Post-intervention morbidity and growth among Zambian children who received multiple micronutrient supplementation using spirulina platensis: evidence from a randomized trial in Zambia

In infants, micronutrient deficiency is known to be associated with growth faltering and morbidity. We recently reported that a 12-month intervention of home fortification of complementary foods using spirulina reduced upper respiratory infections but did not affect the linear growth of Zambian infants. The intervention, originally designed to run for 12 months, was extended by 4 months. This study aimed to evaluate whether a reduction in the morbidity seen with 12-month spirulina supplementation remained persistent after the 16-month intervention, and over the subsequent 1.5-year nonintervention period. The secondary objective was to evaluate if any differences in the growth indicator emerged long-term. We used longitudinal data from a randomized trial conducted in Luapula province, Zambia. A total of 501 infants aged 6-18 months were randomly given daily supplements of maize-soya based porridge with spirulina (SP) or without spirulina (CON). In 2016 and 2018, we collected information on the change in infants’ anthropometric status and morbidity (probable pneumonia, cough, probable malaria, and fever). The registration number of the initial clinical trial is NCT03523182 (Clinical Trial.gov). Children in the SP group were 13% less likely to contract an upper respiratory infection after the 16-month intervention. After the 18-month nonintervention period, children in the SP group were 14% (95% CI: 2%, 25%; P