Antimalarial Drug Efficacy of Artemether-Lumefantrine in Subclinical Malaria in Southeastern Nigeria

Abstract

Introduction: To combat the growing resistance to antimalarial drugs, an assessment of antimalarial drug efficacy is necessary for monitoring and containment. The objective of the study was to assess the therapeutic efficacy of the antimalarial drug, Artemether-Lumefantrine (AL), in local communities in Southeastern Nigeria. The parasite clearance rate was used to determine the antimalarial drug efficacy, wherein the level of the parasites in the patient’s blood was measured after administering the AL drug. Methods: This was a community-based interventional (therapeutic) study that was conducted in two communities: Naze and Ikenegbu, both in Imo State of Southeastern Nigeria. The study population consisted of two groups (subclinical and clinical), males and females aged 18 years and above, that fulfilled the inclusion criteria. A systematic house-to-house sampling technique was employed to select a total of 117 and 66 participants for the subclinical and clinical groups respectively. The study methods adapted the World Health Organization (WHO) standard therapeutic efficacy test protocol. Each participant was treated with Artemether-Lumefantrine, and determined the parasite clearance rate through blood sample microscopy collected during the scheduled follow-up visits. Results: A total of 93 out of the 117 (79.5%) participants in the subclinical group were successfully, followed up, along with 65 out of the 66 (98.5%) participants in the clinical group. On Days 3 and 7, the parasite clearance rates were 86.0% and 87.1% respectively for the subclinical group, and 67.7% and 78.5% respectively for the clinical group. When the parasite clearance rates of the two groups were compared, and analyzed for the two treatment days, the result showed a significantly (p0.05) between the two groups on Day 7. Other studies showed a very high clearance rate of almost 100% on Day 3 and Day 7 compared to our findings which were lower to 90%, suspecting drug resistance. Conclusion and Implications for Translation: Treatment of malaria with Artemether-Lumefantrine provided a better outcome at the subclinical stage than at the clinical stage. Further studies are needed to rule out imminent Artemether-Lumefantrine resistance in the study areas.