Can hand washing reduce disease in low-income countries where people are surrounded by germs? That was the question that Stephen Luby set out to answer with a study of squatter settlements in Karachi, Pakistan, where the drinking water and drainage ditches near homes were highly contaminated and 10 percent of children died before age 5.

Luby, now a senior fellow with the Stanford Woods Institute and a Stanford professor of medicine, highlighted some of his discoveries during a Woods Environmental Forum on Oct. 31.

The carefully controlled study that Luby led in Karachi in 2002 found that children in households where hand washing was practiced suffered 52 percent less diarrhea and 50 percent less pneumonia. Interestingly, there was no difference in those who used antibacterial compared to those who used regular soap.

Building on this work, UNICEF trained 10,000 community hygiene promoters who preached the benefits of hand washing five times a day to people in Bangladesh and saw a 40 percent reduction in disease between 2007 and 2009. Unfortunately, the control group experienced the same decrease, causing great frustration among those who ran the study and prompting Bangladesh officials initially to call it a sham.

This contradiction caused Luby to begin looking at reasons why the study didn’t change habits. By using “smart soap” that measures “soap motion events” researchers discovered that the frequency of hand washing increased 35 percent in the presence of an observer, throwing doubt on previous hand-washing statistics. During interviews, researchers found that people didn’t connect the incidence of disease with hand washing habits and considered soap a nice-but-not-necessary expense.

As a result, Luby and his team are evaluating efforts to make hand washing easier, with low-cost hand-washing stations and inexpensive soapy water, while encouraging adoption of a hand-washing habit by appealing to social aspirations and good mothering.

Luby is also known for his work in tracking the epidemiology of Nipah virus transmission in Bangladesh to bats and warning that it could lead to a global pandemic (read more). His ongoing work includes projects to understand the process of emerging infections, and developing and evaluating interventions to reduce pandemic risk; assessing the health impacts to improve water, sanitation and hygiene with particular attention to interventions that are applicable at scale; and reducing the adverse environmental and health consequences of brick manufacturing in Bangladesh.