Transfusion malaria: treatment with exchange transfusion after delayed diagnosis.

A 65-year-old woman was rehospitalized for increasing mental confusion 16 days after open heart surgery for mitral stenosis. A diagnosis of transfusion-acquired falciparum malaria was made from a routine peripheral blood smear 24 hours after admission. Because progressive encephalopathy developed while she was receiving antimalarial drugs, a therapeutic exchange transfusion was performed. Clinical improvement occurred promptly during the exchange, and the patient went on to complete recovery from her malaria. The putative blood donor involved met the currently accepted standards for blood donors.