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Unsafe hospital wastewater (HWW) is a significant concern, especially in low-and middle-income countries (LMICs) where the health impact is often underreported. Socio-technical systems (STS) theory, which examines the interplay between social and technical elements within complex systems, is widely used in developed countries but rarely applied in LMIC hospitals. STS theory was employed to evaluate the social and technical aspects of HWW treatment and management in Dhaka City, alongside a comprehensive assessment of WWT processes. A mixed-methods approach was used, combining quantitative (structured observations) and qualitative interviews. Structured observations assessed the availability and functionality of WWT systems in selected hospitals. The fieldworkers conducted 30 key-informant interviews across 13 hospitals, including 21 respondents from government and nine from private hospitals. The respondents were cleaners, key health professionals, and public works department (PWD) engineers. We also analyzed relevant government reports and policies. Among the hospitals surveyed, 10 had some form of WWT system, while the remaining three lacked any treatment infrastructure. Of those with WWT, seven utilized anaerobic baffled reactors and three had septic tanks. Interviews revealed that hospital authorities prioritize patient care and medical equipment maintenance over WWT, with limited understanding among hospital staff regarding WWT. PWD-engineers reported frequent staff shortages and bureaucratic delays, affecting the efficiency of WWT system repairs and desludging. Our study identified significant gaps in WWT in Dhaka hospitals, including the limited use of adequate treatment technologies, poor wastewater management knowledge, and many systems in disrepair, leading to hazardous liquid being discharged directly into the environment. The STS approach highlighted the need for policy formulation for HWW regulation, government leadership, adequate financing, technical assistance, and staff capacity building. Addressing these issues comprehensively can lead to safer and more sustainable wastewater management practices in HCFs, ultimately benefiting public health and the environment. [ABSTRACT FROM AUTHOR]

Sanitation approaches in low-income urban areas are predominately on-site sanitation, with septic tanks promoted as an improved sanitation solution. While a septic tank system is designed to contain sludge in the tank and discharge effluent to a soil infiltration system, in many urban contexts effluent from tanks discharge directly to open drains or surface waters. This research addresses the paucity of data on pathogen removal and discharge from septic tanks as operated in low-income contexts and the significance of this public health hazard. This study assessed the performance and risks of "septic tanks" discharging to open drains in a low-income neighbourhood in Dhaka, Bangladesh, considering the influence of usage and tank operation on concentrations of Norovirus GII, Salmonella Typhi, Vibrio cholerae, Giardia, Shigella and E. coli in the effluent and receiving drains. While 66% of septic tanks were functioning within design limits, multiple pathogens were detected in all effluent samples, with a mean concentration of 7.6 log10 MPN/100mL for E. coli and 4.2–5.6 log10 genome copies/100mL for pathogens, excluding S. Typhi which was not detected. Children's exposure to septic tank discharge in drains could result in an 18% risk of illness from Norovirus GII and 3% from Giardia annually. The pathogen reduction between the estimated septic tank inflows and measured effluent concentration ranged from 1.3 log10 MPN reduction for E. coli to 2.2 log10 genome copies reduction for Giardia. Increased coverage of septic tanks was significantly associated with reduced concentrations of Shigella in open drains compared to direct discharge from toilets, with increased reduction for septic tanks operating within design standards. Implementing septic tanks without sub-surface infiltration or treatment of effluent is a major concern. The potential health risk of exposure to septic tank effluent warrants increased attention to appropriate technical design, effluent management and alternatives such as networked sanitation. [ABSTRACT FROM AUTHOR]

Water, sanitation, and handwashing interventions may confer spillover effects on intervention recipients' neighbors by interrupting pathogen transmission. We measured geographically local spillovers in the Water Quality, Sanitation, and Handwashing (WASH) Benefits Study, a cluster-randomized trial in rural Bangladesh, by comparing outcomes among neighbors of intervention versus those of control participants. Geographically defined clusters were randomly allocated to a compound-level intervention (i.e., chlorinated drinking water, upgraded sanitation, and handwashing promotion) or control arm. From January 2015 to August 2015, in 180 clusters, we enrolled 1,799 neighboring children who were age matched to trial participants who would have been eligible for the study had they been conceived slightly earlier or later. After 28 months of intervention, we quantified fecal indicator bacteria in toy rinse and drinking water samples and measured soil-transmitted helminth infections and caregiver-reported diarrhea and respiratory illness. Neighbors' characteristics were balanced across arms. Detectable Escherichia coli prevalence in tubewell samples was lower for intervention participants' neighbors than control participants' (prevalence ratio = 0.83; 95% confidence interval: 0.73, 0.95). Fecal indicator bacteria prevalence did not differ between arms for other environmental samples. Prevalence was similar in neighbors of intervention participants versus those of control participants for soil-transmitted helminth infection, diarrhea, and respiratory illness. A compound-level water, sanitation, and handwashing intervention reduced neighbors' tubewell water contamination but did not affect neighboring children's health.

The number of people served by networked systems that supply intermittent and contaminated drinking water is increasing. In these settings, centralized water treatment is ineffective, while household-level water treatment technologies have not been brought to scale. This study compares a novel low-cost technology designed to passively (automatically) dispense chlorine at shared handpumps with a household-level intervention providing water disinfection tablets (Aquatab), safe water storage containers, and behavior promotion. Twenty compounds were enrolled in Dhaka, Bangladesh, and randomly assigned to one of three groups: passive chlorinator, Aquatabs, or control. Over a 10-month intervention period, the mean percentage of households whose stored drinking water had detectable total chlorine was 75% in compounds with access to the passive chlorinator, 72% in compounds receiving Aquatabs, and 6% in control compounds. Both interventions also significantly improved microbial water quality. Aquatabs usage fell by 50% after behavioral promotion visits concluded, suggesting intensive promotion is necessary for sustained uptake. The study findings suggest high potential for an automated decentralized water treatment system to increase consistent access to clean water in low-income urban communities.

We conducted a randomized, non-inferiority field trial in urban Dhaka, Bangladesh among mothers to compare microbial efficacy of soapy water (30 g powdered detergent in 1.5 L water) with bar soap and water alone. Fieldworkers collected hand rinse samples before and after the following washing regimens: scrubbing with soapy water for 15 and 30 seconds; scrubbing with bar soap for 15 and 30 seconds; and scrubbing with water alone for 15 seconds. Soapy water and bar soap removed thermotolerant coliforms similarly after washing for 15 seconds (mean log10 reduction = 0.7 colony-forming units [CFU], P < 0.001 for soapy water; mean log10 reduction = 0.6 CFU, P = 0.001 for bar soap). Increasing scrubbing time to 30 seconds did not improve removal (P > 0.05). Scrubbing hands with water alone also reduced thermotolerant coliforms (mean log10 reduction = 0.3 CFU, P = 0.046) but was less efficacious than scrubbing hands with soapy water. Soapy water is an inexpensive and microbiologically effective cleansing agent to improve handwashing among households with vulnerable children.