Clinical Features and Predictors of Severity in Children Hospitalized With Human Metapneumovirus: A Multicenter...

Human metapneumovirus (hMPV) is an important cause of pediatric lower respiratory tract infection. We describe the epidemiology and clinical severity of hMPV-associated pediatric hospitalizations in Italy in the post-coronavirus disease 2019 period and identify predictors of pediatric intensive care unit (PICU) admission and prolonged hospitalization.

We conducted a multicenter observational study across 11 tertiary care centers in Italy. Children hospitalized for ≥48 hours with laboratory-confirmed hMPV infection between January 2023 and June 2025 were included. Clinical features were analyzed overall and compared across co-infection categories and age groups. Associations with prolonged hospitalization (>7 days) and PICU admission were evaluated using logistic regression models.

A total of 312 children were hospitalized with hMPV infection (median age 14 months, interquartile range 5-36); 86.2% were <5 years, and 44.6% were infants <1 year. Oxygen supplementation was required in 67.5% of cases, and 10.6% were admitted to the PICU. Co-detected pathogens were identified in 47.1% of cases, without significant differences in severity or outcomes. Infants experienced more severe respiratory involvement, whereas older children more frequently had underlying comorbidities, radiologic consolidation and received antibiotics. In adjusted models, comorbidities, moderate-to-severe respiratory distress, dehydration and higher base excess were independently associated with prolonged hospitalization and PICU admission.

In the post-coronavirus disease 2019 period, hMPV remains a clinically relevant cause of pediatric hospitalization, particularly among infants and children with underlying medical conditions. Simple bedside assessment of respiratory distress and hydration status may support early risk stratification and inform diagnostic-driven clinical management, including antimicrobial stewardship.