Discovery could help fight against deadly koala virus

"We've learned that the retrovirus is far more prevalent in New South Wales and Queensland koalas, compared to the southern populations in Victoria and South Australia," says Michaela Blyton. "Uncovering crucial patterns like these helps us learn how the disease is evolving, how it's spreading, and how we can contain the damage through anti-viral medication or koala breeding programs." (Credit: Vish K/Unsplash)

Virologists are a step closer to understanding a mysterious AIDS-like virus that is affecting koala populations differently across state lines.

The researchers have uncovered another piece of the puzzle in their quest to halt the retrovirus known as KoRV. It’s a condition strongly associated with diseases that cause infertility and blindness.

“We’ve learned that the retrovirus is far more prevalent in New South Wales and Queensland koalas, compared to the southern populations in Victoria and South Australia,” says Michaela Blyton, a postdoctoral research fellow at the Australian Institute for Bioengineering and Nanotechnology at the University of Queensland.

“Uncovering crucial patterns like these helps us learn how the disease is evolving, how it’s spreading, and how we can contain the damage through antiviral medication or koala breeding programs.”

Koala numbers have fallen rapidly over the past decade due to widespread land clearing, climate change induced weather events, and disease.

Blyton’s research has already established the link between KoRV and chlamydia, cystitis, and conjunctivitis, which suggests the virus weakens the animal’s immune system.

In the latest research in the Proceedings of the National Academy of Sciences, Blyton and Keith Chappell, an associate professor in the School of Chemistry and Molecular Biosciences, found KoRV is only present in the genome of koalas from Queensland and NSW while those in Victoria and South Australia appear to be free of the numerous subvariants.

This discovery strengthens the theory that the virus could be contributing to heightened disease levels in northern koala populations, Blyton says.

“Our previous work showed a definite link between KoRV and chlamydia in koalas, and these latest findings indicate that northern koalas should be treated very differently to southern koalas.

“It might mean that in the short term, koala relocations in the north are limited so we’re not introducing new virus subtypes into healthy populations.”

A final solution may be some time away, but the latest findings are a big step towards nullifying the threat posed by disease, Blyton says.

“Ultimately, we might see some kind of anti-viral treatment, or at least improvements to koala breeding programs, but for now this is great news for a species facing threats on multiple fronts.”

Source: University of Queensland