Sanitation and hygiene: undernutrition’s blind spot

02 May 2012

The effects of undernutrition

The undernutrition of babies, infants and children is horrible and a disgraceful blot on our human record. It is not just the immediate suffering, anguish and death. It is also the lasting impact: when stunted at age 2 the damage is largely irreversible. Stunted children are disadvantaged for life – their cognition and immune systems impaired, and their education and earning prospects reduced. Stunting leads to a 10 per cent decrease in lifetime earning. Stunted children start school 7 months later and attend 0.7 years less.

So undernutrition cries out for action and there is plenty of action. The normal, commonsense, humane response is direct and visible – to get more nutrients and food into babies, infants and children. To get it into their mouths. Who could be against that? Not me. It is so obvious, so necessary, so important, so urgent, with such immediate results.

Faecal infections- the missing link?

But, and it is a monumental but, has this distracted attention from a major, and outside famines and acute seasonal crises, I will dare to ask even the main cause: faecally-related infections(FRIs)? Come on, I can imagine you thinking, is he losing his senses? Well.

Environmental enteropathy- the tip of the iceberg?

I have recently seen a video of a presentation made by Dr Jean Humphrey in India, and met her, and heard her at DFID. She works in Zimbabwe and in the Lancet of 19th September 2009 famously argued with convincing evidence that environmental enteropathy (EE) is a more significant cause of undernutrition than diarrhoea. EE is a persistent subclinical condition in which infections damage and reduce the absorptive capacity of the gut and at the same time make it permeable so that nutrient energy has to be continuously diverted to make antibodies to fight the infection. EE is a multisystem disorder, a ‘profound immune system disorder’ which moreover weakens the immune system later in life. That Lancet article stirred things up, and she is now engaged in long-term rigorous field research into EE. She and others are now saying that diarrhoea is just the tip of the iceberg. I agree. But what an iceberg, not just EE!

Here are some bullet points. Are they right?

Diarrhoeas

How significant are the diarrhoeas as causes of undernutrition?

  • Because among faecally-related infections, they are so dramatic, awful, visible and episodic, and so easily measurable, the diarrhoeas have received and continue to receive the major professional attention. Many other conditions are subclinical, continuous, invisible and hard or impossible to measure. The multiple dimensions of EE are a very significant part of this.
  • With oral rehydration therapy, diarrhoeas are less damaging than they were
  • There is rapid recovery between bouts of diarrhoea
  • Studies of the effect of diarrhoeas on linear growth show effects in the range of only 5-20 per cent, and some show none at all
  • In the Gambia where the Dunn Nutrition Laboratory has been doing research for many decades there has been a big drop on the incidence of diarrhoea 1979 – 1993 but no change in stunting. They have found stunting is not explained by inadequate diet or days of diarrhoea!
    The misleading conclusion could be drawn that since diarrhoeas are not so much implicated in undernutrition, sanitation and hygiene are not so important either, and that FRIs in general are not so signficiant

Feeding programmes

What is the evidence of the impact of feeding programmes?

  • A review of 42 studies of feeding programmes found that the very best solved only one third of the problem and some had no effect at all
  • No nutrition intervention has ever normalised linear growth

Faecally-related infections (FRIs)

FRIs are much more than the diarrhoeas and EE.

  • The variety and scale of these infections is quite mind-blowing. There are intestinal parasites – bacterial like gardia (extremely widespread), amoebiasis, and worms like ascaris (1.5 billion infected) that steal food and hookworm (over 700 million infected, 200 million in India) which voraciously consumes blood from the host, and tapeworms which come through intermediate hosts. There are hepatitis A, B and E, typhoid fever, polio and other enteroviruses, schistosomiasis (over 200 million, more than half in Africa), liverfluke, trachoma, and various zoonoses from animals (in addition to tapeworms)’.

So there is much, much more to the iceberg of which the diarrhoeas are the tip, than EE. No one so far has been able to point me to a study of how many of these infections are found in any one undernourished infant or child, nor how they interact. So my question to those who work in nutrition and those who work on faecally-related infections, is this: Does professional specialisation prevent us seeing the enormity of the whole picture? And is the implication of the whole picture that sanitation and hygiene are not only a huge priority in eliminating undernutrition but even, bar famines and seasonal crises, possibly the main means?

Consider India. The latest data indicate that India has 59.4 per cent, almost three fifths, of the open defecation in the world, a proportion which has risen in the past decade. It also has a third of the undernourished children, a figure which has largely resisted herculean attempts to tackle it directly through the mouth with school meals, ration cards and the like. Imagine if suddenly all FRIs were caught and confined safely just below the anus. How much undernutrition would remain?

Robert Chambers is Research Associate at the Institute of Development Studies, Brighton