Proctor and Gamble (P&G), the consumer product conglomerate, helped conduct a study in the slums of Karachi, Pakistan, to see if a new soap with the antibacterial agent triclocarbon could prevent diseases in the community.

Field workers fanned out in 25 randomly chosen slum neighbourhoods in Karachi to distribute soap, some with triclocarbon and some without. The two soaps looked exactly alike. They encouraged people to use the soap generously and wash their hands in these five contexts: after defecation, after cleaning an infant that has defecated, before preparing food, before eating, and before feeding infants. A family was provided two to four bars of soap, with regular replacements.
In 11 'control' slum neighbourhoods, no soap was distributed. Instead, these households received pens and paper. Although the control group was free to continue using soap as they had done in the past, they received no supplies or health education.

For one year, the fieldworkers conducted weekly visits to the families in the study sites to check if their instructions were being adhered to, and collected data. Analysis of the data revealed that the children in the households that received soap and proper instructions experienced a decrease of 50 per cent in pneumonia cases and 53 per cent in diarrhoea cases compared to the control group that wasn't provided with soap.

What was surprising (but disappointing for P&G) was that using soap properly was good enough to decrease incidents of diarrhoea and pneumonia in children. The triclocarbon antibacterial agent in the soap did not provide any extra protection. These findings were stunning because it meant that even if you lived in unhygienic conditions and had access only to contaminated water for drinking and cleaning, using plain soap properly could decrease your chances of catching diseases significantly. This finding became part of a milestone paper that was published in the Lancet in 2005, with Bangladesh-based public health and sanitation expert Stephen Luby as lead author.

More than three and half million children die due to diarrhoea and respiratory infections every year in developing countries such as ours. Using soap generously clearly ameliorates this condition. People have strong ideas of purity in South Asia and wash themselves frequently. But regular, proper use of soap is a must, as it enhances the capacity of water to solubilise and remove pathogens from the hands, thus helping reduce both respiratory and digestive problems. Just washing the 'involved' hand after defecation won't wash you of your sins.