[Respiratory syncytial virus infection].

Human respiratory syncytial virus (RSV) is the most common worldwide cause of lower respiratory tract infections (LRI) in infants less than 12 months of age. RSV isolates can be divided into group A and B. In addition, there were many genotypes within each group, and these genotypes have evolved global setting with temporal and geographic clustering. Many cellular genes encoding cytokines and chemokines which are activated by RSV infection has now been focused for the elucidation of pathophysiology of RSV LRI. The prophylaxis against RSV infection by vaccination has been unsuccessful because of its adverse effects. No valuable anti-RSV drugs for clinical use have been yet developed. Therefore RSV LRI has been treated mainly symptomatically. Recently humanized anti-RSV F protein monoclonal antibody was developed and prescribed for prevention in high-risk infants such as premature ones and those with chronic lung and congenital heart diseases. It reduced the incidence of hospitalization significantly.