Effect of a behavior change intervention on complementary food contamination in rural Bangladesh: a cluster-randomized controlled trial

Children in low-resource settings often consume microbially contaminated food, posing a risk to their health. We evaluated the impact of a food hygiene intervention on complementary food contamination in Bangladesh. A three-year homestead food production intervention was complemented by an eight-month behavior change module to improve household food hygiene practices and evaluated in a cluster-randomized controlled trial including a dedicated study measuring outcomes along the hygiene pathway to intestinal health. In this analysis, we used multilevel regression to assess the intervention’s impact on microbial food contamination, as well as on food hygiene knowledge (n=518) and reported practices (n=531) among mothers of children aged 6-23 months. Complementary food samples were collected from 342 households with children aged 6-18 months and tested for Escherichia coli . Overall, 46% of food samples were contaminated with Escherichia coli (42% intervention, 49% control), and there was no evidence that the intervention reduced food contamination (Odds Ratio: 0.7, 95% CI: 0.3-1.2, p=0.18). A higher proportion of intervention mothers could name all key food hygiene practices (22% intervention vs. 0% control), had access to a basic handwashing station near the kitchen (24% vs. 14%, p=0.03), reported washing hands before food preparation and child feeding (21% vs. 8%, p=0.001), washing and storing feeding utensils safely (61% vs. 49%, p=0.02), and preparing food fresh or reheating stored food (88% vs. 79%, p=0.03), compared to control mothers. The intervention thus improved knowledge and reported food hygiene practices among mothers, but this improvement did not result in a substantial reduction of complementary food contamination.