Comparison of clinical features and laboratory findings of novel coronavirus disease, influenza A and influenza B infections in adult patients applying to the emergency department

This study aims to compare the clinical characteristics and laboratory findings of COVID 19, influenza A, and influenza B infections in adult patients admitted to the emergency department. Respiratory tract infections are common worldwide and place a significant burden on individuals and healthcare systems. The emergence of COVID-19 has highlighted the necessity of distinguishing it from other viral infections, such as influenza A and B, which have similar symptoms but differ in pathophysiology and disease progression. A total of 342 patients diagnosed with COVID-19, influenza A, or influenza B were retrospectively analyzed. Demographic data, clinical symptoms, laboratory results, and radiological findings were collected and compared. The study found that COVID-19 patients had a higher prevalence of chronic diseases and required more hospitalizations compared to influenza patients. While fever, cough, and fatigue were common symptoms across all infections, shortness of breath and hypoxia were more frequently observed in COVID-19 patients. Although laboratory findings were similar among the three groups, blood urea nitrogen (BUN) levels were higher in COVID-19 patients, while C-reactive protein (CRP) levels were lower in influenza B patients. Monocytosis and lymphopenia were common findings in all three groups. As the severity of the disease increased, CRP and leukocyte levels also rose, while the platelet-to lymphocyte ratio decreased. The study concluded that while COVID-19, influenza A, and influenza B share overlapping clinical features and similar laboratory findings, certain markers may assist in distinguishing these infections and could improve patient management and treatment outcomes.