Background:

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.

Methods:

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.

Results:

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< 3 months old (48.9 per 1000), followed by infants 3 to 5 months old (28.4 per 1000), and lower among those> 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.

Conclusion:

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.