Usefulness of the Plasmodium falciparum chloroquine resistance transporter T76 genotype failure index for the estimation of in vivo chloroquine resistance in Burkina Faso.

The prevalence of chloroquine (CQ) treatment failure and the genotype failure index was determined in four sentinel sites in Burkina Faso. In three sites, the genotype failure index varied between 1.7 and 3, a result confirming the relationship between the Plasmodium falciparum CQ resistance transporter (Pfcrt) T76 mutation and CQ resistance. In the remaining site, the genotype failure index was unusually low, 1.1, which was significantly different than that in the other sites (P < 0.00001). These findings are discussed. Often but not always, the prevalence of CQ resistance can be correctly estimated by the Pfcrt T76 genotype failure index.