Viral Load in Infants Hospitalized for Respiratory Syncytial Virus Bronchiolitis Correlates with Recurrent Wheezing at Thirty-Six-Month Follow-Up.

The relationship between viral infection, host immune response in infants with respiratory syncytial virus (RSV) bronchiolitis and subsequent wheezing is discussed. We measured RSV-RNA load and interferon-λ1-3 expression in the nasopharyngeal washings from 68 infants hospitalized for RSV bronchiolitis, and wheezing was assessed 36 months after the first episode of bronchiolitis. Higher RSV-RNA load and higher interferon-λ2/3 levels were found in children with recurrent wheezing at 36-month follow-up.