Distribution, diversity, and biological risk of henipavirus from a One Health perspective: A mini-review

The genus Henipavirus includes highly lethal zoonotic pathogens such as Nipah virus (NiV) and Hendra virus (HeV), both classified as Risk Group 4 agents and recognized as priority pathogens by the World Health Organization (WHO). Recent International Committee on Taxonomy of Viruses (ICTV) taxonomic revisions restrict the genus to only bat-borne viruses, with multiple novel henipaviruses identified recently. In this mini-review, we synthesize current knowledge on henipavirus distribution, diversity, and biological risk. Eight members of the genus have been identified to date. HeV remains geographically confined to Australia, whereas NiV circulates in several countries across South and Southeast Asia. With the exception of HeV and NiV, all other members have been detected solely in bats. Phylogenetic analysis confirms their common ancestry; however, unlike HeV, NiV exhibits marked geographic structuring in its lineage divergence. To help assess relative risk, we summarize henipavirus infection spectrum, receptor usage patterns, and pathogenicity, along with the current state of prophylactic and therapeutic interventions, thereby providing a foundation for evidence-based risk classification. Critical knowledge gaps persist for recently discovered viruses, including the lack of live virus isolates and corresponding in vivo data from animal models, precluding definitive risk assessment. Given the increasing frequency of spillover events—highlighted by the 2026 Nipah outbreaks in India and Bangladesh—there is an urgent need to enhance surveillance and characterization of henipaviruses within a One Health framework. This review provides a consolidated reference for understanding the biological risks posed by henipaviruses and aims to inform preparedness efforts against future threats posed by these viruses.