Molecular surveillance for drug-resistant Plasmodiumfalciparum malaria in Malawi.
We assessed the presence of point mutations associated with resistance to chloroquine (CQ) and sulphadoxine-pyrimethamine (SP) in 178 Plasmodiumfalciparum infections from three geographically distinct sites in Malawi. We confirm that CQ-resistance mutations are now rare in Malawi, being detectable at very low frequencies (2-4%) in infections from two of the three study sites. We also show that over 90% of infections from each of the three study sites carry a set of three dihydrofolate reductase (dhfr) and two dihydropteroate synthase (dhps) mutations strongly associated with SP treatment failure. In this short communication, we present these molecular data and discuss their implications for Malawi's first-line antimalarial treatment policy.
Nkhoma
Standwell
S
Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, PO Box 30096, Chichiri, Blantyre 3, Malawi. snkhoma@mlw.medcol.mw
Molyneux
Malcolm
M
Ward
Stephen
S
D000818:Animals; D000962:Antimalarials / Q000494:pharmacology*; D002738:Chloroquine / Q000494:pharmacology*; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D004094:Dihydropteroate Synthase / Q000737:chemistry / Q000235:genetics; D004338:Drug Combinations; D004351:Drug Resistance / Q000235:genetics; D006801:Humans; D016778:Malaria, Falciparum / Q000188:drug therapy / Q000469:parasitology*; D008295:Malawi; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000235:genetics; D010963:Plasmodium falciparum / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D017354:Point Mutation; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics; D011739:Pyrimethamine / Q000494:pharmacology*; D017422:Sequence Analysis, DNA; D013413:Sulfadoxine / Q000494:pharmacology*; D013762:Tetrahydrofolate Dehydrogenase / Q000737:chemistry / Q000235:genetics
D000962:Antimalarials; D016054:DNA, Protozoan; D004338:Drug Combinations; D026901:Membrane Transport Proteins; C416369:PfCRT protein, Plasmodium falciparum; D015800:Protozoan Proteins; C001205:fanasil, pyrimethamine drug combination; D013413:Sulfadoxine; D002738:Chloroquine; D013762:Tetrahydrofolate Dehydrogenase; D004094:Dihydropteroate Synthase; D011739:Pyrimethamine