Delayed haemolysis secondary to treatment of severe malaria with intravenous artesunate: Report on the experience of a referral centre for tropical infections in Spain.

Background: Post-artesunate delayed haemolysis is described as hemolytic anemia presenting days after malaria treatment in hyperparasitemic patients. Physiopathological mechanisms and clinical manifestations have not been thoroughly characterised.

Methods: We conducted a retrospective study of hospitalised malaria patients who received artemisinin derivatives from January 1, 2010 to December 31, 2015.

Results: 21 patients were included in the study: 11 travellers, 8 travellers visiting friends and relatives and 2 immigrants. Median age was 35.5 years (IQR: 25.7-44.8) and 11 were men. Eight patients received oral and 13 received intravenous (IV) artemisinin-based drugs. Follow-up after the malaria episode was available for 15 patients (12 with IV treatment). Four patients presented with delayed haemolysis 9-14 days after artesunate treatment; all had been admitted with severe malaria, were treated IV and had hyperparasitaemia (17%-33%). Other than hyperparasitaemia, no other factors were associated with artesunate haemolysis. Patients' outcomes were favourable and the only additional therapeutic measure needed was a blood transfusion.

Conclusions: Delayed haemolysis is a frequent complication in hyperparasitemic malaria treated with IV artesunate. Follow-up is mandatory for at least 2 weeks after treatment initiation. This condition is potentially severe but does not appear to be life threatening.