It?s estimated that diarrheal diseases kill more than two million people worldwide each year. Most of the victims are children under age five. Much investment has been made in developing better water systems to solve the problem. But some say hygiene and sanitation should receive equal if not more attention.

Diarrheal and gastro-intestinal diseases are caused by germs or parasites. Once inside the human body, they quickly multiply. Some are excreted and then transmitted to other people through the environment.

Dr. Val Curtis ? of the London School of Hygiene and Tropical Medicine ? is among those calling for greater investment in hygiene and sanitation.

She says, "Sanitation and hygiene are vitally important in preventing the diarrheal. And those diseases are caused by bugs, which live in the gut. And the bugs that live in the gut come out of the gut in human excreta, in feces. So, if human feces are around in the environment, then they are the major source of infection to children. And if, for example, hands aren?t washed after going to the toilet then human fecal material gets on the hands and then can get into food or get onto surfaces or reach other children and make then sick."

She says studies have shown that sanitation and hygiene ? including the simple act of washing hands with soap - offer much greater benefits than simply purifying the water supply.

She says, "We always thought that water supply was so important in reducing intestinal infections. But actually, improving water supply on average seems to only reduce diarrheal infections by about 16 percent. Sanitation is two or three times better than that. And in fact washing hands with soap is three times better than that. So, you get about a 45 to 50 percent reduction in diarrheal diseases from hand washing with soap."

She says the health risks posed by a small amount of fecal matter are very high. "One gram of fecal material can contain a billion viruses and a hundred million bacteria. And imagine a small smear of that stuff on a finger and that finger then goes on to prepare food for the family. That?s actually a superhighway for the bugs. Like a motorway for the bugs to get from the feces of one person to another person and make them sick."

Dr. Curtis is working on programs in seven countries on three continents to increase hand washing with soap.

She says, "We?re finding that even in the most remote, rural areas people do practice hand washing. Unfortunately, they don?t practice hand washing with soap. They have soap in their households, but soap is reserved for washing clothes and for washing their bodies. But this everyday habit of using soap to wash your hands after going to the toilet is not something that people do. When people hear about it and learn about it from our program, almost without exception people think it?s a great idea. And when they get the habit they don?t stop doing it."

The senior lecturer at the London School of Hygiene and Tropical Medicine says hand washing can also reduce respiratory infections. She even goes so far to say that hand washing has an even greater impact on child health than vaccines. She believes it should receive the same attention as childhood vaccination programs.

Dr. Curtis recommends public-private partnerships to promote hand washing.

While hand washing with soap would appear to be a universally accepted act, there is opposition. For example, according to published reports, in Kerala State, India, there is both ?environmental activism and ideological opposition? to the proposal. In fact, preaching the benefits of good hygiene is viewed by some as an insult. Critics also view the hand-washing program as an effort to increase the bottom line of soap manufacturers. Dr. Curtis disagrees, saying all involved in public-private partnerships can benefit, including local governments and local companies that learn new marketing techniques. She says the true bottom line is the many lives that would be saved.