Last century, the invention of the outhouse helped to eliminate hookworm and other parasites in the United States. Now new research shows that the lowly latrine could be a powerful tool in controlling these diseases, which remain widespread among the world's poorest people.

It’s pretty simple. Whether people use it or just have access to it, the latrine could help save hundreds of millions of people from disabling disease. So concludes researchers from the Swiss Tropical and Public Health Institute, who found that in study sites, latrines halved the risk of infection from three common intestinal parasites- hookworm, roundworm and whipworm. Their research was published earlier this week in PLoS Medicine.

Hookworm, roundworm and whipworm- known collectively as the soil-transmitted helminthes or STH’s- are transferred from person to person through contact with feces-contaminated soil. It makes sense then that latrines or toilets would have a major impact on reducing transmission. This isn’t exactly a new idea. Today STH’s are most common in developing countries where there is limited access to clean water and basic sanitation. It wasn’t that long ago though that STH’s were a major problem here in the US, especially in the American South. It was the invention of the outhouse, in combination with anti-helminthic treatments, that helped eradicate these diseases.

The “germ of laziness”

The colorful story of STH elimination in the US is told quite well by Dr. Dickson Despommier on an episode of NPR’s Radiolab. As Despommier tells it, in the early part of the 20th century, millionaire John D. Rockefeller set out to profit from southern industry, but was stymied by the lack of productivity from an unenergetic workforce. Rockefeller funded studies that discovered the cause: a microscopic hookworm which could travel up to 4 feet in soil from a site of defecation. The “germ of laziness,” as they called it, infected a new host through their bare feet and migrated to the intestine, resulting in anemia, malnutrition and poor worker performance.

Rockefeller spearheaded a public health campaign in the South to “unhook the hookworm,” which included the widespread installation of outhouses that buried waste well past 4 feet. Treatment and health education were also major components of the campaign. The educational video below was produced by the International Health Division of the Rockefeller Foundation in 1920.

The success of the campaign could be observed throughout the South. One Virginian school observed, “Children who were listless and dull are now active and alert; children who could not study a year ago are not only studying now, but are finding joy in learning...for the first time in their lives their cheeks show the glow of health.”

Half a billion children still infected

The US and most developed countries have eliminated STH’s, but these diseases still represent a major burden on global health. 576 million, 807 million and 604 million people worldwide suffer from hookworm, roundworm and whipworm respectively, most of which are part of the "bottom billion" or the world's poorest people. Left untreated, these diseases cause internal blood loss leading to iron-deficiency anemia and protein malnutrition. Chronic infection in children contributes to physical and intellectual impairment, learning difficulties and poor school performance.

The cost of these diseases is enormous, but luckily the solution is simple. Like in the US, improvements to sanitation could be a major force in preventing STH’s. Until water and sanitation issues can be addressed though, effective and affordable medicine is available to stop the cycle of disease and poverty. For just 50 cents, we can provide one person with treatment and protection against not just the STH’s, but seven common diseases of poverty for one whole year.

Want to learn more? Visit the WHO site for more information on Water and Sanitation Health (WASH).