Status and prospects of seasonal malaria chemoprevention among children in Sahelian countries: A systematic review and meta-analysis

In areas with seasonal malaria transmission, seasonal malaria chemoprevention (SMC) involves giving children a three-day course of sulfadoxine-pyrimethamine and amodiaquine once a month during the transmission season. This strategy has been used for ten years for children under five years of age. The logistical cost is affordable in malaria-endemic countries and varies slightly depending on accessibility. This systematic review and meta-analysis aims to better assess the effectiveness of seasonal malaria chemoprevention in reducing malaria incidence and prevalence in Sahelian countries, ten years after its introduction. This review followed the Preferred Reporting Items for Systematic Reviews (PRISMA) 2020 guidelines, and was based on Google scholar, MEDLINE (PubMed), the Cochrane library, African Journal Online, and Index Medicus African to compile its data. The combination of keywords such as “malaria”, “Plasmodium”, “malaria chemoprevention”, “Sahel”, “Efficacy”, “Resistance”, as well as Boolean operators (AND, OR) were used to inventory studies published between 2013 and 2023. Eligible studies included randomized clinical trials (RCTs), non-randomized trials, prospective cohort studies, intervention studies and observational studies. For randomized trials (RCTs), Cochrane’s Risk of Bias 2 (RoB 2) tool was used to specifically assess the risk of bias in randomized controlled trials. And for non-randomized trials and observational studies, we applied the ROBINS-I (Risk of Bias in Non-randomized Studies of Interventions) tool, which included a meta-analysis of the studies. The study protocol was registered under the number (PROSPERO registry CRD42023413920), and R software was used for the meta-analysis. The meta-analysis shows that SMC is effective in reducing the incidence of uncomplicated malaria, severe malaria and mortality in children under five. Compared with control groups a reduction in the burden of malaria was observed in children receiving SMC. SMC appears to effectively reduce the incidence of malaria in children under five. However, it should be noted that SMC is always used alongside other prevention strategies, such as indoor residual spraying and long-lasting insecticide-treated nets. However, the epidemiological context of the Sahelian region is changing, and the strategy must be adapted to address the persistence of transmission during the dry season and the increase in malaria cases among older children.