RESUMEN
During the last two decades human infections with Plasmodium knowlesi are increasingly diagnosed in South East Asia and have also been reported in travellers. A severe case of imported P. knowlesi infection in a 73-year old German is presented, who had been travelling through Myanmar and Thailand for three weeks. Microscopy showed a parasitaemia of 3% and different parasite stages including band-forms resembling Plasmodium malariae. Due to the clinical picture of severe malaria and the microscopical aspect (combination of parasites resembling P. malariae and Plasmodium falciparum), P. knowlesi was suspected. The patient was treated with intravenous quinine; he was put on mechanical ventilation and catecholamines due to cardiorespiratory failure. Parasitaemia was cleared rapidly but renal function deteriorated resulting in intermittent haemodialysis. The patient was hospitalized for six weeks but he recovered completely without any physical sequelae. Plasmodium knowlesi mono-infection was confirmed by molecular methods later on.Plasmodium knowlesi infection has to be taken into account in feverish travellers returning from Thailand/Myanmar. Moreover this species can cause life-threatening or even lethal complications. Accordingly severe P. knowlesi infection should be treated like severe P. falciparum infections.