The WHO Guidelines for the treatment of malaria [15] contain recommendations for the treatment of P. vivax and Plasmodiumovale that are based on the need to radically cure patients using primaquine (the only available anti-relapse medicine) while at the same time minimizing the risk of primaquine-induced acute haemolysis in those who are deficient in the enzyme glucose-6-phospate dehydrogenase (G6PD). This evidence concerns the gene G6PD and malaria.