The resurgence of blackwater fever among children in sub-Saharan Africa: A scoping Review

Background: Blackwater fever (BWF), a life-threatening complication of Plasmodium falciparum malaria, has re-emerged as a significant health concern among children in sub-Saharan Africa (SSA). Characterized by acute intravascular hemolysis, hemoglobinuria, and severe anemia, BWF necessitates urgent medical intervention. Despite its clinical severity, data on its burden, risk factors, and management remain fragmented. Therefore, this scoping review aimed to systematically map the existing literature on BWF in SSA, focusing on its epidemiology, clinical presentation, risk factors, management strategies, and outcomes among children in SSA. Methods: Following the Arksey and O’Malley framework, a comprehensive search was conducted across six databases (PubMed, Embase, Cochrane Library, CINAHL, PsycINFO, web of science) and grey literature sourcesincluding preprint servers, conference proceedings, theses, dissertations, WHO reports and clinical trials registries (PACTR, clinicaltrials.gov). Studies published from inception to December 2024 were included. Data were extracted and synthesized narratively, with findings categorized thematically by epidemiology, clinical features, risk factors, management, and outcomes. Results: BWF was geographical clustered in East and Central Africa, particularly Uganda (53.8%) and the DRC (26.9%). Prevalence ranged from 4.4% to 52.7%, with higher incidence during rainy seasons. MBL2 AA polymorphisms, elevated IgG1 and quinine exposure (aOR 50.19-57.33) were significant contributors while G6PD deficiency (G6PDd) had conflicting associations. Clinical hallmarks were dark urine (100% of cases), jaundice (22.7-100%), and severe anemia (23.7-77%) aligning with the “hemolytic triad” reported in BWF. Acute kidney injury (AKI) (16.2-90.6% of cases) and recurrent episodes (50-68% readmission rates) exacerbated morbidity. Diagnosis relied on clinical criteria, with limited laboratory confirmation, while management emphasized artemisinin-based therapies and supportive care. Delays in blood transfusions and renal replacement therapy contributed to poor outcomes. Conclusion: BWF resurgence in SSA highlights critical gaps in diagnostics, equitable care, and adherence to artemisinin-based treatments. Targeted surveillance during malaria peaks, standardized diagnostic protocols, and improved access to supportive therapies are urgently needed to mitigate BWF-associated mortality and morbidity in high-burden regions. Trial registration: OSF https://doi.org/10.17605/OSF.IO/QNPKV