Usefulness of Various Peripheral Blood Leukocyte Count ratios in Malaria Evaluation

Abstract

Malaria is a major public health problem in India. Changes in blood cell counts are a wellknown feature of malaria. Hence an attempt has been made to assess the role of leucocyte ratios in malaria as predictors of malaria infection and its clinical severity. Methods: A retrospective observational cohort study was carried out in a tertiary care teaching hospital over a period of 2 months. A total of 171 samples and 48 controls were included in the study. All the absolute and differential white blood cell counts were done. The neutrophillymphocyte count ratio (NLCR), monocyte-lymphocyte count ratio (MLCR) and monocyteneutrophil count ratio (MNCR) were calculated by using the absolute neutrophil, lymphocyte and monocyte count respectively. The results were analyzed statistically using SPSS software for windows. Results: Among 171 cases 145(84.8%), 19(11.1%), 7(4.1%) were Pl. vivax, Pl. falciparum and mixed malaria respectively. 52 cases were severe and 119 were non-severe. 52, 45, 47, 27 were parasitemia grade 1, 2, 3, 4 respectively. NLCR, MLCR and MNCR showed a sensitivity of 60.8%, 71.7%, 70.8% and specificity of 43.8%, 60.4%, and 56.3% respectively in malaria diagnosis. There was no association of NLCR, MLCR, MNCR with the type and severity of malaria. NLCR, MNCR correlated with varying grade of parasitemia. Conclusion: The results show the ratios NLCR, MLCR and MNCR have a better sensitivity but less specificity. The sensitivity and specificity for MLCR are the highest and can be used as a supportive to a screening test. The ratios can be used to show the presence of malaria parasite but there is no association with the type and severity of malaria. MLCR is a good predictor of malarial presence. NLCR and MNCR are associated with parasitemia.