Novel Hendra virus variant detected by sentinel surveillance of Australian horses

Abstract A novel Hendra virus (HeV) variant was identified from a horse that suffered acute fatal disease consistent with HeV infection through multidisciplinary and interagency syndromic sentinel surveillance research. Novel molecular assays for HeV detection are described in the light of routine testing failure. In silico analysis of the variant receptor-binding protein in comparison with prototypic HeV supported that the monoclonal antibody m102.4 used for post-exposure prophylaxis, as well as the equine vaccine, should be effective also against this novel variant. Similarity of this virus (99%) to a partial sequence detected from a South Australian grey-headed flying fox, along with case exposure to this species in Queensland, suggests the variant circulates at least across the range of this flying fox species. Investigation into HeV diversity, comparative kinetics and pathogenicity, reservoir-species associations, viral–host co-evolution and spillover dynamics should be prioritized. Biosecurity practices should be updated to appreciate HeV spillover risk across all regions frequented by flying foxes regardless of species. Article Summary Line A novel variant of Hendra virus was discovered and isolated from an Australian horse with fatal disease.