Accuracy of Haematology Analyzer in the Diagnosis of Malaria in Comparison with Gold Standard Microscopy

  • Amna Imtiaz Pakistan Institute of Medical Sciences
  • Noshina Noreen
  • Syed Mudassar Ali Raza
  • Sundas Ali
  • Farah Hanif
  • Rafay Ali Khan


Objective: To assess the accuracy of Haematology analyzer in the diagnosis of malaria in comparison with gold standard microscopy.

Methodology: A cross-sectional study was conducted at the Pakistan Institute of Medical Sciences and the Pakistan Atomic Energy Commission in Islamabad, Pakistan. The study was conducted for around six months, from May 2023 to October 2023. The Mindray BC-6200 haematology analyzer was utilised to evaluate a total of 191 samples, comprising 127 samples from that were infected with malaria and 64 samples from healthy controls. When the presence of malaria parasites, identified as Plasmodium vivax and Plasmodium falciparum, was detected in dyed thick blood film, a microscopy examination was carried out as a reference. Analyse-it v4.92.3 was used to create the receiver operating characteristic (ROC) curve analysis. The agreement between BC-6200 and light microscopy was assessed using the Kappa value.

Results: The InR by BC-6200's sensitivity and specificity for P. falciparum and P. vivax infections. The sensitivity of the InR by BC-600 for P. falciparum and P. vivax was 27.9% and 85.5%, respectively. The specificity of the InR by BC-6200 for P. vivax and P. falciparum was 82.7% and 86.5%, respectively.  The infection densities in microscopy varied statistically significantly between the various InR groups (χ2 = 14.50, P < 0.005).An analysis was conducted on the correlation between the cell blood count and the count of InR in both the P. vivax and P. falciparum-infected patient groups. The results showed a clear correlation between InR (P. vivax group R2 = 0.87) and ΔWBC (WBCDIFF–WBCBASO). In the Mindray BC-6200 haematology analyzer, WBCBASO represents the number of WBC counting in the BASO channel with severe membrane degradation, while WBCDIFF represents the number of WBC counting in the DIFF channel with mild lyse.  The volume distribution widths of RBC, HGB, and red blood cells did not differ substantially. The reticulocyte characteristics of the P. vivax/P. falciparum patient group and control group differed significantly (P<0.02), although RBC, HGB, and red blood cell volume distribution width (RDW) did not differ significantly (P > 0.05). There was a significant difference (P<0.02) in the PLT count between the P. vivax/P. falciparum patient groups and the control group.

Conclusion: The results imply that malaria might be screened for in a clinical setting using the BC-6200 haematology analyzer's "InR" flag and "InR#/InR‰" parameters.

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