Clinical characteristics and risk factors for severe community-acquired pneumonia in hospitalized children with human metapneumovirus infection in Shanghai: a retrospective cohort study.

The severe group comprised 28.0% of the cohort.

Key clinical manifestations included fever (98.0%), cough (97.6%), wheezing (56.5%), and pulmonary crackles (84.6%).

Compared to the mild group, the severe group had significantly higher rates of premature birth, wheezing, elevated inflammatory markers (NLR > 1, PCT > 1 ng/mL, CRP ≥ 50 mg/L), and co-infection with Mycoplasma pneumoniae (mycoplasma pneumoniae) (all P < 0.05).