Respiratory syncytial virus, influenza infection, and preexisting chronic conditions were associated with increased severity among children hospitalized with viral respiratory infections, according to a multicenter cohort study published in JAMA Network Open.
The study included 516 pediatric patients younger than 18 years hospitalized with respiratory symptoms between September 2023 and December 2024 at 12 pediatric infectious disease centers in Italy. The median age was 13 months, and 56% were male. Sixty-nine patients (13%) had at least one chronic comorbidity.
Severe disease, defined as a clinical severity score greater than 3, occurred in 34 patients (7%). Twenty-one children (4%) required intensive care unit admission, and three deaths (less than 1%) were reported, all in patients with influenza infection.
Respiratory viruses were identified in 95% of cases. The most common pathogens were rhinovirus/enterovirus (32%), adenovirus (26%), influenza virus (20%), coronavirus (14%), and respiratory syncytial virus (RSV) (13%).
Influenza infection and RSV infection were both associated with approximately four times the odds of severe disease compared with other viral infections, according to the researchers.
Children with influenza had higher intensive care unit (ICU) admission rates compared with those infected with other viruses (12% vs 2%) and longer hospital stays, averaging about 8 days compared with 6 days for other infections. RSV was associated with increased need for oxygen supplementation.
Preexisting chronic conditions were independently associated with severe outcomes. Cardiac or pulmonary diseases and congenital malformations were linked to approximately five times the odds of severe infection. Children with comorbidities were more likely to require ICU care (13% vs 3%) and had longer hospital stays.
Age was not independently associated with disease severity. Although ICU admission was more frequent among patients older than 60 months and oxygen therapy was more common in infants younger than 3 months, overall severity scores and mortality did not differ significantly by age group.
Coinfections were identified in approximately 40% of patients, including viral–viral and viral–bacterial combinations. However, coinfection was not associated with increased disease severity compared with single viral infections.
The findings indicate that viral etiology, particularly RSV and influenza, and underlying chronic conditions were the main factors associated with severe respiratory illness in hospitalized children.
Source: JAMA Network Open
