G6PD and G6PD deficiency: As G6PD deficiency is known to be associated with protection against malaria, including P. vivax,50 its prevalence in P. vivax patients is expected to be lower than in the general population, thus altering the risk-benefit ratio of 8-aminoquinoline therapy.51 A better understanding of the geographical distribution of severe G6PD-deficiency alleles in general and in P. vivax patients in particular would assist development of evidence-based guidelines for 8-aminoquinoline therapy.