A Comparative Study of Hematological Parametersin COVID-19 Positive Cases, Influenza like Illness Patients, and Healthy Subjects

ABSTRACT

Introduction: Since its origin in December 2019, Novel Corona virusinfection has behaved in an unprecedented manner. Viral infectionsare characterized by atypical and reactive lymphocytosis as is seen ininfectious mononucleosis and dengue viral infection respectively.Previous studies on influenza like illnesses have demonstrated the roleof Neutrophil-to-lymphocyte as a preferable diagnostic tool to screeninfluenza virus-infected patients. In addition to these, volume conductivity and scatter has revealed significant findings in volumescatter and conductivity of monocytes and neutrophils in the past ininfluenza and influenza like illnesses.Aims &Objectives: To study the hematological parameters ofCOVID-19 positive cases and to compare the hematological parameters in COVID-19 positive cases, patients with influenza andinfluenza like illness.Materials &Methods: 169 Covid positive cases, 113 influenza andinfluenza like illnesses and 140 healthy controls were included in thestudy. All samples were processed on DXH 800 and all parameterswere recorded.Result: There was significant difference between Covid 19 and influenza and influenza like illness in terms of age, percentage ofneutrophils, percentage of lymphocyte, percentage of monocyte, percentage of eosinophil and basophil. Significant difference was alsofound between mean neutrophilic and mean monocytic volume, and inall the scatter parameters of neutrophils. Neutrophil-to-lymphocyteratio (NLR) and platelet-to-lymphocyte ratio (PLR) also showed significant difference in both the conditions. Multivariate analysis wasperformed and a joint probability was calculated which showed a cutoffin differentiating Covid 19 from influenza and influenza like illnesses.Conclusions: Covid 19 and Influenza can cause different changes inperipheral blood parameters and the diagnostic formula developed inthis study will enable the clinicians to differentiate Covid 19 frominfluenza during the early stages.