G6PD and Plasmodium vivax malaria: While standard 14-days primaquine regimen for radical cure of vivax malaria can safely be given to most adults with normal FST results (e.g. ≥ 30% enzymatic activity), safe administration of shorter high-dose primaquine treatment and tafenoquine requires identification of patients with at least 70% of normal G6PD enzymatic activity (Rueangweerayutet al., 2017).