Molecular markers of in vivo Plasmodium vivax resistance to amodiaquine plus sulfadoxine-pyrimethamine:: Mutations in pvdhfr and pvmdr1

Abstract

BACKGROUND: Molecular markers for sulfadoxine-pyrimethamine (SP) resistance in Plasmodium vivax have been reported. However, data on the molecular correlates involved in the development of resistance to 4-aminoquinolines and their association with the in vivo treatment response are scarce. METHODS: We assessed pvdhfr (F57L/I, S58R, T61M, S117T/N, and I173F/L) and pvmdr1 (Y976F and F1076L) mutations in 94 patients who received amodiaquine (AQ) plus SP in Papua New Guinea (PNG). We then investigated the association between parasite genotype and treatment response. RESULTS: The treatment failure (TF) rate reached 13%. Polymorphisms in pvdhfr F57L, S58R, T61M, and S117T/N and in pvmdr1 Y976F wer..