Chloroquine resistance of Plasmodium falciparum in Brazil detected by a simple in vitro method.

  • 1 January 1971
    • journal article
    • Vol. 45  (2) , 157-67
Abstract
The sensitivity of Plasmodium falciparum to antimalarial drugs is primarily determined by observing changes in the level of parasitaemia after administration of drugs to man. Performance of such a study and interpretation of its results may present certain difficulties, especially when conducted among persons living in malarious areas. The present study was conducted to evaluate the usefulness of a simple in vitro method for detecting chloroquine-resistant strains among infected residents of Mato Grosso, Brazil. The findings indicated the participants were infected with chloroquine-resistant P. falciparum. Subsequent administration of a standard regimen of chloroquine (25 mg/kg) to these subjects confirmed the findings observed in vitro by failing to cure 28 out of 30 infections. This in vitro technique seems to provide a useful method of determining the presence or prevalence of chloroquine-resistant strains in a given area.