Phylodynamics of human metapneumovirus and evidence for a duplication-deletion model in G gene variant evolution.

Background: In December 2024, human metapneumovirus (hMPV) gained global attention amid rising cases in Chinese hospitals, prompting a World Health, Organization (WHO) statement indicating case numbers remained within expected ranges. To assess whether a variant of public health concern was emerging and to examine global hMPV phylodynamics, we conducted a genomic surveillance study in western Washington State.

Study Design: We sequenced hMPV genomes from inpatient and outpatient samples collected between 2021 and 2025 in western Washington State and constructed phylogenomic and phylodynamic trees.