Risk factors for disease severity and increased medical resource utilization in respiratory syncytial virus (+) hospitalized children

MarijkeProesmans, Annabel Rector, ElsKeyaerts, YannickVandendijck, Francois Vermeulen, Kate Sauer,MarijkeReynders, Ann Verschelde, WimLaffut, KristienGarmyn, Roman Fleischhackl, Jacques Bollekens, Gabriela Ispas



We aimed to provide regional data on clinical symptoms, medical resource utilization (MRU), and risk factors for increased MRU in hospitalized respiratory syncytial virus (RSV)-infected Belgian pediatric population.


RSV is a common cause of respiratory tract infection in infants and young children [1], and was estimated to be responsible yearly for at least 33.1 million episodes of acute lower respiratory tract infection worldwide in 2015, resulting in the death of 94,600 to 149,400 children aged <5 years [2]. It has been documented that the clinical presentation of RSV infection in children differs according to age and may be influenced by the differences in their immune reaction to RSV [3]. In a metareview, it was shown that the annual RSV hospitalization rates decreased with increasing age and varied by a factor of 2–3. Risks factors associated with RSV related medical resources utilization included, male sex; age <6 months; birth during the first half of the RSV season; crowding/siblings; and day-care exposure (high strength of evidence) [4].


Study design

This exploratory, prospective, multicenter study (NCT02133092) enrolled patients from clinical pediatric wards of four Belgian hospitals (one tertiary academic center and three regional hospitals: UZ Leuven, AZ Sint-Jan Brugge–Oostende campus Brugge, AZ Sint-Jan Brugge—Oostende campus Henri Serruys, and Heilig Hart ZiekenhuisLier) during the 2013–2014 and 2014–2015 RSV epidemic seasons (Study initiated: 17 December 2013 and Study completed: 21 January 2015). Patients were diagnosed as RSV (+) based on a quantitative RT-PCR (qRT-PCR) homemade/in-house test, or a Sofia RSV fluorescent immunoassay (SOFIA® RSV tests, Quidel), whichever was available first, within 24h after hospitalization. Children with a positive RSV test were monitored daily until discharge or for a maximum of six days (Day 2 to Day 7 of hospitalization).


Baseline characteristics

Seventy-five patients were included in the study. Baseline characteristics were reported for all patients (Table 1) as well as after classifying based on age, symptom duration, and underlying risk (S3 Table in S1 File). Overall, the median (range) age was 4 (0–41) months with more males than females (n = 41/75 [54.7%] vs. n = 34/75 [45.3%]). Majority of patients were infected by RSV-A (n = 68/75 [90.7%]). Underlying risk factors were present in 18.7% of the patients (n = 14/75), with previous or recurrent wheezing (n = 5/75) and congenital heart disease (CHD; n = 4/75) being the most common underlying risk factors. Premature birth (≤37 weeks of gestation) was reported in 20.0% (n = 15/75) of the patients, with a median (range) age of 7 (0–28) months at enrolment. The premature group was elder at the time of hospital admission than the patients without reported prematurity (median [range] age of 3 [0–41] months). Median (range) symptom duration at enrolment was 3.0 (1–5) days, with symptoms being reported for ≤3 days for most patients (n = 43/75 [57.3%]) before being hospitalized.


This study describes the disease progression, medical resources utilization and predictors for oxygen supplementation and duration of hospitalization. in RSV (+) children hospitalized with a LRTI. There were no transfers to ICU or mechanical ventilation (although one of the four sites was a tertiary hospital), indicating that the population studied is representative for moderate severity bronchiolitis hospitalizations.


This exploratory, prospective study provides evidence on disease burden and predictors for increased use of medical resources in hospitalized children. Very young age (<3 months old) and baseline PES3 total score were associated with the probability of receiving and the length of oxygen supplementation, however, none of the factors analyzed were associated with the length of hospitalization. This study emphasizes that the probability and length of oxygen supplementation but not the length of hospitalization could be predicted in hospitalized children.


The authors thank Dr. Marc Van Ranst and Dr.LieselotHouspie for advising on the study conductance, and Leo J. Philip Tharappel (SIRO Clinpharm Pvt Ltd.), Aafrin Khan (SIRO Clinpharm Pvt Ltd) and Robert Achenbach (Janssen Global Services, LLC) for providing medical writing support and editorial assistance.

Citation: Proesmans M, Rector A, Keyaerts E, Vandendijck Y, Vermeulen F, Sauer K, et al. (2022) Risk factors for disease severity and increased medical resource utilization in respiratory syncytial virus (+) hospitalized children: A descriptive study conducted in four Belgian hospitals. PLoS ONE 17(6): e0268532.

Editor: Brenda M. Morrow, University of Cape Town, SOUTH AFRICA

Received: August 5, 2021; Accepted: May 2, 2022; Published: June 6, 2022

Copyright: © 2022 Proesmans et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: The data sharing policy of Janssen Pharmaceutical Companies of Johnson & Johnson is available at As noted on this site, requests for access to the study data can be submitted through Yale Open Data Access (YODA) Project site at

Funding: The study was funded by Janssen Pharmaceutica NV. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: YV, RF, JB, and GI are employees of Janssen Pharmaceutica NV and may own stock in Johnson & Johnson. MP, AR, EK, FV, KS, MR, AV, WL, and KG have no conflict of interest.