Respiratory infections pose major disease burden in hospitalized children

Children hospitalized for viral respiratory diseases carry a significant burden of illness, reports a study.

Specifically, children with respiratory syncytial virus (RSV) infection have a significantly higher risk of clinical outcomes than those with COVID-19 or influenza. However, in-hospital mortality is higher for COVID-19 and influenza than for RSV.

“The substantial clinical burden of RSV, COVID-19, and influenza in young children observed in this study underscores the importance of continued public health measures to prevent infection in this age group, including measures such as immunization and monoclonal antibodies,” the researchers said. [Value Health 2023;26:S340-S341; Value Health 2023;26:S116]

A total of 56,634 children were hospitalized for acute respiratory infections, of whom 43,766 had RSV, 6,697 had COVID-19, and 6,171 had influenza. [Pediatr Infec Dis J 2025;44:1018-1024]

Patients with RSV vs COVID-19 and influenza (mean age 0.7 vs 0.7 and 1.7 years) were more often admitted to the intensive care unit (ICU; 28.2 percent vs 22.4 percent and 21.7 percent) and to require supplemental oxygen (46.1 percent vs 20.2 percent and 26.2 percent) or invasive mechanical ventilation (12.0 percent vs 8.3 percent and 8.2 percent).

In adjusted regression models, RSV was associated with persistently higher risks of supplemental oxygen use, ICU admission, and IMV than COVID-19 and influenza. Risks linked to RSV were highest among children aged <1 year. On the other hand, in-hospital mortality was lower with RSV than with COVID-19 and influenza (0.1 percent vs 0.3 percent and 0.4 percent).

The US Centers for Disease Control and Prevention (CDC) recommends maternal immunization against COVID-19 and influenza, as well as maternal immunization against RSV to prevent RSV-associated lower respiratory tract infections in infants,” the researchers said. [Morb Mortal Wkly Rep 2023;72:1115-1122; Morb Mortal Wkly Rep 2023;72:1377-1382]

“In addition, the CDC recommends COVID-19 and influenza vaccination in children ≥6 months old and monoclonal antibody treatment for infants <8 months of age to prevent severe RSV disease,” they added. [Morb Mortal Wkly Rep 2023;72:1140-1146; Morb Mortal Wkly Rep 2023;72:920-925]

Hospital outcomes

The research team selected patients aged <5 years who were hospitalized for RSV, COVID-19, or influenza between September 2022 and August 2024 from the PINC-AI Healthcare Database (PHD) for retrospective cohort analysis. They assessed hospitalization outcomes such as length of stay, supplemental oxygen use, ICU admission, IMV, and in-hospital death.

Weighted robust Poisson regression models were used to estimate risks and compare RSV with COVID-19 and influenza. Participants were further stratified by age at admission (<1, 1, and 2‒4 years).

“The findings of this study should be interpreted within the context of the study limitations,” the researchers said.

First, hospitalizations occurring outside the PHD catchment network, as well as outpatient care and mortality, were not represented in this study. Second, the database reported age in yearly increments, and it was not possible to analyse infants <6 months of age.

Third, the impact of vaccination was not assessed since the data source did not capture this information consistently. Finally, the researchers considered post-COVID-19 pandemic RSV and influenza seasons, which may differ in clinical disease severity from prepandemic years.