There is a new paper that came out last month which summarises some of the deliberations that were noted in this thread.

Here we report the conclusions of an expert meeting convened by the World Health Organization and the Bill and Melinda Gates Foundation to discuss these findings, and present five key consensus messages as a basis for wider discussion and debate in the WASH and nutrition sectors.

You can find the paper here or in the SuSanA library: bmcmedicine.biomedcentral.com/articles/1...86/s12916-019-1410-x

The implications of three major new trials for the effect of water, sanitation and hygiene on childhood diarrhea and stunting: a consensus statement
Authors: Oliver Cumming, Benjamin F. Arnold, Radu Ban, Thomas Clasen, Joanna Esteves Mills, Matthew C. Freeman, Bruce Gordon, Raymond Guiteras, Guy Howard, Paul R. Hunter, Richard B. Johnston, Amy J. Pickering, Andrew J. Prendergast, Annette Prüss-Ustün, Jan Willem Rosenboom, Dean Spears, Shelly Sundberg, Jennyfer Wolf, Clair Null, Stephen P. Luby, Jean H. Humphrey & John M. Colford Jr.

Abstract
Background
Three large new trials of unprecedented scale and cost, which included novel factorial designs, have found no effect of basic water, sanitation and hygiene (WASH) interventions on childhood stunting, and only mixed effects on childhood diarrhea. Arriving at the inception of the United Nations’ Sustainable Development Goals, and the bold new target of safely managed water, sanitation and hygiene for all by 2030, these results warrant the attention of researchers, policy-makers and practitioners.

Main body
Here we report the conclusions of an expert meeting convened by the World Health Organization and the Bill and Melinda Gates Foundation to discuss these findings, and present five key consensus messages as a basis for wider discussion and debate in the WASH and nutrition sectors. We judge these trials to have high internal validity, constituting good evidence that these specific interventions had no effect on childhood linear growth, and mixed effects on childhood diarrhea. These results suggest that, in settings such as these, more comprehensive or ambitious WASH interventions may be needed to achieve a major impact on child health.

Conclusion
These results are important because such basic interventions are often deployed in low-income rural settings with the expectation of improving child health, although this is rarely the sole justification. Our view is that these three new trials do not show that WASH in general cannot influence child linear growth, but they do demonstrate that these specific interventions had no influence in settings where stunting remains an important public health challenge. We support a call for transformative WASH, in so much as it encapsulates the guiding principle that – in any context – a comprehensive package of WASH interventions is needed that is tailored to address the local exposure landscape and enteric disease burden.

Copied from the paper:

Here, we distil the salient points of consensus from the meeting into five key messages:

1. Despite high compliance, the evaluated WASH interventions – as delivered in these settings – had no effect on linear growth, and mixed effects on diarrhea
2. The biological plausibility of WASH as public health interventions is not challenged by these findings
3. Historically, large, population-level gains in child health have not been achieved without significant improvements in WASH services
4. Current evidence suggests that basic WASH services alone are unlikely to have a large impact on childhood stunting
5. The results of these trials do not undermine the new and ambitious SDG target of safely managed services for all

Happy reading!

Elisabeth

I found this a very interesting thread. While looking over it again, I noticed that on 26 July Jan Willem added an Excel file to his forum post (see above). The file is an overview of WaSH Practitioner questions which were posed in the run-up to the Sanitation Evidence Consensus Meeting convened by WHO, May 24 and 25, 2018

The questions fell into the following categories (see full list in Excel file in Jan Willem's post above this one):
1. Research methods
2. Study results and their validity
3. Study quality
4. Measures to use
5. Programmatic approaches
6. Sanitation chain and other interventions
7. Influencing practice

On 1 August, Jan Willem and Radu then published a blog post on the IRC website here: www.ircwash.org/blog/sanitation-and-health-what-do-we-want-know

I copy the starting paragraph:

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Sanitation and health: what do we want to know?
Published on: 01/08/2018

Jan Willem Rosenboom
Guest blogger | Sr. Program Officer, Water, Sanitation and Hygiene (WSH) team, Bill & Melinda Gates Foundation

Experts meet to discuss reaching a consensus on what the evidence tells us.

This is the first of two blogs written about the “Sanitation and health evidence consensus meeting”, convened by the World Health Organization (WHO) in Seattle on May 24 and 25 of 2018. It was written by Jan Willem Rosenboom and Radu Ban, who are both Sr. Program Officers on the Water, Sanitation and Hygiene (WSH) team at the Bill & Melinda Gates Foundation. This first blog will describe the process used to arrive at the consensus, while the second blog will describe the outcome of the consensus and will come out once the results of the consensus meeting have been published. Also, mark your calendars for a session during the 2018 UNC Water and Health conference dedicated to this consensus! *
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and I copy the end piece of the blog:

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Selected questions
1. How was the evidence we have so far produced?

There are two types of evidence:

Historical studies and cross-sectional evidence, which show a strong link between sanitation and child diarrhoea and growth
Randomised controlled trials (RCTs), which are limited to a 2-year period at most and show mixed results, with some studies finding a link while others do not (possibly due to threshold effects or poor implementation).
Have sustainability and non-household sanitation been taken into account?

2. Which outcome measures are most useful, or needed, for evaluating the performance of sanitation programs, to capture their impact both within and beyond health? Have toilet use and cleanliness, the (un)reliability of diarrhea as an indicator and local exposure routes been taken into account?

3. What can be drawn from the recent studies regarding the hypothesis that exposure to environmental pathogens contributes importantly to stunting?

4. To what extent should programme evaluation go hand-in-hand with impact evaluations? Lack of impact could be due to poor implementation or limited uptake.

5. What is the role of observational, non-experimental studies versus RCTs? Should we pay more attention to complex system modelling for sanitation investment decisions?

6. How can research results be interpreted for other settings? What is the external validity, and how can we increase our confidence in applying insights generally?

7. How important is herd immunity, habitual and exclusive use, and maintenance (cleaning, effective pit emptying and waste treatment)? Look at SaniPath studies: how much shit people are exposed to in their environment. Investments in sanitation alone may not be enough to impact health.

8. Are we able to say anything about the efficacy of reaching different rungs of the sanitation ladder for achieving health outcomes?

9. Given the reasonable theory-based view that the health impacts of sanitation interventions in high-density locations are likely to be dependent on intervention coverage levels: what evidence is available to support links between coverage levels and health effects? Can we achieve an expert consensus despite lack of strong empirical proof?

10. How much impact should anyone realistically expect ANY sanitation intervention to have when (a) young children, including infants, spend a substantial amount of time playing outside of the domestic house and yard, and (b) sanitation interventions do not install barriers between animal vectors and young children? Which minimum sanitation threshold needs to be reached in crowded, low-income settings to achieve a health impact?

What next?
Following the completion of the meeting, a few of the participants have been working on a consensus statement. Once that statement has been finalised, it will be published and at that point, we will release a second blog that will reflect on the consensus, in light of the questions that were asked.
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Thanks for keeping us informed about the progress in this consensus-seeking process!

Regards,
Elisabeth


* This conference:
The Water and Health Conference
www.cvent.com/events/water-and-health-20...6d03c56344d381d.aspx
October 29, 2018 - November 2, 2018
RALEIGH, North Carolina, USA

To the 22 individuals and organizations that responded to this call (through the Forum or by contacting us directly), a big Thank You!
On 24 and 25 May last week, WHO convened the "evidence consensus meeting" in Seattle and the consensus statement is currently in preparation; it will be published as soon as it is completed.

We received close to 70 questions, and not only from practitioners. Some were posed by researchers themselves, and they covered a wide range of important subjects, from research methods, to measures to use, programmatic approaches, the importance of the full sanitation chain (and other interventions, such as water supply and hygiene) as well as questions about study quality, and the validity of results.
Besides the formal results that will be published, I will put out two blogs that will go up on the IRCWaSH website as well as Sanitation Updates: one will summarize the questions we received and how we dealt with them in the meeting. The second will comment on the consensus statement once it goes public.

So for now, thanks again for sharing your questions and concerns, and stay tuned!

July 26 Update: Attached is an overview of all questions we received, summarized in a number of categories.
A first blog describing the run-up to the meeting will follow shortly we hope.

Hi Jan and Radu,

Here I would like share the study findings that CDD Society had conducted under Nexus Project last year, the program aimed on one hand to improve the sanitation situation of a community and on the other, worked on providing nutrient rich food by using the waste generated in the same community. The project involved reusing treated waste water from the wastewater treatment system in food production and distributing these produce to the community.

*From the field experiences of the pilot interventions in one of the housing colony, it was realized that since colony itself has very unhygienic environment due to poor solid waste disposal system, open storm water drains, flies all around, etc., we shouldn't limit our definition of sanitation improvement to wastewater treatment system. The project's aim to impact under nourishment cannot serve the purpose only through nutrient rich food, as the starting point is 'poor sanitation contributes to under-nutrition' and hence "Sanitation" can't be limited to Toilets and Treatments, there are many other parameters that leads to the unhealthy environment. *

*This study findings has helped to plan and implement the interventions needed in the colony for the remaining years under Nexus project and to further scale-up in future the Nexus approach of closing the sanitation loop by addressing issues related to sanitation, health and nutrition. Hence, a**s an outcome of this study the project has taken up a few interventions related to sanitation aspects like conducting IEC campaign for women and children on hygiene practices, solid waste management and on home gardening. * With the above background, my question is *when we say "Closing the sanitation loop by addressing issues related to sanitation, health and nutrition", are we also considering the issues related to solid wastes, hygiene practices or only limited to ' Toilets and treatments'?*

Regards Girija R CDD Society, Bengaluru

My question is, without sanitation can there be good health? Should sanitation researches be health based?

Thank you.

Dennis Ekwere
Focal Person
CYPLP Team
Nigeria.
www.cyplp.net.ng

This document nicely articulates some of the limitations in the WASHB and SHINE trials Om.

One other point to consider is that WASHB and SHINE might have had an impact on environmental contamination, even if they didn't impact health as expected (e.g. infection across multiple pathway). This is because both studies largely relied upon heavily on fecal coliforms (and some helminth ova assays) to measure intermediate environmental contamination. While fecal coliforms are relatively reliable proxies for risk for objects like drinking water and food, where the acceptable threshold of contamination is zero, indicator assays have been repeatedly shown to be poor proxies for assessing contamination levels for objects like soil, surface water, or objects.

From the microbial ecology point of view, it is highly improbable that there would NOT be E. coli or other coliforms everywhere. Bacteria are bacteria, and E. coli in particular are masters at niche tropism. They are shed by a broad variety of wild and domesticated animals, and are all over the place, and they survive in the environment far longer than most people are aware of. In our studies in Haiti, Kenya, and Iowa agricultural watersheds (in summer), E. coli and enterococci were detected in nearly 100% of all soil and surface water samples, at remarkably similar concentrations (evidence of quorum behavior, which is a topic for another thread). Furthermore, we find them even where obvious point or non-point fecal sources are not observed. If your indicator is omnipresent and non-obligate, it's not much of an indicator.

Much of the belief that E. coli doesn't last is probably derived from methodological issues. E. coli and many other types of bacteria can persist in the environment for prolonged periods of time in viable but non-recoverable states. The likelihood of being in a VBNR is influenced by the physical properties of the object, i.e. more likely on dry object surfaces, less likely in moist food or water. If bacteria are in a VBNR state, it requires a special enrichment step to trigger a replicative state. So studies that use indicator assays, without an enrichment step, to compare contamination levels from things like surfaces to food are reporting results that are biased by how well they account for VBNR conditions.

Ergo, the WASHB and SHINE environmental results are probably reasonable estimates of how well all of the different intervention arms affected drinking water quality, and thus drinking water quality linked health effects. But it's impossible at this point to know whether the sanitation arms did in fact reduce human-caused environmental contamination across ecological pathways (soil, objects). Proving this would go a long ways towards proving impact, even in the absence of health effects. I wouldn't be surprised if one of more of these groups have something up their sleeve though.

Interesting and looking forward to read the outcomes of these deliberations.

Previous research has looked at sanitation-either improved or unimproved or presence of toilets and its impact on health outcomes but little has been done to structure research in a way that disaggregation of data is possible i.e investigate and compare causality between rural and peri-urban (SLUMS) settings. From literature, unplanned urbanization is one factor associated with poor health outcomes, and the determinants for poor health in urban settings are varied and diverse from rural populations. In slums overcrowding and limited access to basic services means that environmental reservoirs like water and sanitation become more conducive for microorganisms to survive and increase infectivity. Research covering only rural settings doesn't show residential disparities in how sanitation causes poor health outcomes. WHO's role would also include building capacities of public health and researchers to enhance developing countrys surveillance on sanitation data
Climate change could also impact on how well sanitation systems are functioning. Increased precipitation causes collapsing of sanitation facilities and fecal waste overflows in slums and rural areas. in developing countries, sanitation entrepreneurs using in protective equipment compromise their health and those of communities especially during such instances when illegal dumping of fecal waste is likely to happen. Operations and maintenance aspects of the sanitation technologies need to be buffered against climate change.
Those two comment address the question on pre-conditions that are likely to affect effectiveness of sanitation systems.

Dear Arno,
On behalf of WaterAid, we have written a blog in response to WASH Benefits trial outcomes. Find the attachment and I hope this will be helpful for Jan Willem and his team.
Regards
Om

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Note by moderator (EvM): the mentioned WASH Benefits study has been discussed in this discussion thread (2 pages):
forum.susana.org/research-on-health-bene...s-study?limitstart=0

Hi Jan & Radu,

Agree with all observations made above and specifically with Arno's thoughts on the topic. I live in India in Chennai, Tamil Nadu. Whilst on a volunteering visit to Vellore, one of India's most popular medical tourist destinations, I happened to spend some volunteering time on understanding WaSH issues in poorer informal settlements (slums), which did not clearly have Government provided infrastructure in terms of electricity & water, forget Sanitation facilities, the residents drew up their own area plan maps, open defecation was prevalent with men & children, women set on foot to more private & secure places early in the day . To my eye there was clearly visible evidence of stunting, but the mothers were in denial of the same because to them every child in that slum was the same height, which was their normal.

So for me objective base-lining for impact becomes critical, an objective base-lining is a first step to measure impact, a comprehensive gaps analysis for the entire sanitation value chain and not just containment & collection aspects of it needs to be done. Local primary health centers, hospitals & pharmacies should be the fulcrum of epidemological data collection which can be regressed with water, food quality & AMR. Ideally if we start measuring intervention impacts in a controlled populations like residential schools for example, we can maybe track more reliable, regressive and relevant data which can then possibly be the benchmark in gaps analysis. Until such time we have a controlled sample it becomes very difficult to associate impact with an intervention. Look forward to the report out on the May Conclave. Best wishes to all

My view to the stated sanitation questions are the following:

1. Will sanitation and related interventions improve health and reduce poverty ?

2. Are factors of safety and convenience likely to impact on sanitation intervention?

Kind regards
Lucas Kunene

Arno
Good to hear from you
Try the pdf below

PDF/Water Aid; Tackling the silent killer The case for sanitation
www.wateraid.org/ng/~/media/Publications...e-for-sanitation.pdf

I googled Googeled it and it came up directly.
Fore more details try London School of Hygiene and Tropical Medicine.
They are definitively updated.

Best regards
Björn

Hello,

I know this is "wet" waste focused but I was wondering whether there is any room for including the health benefits of improved solid waste management in this as well? We are a much neglected sector and if you think there are gaps in data for WASH, then solid waste is even greater. There is growing evidence around these health benefits - my organisation, WasteAid, has recently put together a briefing note that, whilst focusing on marine plastics, also takes a good look at the evidence linking improved solid waste and health: wasteaid.org.uk/wp-content/uploads/2018/...-Land-to-the-Sea.pdf

I would also suggest there are close linkages between the potential of WASH interventions to improve health and improved solid waste management (e.g. building drainage systems that then block up with plastic waste, pit latrines blocking with plastic waste) so a holistic approach is important. I also think that the silos that separate WASH and solid waste are somewhat artificial - waste is waste after all.

Mike Webster