The study shows that private toilets are still the best option in the global battle to improve sanitation facilities in developing countries.
The research team found that toilets shared between just a few households are only marginally safer than public latrines for children, says lead author Kelly Baker, an environmental health researcher at the University of Iowa in the United States.
But previous research suggests that if families had access to sanitation products to wash their hands and regularly clean the shared toilet, the risk of under-fives contracting diarrhoea would drop by 36 per cent.
“Latrines serving small groups of households should in theory be cleaned more often and offer sufficient accessibility to prevent open defecation and disposal of human excreta,” says Baker.
She says the findings should influence how development agencies aim to achieve the Sustainable Development Goal on water and sanitation. The researchers suggest that households who continue to share their toilet facilities with several others should be classed as “unimproved” under the goals, even if they have stopped using a public latrine.
Frequent diarrhoea causes dehydration and malnutrition, and is particularly dangerous to small children. The World Health Organization estimates that it kills around 760,000 children under five every year.
The study is based on data from Bangladesh, the Gambia, India, Kenya, Mali, Mozambique and Pakistan. It was published in PLOS Medicine last week (3 May).
The researchers say they believe this is the first study to use clinically and laboratory confirmed, rather than self-reported, diarrhoea to analyse the risks associated with numbers of households sharing a sanitation facility. Andrés Hueso, senior policy analyst on sanitation at charity WaterAid, says one of the study’s limitations is that it compares access to shared sanitation with private sanitation, but not with open defecation. He warns that this must not give the impression that shared sanitation is undesirable.
“We need to remember that in dense slum areas, private sanitation simply isn’t a feasible option,” Hueso says. He worries that the study’s conclusion may inadvertently cut the shared facilities option out of conversations with governments and donors, who may focus on private sanitation only.
But Baker thinks it is unlikely that her work would discourage governments from investing in better sanitation infrastructure.
“My hope is that, rather than viewing our study as a rallying cry against shared toilet facilities, this should prompt investment in additional measures both inside and outside of the latrine — to ensure sanitation safety,” she says.