Clinical Characteristics and In-hospital Outcomes Associated With Respiratory Syncytial Virus vs Other Viral Acute Lower Respiratory Infections in Hospitalized Children Younger Than 2 Years

J Infect Dis. 2025 Jun 2;231(5):1309-1317. doi: 10.1093/infdis/jiae543.

Abstract

Background: Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory infection (ALRI)-associated hospitalizations in children. It is unclear if hospitalized RSV-positive ALRI is clinically different from other viral ALRIs. We aimed to compare the disease impact of hospitalized RSV with other viral ALRI in children aged <2 years.

Methods: We conducted a retrospective study using the electronic medical records of children aged <2 years who were hospitalized with ALRIs at Sydney Children's Hospital Network from 2020 to 2022. We compared demographics and clinical features between RSV-positive cases and RSV-negative ones (ie, positive for other viruses). Poisson quasi-likelihood regression was used to estimate adjusted prevalence ratios for 3 in-hospital outcomes: length of stay, need for respiratory support, and intensive care.

Results: We examined 330 children aged <2 years hospitalized with RSV-positive ALRIs and 330 with RSV-negative ALRIs (positive for other viruses). RSV-positive cases were older (12 vs 8 months, P < .001) and more often presented with cough (99% vs 92%), fever (80% vs 58%), crackles (89% vs 76%), hypoxia (50% vs 36%), and lethargy (36% vs 20%). They were also more likely to undergo chest radiographs (74% vs 49%) and receive antibiotics (65% vs 35%). Adjusted analysis showed that children who were RSV positive had a higher likelihood of an extended length of stay (>2 days; adjusted prevalence ratio, 1.95; 95% CI, 1.14-3.36). However, there were no differences in the need for intensive care or respiratory support.

Conclusions: Children with RSV-positive ALRI exhibited more severe symptoms, received more antibiotics, and had longer hospital stays as compared with those with other viral ALRIs, underscoring the need for effective prevention and treatment strategies for RSV.

Keywords: ALRI; RSV; RSV disease severity; acute lower respiratory infection; children.

MeSH terms

  • Acute Disease
  • Female
  • Hospitalization* / statistics & numerical data
  • Humans
  • Infant
  • Infant, Newborn
  • Length of Stay / statistics & numerical data
  • Male
  • Respiratory Syncytial Virus Infections* / epidemiology
  • Respiratory Syncytial Virus Infections* / therapy
  • Respiratory Syncytial Virus Infections* / virology
  • Respiratory Syncytial Virus, Human
  • Respiratory Tract Infections* / epidemiology
  • Respiratory Tract Infections* / virology
  • Retrospective Studies