Automated detection of malaria with haematology analyzer Sysmex XE-2100

Diagnosis of malaria is usually made by microscopy [Giemsa, Acridine Orange (AO), and Quantitative Buffy Coat (QBC) assay], which requires expertise. Currently, automated haematology analyzers are being used for complete blood count (CBC), in all acute febrile and non-febrile illnesses which simultaneously detects malaria. The normal scattergram by the analyzer (Sysmex 2100) comprises of five parameters i.e. lymphocytes (pink), monocytes (green), neutrophils (blue), eosinophils (red) with a space between the neutrophil and eosinophil populations.

We carried out a prospective study to compare the efficacy of Sysmex XE-2100 (Sysmex Corporation, Kobe) for detection of malaria in comparison to other conventional techniques.

430 cases were analyzed for malaria by microscopy (QBC, AO, Giemsa), ICT (Immunochromatography) and flowcytometric analyzer (Sysmex XE-2100). The abnormal scattergrams were observed as double neutrophil, double eosinophil, grey zone, extended neutrophil zone with a decrease space between eosinophil and neutrophil, and a combination of above patterns.

Out of 70 positive cases [49/70 (70%) P. vivax, 18/70 (25.7%) P. falciparum, and 3/70 (4.2%) both P. vivax and P. falciparum], 52 showed abnormal scattergrams by the analyzer. The sensitivity and specificity of hematology analyzer found to be 74.2% and 88%, respectively.

Flowcytometric analyzer is a rapid, high throughput device which needs less expertization for the diagnosis of malaria. Hence, it can be used in the diagnostic laboratories as an early modality for diagnosis of malaria in suspected as well as clinically in apparent cases.