English Version

What is InfluenzaInfluenza is an acute infectious disease that mainly affects the respiratory system, caused by influenza viruses belonging to the family of Orthomyxoviridae. It is a seasonal disease and circulation of influenza viruses occurs mainly during the winter. Influenza viruses are transmitted by air and therefore highly contagious. The influenza disease is one of the most common infectious diseases on a global scale constituting a serious problem both in terms of mortality and morbidity. Influenza causes a broad spectrum of illness in humans, ranging from symptomless infection to fulminant primary viral or secondary bacterial pneumonia. The influenza illness was described as early as 1679, but the first isolation of the virus in humans dates back to 1933. Later it was discovered that the virus could grow in embryonated eggs and agglutinated chicken red cells . This discovery was fundamental to the study and development of viral vaccines.Influenza viruses are divided into three types different types (A, B and C) according to internal antigens,  mainly  the nucleoprotein (NP): the type A and B viruses, responsible for the symptomatology classical influenza, and the type C of little clinical significance (usually asymptomatic). Vaccinaton is the principal way of preventing influenza and its complications, but it is less effective in immunocompromised patients, compared with healthy individuals.