Assessing the polymorphism of DHFR gene from Plasmodium falciparum in the south of Cte dIvoire

Since 2005, Côte d'Ivoire has adopted new strategies of malaria management including free provision of Artemisinin-based Combination Therapy (ACT) to children less than five years of age and sulfadoxine-pyrimethamine (SP) as Intermittent Preventive Treatment (IPT) for pregnant women. However, introduction of ATCs raises concerns about the extensive use of cheap SP which could increase Plasmodium falciparum resistance level to SP. Therefore, this study aimed to determine the prevalence of the Asn-108 marker in three sites in Southern Côte d'Ivoire. After obtaining consent, blood samples were collected in Anonkoua-kouté, Port-Bouët, and Ayamé sites from 180 patients over 2 years of age and having simple P. falciparum malaria. P. falciparum genomic DNA extracted from these samples was amplified by nested-PCR with pfdhfr specific primers. The amplification products were revealed by electrophoresis on 1.5% agarose gel and then sequenced according to Sanger method. After sequencing, the prevalence of mutation points associated with P. falciparum resistance to pyrimethamine was determined. For the three study sites, 180 DNA fragments, of which 165 (165/180 or 91.66%) were successfully sequenced. Analysis of the 165 sequences indicated a prevalence of 61.29% (76/124) of the Asn-108 mutant allele versus 17.41% (27/155) of the wild type Ser-108 allele. Results also indicated that the prevalence of Ser-108-Asn mutation were 69.07, 69.04 and 82.75% for Anonkoua-Kouté, Port-Bouët and Ayamé, respectively. More than a decade after the adoption of SP as IPT for pregnant women, the prevalence of the marker Asn-108 was relatively high in Anonkoua-kouté, Port-bouët and Ayamé.