Study on the Correlation Between Malaria Infection in Humans and iRBC Alerts on the Sysmex XN-10 Automated Hematology Analyzer

Abstract

Malaria remains a major public health concern in various regions of Thailand, particularly in the southern provinces, where the incidence has shown a marked increase-from 170 reported cases in 2022 to 325 cases in 2023, reflecting a 47.69% rise. The predominant species in this area, Plasmodium knowlesi, is characterized by a shorter incubation period and rapid disease progression, necessitating prompt diagnosis and treatment to reduce both morbidity and transmission rates. Recent advancements in automated hematology analyzers, such as have introduced the capability to flag infected red blood cells (iRBCs), offering potential utility as a preliminary screening tool for malaria. However, evidence regarding its diagnostic performance remains limited.
This comparative study aimed to evaluate the diagnostic accuracy of iRBC flagging relative to standard microscopic examination (thick and thin blood films). Between October 1, 2022, and September 30, 2024, a total of 467 complete blood count (CBC) samples from patients clinically suspected of malaria were analyzed. Of these, 36 cases were confirmed to be malaria-positive via standard methods. The iRBC flag was observed in 34 of these confirmed cases, while 2 cases did not trigger the alert. No false positives were recorded. The iRBC flagging demonstrated a sensitivity of 94.44% and specificity of 100%. These findings indicate that iRBC flagging by the Sysmex XN-10 analyzer is a reliable and efficient tool for preliminary malaria screening. When used in conjunction with conventional diagnostic methods, it can enhance diagnostic accuracy and facilitate timely clinical intervention, contributing to improved disease management and control.

Keywords: Malaria, Plasmodium, iRBC, XN-10