title: Detection of high levels of mutations involved in anti-malarial drug resistance in Plasmodium falciparum and Plasmodium vivax at a rural hospital in southern Ethiopia.
abstract: BACKGROUND
  In Ethiopia, malaria is caused by Plasmodium falciparum and Plasmodium vivax, and anti-malarial drug resistance is the most pressing problem confronting control of the disease. Since co-infection by both species of parasite is common and sulphadoxine-pyrimethamine (SP) has been intensively used, resistance to these drugs has appeared in both P. falciparum and P. vivax populations. This study was conducted to assess the prevalence of anti-malarial drug resistance in P. falciparum and P. vivax isolates collected at a rural hospital in southern Ethiopia.
  
  
  METHODS
  A total of 1,147 patients with suspected malaria were studied in different months across the period 2007-2009. Plasmodium falciparum dhfr and dhps mutations and P. vivax dhfr polymorphisms associated with resistance to SP, as well as P. falciparum pfcrt and pfmdr1 mutations conferring chloroquine resistance, were assessed.
  
  
  RESULTS
  PCR-based diagnosis showed that 125 of the 1147 patients had malaria. Of these, 52.8% and 37.6% of cases were due to P. falciparum and P. vivax respectively. A total of 10 cases (8%) showed co-infection by both species and two cases (1.6%) were infected by Plasmodium ovale. Pfdhfr triple mutation and pfdhfr/pfdhps quintuple mutation occurred in 90.8% (95% confidence interval [CI]: 82.2%-95.5%) and 82.9% (95% CI: 72.9%-89.7%) of P. falciparum isolates, respectively. Pfcrt T76 was observed in all cases and pfmdr1 Y86 and pfmdr1 Y1246 in 32.9% (95% CI: 23.4%-44.15%) and 17.1% (95% CI: 10.3-27.1%), respectively. The P. vivax dhfr core mutations, N117 and R58, were present in 98.2% (95% CI: 89.4-99.9%) and 91.2% (95% CI: 80.0-96.7%), respectively.
  
  
  CONCLUSIONS
  Current molecular data show an extraordinarily high frequency of drug-resistance mutations in both P. falciparum and P. vivax in southern Ethiopia. Urgent surveillance of the emergence and spread of resistance is thus called for. The level of resistance indicates the need for implementation of entire population access to the new first-line treatment with artemether-lumefantrine, accompanied by government monitoring to prevent the emergence of resistance to this treatment.
authors.affiliation: National Centre for Tropical Medicine, Institute of Health Carlos III, C/Sinesio Delgado 4-6, 28029, Madrid, Spain. pmula@isciii.es
authors.forename: Patricia
authors.initials: P
authors.lastname: Mula
authors.forename: Amalia
authors.initials: A
authors.lastname: Fernández-Martínez
authors.forename: Aida
authors.initials: A
authors.lastname: de Lucio
authors.forename: Jose Manuel
authors.initials: JM
authors.lastname: Ramos
authors.forename: Francisco
authors.initials: F
authors.lastname: Reyes
authors.forename: Vicenta
authors.initials: V
authors.lastname: González
authors.forename: Agustín
authors.initials: A
authors.lastname: Benito
authors.forename: Pedro
authors.initials: P
authors.lastname: Berzosa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000962:Antimalarials / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D016054:DNA, Protozoan / Q000235:genetics; D004094:Dihydropteroate Synthase / Q000235:genetics; D004351:Drug Resistance; D005002:Ethiopia; D006780:Hospitals, Rural; D006801:Humans; D007223:Infant; D016778:Malaria, Falciparum / Q000469:parasitology*; D016780:Malaria, Vivax / Q000469:parasitology*; D026901:Membrane Transport Proteins / Q000235:genetics; D008875:Middle Aged; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics; D020125:Mutation, Missense; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000235:genetics; D010966:Plasmodium vivax / Q000187:drug effects* / Q000235:genetics; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D015800:Protozoan Proteins / Q000235:genetics; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics; D055815:Young Adult
chemical_list: D000962:Antimalarials; D016054:DNA, Protozoan; D004094:Dihydropteroate Synthase; D026901:Membrane Transport Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D015800:Protozoan Proteins; D013762:Tetrahydrofolate Dehydrogenase; C513498:Mdr1 protein, Plasmodium falciparum; C416369:PfCRT protein, Plasmodium falciparum