Thursday, October 20, 2016

Access to safe water and sanitation in the US

With the events in Flint, Michigan in the US, over the past year, there's been increased attention in the US to the state of water and sanitation across the country. While there has been a focus on the quality of large infrastructure services (the ASCE gives the US a "D" for drinking water and wastewater infrastructure), the recent national conversation has been moving toward discussions of environmental justice and race. As quoted in a recent NY Times article:
Crumbling infrastructure has been a theme of this country’s reinvigorated public conversation about race ...
However, as this same article explores, in rural Alabama, there are still places in the US that have never had adequate infrastructure.
But in poor, rural places like Lowndes County, there has never been much infrastructure to begin with....
Eli Seaborn, 73, a White Hall councilman, said progress would be slow, like the pace of civil rights gains, where legal discrimination is gone but lingers in other forms. Similar patience is required for sewage, he added. 
A paper published earlier this year found, in piped systems in Alabama, associations with GI illness and water quality (lack of total chlorine or presence of E. coli) and service delivery (low pressure or supply interruptions).

The language in Sustainable Development Goal 6 emphasizes universal and equitable access for all:
  1. By 2030, achieve universal and equitable access to safe and affordable drinking water for all
  2. By 2030, achieve access to adequate and equitable sanitation and hygiene for all and end open defecation, paying special attention to the needs of women and girls and those in vulnerable situations  
Will the US meet the SDG? Can the ongoing public conversation about race and increasing focus on environmental justice bring the US to ensure equitable and universal access to water and sanitation?

Saturday, October 15, 2016

Happy Global Handwashing Day!

Read about our work to make handwashing easier for settings lacking piped water:
Sophisticated Handwashing Without Piped Water: Designing the Povu Poa

Friday, October 7, 2016

Climate and health co-benefits in developing countries

On Wednesday, the threshold for entry into force of the Paris Agreement was achieved and the Agreement will go into effect on Nov 4, 2016. In our recent commentary "Climate and Health Co-Benefits in Low-Income Countries," we make the case for independent monitoring to be required for future carbon emission reduction projects. The Paris Agreement allows for an international carbon trading mechanism to be developed that will allow developed countries to purchase carbon credits from developing countries, where greenhouse gas emission projects usually cost less to implement. We evaluated a carbon financed water treatment filter project in Kenya - the Lifestraw Carbon for Water project - that delivered almost 900,000 filters free of charge to households in Western Kenya. We found much lower levels of usage of the filter than what has been reported by the program - 19% of households reported filter usage 2-3 years after filter distribution compared to program stated usage of 81%. The program is still selling carbon credits online claiming 1 credit is equivalent to 1 ton of C02 emissions reduced and safe water for a Kenyan family for 1 year. Independent monitoring of these types of projects could ensure they are achieving the environmental and health co-benefits they are designed to provide to low income communities. 

Wednesday, September 14, 2016

Environmental Transmission and the F-Diagram in LMICs

I recently published a perspective in Environmental Science: Processes and Impacts on the environmental transmission of enteric pathogens in low and middle income countries.  Its open access and available here.  I recommend you read it - not only because i wrote it - but also because it provides a detailed overview of the state of knowledge about environmental transmission.  I discuss the five most important enteric pathogens- Shigella spp., enterotoxigenic and enteropathogenic E. coli, rotavirus, and Cryptosporidium spp., how infective they are, how much people shed, and who they can infect.  I also discuss the state of knowledge about each of the major environmental reservoirs embedded in the F-diagram.  What I discovered while working on this may be obvious, but to me it was not: enteric pathogens are all completely different! Some are really infectious, others less so.  Some can grow in food and water, others can't.  Some infect household livestock, some only infect humans.  And so - obviously - how they end up in - and move through - the environment will be dramatically different too.  But, unfortunately, we frequently forgot this.  We talk about "enteric pathogens" as a single group, and we look for "diarrheal diseases" as a unifying symptom.  I think this is a mistake.  I think the characteristics of the enteric pathogens show that they are not all the same.  Although some strategies will certainly work against multiple enteric pathogens, there are no strategies that will be effective against all enteric pathogens. 

Wednesday, June 22, 2016

Silent infections

Just out in PLOS Neglected Tropical Diseases is a study that followed around 400 Bangladeshi children for their first two years of life. They found that more than three-quarters (77%) of the children became infected with Cryptosporidium spp at least once before reaching two years of age. Even more surprising is that 67% of these infections were asymptomatic, meaning that the children did not have diarrhea or other symptoms. The authors found that children with Cryptosporidium spp. infection had more than a 2-fold increased risk of severe stunting at age two compared to uninfected children. Aysmptomatic Cryptosporidium spp infections have previously been found to cause stunting among children in Peru, and asymptomatic Giardia infections in Brazil have also been linked to stunting. Silent infections are not limited to protozoa, a global case-control study found that 72% of children under five years with no clinical signs of diarrhea (controls) were infected with at least one pathogenic virus, bacteria, protozoan, or helminth and 31% were infected with two or more of these enteric pathogens. In Dhaka, Bangladesh, a median of 3 enteric pathogens was detected in non-diarrhea stool samples from children 0-12 months old. These studies contribute to growing evidence that asymptomatic infection with enteric pathogens is extremely common and has detrimental impacts on child growth among children in developing countries. Controlling silent infections in these settings will be difficult with treatment alone, suggesting prevention is necessary with environmental and behavioral interventions.

Thursday, May 26, 2016

Something that Probably Never Happened

I read, a lot, the following quote attributed to the U.S. Surgeon General William Stewart from a speech in 1967:
“The time has come to close the book on infectious diseases. We have basically wiped out infection in the United States.” 
The quote is often used in the context of how naive Dr. William Stewart - and the scientific community consensus at the time - was about the ubiquity and tenacity of infectious diseases.  The supposed motivation for the quote was the rise in use and effectiveness of antibiotics, which essentially "closed the book" on disease.  We have the cure!

Looking back from 2016, we see how ridiculous Dr. Stewarts' quote is.  Antibiotic resistance is now a global looming threat.  HIV/AIDS entered the U.S. a year before Dr. Stewart's supposed speech but t wouldn't be discovered for another 15 years.  And innumerable other infectious diseases have been discovered in the intervening years, including Ebola virus, norovirus, and Legonella pneumophila to name a very few.

So it is obvious that Dr. Stewarts' quote is ridiculous.  But what's less obvious is that Dr. Stewart probably never said it.  Bradford Spellberg discusses his failure to ever find a primary source for the quote in a 2008 comment in Clinical Infectious Diseases.  Perhaps its time to "close the book" on maligning Dr. Stewart.  Spellberg gives plenty of other examples of prestigious scientists who incorrectly assumed the age of infection was over - let's use them instead.

Wednesday, May 4, 2016

The Proposed Aggregate Exposure Pathway Concept

The cover for Environmental Science and Technology this week is about the Aggregate Exposure Pathway (AEP) concept, a proposal by  Justin Teeguarden at the Pacific Northwest National Laboratory (USA) and colleagues to organize exposure data from the pollutant source to the target site of action.  The proposal is framed around chemical exposures, and feeds in to the already established Adverse Outcome Pathway (AOP) concept from toxicology.  The goal of the AEP is to create a framework that contributes to the evolution of exposure data from an observational science to a predictive science.

How is this relevant to pipes and potties?  In the nutrition and water, sanitation, and hygiene sectors, we're seeing increasing interest in monitoring exposures to both chemicals and microorganisms.  The latter often includes assessments of exposures to both fecal contamination in general and to specific pathogens.  These exposure and risk assessments benefit substantially from advances in the chemical exposure models.

Which WASH interventions matter most for improving child growth?

In March I had the opportunity to join a panel of researchers at the WHO to discuss strategies for improving child growth and nutrition in urban India.  Throughout the 2-day workshop many references were made to the WASH Benefits and SHINE studies, which are ongoing randomized controlled trials of water, sanitation, hygiene and nutrition interventions in Kenya, Bangladesh and Zimbabwe. 

At the WHO workshop most WASH researchers agreed that handwashing is effective and cheapaccess to toilets significantly reduces stunting in young children, and water delivered close to the home is a foundation of health and well-being. But it's difficult to say conclusively which interventions matter most for child growth without knowing the results of SHINE and WASH-B. 

Some early indications of the SHINE trial's progress were published last December, and rumor has it the much anticipated findings of WASH-Benefits will be shared this year at the ASTMH Annual Meeting.  Even so, a new joint publication by the WHO, UNICEF and USAID makes a strong case for integrating WASH interventions into nutrition programs to improve health outcomes for some of the world’s most vulnerable populations.

Sunday, April 17, 2016

Interesting links on finance and WASH

Some interesting finance-related pieces that tie together nicely:

WaterAid put out a new report Water: At What Cost? The State of the World's Water 2016 that  contains this well-done infographic (h/t From Poverty to Power)

And, on the other side, the breakdown of charges on Antananarivo's piped water bills, through the excellent finance brief series on WASH on the site Public finance for WASH. The cost from the above infographic is water from the tanker truck; the more people that have access to piped water, which is paid for by the surcharge described in the finance brief, the lower the price will get. For example, the WaterAid report states that in Ethiopia, "Piped water from the utility company costs 20 times less than the price Biruktawit has to pay for water from a tap-stand vendor in Oromia, Ethiopia."

Wednesday, March 9, 2016

Safe Water in Schools in the US

Marc Edwards, a professor at Virginia Tech who has been leading the research and political pressure against lead in drinking water pipes for years (see for the VA Tech team's fantastic work in Flint), and Peter Gleick of the Pacific Institute have published a call for "Safe Water in Schools" to rebuild trust between residents of Flint, MI, and the public utility (if you haven't seen the crisis in Flint, MI, check out this for a timeline of what's unfolded in the last year).

The new Sustainable Development Goals for water will likely focus on access to safe water in schools; clearly the US has not achieved this SDG, given how many lead service lines are in fountains in elementary schools across the nation.

Their proposal includes:
"Require and implement a water-quality monitoring program for every school to regularly reconfirm the safety of the tap water and water fountains. For some schools, this program could include the participation of science programs and students, working with independent testing laboratories."
This is a sound and necessary proposal that could be appropriate in both developed and developing country contexts, especially in line with the new SDGs.

Monday, March 7, 2016

Which Sustainable Development Goals provide the most bang for the buck? A viewpoint from the Post-2015 Consensus.

The Copenhagen Consensus Center recently commissioned economists and political scientists across the globe - collectively termed the Post-2015 Consensus - to identify the most effective targets among those adopted by the Sustainable Development Goals. The approach: a cost-benefit analysis of each proposed target in terms of its return on investment (ROI).

Of the proposed 169 targets, the panel identified only 19 offering "bang for the buck," as defined by providing at least $15 on every dollar invested.

The bad news for the WASH sector is investments in water and sanitation (SDG 6) were only estimated to provide $3-6 for each dollar spent, according to the methodology used.  Interestingly, elimination of open defecation provided the greatest ROI among all WASH-related targets.  And ALL investments in water and sanitation were deemed more effective than the climate change adaptation target.

Bjørn Lomborg, director of the Copenhagen Consensus Center, explains some of the challenges and controversy underpinning this study in a recent episode of Freakonomics RadioLomborg argues that by attempting to prioritize everything, in the end you prioritize nothing.  He also suggests that even small efforts to improve the efficiency of the SDGs can have large and lasting postive impacts worldwide.

But I can't help but wonder ... does the analysis of SDG 6 take into account the mounting evidence regarding a link between environmental hygiene and child growth?  The Consensus Panel gives the target "reducing child malnutrition" a ROI of +$45, yet we know the best nutritional interventions have only been able to solve one third of the stunting problem (see slide at ~10 min). It is worth looking closer at how any cost-benefit analysis of WASH accounts for health impacts beyond the usual measures of diarrheal and respiratory disease.


Wednesday, February 3, 2016

Should child growth replace diarrhoea as the primary child health outcome for sanitation trials?

Check out our new commentary in the Lancet Global Health! Here's a key quote:

Although we agree that caregiver-reported diarrhoea can be a biased outcome, we see value in measuring the effect of sanitation interventions on more objective indicators of enteric infections.