Comparison of Clinical Characteristics and Peripheral Blood Tests of COVID-19 and Influenza B Patients

This study aimed to investigate the differences in clinical features and routine peripheral blood testing between coronavirus disease 2019 (COVID-19) infection and influenza B infection. Patients with COVID-19 and influenza B admitted to our fever clinic from January 1, 2022 to June 30, 2022 were recruited. A total of 607 patients were included (301 with COVID-19 infection and 306 with influenza B infection). The results of a statistical analysis showed that 1) patients with COVID-19 infection were older and had a lower temperature and shorter duration from fever onset to clinic visit than patients with influenza B infection; 2) apart from fever, viral infection symptoms appeared to be more common in patients with influenza B infection than in patients with COVID-19 infection, including sore throat, cough, muscle aches, weeping, headache, fatigue, and diarrhea (P < 0.001); and 3) compared with patients with influenza B infection, patients with COVID-19 infection had higher numbers of white blood cells and neutrophils but lower numbers of red blood cells and lymphocytes (P < 0.001). In summary, several important differences were identified between COVID-19 and influenza B, which may help to guide clinicians in their initial diagnosis of these two respiratory viral infections.