Bronchiolitis, Regardless of Its Etiology and Severity, Is Associated With Increased Risk of Asthma: A Population-Based Study

Abstract

An association exists between severe Respiratory Syncytial Virus (RSV)-bronchiolitis and a subsequent increased risk of recurrent wheezing (RW) and asthma. However, a causal relationship remains unproven. Using a retrospective population-based cohort study (339,814 children), bronchiolitis during the first two years (regardless of aetiology and severity) was associated with at least a threefold increased risk of RW/asthma at 2-4 years and an increased prevalence of asthma at ≥5 years of age. The risk was similar in children with mild bronchiolitis as in those with hospitalised-RSV-bronchiolitis and was higher in children with hospitalized-non-RSV-bronchiolitis. The rate of RW/asthma was higher when bronchiolitis occurred after the first 6 months of life. Our results seem to support the hypothesis of a shared predisposition to bronchiolitis (irrespective of aetiology) and RW/asthma. However, 60% of hospitalized bronchiolitis in our setting are due to RSV, which should be paramount in decision-making on imminent RSV prevention strategies.

Factors Predicting Secondary Respiratory Morbidity Following Early-Life Respiratory Syncytial Virus Infections: Population-Based Cohort Study

“…These vulnerabilities may interact with RSV to increase the risk of developing a “wheezy phenotype,” as has been shown in another cohort study from the United States, which indicated that having RSV or rhinovirus wheezing illness at 2–3 years of age in a high-risk cohort was associated with an increased asthma risk at 6 years as compared with having infections during infancy [ 29 ]. Our results are supported by a recent study by Rosas-Salazar et al [ 6 ] but in contrast to a recent study by Munoz-Quiles et al [ 7 ], which reported a higher risk of recurrent wheeze/asthma in children hospitalized with non-RSV bronchiolitis compared with RSV-positive children. However, these analyses included a different case definition than ours as well as the addition of primary care data.…”

“…Numerous small and larger studies have been conducted to establish whether this association is causal, examined comprehensively in a systematic review by Brunwasser et al [ 5 ]. More recently, 2 studies have examined this association in RSV-positive and RSV-negative children, with contrasting results [ 6 , 7 ].…”

Association between age of respiratory syncytial virus infection hospitalization and childhood asthma: A systematic review

“…Among the two prospective cohort studies, Zhou et al excluded severe concomitant chronic diseases and Koponen et al did not provide exclusion criteria [ 14 , 15 ]. Three retrospective studies specifically evaluated the association of age of the first RSV hospitalization and risk of asthma [ 13 , 16 , 17 ]. All of the studies accounted for some confounding factors in their design and statistical analyses, but as with any observational study there could be remaining confounding.…”

“…Two retrospective cohort studies, Homaira et al and Wang et al used the first hospitalization due to asthma to define the asthma outcome, and Muñoz-Quiles et al defined childhood asthma as ICD-10 code of asthma regardless of level of healthcare encounter [ 13 , 16 , 17 ]. Koponen et al used a test of bronchial hyperresponsiveness as an objective criterion of asthma [ 15 ].…”

“…After screening 149 titles and abstracts, 21 studies proceeded to the full-text review; five studies met our inclusion criteria and are included in this systematic review (Fig 1) [13][14][15][16][17]. Tables 1, 2 and S3…”