Distribution of V3 amino acid charges per study group. Distribution of the nett charges of the V3 fragment in children with severe anaemia (cases, Hb<5.0 g/dL) as compared to those without severe anaemia (controls). The distribution is expressed as a percentage of the total number of codons analysed per study group (Controls: n = 28, Cases n = 26). Error bars express 95% Confidence intervals. p = 0.19.