In vitro efficacy of act drugs on Plasmodium falciparum clinical isolates from Kano and Katsina States, Nigeria

Abstract

In vitro drug susceptibility profile of Plasmodium falciparum collected between 2012 and 2014 from malaria patients attending some hospitals in Kano and Katsina States was evaluated in this study. This is to provide base line information on current effectiveness of commonly prescribed ACT drugs (Artemether-lumefantrine AL, Dihydroartemisinin-piperaquine DHP, Artesunate-amodiaquine AA). Plasmodium falciparum isolates were identified by rapid diagnostic test (malaria HRP2 kit) and microscopic examination of Giemsa stained blood films. One hundred and fifty (150) isolates (90 from kano and 60 collected from katsina) were successfully cultivated. In vitro antimalarial drug sensitivity test was carried out using Schizont growth inhibition assay. Fifty percent inhibitory concentrations (IC₅₀) were calculated using Hn nonlin software and dose response curves. The results revealed that all the P. falciparum isolates were 100% sensitive to the three ACTs. The geometric mean IC₅₀ values of the isolates were found to be below the resistance thresholds cut off values as 2.04+0.42nM, 3.67+0.4nM and 4.70+0.43nM for AL, DHP and AA respectively. This suggests that all the ACTs are still efficacious in the treatment of malaria in the two states. Further research is therefore, recommended to confirm these findings using in vivo and molecular approach.

Keywords: ACTs, malaria, in vitro, Plasmodium falciparum