Scrubbing down: free soap, hygiene tips cut kids' illnesses

Science News, Oct 9, 2004 by B. Harder

In urban slums, enhancing family hygiene can prevent about half of childhood diarrhea and respiratory illnesses, including pneumonia, researchers working in Pakistan report. Benefits extend even to infants too young to wash themselves.

Studies have indicated that simply washing hands can reduce the spread of infections in daycare centers and other settings in industrialized countries, but how much of a difference hygiene could make in poor nations remained unclear. Diarrhea and pneumonia each kill nearly 2 million children per year worldwide, making them the leading causes of child mortality.

To test the impact of promoting hand washing, researchers at the Centers for Disease Control and Prevention (CDC) in Atlanta, Procter & Gamble of Cincinnati, and two collaborating organizations provided soap to 600 homes in Karachi, Pakistan. Some families already used soap but may have done so sparingly because of cost.

For 1 year, the researchers made regular visits to each home, resupplying soap as needed and encouraging family members to wash their hands after defecating and before feeding infants or otherwise handling food. The investigators also visited 306 similar households to which they had not distributed soap. In all homes, the researchers counted cases of diarrhea in children up to 15 years old and kept track of respiratory symptoms and skin infections in children age 5 and under.

In soap-supplied homes, children under 5 years old had pneumonia or other respiratory symptoms about half as often as did such children in homes not getting soap. Providing soap also reduced bacterial skin infections among children by nearly 50 percent, says Pavani Kalluri of CDC. She presented these data in Boston on Sept. 30 at a meeting of the Infectious Diseases Society of America.

Children in homes given soap had diarrhea only half as frequently as did kids in other homes. The diarrhea rate for infants under age 1 was cut by nearly 40 percent if a household received soap. Stephen P. Luby of CDC and his colleagues reported the diarrhea findings in the June 2 Journal of the American Medical Association.

This "seminal study" demonstrates the "effectiveness of hand hygiene against infections" in developing countries, says Elaine L. Larson of Columbia University. The results extend hygiene's benefits beyond diarrhea to respiratory ailments, she says.

Procter & Gamble provided two kinds of soap for distribution in the study. Half of the 600 soap-supplied homes got bars of plain soap while half got specially formulated bars that are marketed as antibacterial. The antibacterial product had no more effect on diarrhea or respiratory infections than the standard soap did, Larson observes, adding that this result is consistent with that of studies she has conducted in the United States.