New York, NY
ABSTRACT
PURPOSE OF THE STUDY.: To compare asthma and atopy outcomes of children according to whether they had been admitted to a hospital in the first 12 months with respiratory syncytial virus (RSV)proven bronchiolitis.
STUDY POPULATION.: Data from a large, population-based, birth cohort (Avon Longitudinal Study of Parents and Children) were used.
METHODS.: Outcomes considered were 12-month prevalence of wheeze at 2 ages (between 3042 and 6981 months), cumulative prevalence of doctor-diagnosed asthma at 91 months, and skin-prick testdefined atopy at 7 years. Multivariable logistic-regression models were used to calculate odds ratios for outcomes adjusted for potential confounders.
RESULTS.: A total of 150 infants (1.1% of the cohort) were admitted to a hospital within 12 months of birth with RSV bronchiolitis. The prevalence of wheezing was 28.1% in the RSV group and 13.1% in controls at 30 to 42 months and 22.6% vs 9.6% at 69 to 81 months. The cumulative prevalence of asthma was 38.4% in the RSV group and 20.1% in the controls at 91 months. Atopy was found in 14.6% of those in the RSV group and in 20.7% of the controls at 7 years. RSV bronchiolitis was associated with subsequent wheezing between 30 to 42 months (odds ratio [OR]: 2.3; 95% confidence interval [CI]: 1.33.9) and 69 to 81 months (OR: 3.5; 95% CI: 1.86.6) and with the cumulative prevalence of asthma at 91 months (OR: 2.5; 95% CI: 1.44.3) but not with atopy (OR: 0.7; 95% CI: 0.21.7).
CONCLUSIONS.: In a population-based birth cohort, RSV bronchiolitis was associated with subsequent wheezing and asthma but not with the development of atopy by 7 years of age.
REVIEWER COMMENTS.: Because infants who have severe RSV infection have recurrent wheezing later in life, RSV has been suggested to be a risk factor for asthma. Some also postulate that early RSV infection may predispose children to atopy; however, this has been controversial. Henderson et al show in their large prospective cohort that severe RSV infection requiring hospitalization is associated with wheezing but not atopy. These results indicate that RSV infection may be a risk factor for nonallergic asthma.