Anaemia (Hb<10 g/dl) was present in 24.5% (122/497) of children and associated with P. vivax parasitaemia (OR = 2.9 [95%CI, 1.7–4.9], p = 0.001), P. falciparum parasitaemia (OR = 4.3 [95%CI, 2.0–9.4], p<0.001), hookworm carriage (OR = 2.6 [95%CI, 1.2–5.8], p = 0.026), Plasmodium–helminth coinfection (OR 4.0 [95%CI, 1.4–11.3], p = 0.008) and severe stunting (OR = 1.9 ([95%CI, 1.1–3.3], p = 0.012). Here, GSTM1 is linked to anemia (phenotype).