Gastrointestinal and respiratory morbidity when introducing eggs as complementary food: a randomised controlled trial in South African infants

We investigated the incidence and duration of morbidity symptoms among infants aged 6 to 9 months from a low socioeconomic community receiving one egg daily for 6 months. This was a secondary outcome of a randomised controlled trial (RCT) of 500 infants conducted in Jouberton, South Africa. The primary outcome was linear growth. Morbidity data were collected weekly using a symptoms diary and qualitative data with focus group discussions at the endpoint. Ethical approval was obtained from the North-West University Health Research Ethics Committee. The intervention group had a similar to 5% higher incidence of gastrointestinal morbidity (17.0%) compared to the control group (11.9%). Gastrointestinal morbidity without fever tended to be 1.4 times higher in the intervention group (OR: 1.43, 95% CI: 1.03, 1.93; P = 0.058) and tended to be 4 times higher with fever (OR: 4.07, 95% CI: 0.86, 19.23; P = 0.077). The duration of total gastrointestinal and respiratory morbidity was 1.5 days longer in the intervention group (beta: 1.491; 95% CI 0.064, 2.918; P = 0.041). Complementary feeding with eggs may have contributed towards an increased risk for gastrointestinal morbidity.