Respiratory syncytial virus infection: an emerging or unappreciated infection?

Respiratory syncytial virus (RSV) is a ubiquitous cause of respiratory infection with a worldwide distribution and seasonal occurrence. Natural immunity does not normally follow infection, and reinfection is the rule. Reinfection may even occur within a single season. Although its role in serious lower respiratory tract infection (LRTI) in infants is well recognized, the importance of RSV in disease of older children, adults and, especially in the elderly, is poorly appreciated. In large surveillance studies, RSV is at least as important in contributing to respiratory morbidity and mortality as influenza. These data would suggest that tens of millions of Americans suffer respiratory disease (LRTI and upper respiratory tract infection [URTI]) from RSV each winter. In addition, otitis media and episodic bronchospasm are complications following RSV infection. Unfortunately, there is no vaccine yet available for prevention. Prevention of disease with a hyperimmune globulin (RSVIG) and with a monoclonal antibody (MAb) (palivizuMab) is possible, but only for those neonates and infants at highest risk of morbidity and mortality from RSV infection. Therapy with the only approved antiviral for this indication, ribavirin, is difficult, is of questionable efficacy, and the compound itself is teratogenic. Infection by RSV constitutes an enormous but unappreciated medical need worldwide.