Handwashing with soap could halve the incidence of diarrhoea in children in developing countries

Handwashing with soap could halve the incidence of diarrhoea and lower respiratory infections in children in developing countries, concludes a study published in this week’s issue of The Lancet.

Every year more than 3·5 million children aged less than 5 years die from diarrhoea and acute lower respiratory tract infection, making these two clinical syndromes the largest cause of childhood deaths globally.

Stephen Luby (Centers for Disease Control and Prevention CDC, Atlanta, GA, USA) and colleagues did a randomised controlled trial in adjoining squatter settlements in Karachi, Pakistan, to measure the broad health benefits brought about by improvement of handwashing and bathing with soap. The investigators recruited 36 neighbourhoods to take part in the study. 600 households in these neighbourhoods were assigned to handwashing promotion and 300 to control. Half the households in the handwashing promotion group were given antibacterial soap and half received plain soap. Fieldworkers visted households at least once a week for a year to distribute the soap and encourage handwashing and to record all symptoms in the household. The researchers found that hand washing with soap reduced the incidence of pneumonia by 50% in children under 5 when compared with controls. Handwashing also reduced also the incidence of diarrhoea by 53% and a bacterial skin infection called impetigo by 34% in children younger than 15 years. There was no difference in disease incidence between households given antibacterial soap and those given plain soap.

Dr Luby states: “Our data show that regular handwashing with soap is very effective in preventing diarrhoea and respiratory disease, two of the leading causes of global childhood death. Handwashing with daily bathing also prevents impetigo. Provision of free soap, frequent community meetings, and weekly household handwashing promotion visits to all impoverished households worldwide is prohibitively expensive. Thus, the challenge for the public health community is to identify cost-effective techniques for handwashing promotion that can reach hundreds of millions of households at risk.”