title: Falciparum malaria in the north of Laos: the occurrence and implications of the Plasmodium falciparum chloroquine resistance transporter (pfcrt) gene haplotype SVMNT.
abstract: OBJECTIVE
  The Pfcrt-gene encodes a transmembrane protein located in the Plasmodium falciparum digestive vacuole. Chloroquine resistant (CQR) strains of African and Southeast Asian origin carry the Pfcrt-haplotype (c72-76) CVIET, whereas most South American and Papua New Guinean CQR stains carry the SVMNT haplotype.
  
  
  METHODS
  Eighty-eight samples from an area with reported in vivo Chloroquine and in vitro Amodiaquine-resistance were screened for the K76T mutation and their Pfcrt-haplotype (c72-76) using a new SSOP-ELISA.
  
  
  RESULTS
  Hundred percent of the analysed samples showed the K76T mutation which is highly associated with in vivo drug failure. This very high rate of a CQR-marker is alarming in an area were CQ is still used as first line drug. The distribution of the three main Pfcrt-haplotypes was as follows: 68% CVIET, 31% SVMNT, 0% CVMNT.
  
  
  CONCLUSIONS
  These data show, for the first time, the South American/PNG -haplotype (SVMNT) on mainland Southeast Asia. SVMNT-haplotype and others might be associated with a decreased efficacy of Amodiaquine and could therefore be potential markers for of amodiaquine resistance (AQR). If there is a correlation between AQR and the SVMNT-haplotype as suggested, 31% prevalence of a potential resistance marker is cause for concern.
authors.affiliation: Institute of Tropical Medicine, Berlin, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Dittrich
authors.forename: Michael
authors.initials: M
authors.lastname: Alifrangis
authors.forename: Jörg M
authors.initials: JM
authors.lastname: Stohrer
authors.forename: Vonthalom
authors.initials: V
authors.lastname: Thongpaseuth
authors.forename: Viengxay
authors.initials: V
authors.lastname: Vanisaveth
authors.forename: Rattanaxay
authors.initials: R
authors.lastname: Phetsouvanh
authors.forename: Samlane
authors.initials: S
authors.lastname: Phompida
authors.forename: Insaf F
authors.initials: IF
authors.lastname: Khalil
authors.forename: Tomas
authors.initials: T
authors.lastname: Jelinek
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000962:Antimalarials / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D002738:Chloroquine / Q000627:therapeutic use; D003430:Cross-Sectional Studies; D004351:Drug Resistance / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D007812:Laos / Q000453:epidemiology; D016778:Malaria, Falciparum / Q000188:drug therapy / Q000453:epidemiology / Q000235:genetics*; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D026901:Membrane Transport Proteins; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D009693:Nucleic Acid Hybridization / Q000379:methods; D010963:Plasmodium falciparum / Q000235:genetics*; D015800:Protozoan Proteins; D017211:Treatment Failure
chemical_list: D000962:Antimalarials; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; C416369:PfCRT protein, Plasmodium falciparum; D015800:Protozoan Proteins; D002738:Chloroquine