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

Bain, Robert; Bartram, Jamie; Elliott, Mark; Matthews, Robert L.; McMahan, Lanakila; Tung, Rosalind; Chuang, Patty; Gundry, Stephen

doi:10.3390/ijerph9051609

Cited by 84 publications

(101 citation statements)

References 13 publications

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“…13 On average, our cost estimate for consumables (3.5 ± 2.2 USD) was substantially higher (+108%) than calculated by Crocker et al (1.7 USD). 14 Our finding of higher consumables costs likely reflects importation and delivery expenses, which were not included in the previous analyses.…”

Section: Discussioncontrasting

confidence: 60%

How Much Will It Cost To Monitor Microbial Drinking Water Quality in Sub-Saharan Africa?

Delaire¹,

Peletz²,

Kumpel³

et al. 2017

Environ. Sci. Technol.

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Microbial water quality monitoring is crucial for managing water resources and protecting public health. However, institutional testing activities in sub-Saharan Africa are currently limited. Because the economics of water quality testing are poorly understood, the extent to which cost may be a barrier to monitoring in different settings is unclear. This study used cost data from 18 African monitoring institutions (piped water suppliers and health surveillance agencies in six countries) and estimates of water supply type coverage from 15 countries to assess the annual financial requirements for microbial water testing at both national and regional levels, using World Health Organization recommendations for sampling frequency. We found that a microbial water quality test costs 21.0 ± 11.3 USD, on average, including consumables, equipment, labor, and logistics, which is higher than previously calculated. Our annual cost estimates for microbial monitoring of piped supplies and improved point sources ranged between 8 000 USD for Equatorial Guinea and 1.9 million USD for Ethiopia, depending primarily on the population served but also on the distribution of piped water system sizes. A comparison with current national water and sanitation budgets showed that the cost of implementing prescribed testing levels represents a relatively modest proportion of existing budgets (<2%). At the regional level, we estimated that monitoring the microbial quality of all improved water sources in sub-Saharan Africa would cost 16.0 million USD per year, which is minimal in comparison to the projected annual capital costs of achieving Sustainable Development Goal 6.1 of safe water for all (14.8 billion USD).

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Section: Discussioncontrasting

confidence: 60%

How Much Will It Cost To Monitor Microbial Drinking Water Quality in Sub-Saharan Africa?

Delaire¹,

Peletz²,

Kumpel³

et al. 2017

Environ. Sci. Technol.

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“…Because laboratory tests for these types of organisms are often prohibitively expensive or time consuming, elevated H 2 S levels in water have been used as a marker for potential pathogenic bacterial contaminations in different water sources. 31,32 …”

Section: Introductionmentioning

confidence: 99%

Development of Selective Colorimetric Probes for Hydrogen Sulfide Based on Nucleophilic Aromatic Substitution

et al. 2013

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Hydrogen sulfide is an important biological signalling molecule and an important environmental target for detection. A major challenge in developing H2S detection methods is separating the often similar reactivity of thiols and other nucleophiles from H2S. To address this need, the nucleophilic aromatic substitution (SNAr) reaction of H2S with electron-poor aromatic electrophiles was developed as a strategy to separate H2S and thiol reactivity. Treatment of aqueous solutions of nitrobenzofurazan (7-nitro-1,2,3-benzoxadiazole, NBD) thioethers with H2S resulted in thiol extrusion and formation of nitrobenzofurazan thiol (λmax = 534 nm). This reactivity allows for unwanted thioether products to be converted to the desired nitrobenzofurazan thiol upon reaction with H2S. The scope of the reaction was investigated using a Hammett linear free energy relationship study, and the determined ρ = +0.34 is consistent with the proposed SN2Ar reaction mechanism. The efficacy of the developed probes was demonstrated in buffer and in serum with associated sub-micromolar detection limits as low as 190 nM (buffer) and 380 nM (serum). Furthermore, the sigmoidal response of nitrobenzofurazan electrophiles with H2S can be fit to accurately quantify H2S. The developed detection strategy offers a manifold for H2S detection that we foresee being applied in various future applications.

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“…), and others (Bain et al . ). Such tests primarily target culturable faecal indicator bacteria (FIB) such as E. coli and Enterococci and may use ambient‐temperature incubation (Brown et al .…”

Section: Introductionmentioning

confidence: 97%

Development and field testing of low‐cost, quantal microbial assays with volunteer reporting as scalable means of drinking water safety estimation

et al. 2019

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Aims To evaluate a low‐cost water quality test for at‐scale drinking water safety estimation in rural India. Methods and Results Within a longitudinal study to characterize variability in household drinking water safety in rural Maharashtra, we piloted a low‐cost presence–absence (LCPA) microbial test designed to be used by volunteer residents in rural areas. In comparing the LCPA results with standard laboratory methods for enumeration of Escherichia coli, we found that LCPA tests using modified mTec media were highly sensitive in detecting drinking water of moderate risk (88% of tests were positive at E. coli counts of 11–100 CFU per 100 ml) and high risk (96% of tests were positive at E. coli counts of 101 + CFU per 100 ml). The LCPA tests demonstrated low specificity for E. coli specifically, due to concurrent detection of Klebsiella: 38% of LCPA tests were positive even when E. coli was not detected in a 100 ml sample by membrane filtration, suggesting the test would be conservative in risk estimation. We also found that 47% of participants in rural villages in India were willing to conduct tests and return results after a brief training, with 45% of active participants sending their water testing results via short message service. Conclusions Given their low cost (~US$0.50 as piloted) and open‐source format, such tests may provide a compelling alternative to standard methods for rapid water quality assessments, especially in resource‐limited settings. Significance and Impact of the Study The lack of availability of water quality data constrains efforts to monitor, evaluate and improve the safety of water and sanitation infrastructure in underserved settings. Current water testing methods are not scalable because of laboratory and cost constraints. Our findings indicate the LCPA or similar low‐cost microbial tests could be useful in rapid water safety estimation, including via crowdsourcing.

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

Cited by 84 publications

References 13 publications

How Much Will It Cost To Monitor Microbial Drinking Water Quality in Sub-Saharan Africa?

How Much Will It Cost To Monitor Microbial Drinking Water Quality in Sub-Saharan Africa?

Development of Selective Colorimetric Probes for Hydrogen Sulfide Based on Nucleophilic Aromatic Substitution

Development and field testing of low‐cost, quantal microbial assays with volunteer reporting as scalable means of drinking water safety estimation

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