COVID-19 and influenza: main differences between clinical symptoms

This review analyzes the clinical symptoms, differential diagnosis of COVID-19 and influenza to facilitate clinical diagnosis of both diseases. The development of the COVID-19 epidemic occurred with an exponential growth of the incidence due to the high contagiousness of the virus, asymptomatic carriage. The situation was aggravated by the contagiousness of the patient in the last 2–3 days of the incubation period (before clinical manifestations), which made it difficult to isolate patients and contacts in a timely. The spectrum of damage to the organs and systems is constantly expanding with a more detailed study of the clinical course of COVID-19. Sometimes, the manifestations of COVID-19 persist even during the period of convalescence, which cause a decrease in the performance and quality of life of patients. The article discusses neurological manifestations, gastrointestinal symptoms and features of pneumonia in COVID-19. The clinical features of influenza and the main differences in the clinical course from COVID-19 are also demonstrated.