In Very Young Infants Severity of Acute Bronchiolitis Depends On Carried Viruses

Christophe Marguet,Christophe Marguet,Daniel Siret,François Freymuth,Michael Bubenheim,Marc Lubrano,Marc Lubrano,Chantal Forget,Antoine Deschildre,Laure Couderc,Marie Gueudin,Pascal Le Roux,Marie Gueudin,Astrid Vabret,Marie-Dominique Donnou,Laure Couderc,Rory Edward Morty

doi:10.1371/journal.pone.0004596

Abstract

BackgroundRT amplification reaction has revealed that various single viruses or viral co-infections caused acute bronchiolitis in infants, and RV appeared to have a growing involvement in early respiratory diseases. Because remaining controversial, the objective was to determine prospectively the respective role of RSV, RV, hMPV and co-infections on the severity of acute bronchiolitis in very young infants.Methods and Principal Findings209 infants (median age: 2.4 months) were enrolled in a prospective study of infants <1 year old, hospitalized for a first episode of bronchiolitis during the winter epidemic season and with no high risk for severe disease. The severity was assessed by recording SaO2% at admission, a daily clinical score (scale 0–18), the duration of oxygen supplementation and the length of hospitalization. Viruses were identified in 94.7% by RT amplification reaction: RSV only (45.8%), RV only (7.2%), hMPV only (3.8%), dual RSV/RV (14.3%), and other virus only (2%) or coinfections (9%). RV compared respectively with RSV and dual RSV/RV infection caused a significant less severe disease with a lower clinical score (5[3.2–6] vs. 6[4–8], p = 0.01 and 5.5[5–7], p = 0.04), a shorter time in oxygen supplementation (0[0–1] days vs. 2[0–3] days, p = 0.02 and 2[0–3] days, p = 0.03) and a shorter hospital stay (3[3–4.7] days vs.6 [5–8] days, p = 0.001 and 5[4–6] days, p = 0.04). Conversely, RSV infants had also longer duration of hospitalization in comparison with RSV/RV (p = 0.01) and hMPV (p = 0.04). The multivariate analyses showed that the type of virus carried was independently associated with the duration of hospitalization.ConclusionThis study underlined the role of RV in early respiratory diseases, as frequently carried by young infants with a first acute bronchiolitis. RSV caused the more severe disease and conversely RV the lesser severity. No additional effect of dual RSV/RV infection was observed on the severity.

Highlights

Acute bronchiolitis is the most common respiratory disease in infants under 2 years of age
This study underlined the role of RV in early respiratory diseases, as frequently carried by young infants with a first acute bronchiolitis
No additional effect of dual respiratory syncytial virus (RSV)/RV infection was observed on the severity

Summary

Introduction

Acute bronchiolitis is the most common respiratory disease in infants under 2 years of age. The fact that carrying at least any two viruses augmented the risk to be transferred to PICU has been reported [5] The aim of this prospective study was to assess the clinical severity and viral etiology in infants hospitalized with a first episode of acute bronchiolitis during the epidemic season. Within this very young population, RSV caused more marked severe bronchiolitis than did RV, and RV co-infection but neither aggravated the clinical features nor the length of the hospitalization. RT amplification reaction has revealed that various single viruses or viral co-infections caused acute bronchiolitis in infants, and RV appeared to have a growing involvement in early respiratory diseases. The objective was to determine prospectively the respective role of RSV, RV, hMPV and co-infections on the severity of acute bronchiolitis in very young infants

Methods

Results

Discussion

Conclusion