Plasmodium vivax resistance to chloroquine (R2) and mefloquine (R3) in Brazilian Amazon region

Rev Soc Bras Med Trop. Jan-Feb 1999;32(1):67-8. doi: 10.1590/s0037-86821999000100013.


We report for the first time a patient with malaria due to Plasmodium vivax who showed R2 resistance to chloroquine and R3 resistance to mefloquine in the Brazilian Amazon region based on WHO clinical criteria for diagnosis of malaria resistance. Failure was observed with unsupervised oral chloroquine, chloroquine under rigorous supervision and mefloquine in the same scheme. Finally, the patient was cured with oral artesunate.

Publication types

  • Case Reports

MeSH terms

  • Animals
  • Antimalarials / therapeutic use*
  • Artemisinins*
  • Artesunate
  • Brazil
  • Child
  • Chloroquine / therapeutic use*
  • Drug Resistance
  • Female
  • Humans
  • Malaria / drug therapy*
  • Mefloquine / therapeutic use*
  • Plasmodium vivax / drug effects*
  • Sesquiterpenes / therapeutic use


  • Antimalarials
  • Artemisinins
  • Sesquiterpenes
  • Artesunate
  • Chloroquine
  • Mefloquine