flu 2025

Sun, 03 May 2026 16:23:58 +0000

WHO fact sheet on influenza: includes key facts, definition, symptoms, transmission, seasonal epidemics, effects, prevention, WHO response. Seasonal influenza is an acute respiratory infection caused by influenza viruses which circulate in all parts of the world. It is characterized by a sudden onset of fever, cough (usually dry),. Influenza is an acute viral infection that primarily attacks the upper respiratory tract, including the nose, throat, bronchi and, less frequently, the lungs. The disease occurs worldwide and. Seasonal influenza (the flu) is an acute respiratory infection caused by influenza viruses that circulate globally and year-round. It can cause illness ranging from mild to severe, sometimes.