Emsri PongponratnOranan PrommanoUrai ChaisriParnpen ViriyavejakulPolrat WilairatanaDepartment of Tropical PathologyMahidol UniversityRungsit University2018-06-112018-06-112012-11-05Southeast Asian Journal of Tropical Medicine and Public Health. Vol.43, No.5 (2012), 1080-1081012515622-s2.0-84868103225https://repository.li.mahidol.ac.th/handle/20.500.14594/14543We examined the ultrastructure of Plasmodium malariae-infected erythrocytes in peripheral blood and tissue biopsies of the liver, stomach, and duodenum from three patients infected with P. malariae. Ultrastructural features of P. malariae-infected erythrocytes in peripheral blood appear similar to those described previously. The surface membranes of P. malariae-infected erythrocytes had numerous knobs, as seen in P. falciparum-infected erythrocytes. There was no evidence of P. malariae-infected erythrocytes in the microvessels of the organs. This finding suggests the presence of knobs on P. malariae-infected erythrocytes is not associated with the attachment of P. malariae-infected erythrocytes to vascular endothelium and may be the reason for the mild symptoms of malariae malaria. The failure to find P. malariae-infected erythrocytes in the tissue biopsies using electron microscopy may be due to low parasitemia. More cases with higher parasitemia need to be studied to confirm these findings.Mahidol UniversityMedicineArticleSCOPUS