A Controlled Before and After Study to Measure the Effect of an Urban Sanitation Intervention on Child Health, in Low-income Neighborhoods of Maputo, Mozambique

We have designed a controlled, before-and-after (CBA) effectiveness study to estimate the health impacts of an urban sanitation intervention in informal neighborhoods of Maputo, Mozambique, including an assessment of whether exposures and health outcomes vary by localized population density. The intervention consists of private pour-flush latrines (to septic tank) shared by multiple households in compounds or household clusters. We will measure objective health outcomes in approximately 1000 children (500 children with household access to interventions, 500 controls using existing shared private latrines in poor sanitary conditions), at two time points: immediately before the intervention and at follow-up after 12 months. The primary outcome is combined prevalence of enteric infections among children under 5 years of age. Secondary outcome measures include soil transmitted helminth (STH) re-infection in children following baseline de-worming and prevalence of reported gastrointestinal illness. We will use exposure assessment, fecal source tracking, and microbial transmission modeling to examine whether and how routes of exposure for diarrheagenic pathogens and STHs vary and transmission impacts of the pathogens following introduction of effective sanitation. Our analysis will focus specifically on the impact of localized population density as a potential modifier of sanitation-related exposures.