Prospective Multicenter Study of Viral Etiology and Hospital Length of Stay in Children With Severe Bronchiolitis

Abstract

Objective: To determine whether hospital length of stay (LOS) for acute bronchiolitis is influenced by the infecting pathogen.Design: A prospective observational cohort study was performed during 3 consecutive years.Setting: Sixteen US hospitals participated in the study.Participants: Children younger than 2 years hospitalized with bronchiolitis were included.Main Exposure: The results of nasopharyngeal aspirate polymerase chain reaction pathogen testing served as the main exposure.Main Outcome Measure: Hospital LOS was determined.Results: Of 2207 participants, 72.0% had respiratory syncytial virus (RSV) and 25.6% had human rhinovirus (HRV); the incidence of each of the other viruses and bacteria was 7.8% or less. Multiple pathogen infections were present in 29.8% of the children. There were 1866 children (84.5%) with RSV and/or HRV. Among these 1866 children, the median age was 4 months and 59.5% were male. The median LOS was 2 days (interquartile range, 1-4 days). Compared with children who had only RSV, an LOS of 3 or more days was less likely among children with HRV alone (adjusted odds ratio [AOR], 0.36; 95% CI, 0.20-0.63; PϽ .001) and those with HRV plus non-RSV pathogens (AOR, 0.39; 95% CI, 0.23-0.66; PϽ.001) but more likely among children with RSV plus HRV (AOR, 1.33; 95% CI, 1.02-1.73; P=.04), controlling for 15 demographic and clinical factors. Conclusions:In this multicenter study of children hospitalized with bronchiolitis, RSV was the most common virus detected, but HRV was detected in one-quarter of the children. Since 1 in 3 children had multiple virus infections and HRV was associated with LOS, these data challenge the effectiveness of current RSV-based cohorting practices, the sporadic testing for HRV in bronchiolitis research, and current thinking that the infectious etiology of severe bronchiolitis does not affect shortterm outcomes.

Risk Factors for Requiring Intensive Care Among Children Admitted to Ward With Bronchiolitis

“…The study setting, methods of measurement, and measured variables have been reported previously. 8,9 Briefly, we conducted a multicenter, prospective cohort study during the 2007 to 2010 winter seasons for three consecutive years, as part of the Multicenter Airway Research Collaboration (MARC), a program of the Emergency Medicine Network (EMNet). 8–11 The number of participating sites varied over the 3 years: 13 sites in year 1; 16 sites in year 2; and 14 sites in year 3.…”

“…We performed multivariable logistic regression with the use of generalized estimating equations to investigate predictors of late intensive care use and to account for the clustering of patients at the site level, We chose the covariates (ie, age, sex, birth weight, respiratory rate, and virology results [RSV status and HRV status]) based on clinical plausibility and a priori knowledge. 2,3,7–9,15 In sensitivity analyses, we fit two additional models adding two covariates (i.e., exposure to tobacco smoke, duration of difficulty breathing) separately. We also conducted a sensitivity analysis excluding late intensive care use without mechanical ventilation from the primary outcome.…”

The Effect of Respiratory Syncytial Virus on the Severity of Acute Bronchiolitis in Hospitalized Infants: A Prospective Study from Turkey

“…Recent studies have investigated the differences of the clinical outcome for those with sole viral infection compared to coinfection with or without RSV. Some authors also stated that acute RSV bronchiolitis was associated with more severe diseases compared to patients without RSV (4)(5)(6). However, according to some authors there is no relation between RSV-coinfections and increase in the disease severity (7,8).…”

Use of Cough and Cold Medications in Severe Bronchiolitis before and after a Health Advisory Warning against Their Use

“…A complete description of these studies is available elsewhere. [5–6] Briefly, both studies included children age <2 years with an attending physician diagnosis of bronchiolitis. So participants were more comparable across studies, children enrolled in the pre-health advisory study were included in the current analysis only if they were hospitalized.…”