Long-term effects of respiratory syncytial virus (RSV) bronchiolitis in infants and young children: a quantitative review

One of the major questions regarding long-term side effects of bronchioliti s by respiratory syncytial virus (RSV) is whether or not it induces asthma in later life. In this quantitative review, the data of 10 controlled studi es are analysed. Method: Follow-up studies of RSV bronchiolitis published b etween January 1978 and December 1998 were identified through a MEDLINE sea rch. Studies were selected if (i) postnatal age at the time of the inital i llness was below 12 mo, (ii) all children were hospitalized for RSV bronchi olitis, (iii) the diagnosis RSV was virologically confirmed in all cases, a nd (iv) a control group was used. Results: Six studies met all selection cr iteria. Up to 5 y of follow-up after RSV bronchiolitis in infancy, 40% of c hildren reported wheezing as compared to only 11% in the control group (p < 0.001). Between 5 and 10 y of follow-up 22% of the bronchiolitis group rep orted wheezing against 10% of the control group (p = 0.19). The incidence o f recurrent wheezing as defined by three or more wheezing episodes also dec reased with increasing years of follow-up: at 5 or more years of follow-up the difference between the RSV group and the control group was no longer si gnificant. Furthermore, the presence of either a personal and/or a family h istory of either atopy and/or asthma did not differ between the two groups. Conclusions: Wheezing is common after RSV bronchiolitis in infancy. It may persist for greater than or equal to 5 y of follow-up. However, no signific ant difference between the RSV bronchiolitis and the control group was obse rved regarding recurrent wheezing by 5 y of follow-up. No significant diffe rence between the RSV bronchiolitis and the control group were found regard ing a personal history of atopy, a family history of atopy and/or asthma. T herefore it seems unlikely that RSV bronchiolitis is a cause of atopic asth ma in later life.