Evaluating the impact of a low-cost food storage intervention on complementary food contamination and diarrheal disease in low-income urban households: A randomized controlled trial in Dhaka, Bangladesh

Diarrheal diseases remain a leading cause of under-five mortality globally, yet large-scale water, sanitation, and hygiene (WASH) interventions have shown limited effects on childhood diarrhea and growth, partly because foodborne transmission has been overlooked. In low-income urban settings, complementary foods for young children are often stored for several hours under unsafe conditions, increasing the risk of fecal contamination. This randomized controlled trial evaluated whether a low-cost wire-mesh food cabinet (“meatsafe”), paired with one-time behavior-change communication (BCC), could reduce microbial contamination and diarrhea among children aged 6–24 months in the Korail informal settlement of Dhaka, Bangladesh. A total of 290 households were randomly assigned 1:1 to receive a meatsafe plus food-hygiene handouts or no intervention. Over five biweekly post-intervention visits, we collected stored complementary food samples (≥4 h) for Escherichia coli testing and recorded 7-day caregiver-reported diarrhea. The primary outcome was the prevalence of high-level contamination (≥100 CFU E. coli /g). Prevalence ratios (PRs) were estimated using population-averaged modified Poisson regression adjusted for storage conditions. Across 1,545 food samples, contamination declined in both arms—from 49.6% to 25.2% in controls and 39.0% to 18.6% in the intervention arm—but the intervention had no effect on high-level contamination (adjusted PR = 0.83; 95% CI: 0.55–1.26) or caregiver-reported diarrhea (PR = 0.56; 95% CI: 0.24–1.31). Storing food for more than eight hours remained strongly associated with contamination (aPR = 1.49; 95% CI: 1.20–1.86). Although meatsafe adoption was high (88% at first visit, 99% at last), recall of general hygiene messages was limited. Providing a meatsafe with minimal BCC did not reduce food contamination or child diarrhea, despite excellent uptake. The findings underscore the limits of simple, passive technologies in resource-constrained settings and suggest that future strategies should integrate affordable storage innovations with more intensive and sustained hygiene promotion. Trial registration ClinicalTrials.gov, NCT07332078. Registered 12 January 2026 (retrospectively registered); https://clinicaltrials.gov/study/NCT07332078 .