title: In vitro confirmation of chloroquine-resistant Plasmodium falciparum malaria in KwaZulu.
abstract: In May 1987 and January 1988 the chloroquine sensitivity of Plasmodium falciparum in the Ubombo and Ingwavuma districts of KwaZulu was determined by a modified in vitro microtest in which the patients' plasma was replaced with non-immune human AB serum and the test plates were incubated in an atmosphere of 3% oxygen, 4% carbon dioxide and 93% nitrogen. A success rate of 74% was achieved using this technique. All of 23 successfully tested isolates from malaria patients reporting to clinics and a hospital in these areas were found to be resistant to chloroquine, schizogony being inhibited at 32 pmol per well in the majority of tests. Seventy-five per cent of the isolates obtained through active surveillance in the Ubombo district were found to be resistant in varying degrees. Malarial parasites collected from clinics and a hospital in the endemic area did not change markedly in their in vitro response to chloroquine during the 8-month period May 1987-January 1988.
authors.affiliation: Research Institute for Diseases in a Tropical Environment of the South African Medical Research Council, Durban.
authors.forename: J A
authors.initials: JA
authors.lastname: Freese
authors.forename: B L
authors.initials: BL
authors.lastname: Sharp
authors.forename: S M
authors.initials: SM
authors.lastname: Ngxongo
authors.forename: M B
authors.initials: MB
authors.lastname: Markus
mesh_terms: D000818:Animals; D002738:Chloroquine / Q000494:pharmacology*; D004351:Drug Resistance; D006801:Humans; D008288:Malaria / Q000469:parasitology*; D010963:Plasmodium falciparum / Q000187:drug effects*; D013019:South Africa
chemical_list: D002738:Chloroquine