Systematic review of the biology and medical management of respiratory syncytial virus infection.

Respiratory syncytial virus, the leading cause of serious upper and lower respiratory tract infection in infants and children, accounts for 125,000 hospitalizations and 450 deaths annually in the United States. It also may predispose to development of asthma later in life. Annual epidemics occur from November to April, and virtually all infants are infected by age 2.