title: Assessment of pfcrt 72-76 haplotypes eight years after chloroquine withdrawal in Kinshasa, Democratic Republic of Congo.
abstract: BACKGROUND
  In 2001, the World Health Organization (WHO) has recommended the use of artemisinin-based combination therapy (ACT) as the first-line treatment of uncomplicated malaria cases, as monotherapies had become ineffective in many parts of the world. As a result, the Democratic Republic of Congo (DRC) withdrew chloroquine (CQ) from its malaria treatment policy in 2002 and an artesunate (AS)-amodiaquine (AQ) combination became the ACT of choice in DRC in 2005. AQ-resistance (AQR) has been reported in several parts of the world and mutations in codons 72-76 of the Plasmodium falciparum chloroquine-resistance transporter (pfcrt) gene have been strongly correlated with resistance, especially mutations encoding the SVMNT haplotype. This haplotype was first identified in Southeast Asia and South America but was recently reported in two African countries neighbouring DRC. These facts raised two questions: the first about the evolution of CQ resistance (CQR) in DRC and the second about the presence of the SVMNT haplotype, which would compromise the use of AQ as a partner drug for ACT.
  
  
  METHODS
  A total of 213 thick blood films were randomly collected in 2010 from a paediatric clinic in Kinshasa, DRC. Microscopy controls and real-time polymerase chain reaction (RT-PCR) were performed for Plasmodium species identification. Haplotypes of the pfcrt gene were determined by sequencing.
  
  
  RESULTS
  The K76T mutation was detected in 145 out of 198 P. falciparum-positive samples (73.2%). In these 145 resistant strains, only the CVIET haplotype was detected.
  
  
  CONCLUSIONS
  This study is the first to assess the molecular markers of resistance to CQ and AQ after the introduction of ACT in DRC. The results suggest first that CQR is decreasing, as wild-type pfcrt haplotypes were found in only 26.8% of the samples and secondly that the SVMNT haplotype is not yet present in Kinshasa, suggesting that AQ remains valid as a partner drug for ACT in this region.
authors.affiliation: Biochemistry and Molecular Biology Unit, Department of Basic Sciences, School of Medicine, University of Kinshasa, BP 190 KIN XI, Kinshasa, DR Congo. didimvumbi@gmail.com.
authors.forename: Dieudonné Makaba
authors.initials: DM
authors.lastname: Mvumbi
authors.forename: Raphael
authors.initials: R
authors.lastname: Boreux
authors.forename: Rosalie
authors.initials: R
authors.lastname: Sacheli
authors.forename: Mvumbi
authors.initials: M
authors.lastname: Lelo
authors.forename: Bobanga
authors.initials: B
authors.lastname: Lengu
authors.forename: Situakibanza
authors.initials: S
authors.lastname: Nani-Tuma
authors.forename: Pierrette
authors.initials: P
authors.lastname: Melin
authors.forename: Kayembe
authors.initials: K
authors.lastname: Ntumba
authors.forename: Kalala
authors.initials: K
authors.lastname: Lunganza
authors.forename: Patrick
authors.initials: P
authors.lastname: DeMol
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Hayette
mesh_terms: D000962:Antimalarials / Q000627:therapeutic use*; D002675:Child, Preschool; D002738:Chloroquine / Q000627:therapeutic use*; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D015023:Democratic Republic of the Congo / Q000453:epidemiology; D004351:Drug Resistance; D005260:Female; D005787:Gene Frequency; D006239:Haplotypes; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016778:Malaria, Falciparum / Q000453:epidemiology / Q000469:parasitology*; D008297:Male; D026901:Membrane Transport Proteins / Q000235:genetics*; D050505:Mutant Proteins / Q000235:genetics; D010963:Plasmodium falciparum / Q000235:genetics* / Q000302:isolation & purification; D015800:Protozoan Proteins / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D000962:Antimalarials; D016054:DNA, Protozoan; D026901:Membrane Transport Proteins; D050505:Mutant Proteins; C416369:PfCRT protein, Plasmodium falciparum; D015800:Protozoan Proteins; D002738:Chloroquine