Assessment of Therapeutic Efficacy of Artemisinins Based Combination Therapy (ACT) against Plasmodium falciparum Malaria in Kano and Katsina States, Nigeria

Abstract

Artemisinin-Based Combination Therapy (ACT) has been adopted in Africa as a means of improving the efficacy of malaria treatment and slowing the development of resistance. This study was conducted between January 2013 and December 2014 to evaluate the therapeutic efficacy of different ACTs used in Kano and Katsina States, Nigeria, in subjects with uncomplicated P. falciparum malaria. Malaria-positive subjects were identified by rapid diagnostic test (malaria HRP2 Kit) and microscopic examination of Giemsa-stained blood samples. A total of 652 malaria-positive subjects of all ages with prescriptions of any of the 3 different ACTs (Artemether–lumefantrine (AL), Dihydroartemisinin–piperaquine (DHP), and Artesunate–amodiaquine (AA)) were enrolled. Clinical and parasitological responses of the subjects treated with the ACTs were evaluated using a 28-day follow-up according to WHO protocol for therapeutic efficacy. Genotyping of pre-treatment and post-treatment blood spots was carried out using nested PCR of the MSP2 genetic marker to differentiate new infections from recrudescence in subjects with treatment failure. Out of 652 subjects enrolled, 227 (34.8%) completed the 28-day follow-up. Patients treated with DHP had a significantly lower risk of recurrent parasitaemia due to new infection compared to patients treated with AL and AA (2.4% vs 8.4%, 2.4% vs 16%) at P < 0.005. The cure rates of the 3-treatment arms were found to be 95%, 99%, and 93% for AL, DHP, and AA respectively, with no significant difference in the risk of treatment failure due to recrudescence of the parasites (P > 0.05). The finding has thus indicated that all the ACTs are still efficacious in the treatment of uncomplicated malaria in the areas. Continued resistance monitoring is recommended as the use of ACTs is increasing in Nigeria.