Epidemiological and Genetic Characterization of Human Metapneumovirus in Children - Tianjin, China, 2012-2024.

INTRODUCTION

Human metapneumovirus (HMPV) is a common cause of acute respiratory tract infections (ARTIs) in children. This study characterized the epidemiological patterns of pediatric HMPV infection in Tianjin from 2012 to 2024 and analyzed the genetic features of circulating strains to inform prevention and control strategies.

METHODS

Epidemiological data collected from 2012 to 2024 were retrospectively analyzed to describe the seasonality and age distribution of pediatric HMPV infection. Novel primers were designed for whole-genome sequencing, and circulating HMPV strains were characterized by subtype, recombination signals, amino acid substitutions, and glycosylation sites.

RESULTS

Pediatric HMPV infection in Tianjin showed seasonal and age-related patterns. The dominant type alternated between HMPV-A and HMPV-B every 1-3 years. Four major subtypes, A2b, A2c, B1, and B2, were detected, and A2c predominated in recent years. Genetic and molecular analyses identified recombination signals in several sequences, as well as amino acid substitutions and glycosylation sites.

CONCLUSION

This study characterized the epidemiological patterns of pediatric HMPV infection in Tianjin from 2012 to 2024. The newly designed primers supported whole-genome sequencing and analyses of viral genetic variation and recombination. These findings provide epidemiological and genomic evidence to inform HMPV prevention and control.