PLoS ONE (Jan 2013)

Surveillance of travellers: an additional tool for tracking antimalarial drug resistance in endemic countries.

  • Myriam Gharbi,
  • Jennifer A Flegg,
  • Bruno Pradines,
  • Ako Berenger,
  • Magatte Ndiaye,
  • Abdoulaye A Djimdé,
  • Cally Roper,
  • Véronique Hubert,
  • Eric Kendjo,
  • Meera Venkatesan,
  • Philippe Brasseur,
  • Oumar Gaye,
  • André T Offianan,
  • Louis Penali,
  • Jacques Le Bras,
  • Philippe J Guérin,
  • Members of the French National Reference Center for Imported Malaria Study

DOI
https://doi.org/10.1371/journal.pone.0077775
Journal volume & issue
Vol. 8, no. 10
p. e77775

Abstract

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IntroductionThere 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.MethodologyData 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.ResultsThe 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.ConclusionThe 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.