Genomic characterization of Lao Mobatvirus strains reveals host-associated clustering in Southeast Asian bats.

While members of the genus Orthohantavirus are well-established human pathogens, the zoonotic potential of bat-associated hantavirids, particularly those within the genus Mobatvirus, remains largely unresolved. To investigate the genetic diversity of these lineages in Southeast Asia, we conducted an expanded surveillance programme in Lao PDR from May 2023 to October 2025 in bat populations and wild animals from local wet markets. Using molecular screening and deep sequencing to characterize hantavirids from bat populations and wild animals from local wet markets, we identified 20 positive samples across four bat species, recovering coding-complete genomes for multiple novel variants. Phylogenetic analysis confirmed that these viruses clustered within Mobatvirus, resolving into two major subclades. The first subclade clustered with Quezon and Robina viruses found in fruit-eating bats. The second subclade further split into two lineages corresponding to Ðakrông and Xuân Sơn viruses, which are associated with trident and leaf-nosed bats, respectively. Despite the strong host association observed, the detection of these viruses in a wet market highlights this setting as a potential human exposure interface. These findings significantly expand the known diversity of mobatviruses in Laos and highlight the urgent need for serological surveillance in at-risk human populations to assess the potential for spillover.