Contribution of hematology analyzers (Sysmex XN-Series) in the rapid diagnosis of malaria: case reports.

Pauline Pitti, Françoise Tassin, Aurore Keutgens

Malaria is a potentially severe disease, particularly in Africa. In Europe, the majority of malaria cases come from travelers returning from endemic areas. The non-specific symptomatology may not alert the clinician if this notion of travel is not addressed. However, diagnosis and rapid initiation of treatment prevent the evolution of severe forms of the disease, especially in the case of Plasmodium falciparum infection, which can be life-threatening within 24 hours. Thin and thick blood smears microscopy is the main tools for diagnosis, but some automated hematology analyzers have demonstrated their ability to participate in early diagnosis. We describe two cases illustrating the contribution of the Sysmex XN-9100 automated system for the diagnosis of malaria. The first clinical case described a young man infected with numerous Plasmodium falciparum gametocytes. WNR (white blood cell count) and WDF (white blood cell differenciation) scattergrams showed an additional population, corresponding to gametocytes. The second case focused on a man with neuromalaria and high Plasmodium falciparum parasitaemia. Parasitized red blood cells form an inconspicuous double population on the reticulocyte scattergram, located at the discrimination limit between mature red blood cells and reticulocytes. Scattergram abnormalities, which can be visualized in a few minutes, offer an anticipation of the diagnosis of malaria in comparison to thin and thick smears microscopy, that requiring considerable time and expertise.