Novel variant Hendra virus genotype 2 infection in a horse in the greater Newcastle region, New South Wales, Australia.

The research paper discusses the first detection of a new variant of the Hendra virus in a horse, south of Newcastle, New South Wales, Australia, extending the known range of the virus by around 95 kilometers. The paper underlines the importance of vigilant monitoring and research to manage and understand the risks of such emerging pathogens.

Discovery of the New HeV Variant

In this study, the researchers made the discovery of the novel variant Hendra virus genotype 2 (HeV-g2) in a horse in October 2021. This marks the first contemporary detection of this variant, made through a veterinary priority disease investigation near Newcastle, New South Wales, Australia. This find came about as part of regular surveillance of priority diseases in veterinary science. The researchers were able to identify this variant due to recent improvements in Hendra virus diagnostic assays, achieved after the variant was retrospectively identified in 2015.

The Affected Horse and Extent of Infection

• The infected horse was in extremely poor condition and had to be euthanized.
• This incident demonstrates the most southern detection of a HeV spill-over, extending the southern limit of known Hendra virus cases by approximately 95 kilometers.
• Interestingly, the event happened near a significant urban center, which housed a wide range of horse types, purposes, and husbandry methods. The HeV vaccination rates in this region were low.

Outbreak Response and Management

• The detection of the HeV-g2 variant sparked an urgent multi-agency response. The process included a risk assessment, monitoring of 11 exposed people, and the implementation of biosecurity measures for at-risk animals.
• Despite the swift response, no additional cases in humans or animals were identified.

Importance of One Health Approach

This research underscores the effectiveness of the One Health approach, which emphasizes the interconnectedness of human, animal, and environmental health, in tackling emerging infectious diseases. It also draws attention to the need for further research, particularly in understanding risk perception and strategizing public engagement. This research becomes particularly critical when pet owners have to deal with the death of companion animals and potential human exposure to high-risk viruses.

Significance of Ongoing Research and Surveillance

The occurrence and location of this spill-over event diverged from that of the prototype HeV (HeV-g1). This divergence underscores the benefits of proactive One Health surveillance and research endeavours that enhance understanding of the dynamic transmission and spill-over risks of both HeV genotypic lineages, as well as related but divergent emerging pathogens.