title: Assessment of susceptibility of Plasmodium falciparum to chloroquine, quinine, mefloquine, sulfadoxine-pyrimethamine and artemisinin in southern Viet Nam.
abstract: Resistance to antimalarial chemotherapy is a major concern for malaria control in Viet Nam. In this study undertaken in 1998, 65 patients with uncomplicated Plasmodium falciparum malaria were monitored for 28 days after completion of a 5-day treatment course with artemisinin. Overall 36.9% (24/65) of patients had recurrent parasitaemia during the surveillance period. P. falciparum isolates were tested for sensitivity in vitro to chloroquine, mefloquine, quinine, sulfadoxine-pyrimethamine and results were compared to those from a similar study in 1995. Increased parasite sensitivity to sulfadoxine-pyrimethamine, chloroquine and quinine was demonstrated, with significantly lower mean EC50 and EC99 values in 1998 compared to 1995. Parasite sensitivity to mefloquine did not differ significantly in the 2 surveys. Isolates were also tested for sensitivity in vitro to artemisinin in the 1998 survey. The mean EC50 was 0.03 mumol/L and the EC99 was 0.94 mumol/L. Parasite sensitivity to artemisinin will need to be monitored in view of its increasing use in Viet Nam.
authors.affiliation: National Institute of Malariology, Parasitology and Entomology, Hanoi, Viet Nam.
authors.forename: N V
authors.initials: NV
authors.lastname: Thanh
authors.forename: A F
authors.initials: AF
authors.lastname: Cowman
authors.forename: D
authors.initials: D
authors.lastname: Hipgrave
authors.forename: T B
authors.initials: TB
authors.lastname: Kim
authors.forename: B Q
authors.initials: BQ
authors.lastname: Phuc
authors.forename: L D
authors.initials: LD
authors.lastname: Cong
authors.forename: B A
authors.initials: BA
authors.lastname: Biggs
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000627:therapeutic use*; D037621:Artemisinins; D002675:Child, Preschool; D002738:Chloroquine / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D004351:Drug Resistance; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016778:Malaria, Falciparum / Q000188:drug therapy*; D015767:Mefloquine / Q000627:therapeutic use; D008826:Microbial Sensitivity Tests; D010963:Plasmodium falciparum / Q000187:drug effects*; D011739:Pyrimethamine / Q000627:therapeutic use; D011803:Quinine / Q000627:therapeutic use; D012717:Sesquiterpenes / Q000627:therapeutic use; D013413:Sulfadoxine / Q000627:therapeutic use
chemical_list: D000962:Antimalarials; D037621:Artemisinins; D004338:Drug Combinations; D012717:Sesquiterpenes; C001205:fanasil, pyrimethamine drug combination; D013413:Sulfadoxine; D002738:Chloroquine; C031327:artemisinin; D011803:Quinine; D015767:Mefloquine; D011739:Pyrimethamine