Key points
- Australian researchers have discovered a new bat-borne virus, Salt Gully virus, during routine wildlife surveillance in Queensland.
- The virus is a novel member of the henipavirus family and only the fourth ever isolated, enabling further study into its potential risks to humans and animals.
- CSIRO's expertise helped identify and grow the virus, boosting Australia's early detection of emerging diseases.
Early one cold July morning in bushland near Boonah, south east Queensland, a small team of researchers quietly moved around tarps laid out on the ground beneath a roost of flying foxes. They were collecting urine samples from the forest floor, part of routine surveillance for Hendra virus - part of Australia's ongoing efforts to monitor emerging diseases in wildlife.
Lead researcher Jennifer Barr, an experimental scientist at CSIRO's Australian Centre for Disease Preparedness (ACDP) , was part of the field team.
"Collecting bat urine samples is a complex process. First, we need to observe where the bats are roosting during the day and where they will be most likely to return after feeding through the night.
"Once we know where the bats are likely to go, we have to prepare ourselves for collection. We wear full body personal protective equipment. It's essential, but also can get pretty hot and uncomfortable, so you want to be ready to go once your gear is on.
"That's when the tarps come out. We drape them under the roosting bats in the evening just before they fly out for feeding, aiming to get the tarps laid out as flat as possible. The team returns to the collection site at sunrise, once the bats have returned from feeding all night, and collect the urine before it evaporates or dries out.
"We didn't know it at the time," Mrs Barr said. "But some of those samples held a virus that had never been described before."
The journey of discovery
Back in the lab, initial tests showed a sample was negative for Hendra virus. But further analysis revealed genetic traces of something unusual.
"We discovered a genetic sequence that indicated the sample contained an entirely new henipavirus, so we knew something was there. But despite our best efforts at the time, we couldn't grow it," Mrs Barr said.
The team didn't give up.
"It took a long time, but we tried different bat cell lines until we were able to grow the virus." 
It's not every day researchers discover an entirely new virus.
"It was very exciting! The day we isolated and grew the virus was a significant milestone."
The team named it Salt Gully virus after the location where it was found; a novel member of the Henipavirus family.
What makes Salt Gully Virus different?
Salt Gully virus is only the fourth henipavirus to be isolated, meaning it can be grown in a lab under secure conditions. Cultivating the virus enables further work to investigate the virus's ability to cause disease in humans and animals.
"Now that we've identified the virus, diagnostic tests can be developed. This means if a spillover from bats and disease outbreak were to occur, we'd have the tools to detect this virus earlier – enabling timely measures to prevent further spread," Mrs Barr explained.
Henipaviruses are a group of viruses carried by fruit bats, some of which, like Hendra and Nipah, can cause serious disease in animals and humans.
CSIRO has a long history working with henipaviruses. In 1994, CSIRO scientists isolated and identified Hendra following the first deadly outbreak in Queensland. In 2012, CSIRO, working with partners, developed the world-first commercial Hendra vaccine for horses.
Salt Gully virus belongs to the henipavirus group but appears to behave differently.
Early findings show Salt Gully virus does not rely on the same cell receptors as Hendra or Nipah viruses, suggesting that we can't predict how this virus will affect other species. Importantly, the discovery of Salt Gully virus does not change the current health risk posed by bats. The existing Hendra vaccine for horses remains effective, and no changes to biosecurity protocols are recommended.
Why it matters
The discovery of Salt Gully virus highlights the importance of long-term surveillance and virus discovery in wildlife.
"It's a reminder that viruses can circulate quietly in nature for years without causing disease," said Mrs Barr.
"By identifying and studying them early, we can better prepare for future outbreaks and reduce misinformation," she added.
Flying foxes, which carry Salt Gully virus, are a protected species and play a vital role in pollinating native trees and spreading seeds. CSIRO's research supports a balanced approach to biosecurity, protecting both public health and Australia's unique ecosystems.
Looking ahead
Mrs Barr and the team are continuing to study Salt Gully virus to better understand its characteristics and potential risks. The research, published in the journal Emerging Infectious Diseases , adds to Australia's growing knowledge of bat-borne viruses and strengthens our ability to respond to emerging threats.
"This work is about preparedness," said Mrs Barr.
"It's about understanding what's out there, so we're not caught off guard."
