It can cause mild to severe illness. It is characterized by a sudden onset of fever, cough. Every year, mainly during the winter season, seasonal influenza infects as many as 1 billion people.
Influenza is an acute viral infection that primarily attacks the upper respiratory tract, including the nose, throat, bronchi and, less frequently, the lungs. It can cause illness ranging from mild to severe,. The most common symptoms of influenza (flu) include fever, a dry cough, headache, muscle and joint pain, a sore throat and a runny nose.
Influenza viruses evolve constantly, and twice a year who makes recommendations to update the. Includes key facts, definition, symptoms, transmission, seasonal epidemics, effects, prevention, who response. Who fact sheet on influenza: All of us might be potentially affected by the flu.
The flu happens every year, worldwide. Influenza, or the flu, is both a seasonal and a pandemic virus. Seasonal influenza is an acute respiratory infection caused by influenza viruses which circulate in all parts of the world. The virus is transmitted easily from person to person via droplets.
The best way to avoid getting the flu is to get the flu vaccine every year. Influenza (flu) is a contagious respiratory illness caused by influenza viruses.