Profile of the Pfcrt 76T Gene in the Cities of Man, San-Pedro, and Abengourou Two Decades After the Withdrawal of Chloroquine

Malaria remains a major public health problem worldwide, particularly in Côte d'Ivoire, where it is the leading cause of morbidity. Although chloroquine is no longer used in Côte d'Ivoire, the mutation of the Plasmodium falciparum chloroquine resistance transporter (Pfcrt) gene (K76T) serves as a molecular marker by which to monitor chloroquine resistance. This study was designed to determine the genetic profile of circulating isolates in the country 19 years after the withdrawal of this drug. The study was conducted from October 2021 to August 2022 in Man, San-Pedro, and Abengourou. A total of 300 samples were collected for molecular analysis on Whatman paper (100 per site) from patients who tested positive for Plasmodium falciparum. The analysis was done through the use of nested polymerase chain reaction on the extracted plasmodial DNA, using the TIANLONG kit and enzymatic digestion using the Apo I enzyme for detection of the codon 76-point mutation. The prevalence of the mutant allele 76T was 11.9% (35/294), distributed as follows: 18% (18/100) in Man, 12.5% (12/96) in San-Pedro and 5.1% (5/98) in Abengourou. In comparison, the prevalence of the wild-type K76 allele was 88.1% (259/294), distributed as 82% (82/100) in Man, 87.5% (84/96) in San-Pedro and 94.9% (93/98) in Abengourou. These results show that several years after the withdrawal of chloroquine as a treatment for malaria in Côte d'Ivoire, a decline in chloroquine resistance has been observed.