GSTM1 and infection: Among LDR-FMA diagnosed infections only mixed species (-0.4 g/dl, CL95: 0.2–0.5, p < 0.001) and P. falciparum single infections (-0.5 g/dl, CL95: 0.3–0.7, p < 0.001) were associated with a significant reduction in Hb levels.