Multicenter Study of Viral Etiology and Relapse in Hospitalized Children With Bronchiolitis

Abstract

Background It is unclear whether the infectious etiology of severe bronchiolitis affects short-term outcomes, such as post-hospitalization relapse. We tested the hypothesis that children hospitalized with rhinovirus (RV) bronchiolitis, either as a sole pathogen or in combination with respiratory syncytial virus (RSV), are at increased risk of relapse. Methods We performed a 16-center, prospective cohort study of hospitalized children age <2 years with bronchiolitis. During the winters of 2007 to 2010, researchers collected clinical data and nasopharyngeal aspirates from study participants; the aspirates were tested using real-time polymerase chain reaction. The primary outcome was bronchiolitis relapse (urgent bronchiolitis visit or scheduled visit at which additions to the bronchiolitis medications were made) during the 2 weeks after hospital discharge. Results Among 1836 enrolled children with 2-week follow-up data, the median age was 4 months and 60% were male. Overall, 48% had sole RSV infection, 8% had sole RV infection, and 13% had RSV/RV co-infection. Compared with children with sole RSV infection, and adjusting for 10 demographic and clinical characteristics and clustering of patients within hospitals, children with sole RV infection did not differ in their likelihood of relapse (OR, 0.99; 95%CI, 0.52–1.90; P=0.98), whereas those with RSV/RV co-infection were more likely to have relapse (OR, 1.54; 95%CI, 1.03–2.30; P=0.03). Conclusions In this prospective, multicenter, multiyear study of children hospitalized with bronchiolitis, we found that RSV/RV co-infection was independently associated with a higher likelihood of bronchiolitis relapse. Present data support the concept that the infectious etiology of severe bronchiolitis affects short-term outcomes.

A Clustering Approach to Identify Severe Bronchiolitis Profiles in Children

“…[4,7] The study was part of the Multicenter Airway Research Collaboration (MARC-30 USA), a program of the Emergency Medicine Network (EMNet, http://www.emnet-usa.org). Investigators at 16 sites across 12 U.S. states used a standardized protocol to enroll 2,207 children who were diagnosed by the attending physician as having bronchiolitis (as defined by the American Academy of Pediatrics [28]: acute respiratory illness with some combination of rhinitis, cough, tachypnea, wheezing, crackles, and retractions), and were younger than 2 years.…”

“…[4,7] Emergency department (ED) and daily hospital medical records provided further clinical data; data extracted from records on-site were manually reviewed at the EMNet coordinating center. Researchers collected nasopharyngeal aspirates using a standardized protocol, and performed testing for a large panel of respiratory pathogens (see supplement) using real-time polymerase chain reaction (PCR) assays at the core laboratory (Houston, TX).…”

“…[2] Although bronchiolitis is generally considered a single disease entity, the clinical course and severity are highly variable, [1,3,4] and recent studies have suggested that bronchiolitis is heterogeneous. [3,5,6] For instance, most children with bronchiolitis have a mild-to-moderate disease course, but approximately 3% require hospitalization (severe bronchiolitis).…”

“…[1] Even among hospitalized children, the two most common etiologic viruses, respiratory syncytial virus (RSV) and rhinovirus, are associated with different shortterm clinical outcomes (e.g., hospital length-of-stay, risk of relapse). [4,[7][8][9] In addition, although most hospitalized children have a monophasic illness pattern, they have a wide range of time to recovery. [10] Importantly, beyond these short-term differences, heterogeneity has also been observed in long-term outcomes, such as the risk of developing recurrent wheezing and asthma.…”

Treatment with hypertonic saline in hospitalized infants with acute bronchiolitis

“…A pesar de que la definición difiere de un país a otro, es generalmente aceptado que la bronquiolitis aguda se refiere al primer episodio de aguda sibilancia en niños menores de 2 años. Sin embargo algunos autores invocan que el segundo episodio podría deberse a una recaída de la bronquiolitis secundaria (13) a infección con Rhinovirus .…”