Efficacy Of Automated Hematology Analyser Sysmex Xn1000 In Detection Of Malaria.

Abstract

INTRODUCTION Malaria is an important infectious disease causing significant public health problem and affecting millions of people every year. It is a parasitic disease caused by Plasmodium species. Classical clinical features of malaria include cyclical fever, associated with chills and rigors, body ache, malaise and other non-specific systemic symptoms. Timely diagnosis and treatment of malaria cases reduces the morbidity and mortality associated with it. The gold standard for diagnosis of malaria is the microscopic examination of the stained blood films which is usually labour demanding and time consuming. To overcome these problems and to achieve maximum sensitivity and specificity in the diagnosis of malaria, several alternate methods became popular like the quantitave buffy coat, serological methods and molecular techniques. The major disadvantage of all these methods including the microscopic diagnosis is the clinical request for malaria. During the last few decades, automated hematology analysers came in to the picture in presumptive diagnosis of malaria during CBC analysis, even without an extra request for malaria. These analysers generate several scatter plot and histogram abnormalities by which malaria can be suspected. OBJECTIVE To analyze the efficacy of Sysmex XN1000 hematology analyser in detection of malaria by using WBC-DIFF scatter plots. MATERIALS AND METHODS A prospective cross-sectional study was carried out in 146 patients from both out-patient and in-patient departments, referred to the Department of Pathology in BLDE University’s Shri B.M.Patil Medical College, Hospital and Research centre,Vijayapur in whom peripheral smear for detection of malarial parasite was requested and satisfying the inclusion and exclusion criteria. All the blood samples of cases were collected in K3 EDTA vacutainers and processed on Sysmex XN1000 hematology analyser which is based on the principle of fluorescence flow cytometry. The WBC – DIFF scatter plots of these samples were analysed for abnormalities. Leishman stained peripheral smears were prepared and screened for malarial parasite and correlated with WBC-DIFF scatter plots. RESULTS Using the WBC-DIFF scatter plot abnormalities, the sensitivity and specificity were 84.6 and 91.5% respectively, considering peripheral smear as the gold standard. Further, the positive predictive value was 84.6% and negative predictive value was 91.5% with an accuracy of 89.0%. CONCLUSION Analysis of specific patterns of WBC scatter plots is a rapid process which requires less expertization and can be an important adjuvant diagnostic tool in detection of malaria even in the absence of clinical request. So, it is recommended for the pathologists to review the WBC scatter plots on a routine basis to pick up malarial infection.