Haematological Toxicity of Artemisinin-Based Combination Therapy in Children with Uncomplicated Malaria in Borno State, North East Nigeria

This study analyses haematological toxicity patterns following artemisinin-based combination therapy (ACT) in children with uncomplicated Plasmodium falciparum malaria in Borno State, North East Nigeria, addressing conflicting evidence on ACT-associated delayed anaemia and its determinants in Nigerian paediatric populations. A prospective cohort study enrolled 200 children aged 6 months to 12 years with confirmed uncomplicated falciparum malaria at three primary health centres in Maiduguri. Full blood count was performed at baseline, day 3, day 7, and day 28 following ACT initiation. Parasite clearance was confirmed by blood film and rapid diagnostic test at day 3 and day 7. Primary endpoints were haemoglobin trajectory, reticulocyte count dynamics, and proportion meeting anaemia severity thresholds at each time point. Overall, haemoglobin improved from baseline (mean 8.7 g/dL) to day 7 (mean 9.6 g/dL) and day 28 (mean 10.9 g/dL). However, 14 percent of children experienced a secondary haemoglobin decline between days 7 and 14, consistent with ACT-associated delayed anaemia, a pattern disproportionately frequent in those with initial hyperparasitaemia above 100,000 per microlitre. Reticulocyte count was inversely predictive of delayed anaemia risk. No severe or life-threatening haematological toxicity attributable to ACT was documented. The study provides population-specific haematological toxicity profiling for ACT in Borno State and recommends haemoglobin reassessment between days 10 and 14 for all children treated with high parasitaemia malaria. Keywords: artemisinin combination therapy, malaria, haematological toxicity, delayed anaemia, Borno State.