Molecular analysis of recrudescent parasites in a Plasmodium falciparum drug efficacy trial in Gabon.
Recrudescent Plasmodium falciparum parasites were sampled from 108 children taking part in a drug efficacy trial in Gabon. A finger-prick blood sample was taken from each child before treatment, and a post-treatment sample taken of the recrudescent parasites. Sample deoxyribonucleic acid was amplified by the polymerase chain reaction using primers specific to the P. falciparum antigen genes MSP-1, MSP-2 and GLURP. Seventy-seven children had identical parasites in their pre- and post-treatment samples, indicating genuine recrudescences of resistant parasites. Fourteen children had completely different parasites in their pre- and post-treatment samples, indicating either a fresh infection from a mosquito or growth of a population of parasites not detected in the pre-treatment sample, perhaps due to sequestration. The remaining 17 children had a mixture of pre-treatment and new parasites in their post-treatment samples. This study demonstrated the use of polymorphic markers to confirm whether parasites in patients with clinical recrudescences after drug treatment are genuinely resistant.
Ranford-Cartwright
L C
LC
Institute of Cell, Animal and Population Biology, University of Edinburgh, Scotland, UK.
Taylor
J
J
Umasunthar
T
T
Taylor
L H
LH
Babiker
H A
HA
Lell
B
B
Schmidt-Ott
J R
JR
Lehman
L G
LG
Walliker
D
D
Kremsner
P G
PG
D000293:Adolescent; D000818:Animals; D000962:Antimalarials / Q000627:therapeutic use; D004351:Drug Resistance; D005681:Gabon; D006801:Humans; D016778:Malaria, Falciparum / Q000188:drug therapy / Q000469:parasitology*; D010963:Plasmodium falciparum / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012008:Recurrence
D000962:Antimalarials