The odds ratio of a low haemoglobin (Hb <9.3 g/dL) in cases with parasitaemia compared to no malaria was 4.00 (1.61–8.42) (p = 0.002) and this remained significant even after controlling for age, treatment received, MUAC, MCV and sex (p = 0.001). This evidence concerns the gene GSTM1 and malaria.