Background: Blackwater fever is a complication of malaria infection consisting of a syndrome of febrile intra-vascular haemolysis with severe anaemia and intermittent passage of dark-red to black colour urine. Despite being described since the time of Hippocrates, with numerous reports and studies about this condition which do not lead to an unifying mechanism, the pathogenesis of the blackwater fever remains incompletely understood.
Case presentation: This report describes a case of classic blackwater fever in a returning traveller, without prior history of malaria infection nor usage of anti-malarial prophylaxis, treated with two courses of oral artemether-lumefantrine combination therapy. Unusual persistence of submicroscopic Plasmodium falciparum parasitaemia was detected by PCR for 18 days after initiation of treatment.
Conclusion: To the authors’ knowledge this is the first reported occurrence of a case of blackwater fever associated with prolonged submicroscopic parasitaemia. This unusual case challenges the current knowledge of the pathogenesis of this condition and opens questions that may have important diagnostic and treatment implications.