[Respiratory viriasis. Influenza].

Respiratory viriasis are acute infectious diseases with a usually favorable course. Influenza is the disease caused by influenza viruses A and B; it could cause seasonal periodical epidemics and influenza A is implicated in worlwide pandemias. Influenza complications usually are limited to older patients and to those with comorbilities, especially those with chronic respiratory or cardiovascular diseases. Anti-influenza therapy has an effect on the duration of the symptomatic period and vaccination efficiently decreases the incidence of the infection. Respiratory syncytial virus is the more frequent cause of the acute bronchiolitis in breastfeeding patients. Rinovirus and coronavirus are implicated in the common cold. Coronavirus was the etiological agent of the severe acute respiratory syndrome, described in 2002 in China. Parainfluenza virus is the cause of the laryngeal croup in infants.