Jennyfer Wolf, Richard Johnston, Matthew C Freeman and Annette Prüss-Ustün
Handwashing with soap after faecal contact is key to preventing disease and death from enteric infectious diseases. Our study, recently published in the IJE, is the first to provide global, regional and country estimates of handwashing with soap after potential contact with human faeces, based on representative data on access to handwashing facilities collected for monitoring of the Sustainable Development Goals (SDGs). Our results show that handwashing with soap after using the toilet or other potential contact with human faeces is poorly practised worldwide and that even the necessary equipment – handwashing facilities with soap and water – are inaccessible to billions of people.
The SDGs now explicitly include the presence of handwashing facilities with soap and water in indicator 6.2.1. Given that handwashing with soap is believed to be one of the most cost-effective public health interventions, this additional target elevates the importance of personal hygiene compared with the preceding Millennium Development Goals, which did not include a handwashing indicator. In addition, handwashing with soap – as a proxy or indirect measure for hygiene – is now also being included in burden of disease analyses, which provide a comprehensive picture of health loss from diseases, injuries and risk factors.
Although the addition of a proxy measure for hygiene is an encouraging step, the results of our analysis strongly question the approach of equating access to handwashing facilities with actual handwashing behaviour. We estimate that 74% of the world’s population have access to handwashing facilities with soap and water, but only 26% of events in which hands are potentially contaminated with human faeces are followed by handwashing with soap. Global analysis of the burden of disease needs to reflect this difference between access to and use of handwashing facilities.
Furthermore, both access to handwashing facilities and use of such facilities when they are present showed large regional variations. We estimate that access to soap and water in the home is near-universal in high-income countries, and about half of potential faecal contacts are followed by handwashing with soap and water in these settings. In contrast, in low- and middle-income countries of Africa, only about 18% of people have access to handwashing facilities in the home, and only 14% of those with access are likely to wash their hands after potential contact with faecal matter. The areas where the burden of infectious disease is highest are the same areas where handwashing is least likely to occur; even in households with the necessary materials at hand.
Novel approaches must be developed and scaled to rapidly improve access to and use of handwashing facilities, especially in low- and middle-income settings, to prevent endemic infectious diseases and to mitigate epidemics, such as Ebola virus and cholera. It is clear that simple health-based promotional approaches have not been effective in changing behaviour. We encourage the use of well-established behavioural theory, in both the formative research and intervention design phases, to address context-specific challenges and influence critical pathways for behaviour change and habit formation, such as social norms, social support, cues and reminders, and self-efficacy. Examples include the “behaviour change wheel” and the RANAS (Risks, Attitudes, Norms, Abilities and Self-regulation) approach to systematic behaviour change, both of which can be used for intervention development.
Finally, hygiene is multifaceted and considerably broader than simply handwashing, encompassing behaviour such as bathing and face washing, menstrual hygiene, food hygiene and the correct management of child and animal faeces. Public health interventions and associated monitoring schemes should widen their focus to incorporate all of these behaviours.
Wolf J, Johnston R, Freeman MC, et al. Handwashing with soap after potential faecal contact. Int J Epidemiol 2018; dyy253. https://doi.org/10.1093/ije/dyy253
Jennyfer Wolf is a public health doctor with training in epidemiology and a consultant for the Department of Public Health, Environmental and Social Determinants of Health at the World Health Organization.
Richard Johnston is an environmental engineer and technical officer for water, sanitation and hygiene at the Department of Public Health, Environmental and Social Determinants of Health at the World Health Organization.
Matthew Freeman is an associate professor in the Department of Environmental Health at the Rollins School of Public Health at Emory University.
Annette Prüss-Ustün is an epidemiologist and team leader of Assessment of Environmental Health Impacts at the Department of Public Health, Environmental and Social Determinants of Health at the World Health Organization.