Who is responsible for that pile of poop?

A group of villagers walks through Jiling, in the Nuwakot district of central Nepal, with eyes glued to the ground. They cut narrow paths around rice fields and yield to goats until they find what they are looking for: A brown, stinky, fly-covered pile.

"It's poop," laughs 40-year-old Chandra Kumari. Human poop.

Leading the expedition is Sanjaya Devkota, who works for the U.N. Habitat through the Global Sanitation Fund. He asks who's responsible for the offending pile.

The group thinks a child from a nearby house did it and calls out to the mother. Devkota questions her: "When there's poop out in the open like this, how do you feel?" he asks. "Do you feel good about that? And the flies on it, do they only stay at your house, or do they go to your neighbor's house too?" The woman looks really embarrassed, and the whole thing feels kind of ... icky. But, that's exactly the point.

Devkota is practicing a behavior change strategy called Community Led Total Sanitation. CLTS was pioneered in Bangladesh in 2000 by Kamal Kar, an Indian-born agriculture and natural resources specialist, as a new way to combat open defecation; Bangladesh has since nearly eliminated the practice. The focus is on eliciting shame and disgust as motivation to improve sanitation. Critics question the ethics of a shaming approach, but proponents say it's a promising strategy for a serious public health problem. "It's specifically for people to feel that what they're doing is dirty or unhealthy or not right for their communities," says Alison Bradley. Bradley works with the Water Supply and Sanitation Collaborative Council, a U.N. member organization that supports Devkota's work and advocates CLTS. "The notion that one family is defecating outside and that you know it's pretty gross is part of the process of helping the whole community realize that they need to take charge of their sanitation needs," Bradley explains. Across the globe, bringing an end to open defecation remains a public health puzzle. About 600 million people in India alone defecate outside, and the practice persists in much of the developing world. Today, about 30 percent of Nepali homes don't have toilets — and here a toilet doesn't mean your standard porcelain bowl. It often means an outdoor squat latrine, with some type of cover to keep flies out. Millions still relieve themselves in fields or other places outside.

And that presents a huge health problem.

Open defecation is directly connected with the incidence of diarrheal diseases, as flies that land on feces transmit bacteria to food and drinking water. Persistent diarrhea can stunt a young child's development and kills some 500,000 children a year. Open defecation also puts girls and women at risk of sexual assault while relieving themselves outside after dark. A logical solution might seem to be building toilets or giving people the money to do so. But proponents of CLTS say financial support is not very effective. Bradley says toilets built through such subsidy-based approaches often go unused because the habit of going outside hasn't been undone. Traveling across India, she describes seeing household latrines "used as chicken coops or sometimes even as temples." The 2014 "SQUAT" survey in five Indian states found that in 40 percent of households with a working latrine, someone still defecates outside. Households with toilets built through government support were twice as likely to practice open defecation as people who constructed toilets themselves. Instead of subsidies, CLTS tries to make people want to build toilets themselves. The idea is that if people are truly convinced that using a toilet is better for family and community health, they'll be willing to spend some of what may be very limited income on sanitation.

The "walk of shame" — a tour through a neighborhood led by a CLTS facilitator — draws on the powerful force of social pressure in tight-knit communities. Other CLTS methods include visceral demonstrations of bacterial contamination. One strategy is to show how flies in contact with open feces invisibly contaminate drinking water by touching a piece of human hair — representing a fly's leg — to a pile of stool, dunking the hair in a cup of water and asking someone to drink from the clean-looking but obviously contaminated water. When Eva Kumari Paudel, a community health volunteer in another village in Nuwakot, said she didn't have the money to repair her toilet that was damaged after last year's earthquake, a community mobilizer with U.N. Habitat fingered the small gold hoops snaking down each of her earlobes. "You have money for these ornaments and you're asking for money for your toilet?" he asked her. That's a classic CLTS approach.

The connection between sanitation and dignity is a common theme. Across Nepal billboards decry open defecation as a "social crime." In 2007, the Haryana state of India famously rolled out its "No Toilet, No Bride" campaign, which encouraged families to demand a toilet as part of marriage negotiations. The Global Sanitation Fund pursues CLTS programming in 13 countries, and the methodology has been embraced by global agencies like UNICEF, WaterAid and Plan International. The Nepal government endorsed the CLTS method in its 2011 Sanitation and Hygiene Master Plan. But not everyone agrees with the idea of shaming the poor into sanitary submission. "There are massive downsides. The least of which is that the process is, simply put, condescending and offensive," says Ben Ayers. Ayers runs dZi Foundation, a non-governmental organization that works on development projects in Nepal's mountain regions. dZi tried using some elements of CLTS in its sanitation programming, but community members said the tactics caused too much conflict. "The families without land or resources are, almost by definition, poor and lower or untouchable caste. CLTS creates a dynamic where high-caste families are shaming low-caste families publicly. This only reinforces existing structures of discrimination, which leads inevitably to conflict," Ayers says. Critics also say community-led efforts can spiral into witch-hunts, where people follow each other to catch someone doing the deed outside. Sanjaya Devkota says some communities in Nepal set up systems to fine residents for open defecation with the money going to the person doing the reporting.

But proponents say the shaming approach is justified by the enormous health costs of open defecation. "If my neighbors defecate outside and the chickens eat it and walk in it, they come over and infect my house too," says Shanta Bahadur Tamang. The 69-year-old, who built a toilet at his house, was frustrated seeing open stool during the walk around his village. If CLTS works the way it's supposed to, he'll channel his anger to pressure the 582 households in Jiling without toilets to use their own resources to build them, meeting the village's goal of being open-defecation free by September.

So far, CLTS is showing modest success globally. A 2009 study out of Duke University compared around 500 village households in India's Orissa state exposed to a "shaming approach" with another 500 in a control group. Families below the poverty line in both groups got a subsidy for toilet construction. Shame proved to be more effective than subsidies, though a combined "shame and subsidy" approach was better than shame alone. A 2013 impact evaluation of a CLTS based approach in Indonesia that interviewed around 2,100 households found that communities that received the intervention were 23 percent more likely to build a toilet than those who didn't and had a 30 percent lower rate of diarrhea. And a randomized trial of a CLTS intervention in Mali, involving around 4,500 households, published last year in the Lancet, found kids in villages with the intervention were slightly less likely to be stunted or underweight than kids in control villages.

Amanda Glassman, director of Global Health Policy at the Center for Global Development, says the use of shame remains the subject of ongoing debate in sanitation circles. She says the research shows "that lives are saved, that disease is prevented, that kids are healthier and live through childhood. That we know for sure, and then the question is, are the tactics worth it." Glassman says there are definite ethical questions, but "it's unethical to let children die too."

The next challenge [for researchers and development workers] will be to figure out how to lessen the shame and still get results. Sanjaya Devkota says Nepal was making progress on its goal of eliminating open defecation by 2017 until last year's earthquake made shelter a much more pressing concern. But he hopes that those who were already convinced to invest in toilets will continue to do so. Even if the motivational methods might seem a little harsh.

I ask Chandra Kumari if being called out on her community's hygiene practices bothers her. She quickly protests: "I'm not ashamed! I think this is good. If we're staying in a dirty place and people come to remind us not to do that, it's a good thing."

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