A new deadly variant of the Hendra virus has killed a horse in West Wallsend, making it the first non-historical detection of the variant in a horse in NSW and the southernmost Hendra detection ever recorded.

A vet attended the West Wallsend property in response to a report that a horse showed neurological signs of infection. Photo supplied: CSIRO

Hendra virus is a zoonotic disease hosted by native flying foxes and can be transmitted to horses. Infected horses can pass it on to humans, and it can be fatal.

The detection of the virus was confirmed through testing at the NSW Department of Primary Industries’ (DPI) Elizabeth Macarthur Agricultural Institute laboratory and the Australian Centre for Disease Preparedness.

A vet attended the West Wallsend property in response to a report that a horse showed neurological signs of infection.

Although no other horses on the property showed any signs of illness, a district veterinarian from Hunter Local Land Services has issued an Individual Biosecurity Direction for any animals and people on and off the property for 21 days. 

CSIRO scientists recently uncovered the new genetic variant (HeV-g2) in flying foxes, confirming that the virus could be found across a broad region of Australia. 

The paper detailing the findings was published only days after the new variant was found in the West Wallsend horse.

After monitoring flying fox samples from 2013-2021, researchers found the new genetic type in flying foxes from Victoria, South Australia and Western Australia. Previous studies had only found the virus in flying foxes from Queensland and parts of NSW. 

Despite the virus being found in flying foxes across Australia, CSIRO scientist Dr Kim Halpin said the actual transmission of the disease from flying foxes to horses had still only been reported in Queensland and NSW.

Hendra Virus can be transmitted from Flying Foxes to horses and from horses to people. Photo supplied: NSW Government Environment

“Because Hendra Virus Genotype 2 is so genetically similar to the original Hendra virus, there is a potential risk to horses wherever flying foxes are found in Australia,” Dr Halpin said. 

“It’s important to note that Hendra has never been reported to spread directly from flying foxes to humans; it’s always been transmitted from infected horses to humans. So we expect this new genetic type would behave the same way.”

Equine Veterinarians Australia President Dr Steve Dennis said the findings were a reminder for horse owners or people who work closely with horses that measures must be in place to help reduce risks of infection.

“Owners and any people who interact with horses can reduce the risk of infection from Hendra virus and other zoonotic viruses through vaccination of horses or humans where available, wearing appropriate PPE, and seeking veterinary attention for sick horses,” Dr Dennis said.  

Another project called Horses as Sentinels, led by the University of Sydney and CSIRO, detected the same genetic type of Hendra virus earlier this year in samples collected from a horse in Queensland in 2015.

Minister for Agriculture and Northern Australia David Littleproud said these researchers were supported by Australian Government funding through the Biosecurity Innovation Program.

“Researchers from CSIRO and the University of Sydney investigated laboratory samples from horses which were previously suspected of having Hendra virus but had all tested negative,” Littleproud said.

“They found evidence of a novel virus, later confirmed as a new variant, and have now developed a diagnostic tool specific to detect it.”

This new test has been developed alongside vets and laboratories to protect horses and prevent any spillover of infection into humans.

Minister for Science and Technology Melissa Price said the new test would greatly benefit frontline equine workers and veterinarians, helping to reduce infection risks.

“This new test shows the practical application of this research and the science that underpins it, which could save lives,” Price said.

“Horses that may have tested negative under previous tests can now be confirmed as positive Hendra cases, which allows the risk to be managed through the use of personal protection equipment and appropriate biosecurity practices.”

More information for horse owners about the Hendra virus can be found at outbreak.gov.au.

Hayley McMahon

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