Comparison of Aflatoxin Contamination and Dietary Exposure From Complementary Foods Among Rural Tanzanian Infants Enrolled in the Mycotoxin Mitigation Trial

Dietary aflatoxins (AF) exposure in early childhood may contribute to growth restriction. The Mycotoxin Mitigation Trial (MMT) was a cluster-randomized trial designed to assess the effect of providing low-AF maize and groundnut flours (intervention) on infant growth compared to those consuming typically available flours (standard of care [SoC]). The SoC serves as a control, representing the normal frequency and concentration ranges of AF in this region. MMT initiated at infant age 6 months and ended at 18 months, with the intervention group receiving low-AF flours monthly throughout. This sub-study served as one check point in the MMT to assess if there was a difference in AF frequency and concentration in high-risk foods between the two arms. At the MMT midpoint (infant age 12 months), infant foods were collected during household visits within 20 pre-selected clusters (10/arm). Maize/groundnut blend and groundnut flours used in the preparation of foods consumed by infants were analyzed for total AFs by ELISA, with 10% confirmed by HPLC. In total 559 foods were sampled; sampling was on one occasion per household. Chi-square test was used to compare categories of AF contamination in infant foods, and an unpaired <i>t</i>-test was used to compare both contamination by arm, and to compare estimates of AF ingestion between arms. In the intervention arm, 23% of groundnut flour and 6% of blended flour samples had AF levels greater than 10 μg/kg, the legal limit in Tanzania, compared to 45% and 43%, respectively, in the SoC (control) arm (<i>p</i> < 0.05). Further, estimated ingestion of AF was lower for the low-AF supplied blended flours (<i>p</i> = 0.03) and groundnut (<i>p</i> = 0.04). Importantly, the extremely high levels of AF ingestion (> 1000 ng/kg bw/day) observed in the SoC arm were absent in the intervention arm. The provision of low-AF flours in the intervention households reduced the frequency and concentrations of AF contamination compared to the SoC, and thus reduced the estimated dietary exposure to infants, at the midpoint of the trial.