suspected once infected red blood cells (oirbc) in severe malaria with complications after oral artemisinin treatment

Artemisinin therapy has been recommended for severe malaria due to its effectiveness and safety. however, several cases of hemolytic anemia after artemisinin treatment have been reported, especially with parenteral administration. a 26-year-old male patient complained of fever for seven days. microscopic examination results showed a ring form of plasmodium falciparum. the patient’s complaints improved after treatment with oral dihydroartemisinin-piperaquine was completed, but the next day, respiratory problems, signs of hemolytic anemia, acute kidney injury, and blackwater fever occurred. serial microscopic examinations of the patient showed an improvement in the parasitemia index, ruling out the possibility of drug resistance. in the giemsa stain of peripheral blood after treatment, there were deformed erythrocytes and increased spherocytes. these shapes are likely caused by previously plasmodium-infected erythrocytes called “once infected red blood cells” (oirbc). the shorter lifespan of oirbc can cause hemolytic anemia after malaria treatment with artemisinin. monitoring and counting the number of oirbc can be one of the prognostic factors for severe malaria with complications of hemolytic anemia after artemisinin therapy. to assist in the calculation, the micror parameter of the sysmex xn hematology analyzer can be used to predict the percentage of oirbc in peripheral blood. post-artemisinin therapy monitoring, both oral and parenteral, needs to be considered due to the possibility of hemolytic anemia. micror parameters and peripheral blood images can potentially indicate the presence of oirbc, a risk marker for hemolytic anemia after treatment.