Our findings suggest that on the Thailand-Myanmar border the use of G6PD RDTs to identify patients with G6PD deficiency before supervised primaquine is likely to provide significant health benefits (equivalent to between 1 and 9 days of perfect health) compared to giving chloroquine alone or giving 14 day primaquine without G6PD testing. The gene discussed is G6PD; the disease is G6PD deficiency.