Clinical characteristics, co-detection patterns and prognostic risk factors of human metapneumovirus infection in children: a retrospective study

Objective To investigate clinical characteristics, co-detection patterns, and prognostic risk factors of human metapneumovirus (hMPV) infection in children. Methods Retrospective study of 621 children with laboratory-detected hMPV infection. Clinical data, laboratory indicators, and co-detection status were analyzed. Multivariate logistic regression identified independent risk factors for severe pneumonia. Results Median age was 3.50 years (IQR 1.75–4.75). Of 621 patients, 399 (64.3%) had Single-detection and 222 (35.7%) co-detection, with viral-viral co-detection dominant (68.9%) and rhinovirus the most common co-pathogen (39.6%). Only platelet count and aspartate aminotransferase differed significantly between groups (both P<0.01), with all inflammatory markers improving post-treatment (all P<0.001). Viral-bacterial co-detection was associated with longer hospitalization (median 6.5 days) and higher severe pneumonia rate (14.5%, both P<0.01). Multivariate analysis identified Streptococcus pneumoniae co-detection (aOR=8.43, 95%CI:1.50–47.32), prolonged fever duration (aOR=1.19, 95%CI:1.02–1.38), and procalcitonin ≥0.5 ng/mL (aOR=4.27, 95%CI:1.76–10.33) as independent risk factors for severe pneumonia. Older age (3–5 years: aOR=0.20; >5 years: aOR=0.03) showed significant protective effects. Conclusion hMPV infection is most prevalent in preschool children. Viral-bacterial co-detection was associated with worse clinical outcomes. S. pneumoniae co-detection, prolonged fever, and elevated procalcitonin were independently associated with increased risk, while older age was associated with reduced risk. These findings support early risk stratification and targeted intervention.