A-157 Rapid Identification and Monitoring of Malaria in a Non-Endemic Region Using Advanced Hematology and Digital Morphology Tools

Abstract Background Malaria remains a global health challenge, yet its occurrence in non-endemic regions presents unique diagnostic and clinical management difficulties. The most advanced hematology analyzers provide key RBC parameters like INR (infected RBC), which enable early detection of malaria. The digital morphology analyzer is an important complement in such cases, as it quickly helps identify irregular RBCs, saving time to trigger the confirmatory testing and prompt intervention. This case highlights the role of integrated hematology and digital morphology tools in detecting Plasmodium vivax in a pediatric patient in Chile, a malaria-free country. Methods Initial hematology tests using Mindray BC-6200 hematology analyzer indicated mild anemia, thrombocytopenia. INR (Infected Red Blood Cells) refers to the percentage of RBCs infected with malaria parasites, which is used to aid in the early detection of malaria triggering the examination of the smear. Digital morphology analysis with the MC-80 identified parasitized erythrocytes. After these findings, a thick blood smear and immunochromatographic rapid test were performed showing positive results. Polymerase Chain Reaction (PCR) confirmed P. vivax. Follow-up assessments post-treatment included additional CBC tests, INR% monitoring, and peripheral blood smears. Results Initial Admission: A 11-years-old male patient is admitted to the hospital on 16/04/2024, having fever for 4 consecutive days, prompting further tests. The patient came to Chile from a Malaria endemic country. The initial blood test showed alarm signals for abnormal dispersion and RBC resistance to the lysing reagent, suggesting the onset of anemia. Platelet count was 40 10^3/uL. The INR% test revealed 1.77%, leading to the suspicion of malaria. For confirmation, a peripheral blood smear was performed using May-Grünwald Giemsa stain. The digital morphology system Mindray MC-80 could efficiently photograph large numbers of parasitized cells in the smear. These findings sped up the laboratory process and allowed for quicker activation of the malaria protocol. The positive result by chromatography rapid test and the findings on the thick drop examination on microscope confirmed the plasmodium diagnostic. A molecular test (PCR) test verified a load of 5,310 parasites per mL, identifying Plasmodium vivax as the species. On Post-Treatment control, no alarms detected in RBC/WBC parameters. Hemoglobin, hematocrit, platelet counts normalized. INR% dropped to 0%, confirming no parasitized RBCs. On the Follow-up appointment (July 1, 2024), there was a slight decrease in hemoglobin and hematocrit values. INR% of 0.02% suggested a possible relapse. MC-80 imaging detected one parasitized RBC. Thick drop examination on microscope did not find infection and chromatography rapid test was negative, but molecular PCR test confirmed the presence of Plasmodium vivax DNA Conclusion This case highlights the significance of using advanced hematology analyzers and digital morphology systems for diagnosing and monitoring malaria, even in non-endemic regions. The combined use of advanced RBCs parameters such as INR and precise cell identification through digital morphology tools enhanced clinical decision-making and minimized human error, leading to timely intervention. Continuous monitoring is essential in preventing relapse in cases with low parasitic loads, demonstrating the potential of these integrated tools in managing imported infectious diseases.