Declining artesunate-mefloquine efficacy against falciparum malaria on the Cambodia-Thailand border

Emerg Infect Dis. 2008 May;14(5):716-9. doi: 10.3201/eid1405.071601.

Abstract

Resistance to many antimalaria drugs developed on the Cambodia-Thailand border long before developing elsewhere. Because antimalaria resistance is now a global problem, artemisinin-based combination therapies (ACTs) are the first-line therapies in most malaria-endemic countries. However, recent clinical and molecular studies suggest the emergence of ACT-resistant Plasmodium falciparum infections in the Cambodia-Thailand border area, where standard ACT is artesunate and mefloquine. These ACT failures might be caused by high-level mefloquine resistance because mefloquine was used for monotherapy long before the introduction of ACT. This observation raises 2 questions. First, how can existing P. falciparum-resistant strains be controlled? Second, how can the evolution of new ACT- resistant strains be avoided elsewhere, e.g., in Africa? Enforcement of rational drug use and improved diagnostic capacity are among the measures needed to avoid and contain ACT resistance.

MeSH terms

  • Animals
  • Antimalarials* / administration & dosage
  • Antimalarials* / pharmacology
  • Antimalarials* / therapeutic use
  • Artemisinins* / administration & dosage
  • Artemisinins* / pharmacology
  • Artemisinins* / therapeutic use
  • Cambodia / epidemiology
  • Directly Observed Therapy
  • Drug Resistance* / genetics
  • Drug Therapy, Combination
  • Humans
  • Malaria, Falciparum / drug therapy*
  • Malaria, Falciparum / epidemiology
  • Malaria, Falciparum / parasitology
  • Mefloquine* / administration & dosage
  • Mefloquine* / pharmacology
  • Mefloquine* / therapeutic use
  • Plasmodium falciparum / drug effects*
  • Plasmodium falciparum / genetics
  • Polymerase Chain Reaction
  • Thailand / epidemiology
  • Treatment Failure

Substances

  • Antimalarials
  • Artemisinins
  • Mefloquine