title: Drug resistance associated genetic polymorphisms in Plasmodium falciparum and Plasmodium vivax collected in Honduras, Central America.
abstract: BACKGROUND
  In Honduras, chloroquine and primaquine are recommended and still appear to be effective for treatment of Plasmodium falciparum and Plasmodium vivax malaria. The aim of this study was to determine the proportion of resistance associated genetic polymorphisms in P. falciparum and P. vivax collected in Honduras.
  
  
  METHODS
  Blood samples were collected from patients seeking medical attention at the Hospital Escuela in Tegucigalpa from 2004 to 2006 as well as three regional hospitals, two health centres and one regional laboratory during 2009. Single nucleotide polymorphisms in P. falciparum chloroquine resistance transporter (pfcrt), multidrug resistance 1 (pfmdr1), dihydrofolate reductase (pfdhfr) and dihydropteroate synthase (pfdhps) genes and in P. vivax multidrug resistance 1 (pvmdr1) and dihydrofolate reductase (pvdhfr) genes were detected using PCR based methods.
  
  
  RESULTS
  Thirty seven P. falciparum and 64 P. vivax samples were collected. All P. falciparum infections acquired in Honduras carried pfcrt, pfmdr1, pfdhps and pfdhfr alleles associated with chloroquine, amodiaquine and sulphadoxine-pyrimethamine sensitivity only. One patient with parasites acquired on a Pacific Island had pfcrt 76 T and pfmdr1 86Y alleles. That patient and a patient infected in West Africa had pfdhfr 51I, 59 R and 108 N alleles. Pvmdr1 976 F was found in 7/37 and two copies of pvmdr1 were found in 1/37 samples. Pvdhfr 57 L + 58 R was observed in 2/57 samples.
  
  
  CONCLUSIONS
  The results indicate that P. falciparum from Honduras remain sensitive to chloroquine and sulphadoxine-pyrimethamine. This suggests that chloroquine and sulphadoxine-pyrimethamine should be efficacious for treatment of uncomplicated P. falciparum malaria, supporting current national treatment guidelines. However, genetic polymorphisms associated with chloroquine and sulphadoxine-pyrimethamine tolerance were detected in local P. vivax and imported P. falciparum infections. Continuous monitoring of the prevalence of drug resistant/tolerant P. falciparum and P. vivax is therefore essential also in Honduras.
authors.affiliation: Malaria Research Laboratory, Infectious Diseases Unit, Department of Medicine, Karolinska University Hospital/Karolinska Institutet, Retzius väg 10, 171 77 Stockholm, Sweden. irina.jovel@ki.se
authors.forename: Irina T
authors.initials: IT
authors.lastname: Jovel
authors.forename: Rosa E
authors.initials: RE
authors.lastname: Mejía
authors.forename: Engels
authors.initials: E
authors.lastname: Banegas
authors.forename: Rita
authors.initials: R
authors.lastname: Piedade
authors.forename: Jackeline
authors.initials: J
authors.lastname: Alger
authors.forename: Gustavo
authors.initials: G
authors.lastname: Fontecha
authors.forename: Pedro E
authors.initials: PE
authors.lastname: Ferreira
authors.forename: Maria I
authors.initials: MI
authors.lastname: Veiga
authors.forename: Irma G
authors.initials: IG
authors.lastname: Enamorado
authors.forename: Anders
authors.initials: A
authors.lastname: Bjorkman
authors.forename: Johan
authors.initials: J
authors.lastname: Ursing
mesh_terms: D000962:Antimalarials / Q000494:pharmacology*; D002738:Chloroquine / Q000494:pharmacology; D004351:Drug Resistance; D006721:Honduras; D006801:Humans; D016778:Malaria, Falciparum / Q000469:parasitology*; D016780:Malaria, Vivax / Q000469:parasitology*; D010963:Plasmodium falciparum / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D010966:Plasmodium vivax / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D020641:Polymorphism, Single Nucleotide; D011319:Primaquine / Q000494:pharmacology; D015800:Protozoan Proteins / Q000235:genetics
chemical_list: D000962:Antimalarials; D015800:Protozoan Proteins; D002738:Chloroquine; D011319:Primaquine