Quality of water sources in Southwestern Uganda using the compartment bag test (CBT): a cross-sectional descriptive study

The aim of this study was to assess the bacteriological quality of water sources in the two rural areas of Uganda using the compartment bag test (CBT). In total, 200 water samples were collected from 69 different water sources and processed within 6 h of collection. Positive and negative controls were processed each day together with water samples. Physical parameters were measured in situ . Descriptive statistics were used to generate mean, minimum, maximum, standard deviations and percentages. The results indicated that 29% of the water sources met the National Standards and World Health Organization (WHO) Guidelines for drinking water. Sixty percent of the borehole, 44% of gravitational ﬂ ow taps and 14% of roof rain water met the required standards. Of the open water sources, 75% of the rivers, 50% of open channels and 43% of unprotected dug wells plus 25% of protected springs and 9% of gravitational ﬂ ow schemes had most probable number counts > 100 Escherichia coli /100 mL of water. Most of the water sources in the study areas were not ﬁ t for human consumption without prior treatment. The CBT was found to be robust and easy to use in all ﬁ eld situations. The mean physical parameters of water sources were within the acceptable limits. The aim of this


INTRODUCTION
Access to safe water and sanitation is a basic human right as recognized by the United Nations General Assembly in 2010 (World Health Organization (WHO) ). Globally, 1.8 billion people lack access to safe drinking water (Onda et al. ; Bain et al. a). In 2015, it was estimated that 663 million people worldwide still use unimproved water sources, including unprotected wells, springs and surface water. Nearly half of all people using unimproved drinking water sources live in sub-Saharan Africa; while one-fifth live in Southern Asia (WHO/UNICEF ). Three out of 10 people lack safely managed water services (UNICEF ). Safe drinking water and hygienic toilets protect people from disease and enable societies to be more productive economically. However, the suitability of water for various uses depends on the biological, physico-chemical and radiological properties of water. Water supply and its accessibility is Goal number 6 of the Sustainable Development Goals (SDG 6), and it aims at ensuring availability and sustainable management of water and sanitation for all by 2030 (UNDP ). Safe and affordable drinking water for all by 2030 requires that we invest in adequate infrastructure, provide sanitation facilities and encourage hygiene. In order to achieve this target, 6.1 of SDG 6 is to have active monitoring of the microbial water quality of drinking water through the enumeration of Escherichia coli in water samples. Currently, the approved methods for the enumeration of E. coli in drinking water samples require the use of specialized equipment, including an electrically powered incubator, and entail complicated procedures that must be performed by trained personnel (Bain et al. ).
Most rural communities in Uganda lack access to improved water sources which are often nonfunctional. As In a study conducted by Ssenyonga et al. (), he established that one in every five children under 5 years of age in Uganda had an episode of diarrhea within a period of 2 weeks. This puts diarrhea among the top diseases in children under 5 years in Uganda and is a disease of public health concern in the country (Ssenyonga et al. ).
Exposure to diarrhea-causing agents is frequently related to sources of water used (Mbonye ; Ssenyonga et al. ; Godana & Mengistie ). Studies have shown that there are benefits of using water source to prevent diarrhea (Mbonye ).
Many areas of the world, including Uganda, that lack access to improved drinking water sources are located in remote rural regions where little or nothing is known about the microbial quality of drinking water sources used by the community and households. In such low-resource settings, which may also be very isolated, accessible methods for determining the microbial quality of drinking water sources are lacking. Furthermore, standard methods used to monitor the microbial water quality for regulatory compliance in even developed countries may be extremely difficult to use in these types of settings (Bain et al. ). Therefore, there is a need for a low-cost, portable, simple method that does not require specialized and highly skilled analysts, additional equipment and materials, such as an incubator, and can be performed onsite to determine the microbial quality of drinking water in low-resource settings ( containing a chromogenic glucuronide substrate, 5-bromo-4-chloro-3-indolyl-β-D-glucuronic acid (X-gluc), is added to a water sample, and the amended water is swirled to fully dissolve the medium. Once the medium reagent is dissolved, the sample is transferred to a sterile CBT. The sample is then distributed among the five compartments by tilting the bag from side to side and manual adjustment (squeezing) of the compartment volumes. An external two-piece spring plastic clip is placed across the bag above the liquid levels in the compartments but below the tops of the compart- Performance evaluation of the CBT for E. coli in drinking water has been conducted by a number of researchers.
Performance of CBT was conducted to explore the use of CBT to detect E. coli compared to a standard test using Colilert medium in Quanti-Tray at various incubation temperatures. The CBT was also evaluated in the field settings by incorporating the CBT in a demographic household survey in Peru and Liberia. In Tanzania, a household survey was conducted to evaluate the CBT as a health behavior and education tool. The outcomes of these surveys were (i) demonstrated that the CBT detects and quantifies E. coli comparable to standard methods. The challenge of using the CBT in the enumeration of E. coli is when counts in some water samples are beyond 100 E. coli/ 100 mL water samples, it becomes Too Numerous To Count, which is not acceptable for the Uganda National water quality test can be done by trained laboratory technicians using the standard methods, which are costly and technically demanding to run. This study is the first time in Uganda a field-portable, quantitative water microbiology test to detect and enumerate the E. coli contamination in water samples using this valuable CBT that was successfully used.

Research design
A cross-sectional descriptive research design was used for this study. This was chosen in order to detect and quantify E. coli as the indicator of fecal contamination in the household storage water and water sources being used by the study population.

Description of the study area
The study was conducted in two rural sub-counties of

Collection of water samples
Samples from the water sources were collected for 2 months from July 2015 to 1 August 2015. The month of June 2015 had doubled the long-term rainfall, but July and August 2015 were very dry (UNMA ). In total, 69 samples were collected from the different water sources; gravitational flow scheme (34), protected spring (4), roof rain water (7), river water (8), boreholes (5), unprotected dug well (5) and channel water (6) using the WHO water sample collection guidelines (Godana & Mengistie ).
The water samples collected were kept at room temperature until they were analyzed. This is an advantage of handling (1,413 μS/cm) calibration solution, meter calibrated at 25 C. The electrodes were rinsed with de-ionized water between samples. The water turbidity was measured in situ using a simple extinction method.

Microbiological analysis of water samples
The commercially available CBT and its methodology were

Data analysis
All information were added to an Excel spreadsheet and copied into STATA 12 for further analysis. Descriptive parameters were used to indicate mean, minimum, maximum, standard deviations and percentages.

Physical parameters in water sources
The mean temperature of the water sources varied from Nearly all the turbidity of the water sources were 5 NTU or below with only one borehole source with a recorded value of 20 NTU and one unprotected hand dug well was also measured (133.2 NTU). The mean of physical parameters of the water sources fell within the acceptable limits set by the Uganda National Standards for drinking water and the WHO Guidelines (Table 1).

Microbiological quality of water sources
The percentages of the water sources with E. coli MPN/ 100 mL with WHO water quality risk categories are shown in Table 2    widespread and routine microbiological testing of household drinking water on samples collected during the survey. The CBT therefore has a potential application for local water quality monitoring, such as water surveillance monitoring by district health officers (DHOs). Water quality monitoring is important in achieving the progressive realization of the human right to safe water (Bain et al. b).
Another advantage of using the CBT in water quality analysis over the established standard methods is its simplicity to use and the reading/scores of CBT depend on the color changes in the media after the incubation period. Despite the CBT being robust in water quality analysis, it has some limitations. One of the limitations of CBT is its applicability to some types of water samples is its upper

CONCLUSIONS AND RECOMMENDATION
This study has shown that the water in the study area was not fit for human consumption without prior treatment.
The high number of E. coli counts observed in the two sub-counties reflected the poor quality of water used by these community members. There is an urgent need for the protection of water sources in the rural communities supported by a strong environmental awareness campaign to help rural communities to participate positively to protect and manage the quality of their water sources. To overcome the drawbacks of the existing microbial water testing methods (which are expensive, time-consuming and require expertise and fully equipped laboratories), the CBT kit proved to overcome these challenges. The CBT should be used as a health behavior/health education tool to improve the perception of water quality issues by the community. We therefore recommend the roll out of CBT by all public health officers at the districts/communities at village levels to monitor the microbiological quality of water sources.

LIMITATIONS
This study was conducted in two rural sub-counties of Rugando

Consent for publication
Not applicable.

Availability of data and material
All data supporting our findings are contained in the paper.
There are no restrictions to data sources; however, details of the full data may be accessed through Professor Richard Onyuthi Apecu.
(http://www.african snows.org/). The WELLCOME TRUST, UK did not participate in the design, data collection, analysis and interpretation of data or the writing of the paper.

AUTHORS' CONTRIBUTIONS
ROA participated in the conception, design, data collection, analysis, drafting and approval of the manuscript. LA participated in the conception, data collection and approval of the manuscript. EM participated in the conception, drafting and approval of the manuscript. FB participated in the conception, design, drafting and approval of the manuscript.
AT participated in the conception, design and approval of the manuscript. NP was PI of the project and participated in the conception, design, drafting, training and final approval of the manuscript.