Department Sanitation, Water and Solid Waste for Development

Nearly half of the global population relies on non-sewered sanitation systems, a figure growing twice as fast as populations served by sewer connections. In urban areas of Asia and Sub-Saharan Africa, 60 to 100% of residents depend on non-sewered sanitation, particularly in informal settlements that often lack essential services. These conditions increase the risk of communicable diseases. While wastewater-based surveillance (WBS) has been successfully applied in sewered areas, particularly during the COVID-19 pandemic, its use in non-sewered sanitation systems remains underexplored. Non-sewered wastewater, or fecal sludge, is highly variable in composition, and unsafe disposal practices often lead to contamination of the urban environment through open ditches, floodwaters, and raw produce. These exposure points offer opportunities for environmental monitoring, adapting WBS methods to assess pathogen presence in diverse environmental samples.

This project aims to validate environmental surveillance approaches by developing and field-testing sampling plans representative of urban areas with non-sewered sanitation in low- and middle-income countries. The study will be conducted in Kampala, Uganda, leveraging its mix of sewered and non-sewered sanitation systems and rapid urbanization. Sampling will encompass a variety of environmental media, including sewer-based wastewater, fecal sludge, floodwaters, open drainage systems, and raw produce. The study will focus on detecting respiratory and gastrointestinal pathogens to establish scalable methods for population-representative monitoring. Results will provide the foundation for further research and the development of early-warning public health systems to mitigate the spread of infectious diseases in complex urban settings.

• Prof. Charles Niwagaba (Makerere University)
• National Water and Sewerage Corporation (NWSC)

Eawag discretionary fund