Post by: Sophie Budge
Where: Sidama zone, SNNPR, southern Ethiopia
When: December 2017 – ongoing
Partners: People in Need, Hawassa, Ethiopia; Hawassa University College of Medicine & Health Sciences, Hawassa, Ethiopia
In November 2016, The Guardian posted an article highlighting the critical role of sanitation in reducing infant deaths from diarrhoea and malnutrition. Clear and articulate, the link is clear. It’s estimated that diarrhoea kills around half a million children under five every year, with a large proportion of deaths due to poor WASH (Water, Sanitation and Hygiene). Correspondingly, a large reduction in infant mortality since the mid-90s seems at least in part down to investments in even basic sanitation . There’s been a significant increase in coverage of improved WASH since the millennium – but whilst diarrhoeal mortality is down , diarrhoeal episodes largely haven’t decreased  and malnutrition has risen in some areas. We simply aren’t successfully preventing infection in the first place.
After decades of research, the link between nutrition, infection and malnutrition is unclear. Efforts continue to determine the exact causes of stunting in particular, a definition used to categorise children who fail to reach an average height for their age. Whilst other forms of malnutrition, such as wasting (low weight-for-height), reflect a child’s current nutritional status, stunting is the best indicator of a child’s overall well being and of social inequality and environmental conditions . It’s therefore no surprise that causes operate at multiple levels. These range from the furthest (distal) factors (e.g. socioeconomic and political variables) through to mid-level variables (maternal education, women’s empowerment, poor healthcare facilities) to the more immediate (proximal) factors (quantity and quality of food, infection, low birth weight). A while back UNICEF developed a framework to identify these factors – a strong operational base for both researchers and implementers.
Rationally, there can’t be a magic bullet to such a multifaceted issue. Once, a poor diet was thought to be the main contributor to malnutrition. Makes sense: food is fuel. And there’s evidence that some interventions support growth – for example, micronutrient supplementation (zinc, vitamin A) or improved breastfeeding . However even if we massively scaled up these interventions, we’d probably only prevent around a fifth of stunting . Diarrhoea is another posited immediate cause. Repeated bouts during infancy means a lot of nutrient losses and the diarrhoea-infection-malnutrition cycle is vicious: undernourished children are at higher risk of infections and of death from diarrhoea. But diarrhoea surely suggests infection – and that’s where WASH comes in.
WASH, by design, should prevent infection by blocking the transmission routes whereby pathogens reach us (see examples on page 26 here). In a perfect world, better WASH = reduced pathogen transmission = less infections = improved growth. Straightforward right? Unfortunately, apparently not. Recent large, very well designed trials assessing WASH and child health outcomes haven’t shown anything consistent  and the WASH world is left questioning: do improvements in WASH lead to improvements in infant health? And when? Reviews of the evidence say yes, but also gains are smaller than we anticipate. In our bid to further progress, it may be that we’re just not thinking broadly enough.
In populations where WASH infrastructure is poor, faecal contamination is widespread. Where there’s little water and measures to prevent transmission, people are frequently exposed to enteropathogens through contaminated water, food and objects which handwashing may not overcome. Normal age-related behaviours means infants have an increased infection risk from multiple transmission routes, including from their own contaminated hands and floors. We don’t yet fully understand how pathogens move through the environment and reach us. However, it’s apparent that over 60% of infectious diseases are caused by zoonotic (animal transmitted) pathogens  and globally, 86% of environmental faecal contamination comes from livestock . Yet strangely, WASH intervention design remains stubbornly focused on containing and eliminating the burden of contamination from human faeces – overlooking the fact that when humans and animals live together, the pathogen load is greater. Zoonotic infection is associated with diarrhoea, stunting, and dysfunction of the gut (for a good review see here). There’s a lot of confusion over the benefits versus risks of domestic animal ownership, and confounding is problematic, but continued exposure to animal faeces is an overlooked risk factor in disease transmission. It seems obvious that the dirtier our environment, the less healthy we’re likely to be. Decades of animal literature show animals don’t grow in dirty and contaminated conditions  and poor environmental hygiene is linked to malnutrition, even independent of diarrhoea [6,8,9]. Thus beyond providing basic WASH to households, there’s a high socioeconomic (i.e. hygiene) threshold that societies must reach to overcome malnutrition . Achieving that level necessitates adequate WASH (particularly piped water), but also improved dietary quality and quantity, good housing and, importantly, hygienic animal husbandry practices – including the separation of animals and people within the home. Whist these things may not be sufficient alone, they are necessary components of good environmental hygiene and to reduce pathogen transmission.
This mostly sums up my research. Over the past couple of years, I, my supervisors and the team at People in Need have reviewed correlations between malnutrition, infection, WASH and transmission pathways within the home, described the relationship between household contamination and domestic animal husbandry in Sidama zone, Ethiopia and more specifically links between infant Campylobacter infection, poultry ownership and malnutrition (paper under review). In early 2020, we launch the CAMPI trial (Campylobacter-Associated Malnutrition Play space Intervention trial) – a randomised, controlled feasibility trial of a household play space to reduce infant Campylobacter infection in Sidama, SNNPR, Ethiopia. Whilst the trial primarily aims to evaluate feasibility, we hope to provide further evidence for the exposure-infection hypothesis and possible solutions to help reduce infant infection in rural, subsistence settings. Tackling the remaining global burden of diarrhoea and malnutrition will mean addressing all factors, from the very distal to the most proximal. A play space alone won’t be sufficient, but while our evidence base , shared will and technical guidance to do something truly ‘transformative’ grows – and until societies reach that critical threshold – perhaps it’s a necessary component. We’ll let you know what we find.
Sophie Budge is a PhD student at Cranfield University with People in Need and runs the WASHing Up site. She is interested in global child health, epidemiology and nutrition.
You can follow her on twitter here.
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