title: Plasmodium vivax dhfr and dhps mutations in isolates from Madagascar and therapeutic response to sulphadoxine-pyrimethamine.
abstract: BACKGROUND
  Four of five Plasmodium species infecting humans are present in Madagascar. Plasmodium vivax remains the second most prevalent species, but is understudied. No data is available on its susceptibility to sulphadoxine-pyrimethamine, the drug recommended for intermittent preventive treatment during pregnancy. In this study, the prevalence of P. vivax infection and the polymorphisms in the pvdhfr and pvdhps genes were investigated. The correlation between these polymorphisms and clinical and parasitological responses was also investigated in P. vivax-infected patients.
  
  
  METHODS
  Plasmodium vivax clinical isolates were collected in eight sentinel sites from the four major epidemiological areas for malaria across Madagascar in 2006/2007. Pvdhfr and pvdhps genes were sequenced for polymorphism analysis. The therapeutic efficacy of SP in P. vivax infections was assessed in Tsiroanomandidy, in the foothill of the central highlands. An intention-to-treat analysis of treatment outcome was carried out.
  
  
  RESULTS
  A total of 159 P. vivax samples were sequenced in the pvdhfr/pvdhps genes. Mutant-types in pvdhfr gene were found in 71% of samples, and in pvdhps gene in 16% of samples. Six non-synonymous mutations were identified in pvdhfr, including two novel mutations at codons 21 and 130. For pvdhps, beside the known mutation at codon 383, a new one was found at codon 422. For the two genes, different combinations were ranged from wild-type to quadruple mutant-type. Among the 16 patients enrolled in the sulphadoxine-pyrimethamine clinical trial (28 days of follow-up) and after adjustment by genotyping, 3 (19%, 95% CI: 5%-43%) of them were classified as treatment failure and were pvdhfr 58R/117N double mutant carriers with or without the pvdhps 383G mutation.
  
  
  CONCLUSIONS
  This study highlights (i) that genotyping in the pvdhfr and pvdhps genes remains a useful tool to monitor the emergence and the spread of P. vivax sulphadoxine-pyrimethamine resistant in order to improve the national antimalarial drug policy, (ii) the issue of using sulphadoxine-pyrimethamine as a monotherapy for intermittent preventive treatment of pregnant women or children.
authors.affiliation: EA4170, Parasitology and Tropical Medicine, University Lyon 1, Lyon, France. cbarnadas@free.fr
authors.forename: Céline
authors.initials: C
authors.lastname: Barnadas
authors.forename: Magali
authors.initials: M
authors.lastname: Tichit
authors.forename: Christiane
authors.initials: C
authors.lastname: Bouchier
authors.forename: Arsène
authors.initials: A
authors.lastname: Ratsimbasoa
authors.forename: Laurence
authors.initials: L
authors.lastname: Randrianasolo
authors.forename: Rogelin
authors.initials: R
authors.lastname: Raherinjafy
authors.forename: Martial
authors.initials: M
authors.lastname: Jahevitra
authors.forename: Stéphane
authors.initials: S
authors.lastname: Picot
authors.forename: Didier
authors.initials: D
authors.lastname: Ménard
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000962:Antimalarials / Q000494:pharmacology* / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D004094:Dihydropteroate Synthase / Q000235:genetics*; D004338:Drug Combinations; D004351:Drug Resistance; D005260:Female; D006801:Humans; D007223:Infant; D008270:Madagascar / Q000453:epidemiology; D016780:Malaria, Vivax / Q000188:drug therapy / Q000453:epidemiology / Q000469:parasitology*; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D010966:Plasmodium vivax / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D015800:Protozoan Proteins / Q000235:genetics; D011739:Pyrimethamine / Q000494:pharmacology* / Q000627:therapeutic use; D017422:Sequence Analysis, DNA; D013413:Sulfadoxine / Q000494:pharmacology* / Q000627:therapeutic use; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics*; D016896:Treatment Outcome
chemical_list: D000962:Antimalarials; D004338:Drug Combinations; D015800:Protozoan Proteins; C001205:fanasil, pyrimethamine drug combination; D013413:Sulfadoxine; D013762:Tetrahydrofolate Dehydrogenase; D004094:Dihydropteroate Synthase; D011739:Pyrimethamine