TOPLINE

Among children and adolescents hospitalized for severe bronchiolitis in the first 2 years of life, those whose illness was caused by respiratory syncytial virus (RSV) subgroup B were more likely than those with RSV subgroup A to report wheezing that restricted speech and nighttime dry cough at school age, whereas current asthma prevalence and lung function did not differ significantly.

METHODOLOGY

• This prospective, cross-sectional study conducted from September 2023 to June 2025 in Madrid, Spain, included 185 children and adolescents (age, 5-18 years; 53.5% boys) who had been hospitalized for severe bronchiolitis caused by RSV subgroup A or B. They were assessed at a follow-up visit, and their medium-term respiratory outcomes were compared by RSV subgroup (A vs B).
• All participants had been hospitalized during the first 2 years of life, between 2004 and 2017, for bronchiolitis caused by a single RSV infection: 129 with subgroup A and 56 with subgroup B.
• Current asthma was defined as wheezing or whistling sounds from the chest during the previous 12 months, reported by families on a Spanish-validated asthma symptom questionnaire. The same questionnaire also included questions on severe wheezing that restricted speech and nighttime dry cough unrelated to infections.
• Participants underwent lung function testing, an exhaled nitric oxide test, and skin-prick tests for sensitization to common airborne allergens.

TAKEAWAY

• Severe wheezing that restricted speech was more common among children previously hospitalized for bronchiolitis caused by RSV-B than among those hospitalized for bronchiolitis caused by RSV-A  (odds ratio [OR], 2.62; 95% CI, 1.3-5.4). 
• Nighttime dry cough unrelated to infections was also more frequent among the children hospitalized for bronchiolitis caused by RSV-B than RSV-A (16.9% vs 7.7%; P = .044).
• In adjusted analyses, prior bronchiolitis caused by RSV-B was independently associated with nighttime dry cough (OR, 3.98; P  = .018), alongside allergic rhinitis, maternal asthma, and maternal smoking during pregnancy.
• Current asthma rates, lung function, exhaled nitric oxide levels, and allergic sensitization were not significantly different across the two groups.

IN PRACTICE

"[S]ince a history of HRSV-B [human RSV subgroup B] bronchiolitis appears to be associated with a poorer prognosis, closer monitoring of this patient group—with better medical management of respiratory symptoms during the first years of life—could lead to reduced medium-term morbidity," the authors wrote.

SOURCE

The study was led by María Arroyas Sánchez, Severo Ochoa University Hospital, Madrid, Spain. It was published online on September 20, 2026, in Pediatric Pulmonology.

LIMITATIONS

The study's sample size fell short of the target, and it included far fewer children in the RSV-B group than in the RSV-A group. Symptoms were assessed at a single visit and relied on recall, and many eligible patients did not enroll, mostly for logistical reasons; therefore, recall and selection bias may have affected the results.

DISCLOSURES

The study was funded by Merck, Sharp & Dohme, Horizon Europe, and Instituto de Salud Carlos III. The authors reported having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.