Robert Bain; Ryan Cronk; Jim Wright; Hong Yang; Tom Slaymaker; Jamie Bartram

“ The health sector plays a substantive role in drinking-water quality standard setting in many countries; this is logical since the underlying rationale is based on health concerns. The evidence presented here suggests that failures in water safety are frequent in LMICs, and that effective standard setting would combine outcomes measures (such as the measurement of FIB) with the verification of preventive or protective measures through sanitary inspection, water safety plans, or similar approaches. ”

“ The health sector also plays an important role in environmental health including drinking-water quality surveillance in many countries. However in many LMICs surveillance of water quality is limited outside large consolidated urban centers and enforcement of guidelines can be weak [82] . Surveillance is typically weakest in rural areas where levels of access to “improved sources” are lowest and the likelihood of contamination is greatest. The lack of disaggregated data for peri-urban and urban slum areas is also a problem in many countries. ”

“ Studies report sanitary risks in some sources that are not found to contain detectable FIB, indicating that infrequent monitoring does not provide assurance of water safety. Conversely, low sanitary risk scores are reported for water sources that contain FIB, indicating that sanitary inspections alone do not capture water safety fully. Although individual studies report different levels of sanitary risk, the data are too few to draw general conclusions. Moreover, the use of different questions for each source type and their equal weighting limits the comparability of sanitary risk scores. ”

“ Health policy makers framing post-2015 goals for achieving universal health coverage and reducing the global burden of disease need to ensure that targets and indicators go beyond health care services and address underlying determinants of health including progressive improvements in access to safe drinking-water, sanitation, and hygiene services. ”

“ To capture additional studies would have required the screening of tens of thousands of records, as we were unable to identify more specific search terms. Two sources of water quality information that could be used in future studies and monitoring: regulatory surveillance and utility quality control data are likely to be extensive and not well represented as they may not be published and publicly available. Publicly available data from these sources rarely matched our inclusion criteria, usually because of failure to report sample sizes or associate water quality with source type. ”

“ Given the vulnerability of the populations using them and the potential for health facilities to serve as models for the wider community, the health sector has both a duty of care and an opportunity to advance health through better management of water safety in its own facilities. ”

“ Fecal contamination of drinking-water in LMICs is widespread. We demonstrate that improved sources are in general safer than unimproved sources of drinking-water, but they are not universally nor consistently free of fecal contamination. In 38% of 191 studies at least a quarter of samples from improved sources exceeded WHO recommended levels of FIB. By equating “use of an improved source” with “safe,” international estimates greatly overstate access to safe drinking-water. ”

“ WHO publishes widely recognized Guidelines for Drinking-water Quality (GDWQ) (4th edition) that include criteria for assessing health risks and setting targets for improving water safety [11] . Direct measurement of pathogens is complex but techniques for assessing fecal contamination using fecal indicator bacteria (FIB) are well established and widely applied. The WHO GDWQ recommend using E. coli, or alternatively thermotolerant coliform (TTC) , and new enzymatic methods have made quantification simpler, cheaper, and more robust [18] , [19] . ”

“ Data Extraction and Matching
Where possible we extracted or calculated the following information for each type of water source in the studies: (i) total number of samples and proportion containing E. coli or TTC; (ii) proportion of samples within microbial risk categories (<1 or not detected, 1–10, 10–100, and >100 E. coli or TTC per 100 ml) ; (iii) geometric mean, mean, or median levels of E. coli or TTC; and (iv) risk categories according to the sanitary inspection (“low,” “medium,” “high,” and “very high” risk) as reported in the studies. ”

“ For intervention studies (other than the provision of an improved source, for example the protection of unprotected springs) , estimates could be based on either the baseline or control group; when both were available we used whichever had the largest sample size. For studies reporting both E. coli and TTC, we used only the E. coli results. ”

“ Protection of groundwater (OR = 0.26 [95% CI 0.11–0.60] ; p = 0.002; Table 3) and treatment of piped water (OR = 0.07 [95% CI 0.02–0.27] , p<0.001; Table 3) were both strongly related to better water quality. Contamination of stored water was more likely than water at the source (OR = 2.09 [95% CI 1.16–3.78] , p = 0.015; Table 3) , including for piped supplies (OR = 2.35 [95% CI 1.08–5.12] , p = 0.032; Table S1) .
Within Studies Analysis: Meta-analysis
Figure 4 is a forest plot showing the ORs of contamination for improved sources compared to unimproved sources from eligible studies. ”

“ The researchers included studies that contained extractable data on Escherichia coli or thermotolerant coliform (the WHO recommended indicators of fecal contamination) collected by appropriate techniques. The authors also assessed studies for bias and quality and used a statistical method (random effects meta-regression) to investigate risk factors and settings where fecal contamination of water sources was most common. ”

“ There is an opportunity to enhance current outbreak investigation, advancing its role from one of curtailment to general prevention, thereby improving the ability to retrieve information that can be generalized for future prevention. ”

“ Wright, JA & Gundry, SW (2012) , Water accessibility: boost water safety in rural China, vol. 484, p. 318, 22517153 YangHWrightJAGundrySW, pmid:22517153 ↑ , Review-WQ-sampling-Geneva-18-19June2012_final.pdf> ↑ Jimenez, A & Perez-Foguet, A (2008) , Improving water access indicators in developing countries: a proposal using water point mapping methodology, vol. 8, pp. 279–287 JimenezAPerez-FoguetA ↑ Brown, J & Clasen, T (2012) , High adherence is necessary to realize health gains from water quality interventions, vol. ”