RSV Infection, Even Without Bronchiolitis, Is Associated with Later Childhood Asthma

Bronchiolitis caused by respiratory syncytial virus (RSV) in infancy is associated with later childhood asthma, but it's not clear whether less-severe RSV disease in infancy also increases asthma risk. To clarify this issue, researchers recruited 2000 healthy full-term babies in central Tennessee and contacted parents every 2 weeks during each child's first RSV season. Nasal washes from children with acute respiratory infections were tested for RSV by polymerase chain reaction, and disease severity was assessed. All children had RSV serum antibody titers at age 1 year and were followed for 5 years for asthma symptoms, diagnosis, or treatment.

At age 1 year, 54% of children had evidence of RSV infection. Compared with children who had RSV as …