The difference in clinical features and prognosis of severe adenoviral pneumonia in children of different ages

This study aims to analyze the difference in clinical features and prognosis of severe adenovirus pneumonia (SAP) in children of different ages and analyze the risk factors for poor prognosis in children with SAP. A retrospective observational study was performed to describe the clinical features and analyze the risk factors for death and postinfectious bronchiolitis obliterans (PIBO) in 303 children hospitalized with SAP from January 2015 through to January 2020. The participants were divided into four age groups: <6 months (n = 25, 8.3%); 6-12 months (n = 98, 32.3%); 12-36 months (n = 118, 38.9%); and >36 months (n = 62, 20.5%). Fever rate, peak, and duration were the lowest in the <6 months group, while no significant difference was found among other age groups. Serum levels of lactate dehydrogenase and a load of adenovirus were the lowest in the <6 months group, and the highest in the 6-12 and 12-36 months groups, respectively. A total of 80.9% of patients recovered, 3.3% of patients died, and 15.8% of patients were diagnosed with PIBO. The mortality rate showed no significance between age groups. The >36 months group had the highest recovery rate and the lowest incidence of PIBO, while the 6-12 months group had the lowest recovery rate and the highest incidence of PIBO. Independent risk factors for PIBO among all participants from the four groups were invasive mechanical ventilation, administration of intravenous steroids, duration of fever, and male gender. Independent risk factors for death among all participants from the four groups were hypercapnia, low albumin levels, and invasive mechanical ventilation. Risk factor analysis of different ages was not possible due to the limited sample size. The morbidity, clinical features, and prognosis of SAP are affected by children's ages. Pediatric patients with a longer duration of fever, hypercapnia, low serum albumin levels, invasive mechanical ventilation, and intravenous steroids use are more likely to develop a poor prognosis in SAP, especially if the patient is male.