Antimalarial Susceptibility Profile of Plasmodium falciparum Isolated from Human Population in Selected Health Facilities in Keffi Metropolis, Nasarawa State, Nigeria

Aim: This study was aimed to determine the susceptibility profile of Plasmodium falciparum to antimalarial drugs to assess the efficacy of the ones in use.

Study Design: This is a hospital-based descriptive study design.

Place and Duration of Study: Department of Microbiology, Faculty of Natural and Applied Sciences, Nasarawa State University, Keffi, between December, 2023 and April, 2024.

Methodology: A total of 385 blood samples were collected and screened for malaria parasites by microscopy. Species-specific screening was done using Rapid Diagnostic Test (RDT). Stock/working solutions of selected antimalarial drugs were prepared using standard protocols. The parasite cultivation and its susceptibility to selected antimalarial drugs was determined using the WHO protocol. Matured schizonts were quantified. The degree of antimalarial drugs inhibition of scizonts maturation was determined and the drugs 50% inhibitory concentration (IC50) required to prevent parasite schizont maturation indicating resistance was determined.

Results: Malaria prevalence by microscopy was 29.9% (95% CI = 25.34 to 34.71%) and 26.7% by RDT. The RDT had a sensitivity of 89.6% (95% CI = 82.48% to 94.49%), specificity of 100.00% (95% CI = 98.64% to 100.00%), Positive Predictive Value of 100.00% (95% CI = 96.48% to 100.00%); and Negative Predictive Value of 95.8% (95% CI = 92.94% to 97.46%). The accuracy of the RDT was 96.88% (95% CI = 94.62 to 98.38%). Six out of the 35 isolates showed 17.1% resistance to Artemether + Lumafantrine.

Conclusion: Malaria is present in the study population and is resistant to some of the antimalarial drugs in use. The need for periodic antimalarial drugs surveillance to determine the efficacy of drugs in use is highly recommended.