Blackwater Fever Complicated by Severe Acute Kidney Injury and a Therapeutic Dilemma: A Case Report from Niger.

Abstract

Introduction: Blackwater fever (BWF) is a rare complication of antimalarial treatment characterized by acute intravascular hemolysis. Its diagnosis is mainly clinical, particularly based on the presence of dark-colored urine.

Case presentation: We report the case of a 50-year-old woman admitted to the Infectious and Tropical Diseases Department of the National Hospital of Zinder for fever, jaundice, and acute kidney injury in the context of persistent Plasmodium falciparum infection and repeated antimalarial treatments, including artesunate. Clinical and laboratory findings were suggestive of severe intravascular hemolysis, with severe acute kidney injury (serum creatinine: 1104.1 µmol/L). After renal replacement therapy was initiated and urine output resumed, the patient developed dark 'Coca-Cola'-colored urine, suggestive of hemoglobinuria. Blackwater fever was strongly suspected based on the overall clinical context. The patient underwent eight sessions of hemodialysis and received alternative antimalarial therapy. The outcome was favorable, with progressive recovery of renal function.

Conclusion: This case highlights the diagnostic and therapeutic challenges of suspected blackwater fever in a patient with persistent Plasmodium falciparum infection and repeated antimalarial exposure. Although repeated artesunate exposure raises the possibility of a drug-related contribution, causality cannot be established. Early recognition of hemolysis and acute kidney injury, together with appropriate antimalarial and supportive treatment, is essential.