Respiratory Syncytial Virus-associated Hospitalizations Among Infants and Young Children in the United States, 1997–2006

Abstract
Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract disease among young children in the United States. RSV-associated hospitalization increased among children in the United States during 1980 through 1996. In this study, we updated national estimates of RSV hospitalization rates among US children through 2006. We conducted a retrospective analysis of hospital discharges for lower respiratory tract illness (LRTI) in children <5 years old from the National Hospital Discharge Survey. LRTI hospitalizations were identified by using International Classification of Diseases, Ninth Revision, Clinical Modification codes. RSV-coded hospitalizations were International Classification of Diseases, Ninth Revision, Clinical Modification codes 466.11, 480.1, and 079.6. RSV-associated hospitalizations were the sum of RSV-coded hospitalizations and a proportion of hospitalizations coded as bronchiolitis and pneumonia during the RSV season. RSV-coded hospitalizations accounted for 24% of an estimated 5.5 million LRTI hospitalizations among children <5 years of age during the 10 study years, 1997–2006. The RSV-coded hospitalization rate in infants <1 year old was 26.0 per 1000, with no significant difference between study years. The hospitalization rate was highest among infants 1 year old (1.8 per 1000). An estimated 132,000 to 172,000 RSV-associated hospitalizations occurred annually in children <5 years of age. RSV hospitalization rates remained steady during 1997 to 2006 and were a substantial burden in the United States, especially among infants and young children. A safe and effective RSV vaccine is needed.