Increasing prevalence of wildtypes in the dihydrofolate reductase gene of Plasmodium falciparum in an area with high levels of sulfadoxine/pyrimethamine resistance after introduction of treated bed nets

TY - JOUR

T1 - Increasing prevalence of wildtypes in the dihydrofolate reductase gene of Plasmodium falciparum in an area with high levels of sulfadoxine/pyrimethamine resistance after introduction of treated bed nets

AU - Alifrangis, Michael

AU - Lemnge, Martha M

AU - Rønn, Anita M

AU - Segeja, Method D

AU - Magesa, Stephen M

AU - Khalil, Insaf F

AU - Bygbjerg, Ib C

N1 - Keywords: Animals; Antimalarials; Bedding and Linens; Child, Preschool; Culicidae; DNA Primers; DNA, Protozoan; Dihydropteroate Synthase; Drug Combinations; Drug Resistance; Female; Folic Acid Antagonists; Genotype; Humans; Infant; Insecticides; Malaria, Falciparum; Male; Mosquito Control; Mutation; Plants; Plasmodium falciparum; Polymerase Chain Reaction; Prevalence; Pyrimethamine; Sulfadoxine; Tanzania; Tetrahydrofolate Dehydrogenase

PY - 2003

Y1 - 2003

N2 - In Magoda and Mpapayu villages in Tanzania, we have previously found comparable high prevalence of Plasmodium falciparum resistance to sulfadoxine/pyrimethamine (S/P) in vivo and of mutations in the dihydrofolate reductase (dhfr) and dihydropteroate synthetase (dhps) genes of P. falciparum responsible for resistance to S/P. In December 1998, Magoda received insecticide-treated nets (ITNs), whereas ITNs were introduced in Mpapayu in March 2001. We have studied the effect of ITNs on P. falciparum resistance genes by monitoring the prevalence of dhfr and dhps genotypes in children less than five years old living in the villages from 1998 to 2000. In 2000, after two years of bed net use, the prevalence of wild types in codon 51, 59, and 108 of dhfr increased significantly in Magoda compared with previous years. Furthermore, the prevalence of dhfr wild types was significantly higher in Magoda than in Mpapayu in 2000. The impact of ITNs on the transmission intensity seems not only to affect the overall malaria morbidity, but may even facilitate restoration of susceptibility to antimalarial drugs.

AB - In Magoda and Mpapayu villages in Tanzania, we have previously found comparable high prevalence of Plasmodium falciparum resistance to sulfadoxine/pyrimethamine (S/P) in vivo and of mutations in the dihydrofolate reductase (dhfr) and dihydropteroate synthetase (dhps) genes of P. falciparum responsible for resistance to S/P. In December 1998, Magoda received insecticide-treated nets (ITNs), whereas ITNs were introduced in Mpapayu in March 2001. We have studied the effect of ITNs on P. falciparum resistance genes by monitoring the prevalence of dhfr and dhps genotypes in children less than five years old living in the villages from 1998 to 2000. In 2000, after two years of bed net use, the prevalence of wild types in codon 51, 59, and 108 of dhfr increased significantly in Magoda compared with previous years. Furthermore, the prevalence of dhfr wild types was significantly higher in Magoda than in Mpapayu in 2000. The impact of ITNs on the transmission intensity seems not only to affect the overall malaria morbidity, but may even facilitate restoration of susceptibility to antimalarial drugs.

M3 - Journal article

C2 - 14628937

SN - 0002-9637

VL - 69

SP - 238

EP - 243

JO - Journal. National Malaria Society

JF - Journal. National Malaria Society

IS - 3

ER -