Respiratory viral detection and severity risk factors in hospitalized children with community-acquired pneumonia following relaxation of COVID-19 non-pharmaceutical interventions: a 20-month retrospective cohort in Guilin, China

Background After the withdrawal of COVID-19 non-pharmaceutical interventions (NPIs) in China, we characterized the demographic, clinical and virological features of virus-positive community-acquired pneumonia (CAP) in children younger than 5 years during the post-NPI period. Methods We conducted a retrospective study using electronic medical records from a tertiary hospital in Guilin, China. We enrolled 1,255 children hospitalized with CAP between December 2022 and July 2024. All participants were tested for five respiratory viruses: respiratory syncytial virus (RSV), parainfluenza virus (PIV), adenovirus (ADV), influenza-A (Flu-A) and influenza-B (Flu-B). Results Of 1,255 hospitalized CAP cases, 681 (54%) were virus-positive, including 112 (16% of virus-positive cases) who met severe CAP (SCAP) criteria. RSV showed the highest detection rate (23%, 292/1,255), followed by PIV, ADV, Flu-A and Flu-B; detection patterns differed significantly across age groups. Bacterial co-detection was common among virus-positive cases. Multivariable analysis identified bacterial co-detection (OR 1.90, 95% CI [1.12–3.23]), wheeze (OR 1.59, 95% CI [1.02–2.49]), and chronic comorbidities (OR 2.44, 95% CI [1.5 7–3.78]) as independent risk factors for severe disease, whereas rhinorrhoea was associated with reduced severity (OR 0.43, 95% CI [0.27–0.66]). Conclusion Among virus-positive cases, RSV was the most frequently detected virus in children younger than 5 years hospitalized with CAP during the post-NPI period in Guilin, China. Early identification of independent risk factors for SCAP may help clinicians’s recognition high-risk children promptly.