Assessing disease burden from pathogen release through untreated hospital wastewater to neighboring communities in Dhaka city

Hospitals in low-resource settings discharge untreated wastewater containing fecal pathogens, posing substantial health risks to surrounding communities. This study aims to model fecal pathogen flows from a government hospital and neighboring communities in Dhaka, Bangladesh, and to quantify associated disease burdens across neighboring communities with varying sanitation conditions. Using a systems modeling approach integrating Quantitative Microbial Risk Assessment (QMRA) and Disability-Adjusted Life Years (DALYs), we estimated health risks from five key pathogens (Vibrio cholerae, Norovirus GII, Shigella/EIEC, Giardia spp., and Rotavirus-A) across selected sanitation options. Data were drawn from field observations, hospital-based surveillance and published literature. The model evaluated multiple sanitation options in both hospital and communities, including the current base case, no-containment, functional anaerobic baffled reactors (ABRs), ABRs combined with constructed wetlands, and ABRs with tertiary wastewater treatment systems. Findings show that the unmanaged base cases resulted in a total burden of 20.1 DALYs per 1000 people per year, while the no-containment scenario reached 23.3 DALYs per 1000 people per year. In contrast, a well-managed tertiary treatment system in hospital combined with community ABRs reduced the burden to 14.3 DALYs per 1000 people per year -a 91% reduction. Hospital-level sanitation improvements alone had limited downstream health effects; community DALYs remained high across all community-level sanitation options, with low-income community consistently showing the highest burden (6.20 DALYs per 1000 people per year). Minimal differences were also observed between managed and unmanaged scenarios in community settings. This research underscores the critical need for effective hospital wastewater treatment and coordinated community sanitation interventions. A combined focus on hospital and community-level systems is essential to reduce environmental contamination and achieve meaningful public health gains.