low-resource settings that face severe water quality issues due to the inaccessibility of laboratories. This study aimed to evaluate a new low-cost method (the compartment bag test (CBT)) in rural Nicaragua. The CBT was used to quantify the presence of Escherichia coli in drinking water wells and aimed to determine the source(s) of any microbial contamination. Results indicate that the CBT is a viable method for use in remote rural regions. The overall quality of well water in Pueblo Nuevo, Nicaragua was deemed unsafe, and results led to the conclusion that animal fecal wastes may be one of the leading causes of well contamination. Elevation and depth of wells were not found to impact overall water quality. However rope-pump wells had a 64.1% reduction in contamination when compared with simple wells.