Fig. 3.

Malaria susceptibility increases transiently during iron supplementation and anemic children receiving iron supplements have increased numbers of young RBCs.

A) P. falciparum in vitro growth rates in RBCs from anemic children increase over time with iron supplementation (12 mg iron daily for 84 d). Parasite growth assays were conducted in RBCs from children at Day 0, Day 49, and Day 84 using strain FCR3-FMG. Growth rates are reported relative to growth in RBCs from non-anemic donors. Each dot represents the mean of triplicate assays and error bars represent the 95% CI. Differences between growth rates at the different timepoints were significant (p < 0.0001 by one-way ANOVA); specifically, post-hoc analysis with Tukey's test indicates significant differences between Day 0 and Day 49 (***p < 0.001) and Day 49 and Day 84 (***p < 0.001), as well as Day 0 and Day 84 (**p < 0.01). n = 158 children at Day 0, n = 91 children at Day 49, and n = 87 children at Day 84.

B) Levels of CD71 positive RBCs increase over time in anemic children undergoing iron supplementation. Percent CD71-positive RBCs was measured by flow cytometry analysis of CD71 surface expression. Error bars represent the 95% CI; one-way repeated measures ANOVA indicates the means are significantly different between Days (p < 0.01, n = 31); post-hoc analysis with Tukey's test indicates significant differences between Day 0 and Day 49 (**p < 0.001) but not between Day 49 and Day 84, nor Day 0 and Day 84.