Improved water and sanitation (WASH) is a key element in improved child nutritional status. Data pooled from nine longitudinal studies from Bangladesh, Brazil, Guinea-Bissau, Ghana and Peru), demonstrated that the adjusted odds of stunting at 24 months of age increased by a factor of 1.05 with each episode of diarrhoea in the first 24 months of a child’s life (Black et al., 2008). Of several disease prevention strategies that reduce the burden of infections (and hence affect nutritional status), hygiene interventions (hand washing, water quality treatment, sanitation and hygiene) are regarded as core to affect nutritional status (Bhutta et al., 2008). Gunther and Fink (2010) used 172 datasets from 70 countries to analyze the effects of access to water and sanitation on infant mortality and morbidity. Their cross-country analysis showed that access to improved water and sanitation reduced the incidence of diarrhea in children less than five years by 5–17 percent and showed a 5–20 percent reduction in infant mortality.

Further, where it has been carefully evaluated (e.g. Pattanayak, 2009), Community Led Total Sanitation (CLTS) has been shown to create defecation-free open spaces and rapidly increase latrine construction. It is not known whether this reduces diarrhoea rates, and the evidence so far is thin (Fewtrell et. al. 2005; Cairncross et. al. 2003).

Other studies have provided evidence of sanitation as a preventive intervention for stunting, such as in Peru (Checkley et al., 2004). Data collected in the late 1980’s from eight DHS datasets in Sub-Sahara Africa, Asia, North Africa, and the Americas were combined and analyzed (sample size almost 17,000). Improvements in sanitation were associated with increases in height ranging from 0.8cm to 1.9cm but differences of such magnitude are not always found following nutritional interventions.

Esrey (1996) also established a 13–44 % reduction in diarrhea with access to flush toilets and an 8.5 % reduction with latrines, concluding that access to good sanitation has greater effects on health than access to good water. However, Gunther and Fink (2010) faulted this study because it included only 8 countries of the 63 countries with available DHS datasets in 1995. Waddington et al. (2009), on the other hand, in a global review showed that improved sanitation led to a reduction of 37 percent in the incidence of diarrhea, but saw no significant effect from improved water accessibility.

Improved sanitation also has an important role to play in reducing the transmission of soil-transmitted helminthes (STH). STH are one of the world’s most important causes of physical and intellectual growth retardation. It is estimated that 47% of children in the developing world between the ages 5-9 are infected with any of the three main types of STH: hookworm, or roundworm, or whipworm (Maternal and Child Nutrition 2008). It has been reported that Ascaris diverts about one third of the nutritional intake of a child with a typical worm burden. Hookworm is a major cause of anaemia. Trichuris is a serious cause of stunting in children.

A meta-analysis of the effects of de-worming studies on nutrition status of children showed the potential of administering anthelmintic drugs to reduce the burden of worms. (Hall et al, 2008). It was not possible to be conclusive about the absolute magnitude of any effects of giving treatment. Nevertheless, it was indicated that if the prevalence of intestinal nematodes is 50% or more, then giving anthelmintic drugs leads to significant extra gains in weight, height, mid-upper arm circumference and skinfold thickness in comparison with untreated controls. As this is a meta review, the information varies case by case, all of the children range in age between 1-15, usually either primary school or secondary school focussed, however with some overlap. The study was global with studies from 23 countries (although Nigeria was not one of them). The participating children showed an average weight gain of 210gm in children (a considerable average impact in terms of nutritional status). Yet, de-worming is essentially an end-of-pipe solution (WHO, 2007): reinfection rates are relatively high after treatment. For example, in a study of over 1800 children in Brazil, Moraes and Cairncross (2004) found that sewerage and drainage infrastructure could significantly reduce transmission (and reinfection).

This suggests that long-term strategies incorporating education on personal hygiene, provision of toilets and of access to safe water are important elements in strategies to sustainably reduce the disease (WHO 2007) and thereby improve child nutrition.