Molecular surveillance of Plasmodium falciparum resistance to sulfadoxine-pyrimethamine among pregnant women attending antenatal clinics in Bobo-Dioulasso, Burkina Faso.

Abstract

This study aimed to assess the prevalence and risk factors of molecular markers of Plasmodium (P.) falciparum resistance to sulfadoxine-pyrimethamine (SP) among pregnant women in Bobo-Dioulasso, and to examine their association with maternal anaemia. This cross-sectional study was conducted between October and December 2022 among 288 SP-naïve pregnant women attending antenatal care at the Centre Médical Urbain of Lafiabougou. Dried blood spots were collected, and P. falciparum infection was detected using quantitative polymerase chain reaction (qPCR) targeting the varATS gene. Positive samples were genotyped for mutations in the Pfdhfr and Pfdhps genes using a nested PCR approach followed by restriction fragment length polymorphism analysis. Multivariable logistic regression models were used to identify predictors of resistance markers and maternal anaemia. Among the 172 qPCR-confirmed P. falciparum-positive samples, the Pfdhfr triple mutant haplotype (N51I, C59R, S108N) was detected in 33.7% of cases, while the Pfdhps A437G mutation was present in 82.7%. No Pfdhfr I164L or Pfdhps K540E mutations were observed. Gestational age was independently associated with carriage of the triple Pfdhfr mutation (adjusted OR = 2.2, 95% CI: 1.1-4.5). Both gestational age (adjusted OR = 2.5, 95% CI: 1.2-4.9) and infection with parasites carrying the triple Pfdhfr mutation (adjusted OR = 3.9, 95% CI: 1.8-8.3) were significant predictors of maternal anaemia. The relatively high prevalence of SP resistance markers indicates sustained drug pressure in this setting. Although SP appears to remain effective for intermittent preventive treatment in pregnancy, continued molecular surveillance is warranted to inform malaria control policies.