Clinical Features and Outcomes of Severe Pneumonia in Pediatric Human Metapneumovirus Infections.

OBJECTIVE

Human metapneumovirus (hMPV) is a significant agent of respiratory infections in pediatric populations. Despite its global prevalence, the epidemiological characteristics and clinical burden of hMPV infections remain insufficiently recognized. This study aimed to evaluate the clinical features and outcomes of severe pneumonia among children hospitalized with hMPV infection.

MATERIALS AND

METHODS

This retrospective study analyzed pediatric patients diagnosed with hMPV infection at Hacettepe University İhsan Doğramacı Children's Hospital between January 2018 and December 2024. Demographic, clinical, and laboratory data were systematically reviewed to identify factors associated with severe pneumonia.

RESULTS

A total of 116 children with hMPV infection were included, of whom 17.2% (n = 20) developed severe pneumonia requiring respiratory support. Notably, 85% (n = 17) of these severe cases occurred in children under 5 years of age, and 90% (n = 18) had underlying chronic medical conditions. In cases of non-severe pneumonia, hMPV monoinfection was identified in 74.8% (n = 56) of patients, while 25.2% (n = 19) had coinfections, most commonly involving rhinovirus (14.7%, n = 17). Conversely, among severe pneumonia cases, hMPV monoinfection was predominant (90%, n = 18), with coinfections detected in only 10% (n = 2). A substantial increase in hospitalization rates was observed in 2024 (36%), potentially indicating an evolving disease severity. Additionally, 1 infection-related mortality (3.1%) was recorded in an older pediatric patient.

CONCLUSION

Severe pneumonia in this single-center series was mainly linked to hMPV monoinfection, with hospitalizations rising in 2024. These findings underscore the clinical impact of hMPV and the need for strengthened surveillance and timely diagnostics, while informing preventive strategies, including future vaccines/therapeutics.