44.1% of cases and 42.5% of controls were anaemic (Hb < 11g/dl), There were no differences between cases and controls in prevalence of severe anaemia (Hb < 8 g/dl, mean 5.9%), G6PD deficiency (mean 18.7%), or sickle cell trait (mean 44.5%), (all p > 0.3). Here, GSTM1 is linked to G6PD deficiency.