Assessment of sulfadoxine-pyrimethamine resistance markers in plasmodium falciparum samples collected from Kasagati Health Centre IV in 2016

Abstract

Sulphadoxine-pyrimethamine (SP), commonly referred to as fansidar is an anti-folate drug that was introduced in Uganda in 2000 as a first-line treatment of uncomplicated malaria. It’s use was short lived as point mutations in the dihydrofolate reductase and dihydropteroate synthase genes caused it’s resistance and was replaced by artemether-lumefantrine as the first-line malaria drug treatment in Uganda in 2006. However, SP still remains the recommended drug for intermittent preventive treatment in pregnant women and infants (IPTP/I) owing to its safety profile. This study assessed the prevalence of mutations in dihydrofolate reductase (Pfdhfr) and dihydropteroate synthase (Pfdhps) genes associated with SP resistance in samples collected in Kasangati health centre V1 in 2016. Ten years after policy change. METHOD: A cross sectional study was done where 85 stored positive malaria blood samples that were collected from Kasangati health centre VI were retrived, DNA extracted and pfdhfr and pfdhps polymorphisms were analyzed using nested-PCR and restricted enzyme digestion. RESULTS: Among 85 isolates, all carried Pfdhfr 108N and more than 90% had Pfdhfr 59R alleles. For the pfdps, only 61 samples amplified out of the 85 samples, 437G was found at 96.7% and 540E was at 95.1%. The present study highlights an elevated frequency of Pfdhfr and Pfdhps mutant alleles. CONCLUSION: Although SP is no longer recommended as first-line treatment for P. falciparum infection, its resistance is still high in Uganda which is due to the fact that it is widely recommended for IPT, IPTp and possibly still available over the counter for self-treatment. These has showed that its usage still exerts enough pressure to drive resistance.