Expanding the WASH Perspective: How do Water, Animals, Sanitation, and Hygiene Relate to Child Height?.

摘要

The lack of safe water, sanitation, and hygiene (specifically hand washing) (WASH) is responsible for millions of cases of infectious diarrhea in children under five. Childhood enteric infections lead to malnutrition, inflammation, and ultimately, stunted growth. Low height-for-age (HAZ) (i.e., stunting) is associated with diminished cognition, suppressed immunity, and reduced economic productivity in adulthood. Although the underlying framework between WASH and child height is well established, the empirical evidence is limited. The question of whether the individual components of household WASH are synergistic in relation to child height remains unanswered, as does the problem of whether household and neighborhood WASH act together to influence child height. One reason for the inconsistency is that observational WASH studies often do not adjust for child dietary intake. Another reason is that WASH research has focused on human fecal contamination, but in impoverished areas where households depend on domestic animals for food and income, domestic animal feces may also play a role in child height.;This dissertation is comprised of three papers on the relationship between child HAZ and water, animals, sanitation, and hygiene. We used the 2011 Uganda Demographic and Health Survey to perform multiple linear regressions adjusted for dietary intake of children under two. Paper 1 evaluated the relationship between child HAZ and household ownership of native cattle, nonnative cattle, goats, sheep, chickens, and pigs. We found that nonnative cattle ownership was positively associated with HAZ in rural children 0 to < 2 years old (+1.32 HAZ; 95% confidence interval [CI]: 0.2 to 2.5) and 2 to < 5 years old (+0.58 HAZ; 95% CI: 0.003 to 1.2), and urban children 2 to < 5 years old (+1.08 HAZ; 95% CI: 0.38 to 1.8). Sheep ownership was positively associated with HAZ in rural children 2 to < 5 years old (+0.29 HAZ; 95% CI: 0.002 to 0.58) and goat ownership was positively associated with HAZ in rural children 0 to < 2 years old (+0.27 HAZ; 95% CI: 0.003 to 0.55). Children that lived in households that owned nonnative cattle consumed dairy more frequently; yet the relationship between child HAZ and nonnative cattle ownership was not mediated by child dairy consumption. Paper 2 evaluated the relationship between HAZ of children under five and the individual and combined elements of household water, sanitation, and hygiene. We found that water treatment was positively associated with HAZ in rural households (+0.25 HAZ; 95% CI: 0.02 to 0.41), and that hand washing with water and soap was positively associated with HAZ in urban households (+0.43 HAZ; 95% CI: 0.02 to 0.6). In addition, we used a Guttman scale to determine that most households adopted WASH improvements in the following order: 1) Drinking water, 2) water treatment, 3) sanitation, and 4) hand washing with water and soap. Paper 3 evaluated the relationship of child HAZ with the combined effect of neighborhood and household sanitation, as well as with the effect of neighborhood ownership of goats, chickens, and pigs. We observed that improved sanitation of the surrounding households had a significant benefit for the height of children who lived in households with unimproved sanitation infrastructure, but we did not observe this relationship for children who lived in households with existing improved sanitation. We also found a positive relationship between child HAZ and neighborhood goat ownership (+0.006; 95% CI: 0.002 to 0.01) in rural areas, but no evidence for a mediating effect of meat or dairy consumption.;This research indicates that the WASH sector continue to prioritize the prevention of child exposure to human fecal contamination in the household and neighborhood. Sanitation may be a primary building block for child height, since children from unsanitary households can benefit from the sanitation investments of their neighbors. We found that domestic animals may not be detrimental to child height, and that ownership of nonnative cattle, sheep, and goats is beneficial for child height. The dual provision of household and neighborhood sanitation, optimal child feeding, and promotion of modifiable WASH behaviors such as water treatment and hand washing, may be effective approaches to prevent stunting.