Return of widespread chloroquine-sensitive Plasmodium falciparum to Malawi.
BACKGROUND
The return of chloroquine-sensitive Plasmodium falciparum to the limited area of Blantyre, Malawi, has been well demonstrated in several studies.


METHODS
To characterize chloroquine susceptibility over a wide geographic area, infants and children aged 6-59 months were selected using 2-stage cluster sampling in 8 Malawian districts. Pyrosequencing of the pfcrt gene codon 76 region was performed for children with asexual parasitemia.


RESULTS
Of 7145 children, 1150 had microscopic asexual parasitemia, and sequencing was performed in 685, of whom 1 had a chloroquine-resistant genotype.


CONCLUSIONS
Systematic countrywide sampling demonstrates that the chloroquine pfcrt genotype has reached near-fixation, raising the possibility of reintroducing chloroquine for malaria prevention and treatment.
Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore Department of Medicine, University of Minnesota, Minneapolis.
Anne E P
AE
Frosch
Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore.
Miriam K
MK
Laufer
Malaria Alert Center.
Don P
DP
Mathanga
Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore.
Shannon
S
Takala-Harrison
Malaria Branch, Centers for Disease Control and Prevention, Atlanta, Georgia.
Jacek
J
Skarbinski
Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore.
Cassidy W
CW
Claassen
Department of Pharmacology, University of Malawi College of Medicine, Blantyre.
Fraction K
FK
Dzinjalamala
Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore.
Christopher V
CV
Plowe
D000962:Antimalarials / Q000494:pharmacology*; D002675:Child, Preschool; D002738:Chloroquine / Q000494:pharmacology*; D003430:Cross-Sectional Studies; D005838:Genotype; D060005:Genotyping Techniques; D006801:Humans; D007223:Infant; D016778:Malaria, Falciparum / Q000453:epidemiology* / Q000469:parasitology*; D008295:Malawi; D008297:Male; D026901:Membrane Transport Proteins / Q000235:genetics*; D021261:Parasitic Sensitivity Tests; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D015800:Protozoan Proteins / Q000235:genetics*; D017422:Sequence Analysis, DNA
D000962:Antimalarials; D026901:Membrane Transport Proteins; C416369:PfCRT protein, Plasmodium falciparum; D015800:Protozoan Proteins; D002738:Chloroquine
Africa; Malawi; PfCRT; Plasmodium falciparum; chloroquine; malaria; resistance