Seasonal malaria chemoprevention and mutations in Pfdhfr and Pfdhps genes in children in the health district of Nanoro, Burkina Faso.

Abstract

Introduction: Seasonal malaria chemoprevention (SMC) is an effective malaria preventive intervention in sub-Saharan Africa. As with other drug-based interventions, large-scale deployment increases drug pressure, which may result in drug-resistant parasite strains thereby jeopardising the impact of the intervention. Mutations in Pfdhps and Pfdhfr genes are known to be associated with resistance to sulfadoxine and pyrimethamine, respectively, making the surveillance of molecular markers crucial in settings where SMC is widely applied. This study aimed at assessing the distribution of Pfdhfr and Pfdhps alleles before and after the 2021 annual campaign of SMC in the health district of Nanoro in Burkina Faso.

Materials and methods: Randomly selected dried blood spots collected prior (n=100) and after (n=100) the 2021 SMC campaign were used for the detection of mutation in codons 51, 59 and 108 of the Pfdhfr gene and in codons 437 and 540 of Pfdhps gene using a nested PCR with restriction fragment length polymorphism approach.

Results: The prevalence of Pfdhfr and Pfdhps mutant alleles were very high before and after SMC, ranging from 88.42% to 97.98%. However, no significant change in the prevalence of Pfdhfr and Pfdhps mutant alleles was observed in the period before and after SMC campaign (p>0.05). No mutation was observed in Pfdhps codon 540. In addition, the prevalence of the Pfdhfr triple mutant and Pfhfr-dhps quadruple mutant was higher in the study area but with no significant variation before and after SMC campaign (p>0.05). .

Conclusions: The prevalence of Pfdhfr and Pfdhps mutant alleles were higher either in pre or post SMC. However, no significant variation in the prevalence of these alleles was observed following the SMC campaign suggesting that these high mutation frequencies may be the result of continuous use of SMC in Burkina Faso since 2014.