Increase of parasites carrying lumefantrine-tolerance molecular markers and lack of South East Asian artemisinin-resistance mutations in samples collected from 2013 to 2016 in Côte d'Ivoire.

One of the major obstacles to malaria elimination in the world is the resistance in to most antimalarial drugs. This study aimed to estimate the prevalence of molecular markers of antimalarial drugs resistance in Côte d'Ivoire. Samples were collected from 2013 to 2016 from asymptomatic and symptomatic subjects in Abengourou, Abidjan, Grand Bassam, and San Pedro. A total of 704 participants aged between 1 year and 65 years (Mean age: 9 years ± 7.7) were enrolled. All the dried filter paper blood spots were genotyped by sequencing. ) gene were analyzed for all the samples, while 344 samples were examined for . Overall, the success rate of molecular tests was 98.8% (340/344), 99.1% (341/344), and 94.3% (664/704) for 1 N86Y, 1 Y184F, and genes respectively. Molecular analysis revealed twenty (5.9%; 20/340) and 219 (64.2%; 219/341) mutant alleles for 1 86Y and 1 184 F, respectively. Twenty-nine mutations in gene (4.4%; 29/664) with 2.7% (18/664) of non-synonymous mutations was found. None of the mutations previously described in South East Asia (SEA) involved in resistance to artemisinin derivatives were observed in this study. According to year of collection, a decrease of the prevalence of mutation (from 3.6 to 1.8%) and N86Y mutation (from 8.5 to 4.5%) and an increase of mutant allele of Y184F proportion (from 39.8 to 66.4%) were found. Comparing to previous studies in the country, this study showed an increase in lumefantrine tolerance of strains. This demonstrates the importance of establishing a strong system for molecular surveillance of malaria in Côte d'Ivoire.