title: Surveillance of travellers: an additional tool for tracking antimalarial drug resistance in endemic countries.
abstract: BACKGROUND
  There are growing concerns about the emergence of resistance to artemisinin-based combination therapies (ACTs). Since the widespread adoption of ACTs, there has been a decrease in the systematic surveillance of antimalarial drug resistance in many malaria-endemic countries. The aim of this work was to test whether data on travellers returning from Africa with malaria could serve as an additional surveillance system of local information sources for the emergence of drug resistance in endemic-countries.
  
  
  METHODS
  Data were collected from travellers with symptomatic Plasmodium falciparum malaria returning from Senegal (n = 1,993), Mali (n = 2,372), Cote d'Ivoire (n = 4,778) or Cameroon (n = 3,272) and recorded in the French Malaria Reference Centre during the period 1996-2011. Temporal trends of the proportion of parasite isolates that carried the mutant genotype, pfcrt 76T, a marker of resistance to chloroquine (CQ) and pfdhfr 108N, a marker of resistance to pyrimethamine, were compared for travellers and within-country surveys that were identified through a literature review in PubMed. The in vitro response to CQ was also compared between these two groups for parasites from Senegal.
  
  
  RESULTS
  The trends in the proportion of parasites that carried pfcrt 76T, and pfdhfr 108N, were compared for parasites from travellers and patients within-country using the slopes of the curves over time; no significant differences in the trends were found for any of the 4 countries. These results were supported by in vitro analysis of parasites from the field in Senegal and travellers returning to France, where the trends were also not significantly different.
  
  
  CONCLUSIONS
  The results have not shown different trends in resistance between parasites derived from travellers or from parasites within-country. This work highlights the value of an international database of drug responses in travellers as an additional tool to assess the emergence of drug resistance in endemic areas where information is limited.
authors.affiliation: Unité Mixte de Recherche 216, Institut de Recherche et de Développement, Paris, France ; PRES Sorbonne Paris Cité, Faculté de Pharmacie, Paris, France ; WorldWide Antimalarial Resistance Network, Oxford, United Kingdom ; Ecole des Hautes Etudes en Santé Publique, Sorbonne Paris Cité, Rennes, France.
authors.forename: Myriam
authors.initials: M
authors.lastname: Gharbi
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Flegg
authors.forename: Bruno
authors.initials: B
authors.lastname: Pradines
authors.forename: Ako
authors.initials: A
authors.lastname: Berenger
authors.forename: Magatte
authors.initials: M
authors.lastname: Ndiaye
authors.forename: Abdoulaye A
authors.initials: AA
authors.lastname: Djimdé
authors.forename: Cally
authors.initials: C
authors.lastname: Roper
authors.forename: Véronique
authors.initials: V
authors.lastname: Hubert
authors.forename: Eric
authors.initials: E
authors.lastname: Kendjo
authors.forename: Meera
authors.initials: M
authors.lastname: Venkatesan
authors.forename: Philippe
authors.initials: P
authors.lastname: Brasseur
authors.forename: Oumar
authors.initials: O
authors.lastname: Gaye
authors.forename: André T
authors.initials: AT
authors.lastname: Offianan
authors.forename: Louis
authors.initials: L
authors.lastname: Penali
authors.forename: Jacques
authors.initials: J
authors.lastname: Le Bras
authors.forename: Philippe J
authors.initials: PJ
authors.lastname: Guérin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000962:Antimalarials / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D002738:Chloroquine / Q000494:pharmacology*; D016054:DNA, Protozoan / Q000235:genetics; D004351:Drug Resistance; D005260:Female; D005819:Genetic Markers; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016778:Malaria, Falciparum / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology*; D008297:Male; D026901:Membrane Transport Proteins / Q000235:genetics; D008875:Middle Aged; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D011159:Population Surveillance; D011379:Prognosis; D015800:Protozoan Proteins / Q000235:genetics; D012675:Senegal / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000962:Antimalarials; D016054:DNA, Protozoan; D005819:Genetic Markers; D026901:Membrane Transport Proteins; C416369:PfCRT protein, Plasmodium falciparum; D015800:Protozoan Proteins; D002738:Chloroquine