Children hospitalized with human metapneumovirus (hMPV) infection experience substantial clinical burden, especially infants and those with underlying comorbidities, according to a study.
“Simple bedside assessment of respiratory distress and hydration status may support early risk stratification and inform diagnostic-driven clinical management, including antimicrobial stewardship,” the investigators said.
This multicentre observational study was conducted across 11 tertiary care centres in Italy and involved a total of 312 children (median age 14 months) hospitalized for ≥48 h with laboratory-confirmed hMPV infection between January 2023 and June 2025.
The investigators analysed clinical features and compared these across co-infection categories and age groups. They also explored the association between prolonged hospitalization (>7 days) and paediatric intensive care unit (PICU) admission using logistic regression models.
Of the paediatric patients, 86.2 percent were <5 years of age, and 44.6 percent were infants aged <1 year. The majority (67.5 percent) required oxygen supplementation, while one in 10 (10.6 percent) were admitted to the PICU. [Pediatr Infec Dis J 2026;45:957-963]
Pathogens
Co-detected pathogens were found in nearly half of the patients (47.1 percent), with no significant differences in severity or outcomes. Notably, infants suffered more severe respiratory involvement, while older children were more likely to have underlying comorbidities, radiologic consolidations, and received antibiotic therapy.
“Almost half of [the] patients had a co-detected pathogen, but overall severity and outcomes were broadly comparable across mutually exclusive co-infection categories,” the investigators said.
“Bacterial co-infection was associated with higher rates of pharyngitis and moderate-to-severe respiratory distress, while viral co-infections, including respiratory syncytial virus, were not associated with worse outcomes,” they added. [BMC Pediatr 2025;25:709]
Adjusted models demonstrated the independent association of comorbidities, moderate-to-severe distress, dehydration, and higher base excess with prolonged hospitalization and PICU admission.
“These findings reinforce that hMPV is a clinically relevant cause of paediatric lower respiratory tract infection requiring hospitalization, particularly in early childhood,” the investigators said. [Clin Infect Dis 2021;72:108-117]
Wheezing
Fever and cough were the leading symptoms among hospitalized children, but wheezing and moderate-to-severe respiratory distress were common as well, according to the investigators.
Previous studies have established the association between hMPV infection and wheezing in early childhood, particularly among infants, with uncertainty regarding the long-term sequelae including recurrent wheeze or asthma. [J Infect Dis 2004;189:1388-1396; J Allergy Clin Immunol 2004;114:239-247; J Allergy Clin Immunol 2005;115:1311-1312; Immunol Allergy Clin North Am 2019;39:391-401]
“Our findings further support including hMPV in the differential diagnosis of infants presenting with acute wheeze during the respiratory virus season,” the investigators said.
Diagnostic uncertainty
Moreover, most radiologic findings were not specific. Consolidation was common, while pleural effusion was rare, consistent with findings from previous studies. [Pediatr Radiol 2017;47:1745-1750; Bol Med Hosp Infant Mex 2025;82:238-244]
In older children, the combination of consolidation and increased inflammatory markers may imitate bacterial pneumonia, resulting in diagnostic uncertainty and excessive antibiotic exposure.
“Further studies using formal predictive performance analyses are needed to compare these clinical markers with pathogen-based, laboratory-based, or combined risk stratification approaches,” the investigators said.
“If validated in future studies, these pragmatic clinical markers may support earlier risk stratification, guide management decisions, and inform future preventive strategies targeting both infants and medically vulnerable older children,” they added.