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 evalu ate 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) devel oped 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 medi cal 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 predom inant (90%, n = 18), with coinfections detected in only 10% (n = 2). A substantial increase in hospi talization 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 monoin fection, with hospitalizations rising in 2024. These findings underscore the clinical impact of hMPV and the need for strengthened surveillance and timely diagnostics, while informing pre ventive strategies, including future vaccines/therapeutics.

Cite this article as: Aykac K, Develi ZT, Onel D, et al. Clinical features and outcomes of severe pneumonia in pediatric human metapneumovirus infections. Turk Arch Pediatr. Published online December 29, 2025. doi:10.5152/TurkArchPediatr.2025.25295.