Efficacy of Artesunate-amodiaquine Combination Therapy against Plasmodium falciparum Malaria in a Forty-two Day Follow-up in the Ikata-Likoko Area of Southwest Cameroon

Aims: The main aim of this study was to monitor the efficacy of artesunate-amodiaquine (AS-AQ) against Plasmodium falciparum malaria in a 42 day follow-up in the Ikata-Likoko area of Southwest Cameroon. Specifically the late clinical failure (LCF), late parasitological failure (LPF), adequate clinical and parasitological response (ACPR) and variation in haematological parameters were assessed.

Study Design: Participants positive for P. falciparum parasitaemia in a baseline study were enrolled into the study and treated with AS-AQ following the WHO 2010 guidelines for the treatment of uncomplicated malaria. Follow-up was done according to WHO 2009 protocol for efficacy testing of antimalarial drugs. The study period was from June to September 2014.

Methods: During the follow-up, temperature, malaria parasitaemia (MP) and haematological parameters were recorded. Axillary temperature was used to monitor fever, MP through microscopy of Giemsa stained blood smears while haematological parameters were monitored through full blood count measured using an electronic blood cell analyser.

Results: The results showed LCF of 4% (4/101). The ACPR was 96.0% (97/101). Mean values of haematocrit (HCT) reduced significantly (P=.04) by day 14 before increasing. A constant reduction in mean cell volume (MCV) values were observed with the initial value being the highest (P=.04). Mean corpuscular haemoglobin concentration (MCHC) values increased significantly (P=.02) by day 28 and remained comparable. Fever reduced to 3% (3/101) by day 7, while mean body temperature remained below 37.5ºC after treatment. The mean temperature on day 0 (37.89ºC) was significantly highest (P=.03). Mild adverse events including abdominal pain, nausea, dizziness, anorexia and fatigue were observed in 21 (15.4%) participants.

Conclusion: AS-AQ remains effective against P. falciparum in the Ikata-Likoko area. However, there is need for continuous monitoring of its efficacy.