By observing handwashing behavior in 347 households from 50 villages across rural Bangladesh in 2007, Stephen Luby and colleagues found that hand washing with soap or hand rinsing without soap before food preparation can both reduce the burden of childhood diarrhea.
Standard public health interventions to improve hand hygiene in communities with high levels of child mortality encourage community residents to wash their hands with soap at five separate key times, a recommendation that would require mothers living in impoverished households to typically wash hands with soap more than ten times per day. We analyzed data from households that received no intervention in a large prospective project evaluation to assess the relationship between observed handwashing behavior and subsequent diarrhea.
Fieldworkers conducted a 5-hour structured observation and a cross-sectional survey in 347 households from 50 villages across rural Bangladesh in 2007. For the subsequent 2 years, a trained community resident visited each of the enrolled households every month and collected information on the occurrence of diarrhea in the preceding 48 hours among household residents under the age of 5 years. Compared with children living in households where persons prepared food without washing their hands, children living in households where the food preparer washed at least one hand with water only (odds ratio [OR] = 0.78; 95% confidence interval [CI] = 0.57–1.05), washed both hands with water only (OR = 0.67; 95% CI = 0.51–0.89), or washed at least one hand with soap (OR = 0.30; 95% CI = 0.19–0.47) had less diarrhea. In households where residents washed at least one hand with soap after defecation, children had less diarrhea (OR = 0.45; 95% CI = 0.26–0.77). There was no significant association between handwashing with or without soap before feeding a child, before eating, or after cleaning a child's anus who defecated and subsequent child diarrhea.
The resurgence of donor interest in regarding water and sanitation as fundamental public health issues has been a welcome step forward and will do much to improve the health of the 1.1 billion people world-wide without access to clean water and the 2.4 billion without access to improved sanitation. However, improving hygiene practices is also very important—studies have consistently shown that handwashing with soap reduces childhood diarrheal disease—but in reality is particularly difficult to do as this activity involves complex behavioral changes. Therefore although public health programs in communities with high child mortality commonly promote handwashing with soap, this practice is still uncommon and washing hands with water only is still common practice—partly because of the high cost of soap relative to income, the risk that conveniently placed soap would be stolen or wasted, and the inconvenience of fetching soap.
Handwashing promotion programs often focus on five “key times” for handwashing with soap—after defecation, after handling child feces or cleaning a child's anus, before preparing food, before feeding a child, and before eating—which would require requesting busy impoverished mothers to wash their hands with soap more than ten times a day.
In addition to encouraging handwashing only at the most critical times, clarifying whether handwashing with water alone, a behavior that is seemingly much easier for people to practice, but for which there is little evidence, may be a way forward. In order to guide more focused and evidence-based recommendations, the researchers evaluated the control group of a large handwashing, hygiene/sanitation, and water quality improvement program—Sanitation, Hygiene Education and Water supply-Bangladesh (SHEWA-B), organized and supported by the Bangladesh Government, UNICEF, and the UK's Department for International Development. The researchers analyzed the relationship between handwashing behavior as observed at baseline and the subsequent experience of child diarrhea in participating households to identify which specific handwashing behaviors were associated with less diarrhea in young children.
The SHEWA-B intervention targeted 19.6 million people in rural Bangladesh in 68 subdistricts. In this study and with community and household consent, the researchers organized trained field workers, using a pretested instrument, to note handwashing behavior at key times and recorded handwashing behavior of all observed household at baseline in 50 randomly selected villages that served as nonintervention control households to compare with outcomes to communities receiving the SHEWA-B program. The fieldworkers recruited community monitors, female village residents who completed 3 days training on how to administer the monthly diarrhea survey, to record the frequency of diarrhea in children aged less than 3 years in control households for the subsequent two years. The researchers used statistical models to evaluate the association between the exposure variables (household characteristics and observed handwashing) and diarrhea.
Using these methods, the researchers found that compared to no handwashing at all before food preparation, children living in households where the food preparer washed at least one hand with water only, washed both hands with water only, or washed at least one hand with soap, had less diarrhea with odds ratios (ORs) of 0.78, 0.67, and 0.19, respectively. In households where residents washed at least one hand with soap after defecation, children had less diarrhea (OR = 0.45), but there was no significant association between handwashing with or without soap before feeding a child, before eating, or after cleaning a child's anus, and subsequent child diarrhea.
These findings from 50 villages across rural Bangladesh where fecal environmental contamination, undernutrition, and diarrhea are common, suggest that handwashing before preparing food is a particularly important opportunity to prevent childhood diarrhea, and also that handwashing with water alone can significantly reduce childhood diarrhea. In contrast to current standard recommendations, these results suggest that promoting handwashing exclusively with soap may be unwarranted. Handwashing with water alone might be seen as a step on the handwashing ladder: handwashing with water is good; handwashing with soap is better. Therefore, handwashing promotion programs in rural Bangladesh should not attempt to modify handwashing behavior at all five key times, but rather, should focus primarily on handwashing after defecation and before food preparation. Furthermore, research to develop and evaluate handwashing messages that account for the limited time and soap supplies available for low-income families, and are focused on those behaviors where there is the strongest evidence for a health benefit could help identify more effective strategies.
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A four-part collection of Policy Forum articles published in November 2010 in PLoS Medicine, called “Water and Sanitation,” provides information on water, sanitation, and hygiene
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