Stephen W. Gundry

Household drinking water in developing countries: a systematic review of microbiological contamination between source and point-of-use

Objective  To assess the extent and causes of microbiological contamination of household drinking water between source and point‐of‐use in developing countries.

Accounting for water quality in monitoring access to safe drinking-water as part of the millennium development goals: lessons from five countries

OBJECTIVE To determine how data on water source quality affect assessments of progress towards the 2015 Millennium Development Goal (MDG) target on access to safe drinking-water. METHODS Data from five countries on whether drinking-water sources complied with World Health Organization water quality guidelines on contamination with thermotolerant coliform bacteria, arsenic, fluoride and nitrates in 2004 and 2005 were obtained from the Rapid Assessment of Drinking-Water Quality project. These data were used to adjust estimates of the proportion of the population with access to safe drinking-water at the MDG baseline in 1990 and in 2008 made by the Joint Monitoring Programme for Water Supply and Sanitation, which classified all improved sources as safe. FINDINGS Taking account of data on water source quality resulted in substantially lower estimates of the percentage of the population with access to safe drinking-water in 2008 in four of the five study countries: the absolute reduction was 11% in Ethiopia, 16% in Nicaragua, 15% in Nigeria and 7% in Tajikistan. There was only a slight reduction in Jordan. Microbial contamination was more common than chemical contamination. CONCLUSION The criterion used by the MDG indicator to determine whether a water source is safe can lead to substantial overestimates of the population with access to safe drinking-water and, consequently, also overestimates the progress made towards the 2015 MDG target. Monitoring drinking-water supplies by recording both access to water sources and their safety would be a substantial improvement.

A Summary Catalogue of Microbial Drinking Water Tests for Low and Medium Resource Settings

Microbial drinking-water quality testing plays an essential role in measures to protect public health. However, such testing remains a significant challenge where resources are limited. With a wide variety of tests available, researchers and practitioners have expressed difficulties in selecting the most appropriate test(s) for a particular budget, application and setting. To assist the selection process we identified the characteristics associated with low and medium resource settings and we specified the basic information that is needed for different forms of water quality monitoring. We then searched for available faecal indicator bacteria tests and collated this information. In total 44 tests have been identified, 18 of which yield a presence/absence result and 26 of which provide enumeration of bacterial concentration. The suitability of each test is assessed for use in the three settings. The cost per test was found to vary from

A spatial analysis of pit latrine density and groundwater source contamination.

0.60 to

The H(2) S test versus standard indicator bacteria tests for faecal contamination of water: systematic review and meta-analysis.

5.00 for a presence/absence test and from

Water accessibility: Boost water safety in rural China

0.50 to

Public perception of drinking water safety in South Africa 2002–2009: a repeated cross-sectional study

7.50 for a quantitative format, though it is likely to be only a small component of the overall costs of testing. This article presents the first comprehensive catalogue of the characteristics of available and emerging low-cost tests for faecal indicator bacteria. It will be of value to organizations responsible for monitoring national water quality, water service providers, researchers and policy makers in selecting water quality tests appropriate for a given setting and application.

Household characteristics associated with home water treatment : an analysis of the Egyptian Demographic and Health Survey

This study aims to assess the relationship between chemical and microbial contamination of groundwater sources and a range of potential hazards in two peri-urban areas of Kisumu, Kenya where shallow wells and pit latrines are widely used. From 1998 to 2004, 263 samples were taken from 61 groundwater sources and tested for thermotolerant coliforms. Eighteen of these sources were also tested for chemical contaminants, including nitrate, chloride and fluoride. The locations of all water sources, buildings and pit latrines in the study area were surveyed. Local pit latrine densities were calculated using a geographic information system. Ten out 18 samples were above the World Health Organization guideline values for nitrate, 236 out of 263 were positive for thermotolerant coliforms, and all were above the guideline values for fluoride. There was neither a relationship between thermotolerant coliform levels and daily rainfall patterns nor with sanitary risk inspection scores for samples from shallow wells (r = 0.01, p = 0.91, n = 191). The density of pit latrines within a 100-m radius was significantly correlated with nitrate and chloride levels (r = 0.64, p = 0.004 and r = 0.46, p = 0.05, respectively) but not with thermotolerant coliforms (r = 0.22, p = 0.11). These results illustrate both the public health risks associated with shallow groundwater sources, on-site sanitation and high population density. These findings have implications for current policies that promote latrine construction, especially in peri-urban areas of high population density. More comprehensive studies of larger communities should be commissioned to extend this analysis of the links between latrine density and groundwater contamination and so identify the contingent policy risks.

Household water treatment in china.

Objectives  To assess the diagnostic accuracy of the H2S test for microbiological contamination of domestic water across different settings, as a basis for providing guidance on its use.

Synthesis and application of resorufin β- D -glucuronide, a low-cost chromogenic substrate for detecting Escherichia coli in drinking water

Two documents with crucial implications for the future of personalized medicine were released last month: a report from the US Institute of Medicine (IOM) emphasizing the importance of open data sharing (see go.nature.com/ hofgoc) and a US Supreme Court decision ruling against two patents (see go.nature.com/ lj9kyl), which could have the opposite effect. This creates a quandary for companies aiming to pursue personalized treatments or methods, because those that adopt the IOM’s advice to share their information now face greater hurdles to protecting their contributions through patents. Companies should not be discouraged from exploring personalized medicine — to do so would deny society the benefit of tailored therapies. Likewise, firms that prefer to keep personalization algorithms secret will hinder scientific progress. Instead, companies could sell value-added products that use open algorithms and statistical models — much like Google and IBM, for example, which have embraced open-source software. To deliver effective treatments to patients, we need to find a way to reward companies for investing in personalized medicine while allowing the scientific community to advance knowledge rapidly. Jeffrey T. Leek, Roger D. Peng Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA. jtleek@gmail.com R. Reeves Anderson Arnold & Porter LLP, Washington DC, USA. Soil remedies for small-scale farming