G6PD and malaria: There may be host survival advantage in forcing malaria parasites to live in a red blood cell cytosol deprived of the detoxifying effects of G6PD activity (the sole source of electrons for NADP+ and oxidised glutathione).78 Achieving this with P. vivax infection would require reticulocytes having greatly reduced G6PD activity (as in panel I of Fig. 5).