The Maputo Sanitation (MapSan) Trial is a landmark study that has reshaped global understanding of what sanitation can achieve in dense, low-income urban settings.
Implemented in Maputo, Mozambique, in areas where Water & Sanitation for the Urban Populations (WSUP) initiatives were being undertaken and led by the London School of Hygiene & Tropical Medicine, the University of North Carolina, and Mozambique’s Instituto Nacional de Saúde, MapSan is one of the most rigorous urban sanitation health studies ever conducted.
Running over five years, the controlled trial followed children under five living in neighbourhoods with and without WSUP’s high-quality shared sanitation. The intervention provided pour-flush toilets connected to septic tanks, shared by small clusters of households, and maintained through a community-led management model that prioritised cleanliness, safety, and long-term operation.
The results were transformative. Children born into compounds with access to these high-quality shared toilets were 31% less likely to experience stunting than those in control areas. By significantly reducing exposure to dangerous enteric pathogens such as Shigella, E. coli, Ascaris, and Trichuris, the intervention addressed one of the hidden drivers of chronic malnutrition. This matters because stunting has lifelong consequences: stunted children earn up to 20% less as adults, and even small losses in height are associated with reduced economic productivity.
MapSan also delivered powerful benefits beyond physical health. Residents reported reduced stress, improved well-being, and a renewed sense of dignity. For women and girls, access to nearby, well-lit, lockable toilets reduced fear, improved safety, and restored privacy, outcomes that are rarely captured in global sanitation metrics but are central to lived experience.
Community members were not just beneficiaries but partners. Local caretakers and residents were trained to manage and maintain facilities, creating accountability, ownership, and livelihoods. This model demonstrates that shared sanitation can be sustainable, scalable, and locally embedded.
The implications are profound. In rapidly growing cities where private household toilets remain unattainable for millions, MapSan proves that high-quality shared sanitation is not a stopgap, but a scientifically validated public health solution. Yet under current WHO/UNICEF Joint Monitoring Programme definitions, even the best shared sanitation is classified as a “limited service,” discouraging investment.
With robust evidence now available, from MapSan and complementary studies such as QUISS, the case for recognising high-quality shared sanitation within post-2030 global frameworks is stronger than ever. MapSan challenges us to redefine progress: not as perfection achieved someday, but as dignity, health, and opportunity delivered today.
Want to help scale MapSan-style sanitation solutions across African cities? Get in touch: partnerships@wsup.invicomm.com