Children were hospitalized most commonly due to respiratory syncytial virus (RSV) compared with influenza and COVID-19 during a season with respiratory pathogen cocirculation.
Among younger children with respiratory syncytial virus (RSV), hospitalization and higher oxygen support were required compared with children who had influenza and COVID-19 in a season of cocirculation in respiratory pathogens, according to a new study from The Journal of Pediatrics.
Respiratory tract infections, including RSV and influenza, are not only a leading cause of hospitalization in children, but they are also associated with high mortality in children. Patients who are 2 years and younger and with underlying health conditions are at the greatest risk. However, the severity and presentation of RSV and influenza compared with COVID-19 infection have been areas with little research. The present study aimed to “compare demographic characteristics, clinical features, and outcomes of children with RSV, influenza, or [COVID-19] in hospitalized children.”
A retrospective cohort study was conducted in children who had been hospitalized with RSV, COVID-19, or influenza. Data were used from the CDC’s Emerging Infections Program Respiratory Virus Hospitalization Surveillance Network, which collects data about laboratory-confirmed influenza, RSV, and COVID-19 in the Denver metropolitan. The population of the study was limited to children admitted to Children’s Hospital Colorado from October 1, 2021, to April 30, 2022. These dates corresponded to a period in which all children needed to be tested for COVID-19 via a polymerase chain reaction (PCR) test on admission.
The cohort included both symptomatic and asymptomatic children who had at least 1 positive PCR test within 14 days of admission or during admission. Children who were 18 years or older at admission, had a discharge diagnosis of multisystem inflammatory syndrome, or were coinfected with influenza, RSV, or COVID-19 were excluded from the study. Children who had a known coinfection of other respiratory pathogens were not excluded.
Vaccination status was obtained from the Colorado Immunization Information System state vaccine registry data, electronic health record data, and primary care provider outreach. Partially vaccinated individuals were defined as a child who had only received 1 dose of a COVID-19 vaccine or received their second dose within 2 weeks of thei test date. Vaccinated individuals for influenza were defined as children 6 months and older who had received at least 1 dose of influenza vaccine for a season.
There were 899 inpatient stays from 867 children included in this study. There were 490 cases of RSV, 306 with COVID-19, and 51 with influenza; the children had a median (IQR) age of 1.5 (0.4-4.1) years.
Children with RSV were younger (median age, 1 year) compared with children with COVID-19 (2.7 years) and influenza (6.1 years). Children with RSV also had high rates of diagnosed bronchiolitis (69.2%), pneumonia (16.1%), asthma exacerbation (8.8%), and acute respiratory failure (9.2%). Among children with COVID-19, however, there were lower rates of bronchiolitis (15.0%), pneumonia (10.1%), and acute respiratory failure (13.7%). Further, those with influenzaa higher rate of diagnosed acute asthma exacerbation (21.6%), but lower rates of pneumonia (7.8%) and acute respiratory failure (7.8%).
Length of stay was longest for children with a diagnosis of RSV, with a median length of 4 days compared with 3 days for COVID-19 and influenza. The median age of children admitted to the intensive care unit (ICU) was 1.86 (0.44-5.96) years for COVID-19, 6.09 (2.05-8.68) years for influenza, and 0.56 (0.11-1.61) years for RSV. High flow use (22.9%) and noninvasive positive pressure ventilation (18.6%) were highest in children with RSV. There were also 2 deaths in children with RSV vs 1 death in children with COVID-19 and no deaths in influenza.
A multivariable log-binomial regression analysis found that the risk of ICU admission was highest in children with influenza (relative risk [RR], 1.97; 95% CI, 1.22-3.19). Risk of pneumonia (RR, 2.32; 95% CI, 1.54-3.52) and bronchiolitis (RR, 2.93; 95% CI, 2.28-3.78) were higher in children with RSV. Children with RSV were also more likely to have a length of stay longer than 4 days (RR, 1.40; 95% CI, 1.12-1.76) and require higher oxygen support (RR, 2.01; 95% CI, 1.54-2.63).
Data from this study were from a single center and retrospective, the study was limited to hospitalized children, and population-based estimates of disease burden could not be provided, marking limitations on generalizability of these findings.
The researchers concluded that a season with circulation of RSV, influenza, and COVID-19 contained hospitalizations that were primarily due to RSV and from respiratory illnesses, and required higher levels of oxygen.
Rao S, Armistead I, Tyler A, Lensing M, Dominguez SR, Alden NB. RSV, influenza, and COVID-19 hospitalizations in children in Colorado during the 2021-2022 respiratory virus season. J Pediatr. Published online May 16, 2023. doi:10.1016/j.jpeds.2023.113491