Improved Child Feces Management Mediates Reductions in Childhood Diarrhea from an On-Site Sanitation Intervention: Causal Mediation Analysis of a Cluster-Randomized Trial in Rural Bangladesh

Jesse D Contreras; Mahfuza Islam; Andrew Mertens; Amy J Pickering; Benjamin F Arnold; Jade Benjamin-Chung; Alan E Hubbard; Mahbubur Rahman; Leanne Unicomb; Stephen P Luby; John M Colford Jr; Ayse Ercumen

doi:10.1007/s44197-024-00210-y

Improved Child Feces Management Mediates Reductions in Childhood Diarrhea from an On-Site Sanitation Intervention: Causal Mediation Analysis of a Cluster-Randomized Trial in Rural Bangladesh

J Epidemiol Glob Health. 2024 Mar 20. doi: 10.1007/s44197-024-00210-y. Online ahead of print.

Authors

Jesse D Contreras¹, Mahfuza Islam², Andrew Mertens³, Amy J Pickering^{4

5}, Benjamin F Arnold⁶, Jade Benjamin-Chung^{5

7}, Alan E Hubbard³, Mahbubur Rahman⁸, Leanne Unicomb⁸, Stephen P Luby⁹, John M Colford Jr³, Ayse Ercumen^{10

11}

Affiliations

¹ Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, 48103, USA.
² Department of Environmental Health Sciences, School of Public Health, University of California, Berkeley, Berkeley, CA, 94720, USA.
³ Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, Berkeley, CA, 94720, USA.
⁴ Department of Civil and Environmental Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA.
⁵ Chan Zuckerberg Biohub, San Francisco, CA, 94158, USA.
⁶ Francis I. Proctor Foundation, University of California, San Francisco, San Francisco, CA, 94158, USA.
⁷ Department of Epidemiology and Population Health, Stanford University, Palo Alto, CA, 94304, USA.
⁸ Environmental Health and WASH, Health Systems and Population Studies Division, International Centre for Diarrhoeal Disease Research Bangladesh (icddr,b), Dhaka, 1212, Bangladesh.
⁹ Woods Institute for the Environment, Stanford University, Stanford, CA, 94305, USA.
¹⁰ Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, 27695, USA. aercume@ncsu.edu.
¹¹ Jordan Hall Addition 2225, Raleigh, NC, 27606, USA. aercume@ncsu.edu.

PMID: 38507184
DOI: 10.1007/s44197-024-00210-y

Abstract

Background: The WASH benefits Bangladesh trial multi-component sanitation intervention reduced diarrheal disease among children < 5 years. Intervention components included latrine upgrades, child feces management tools, and behavioral promotion. It remains unclear which components most impacted diarrhea.

Methods: We conducted mediation analysis within a subset of households (n = 720) from the sanitation and control arms. Potential mediators were categorized into indicators of latrine quality, latrine use practices, and feces management practices. We estimated average causal mediation effects (ACME) as prevalence differences (PD), defined as the intervention's effect on diarrhea through its effect on the mediator.

Results: The intervention improved all indicators compared to controls. We found significant mediation through multiple latrine use and feces management practice indicators. The strongest mediators during monsoon seasons were reduced open defecation among children aged < 3 and 3-8 years, and increased disposal of child feces into latrines. The strongest mediators during dry seasons were access to a flush/pour-flush latrine, reduced open defecation among children aged 3-8 years, and increased disposal of child feces into latrines. Individual mediation effects were small (PD = 0.5-2 percentage points) compared to the overall intervention effect but collectively describe significant mediation pathways.

Discussion: The effect of the WASH Benefits Bangladesh sanitation intervention on diarrheal disease was mediated through improved child feces management and reduced child open defecation. Although the intervention significantly improved latrine quality, relatively high latrine quality at baseline may have limited benefits from additional improvements. Targeting safe child feces management may increase the health benefits of rural sanitation interventions.

Keywords: Child feces; Diarrheal disease; Intervention; Latrine; Mediation; Sanitation.

Abstract

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