As a researcher in the field of sanitation, I am very much looking forward to reading the outcome of the May meetings. One aspect I thought I would add is around whether specific individuals are more susceptible to improvements in sanitation? I am in particular thinking about gender. A recent study of mine with Paul Lesmes shows that improvements in sanitation lead to improved child health, and that this effect is particularly driven by girls (www.sciencedirect.com/science/article/pii/S0305750X18300433). And we were not the only ones to find this gender dimension. Of course, this might be very much linked to the question on pre-conditions, but possibly interesting to consider.
Best wishes,
Britta

I very much agree with the points that Kelly and Arno have made. It's probably next to impossible to single out sanitation (and even limited to: toilets) on their own as there are so many more parameters that lead to a healthy, "sanitary" environment. Toilets are a very much needed piece of the puzzle but without the other pieces of the puzzle it may not have much measurable impact on the community's health.

Another thought that I had: Would this discussion on health evidence also consider how improved sanitation can help curb antimicrobial resistance (AMR)?

Arno summed up the issues nicely in various forum posts here: forum.susana.org/254-micro-pollutants-ph...-chemical-pollutants
We also wrote a paragaph about it in the Wikipedia article on AMR here:
en.wikipedia.org/wiki/Antimicrobial_resi...anitation%2C_hygiene

Water, sanitation, hygiene [edit | edit source]

Infectious disease control through improved water, sanitation and hygiene (WASH) infrastructure needs to be placed at the center of the antimicrobial resistance (AMR) agenda. The spread of infectious diseases caused by inadequate WASH standards is a major driver of antibiotic demand in developing countries.[34] Growing usage of antibiotics together with persistent infectious disease levels have led to a dangerous cycle in which reliance on antimicrobials increases while the efficacy of drugs diminishes.[34] The proper use of infrastructure for water, sanitation and hygiene (WASH) can result in a 47–72 percent decrease of diarrhea cases treated with antibiotics depending on the type of intervention and its effectiveness.[34] A reduction of the diarrhea disease burden through improved infrastructure would result in large decreases in the number of diarrhea cases treated with antibiotics. This was estimated as ranging from 5 million in Brazil to up to 590 million in India by the year 2030.[34] The strong link between increased consumption and resistance indicates that this will directly mitigate the accelerating spread of AMR.[34] Sanitation and water for all by 2030 is Goal Number 6 of the Sustainable Development Goals.

An increase in hand washing compliance by hospital staff results in decreased rates of resistant organisms.[92]

And if sanitation is meant to include wastewater treatment (which it should), then more advanced treatment of hospital wastewater could be another route where sanitation can help to combat AMR.

Coming back to Jan-Willem's post where he said:
"Are particular sanitation interventions more likely to have protective effects?"
we should make sure we all have the same understanding what we mean with "sanitation interventions". I think many of the randomized controlled trials conducted recently looked only at toilet use at the household level, and maybe handwashing, but not at broader sanitation issues, such as animal feces (Kelly's post above), toilets away from home, hospital wastewater, municipal wastewater, drainage, solid waste, fecal sludge management.


Elisabeth

Jan Willem/Radu

The UNICEF publication by Joanna Esteves Mills and Oliver Cummings from 2016 www.unicef.org/wash/files/The_Impact_of_...view_of_Evidence.pdf

will be useful in categorizing the discussion. It provides evidence for WASH impact in the following areas:
diarrhoea
undernutrition
complementary food hygiene
female psycho-social stress
maternal and newborne health
menstrual hygiene management
school attendance
oral vaccine performance
NTDs
disability

I think if one bundles access to safe water with sanitation then the evidence for improved health parameters will become significant. If on the other hand one restricts the lens to toilets and sanitation systems, the level of significance may drop mainly due to noise in the epidemiological data. Levels and types of sanitation create this variability.

This is shown in "The impact of sanitation on infectious disease and nutritional status: A systematic review and meta-analysis" by Freeman et al. 2017. www.sciencedirect.com/science/article/pii/S1438463917301529


That the British Medical Journal in its 2007 survey found 11300 of its readers voting that the sanitary revolution (clean water and sewage disposal) was the most significant medical milestone since 1840 is again evidence that safe water and sanitation must go hand in hand in the discussion surrounding evidence. www.ncbi.nlm.nih.gov/pmc/articles/PMC1779856/

Regards

Hi Jan and Radu,

I realize this thread is aimed at practioners, but I just wanted to bring up another point as a sanitation research that would be worthwhile for considering at your meeting. Understanding the relative benefits of particular sanitation typologies and the pre-conditions that impact the effectiveness of interventions is important. However, there are some higher level issues raised by WASH B and SHINE, which are 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 zoonotic vectors and young children and how do you measure the impact of sanitation. I am sure giving one household a latrine reduces the risk of child infection by some fraction of a point. Spatially clustering household latrine implementation probably has an even bigger impact. But there is a threshold of environmental safety that can be achieved without addressing domestic animal management and the blurring of public-private boundaries of life in crowded, low income settings. If researchers don't acknowledge that baseline and use appropriate tools that can distinguish between human and animal sources of enteric pathogens, you probably won't accurately quantify the true impact that can be gained from sanitation. WASH B and SHINE didn't really measure the impacts of their trials in a way that would allow extraction of this type of information, which still leaves the overall question as how much have we really learned about the impact of sanitation in a world swimming in animal shit.

Best,

Kelly

Colleagues,

Following the publication of results from a number of recent studies investigating links between improvements in sanitation and health (such as the WaSHBenefits study, studies in Tamil Nadu, Madya Pradesh and Orissa in India and others) some of you have contacted us with questions and concerns about the seeming lack of consensus about the relationship between sanitation and health demonstrated in those studies.

Looking at a number of historical studies, it is hard to imagine that improvements in sanitation did not play a significant role in improving population health. And indeed, older as well as more recent historical evidence from US, Europe and developing countries establish causal relationships between sanitation and health. However, when considering more granular evidence considering the effects of individual and categories of interventions, there is less alignment.

Understandably, this has led to concerns about the meaning of this evidence, and questions about how it should be interpreted and used by practitioners, working to design and implement sanitation programs.

Partly in response to those concerns, WHO is convening an expert meeting in May this year, to develop a “consensus statement” around two specific questions:
• Are particular sanitation interventions more likely to have protective effects?
• What pre-conditions are likely to impact the effectiveness of these sanitation interventions?

The meeting will bring together researchers, from both life and social science backgrounds from around the world for two days of deliberations, informed by evidence and identifying points of agreement and contention. The MEDS team at the foundation strongly supports the organization of this meeting, and to make sure that issues relevant to practitioners are considered (and hopefully answered) during the discussions, we would like to invite you to share with us the most important questions you (and your teams) face when considering the use of evidence in program design.

The consensus meeting is scheduled to take place on May 24 and 25. To allow for review and incorporation into the agenda, the deadline for the submission of questions for consideration is end of day Thursday May 17.

There is no particular format for submission, although when we say we are looking for questions, we mean just that; a short sentence with a question mark at the end (no need to over-think it). If you are concerned that there is the possibility of mis-interpretation, you should feel free to provide some context and explanation.

Following the meeting, the results will be published and broadly disseminated.

We look forward to hearing from you what concerns you. If you have any questions about the process (or the scope) of this effort, please feel free to get in touch.

Best regards,
Jan Willem Rosenboom and Radu Ban.