P. vivax relapse may be associated with reduced primaquine metabolism.7,8 Factors other than human cytochrome P450 2D6 (CYP2D6) phenotype, however, such as personnel adherence or parasite tolerance to primaquine, were found likely to contribute.9 This report describes confirmed malaria cases reported to the CMR database during the 15-year period from 2008 to 2022. This evidence concerns the gene CYP2D6 and malaria.