Escherichia coli contamination of child complementary foods and association with domestic hygiene in rural Bangladesh

Objective: To determine the frequency and concentration of Escherichia coli in child complementary food and its association with domestic hygiene practices in rural Bangladesh.

Method: A total of 608 households with children <2 years were enrolled. We collected stored complementary food samples, performed spot checks on domestic hygiene and measured ambient temperature in the food storage area. Food samples were analysed using the IDEXX most probable number (MPN) method with Colilert-18 media to enumerate E. coli. We calculated adjusted prevalence ratios (APR) to assess the relationship between E. coli and domestic hygiene practices using modified Poisson regression, adjusting for clustering and confounders.

Result: Fifty-eight percentage of stored complementary food was contaminated with E. coli, and high levels of contamination (≥100 MPN/dry g food) were found in 12% of samples. High levels of food contamination were more prevalent in compounds where the food was stored uncovered (APR: 2.0, 95% CI: 1.2-3.2), transferred from the storage pot to the serving dish using hands (APR: 2.0, 95% CI: 1.3-3.2) or stored for >4 h (APR: 2.5, 95% CI: 1.5, 4.2), in compounds where water was unavailable in the food preparation area (APR: 2.6, 95% CI: 1.6, 4.2), where ≥1 fly was captured in the food preparation area (APR: 1.6, 95% CI: 1.0, 2.6), or where the ambient temperature was high (>25-40 °C) in the food storage area (APR: 2.7, 95% CI: 1.5, 4.4).

Conclusion: Interventions to keep stored food covered and ensure water availability in the food preparation area would be expected to reduce faecal contamination of complementary foods.