Tony Eastley: A team of Australian researchers claim to have made a breakthrough in treating the debilitating arthritis triggered by the Ross River virus.

The disease is the most common mosquito borne virus in Australia and can cause painful inflammation and arthritis.

The research published in the latest Journal of Infectious Diseases offers new hope and some relief for sufferers as Lindy Kerin reports.

Lindy Kerin: Ross River Virus is now found across the country and affects between five and eight thousand Australians every year.

About a third of those infected will suffer severe aches and pains in their joints.

Professor Suresh Mahalingam and his colleagues at the University of Canberra have been studying Ross River virus for the past four years.

Now they've identified the cell responsible for causing the joint inflammation and tissue damage.

Suresh Mahalingam: Many of the viruses in the world, not necessarily just Ross River, but lots of other viruses, like HIV, Dengue, flu and many more actually are known cause rheumatic symptoms associated with joint arthritis.

What we do not know is how did they do that, so unfortunately there are not many excellent models available to understand the mechanism of how these viruses trigger this sort of disease. So we have Ross River as an excellent model, it's the only model available world wide to help us understand how these viruses trigger these sort of conditions.

So that is my focus, so that is the implications of our research in terms viral infections in general.

Lindy Kerin: And what have you found?

Suresh Mahalingam: Using our animal model, what we found is that when the virus infects, it triggers the recruitment of cells, these particular cells are called macrophages.

They actually congregate in the joint tissues and the muscle tissues and once they are there, they tend to pump out a lot of toxic proteins and those toxic proteins are responsible for the downstream inflammatory response or condition called arthritis, but they also contribute to the development of tissue damage.

So what we have done is that by actually depleting the cells in the animal model and then we give this virus into the animals, we actually have virus replicating to high levels just as they would in animals which are not depleted of these cells but these animals are quite healthy, they don't develop any signs of disease whatsoever.

Lindy Kerin: Professor Mahalingam says his team trialled an anti-inflammatory drug already on the market, and have had some positive results.

Suresh Mahalingam: It's called Sulfasalazine. This drug actually is used for the treatment of Crohn's disease and colitis. And we have utilised this drug in the animal model and showed clearly that it can actually ameliorate arthritic condition in mice.

Lindy Kerin: The research could have widespread implications for the treatment of other viral arthritis around the world.

Professor Mahalingam says Ross River virus is closely associated to another mosquito borne disease called Chikungunya, which infects millions of people in India.

He hopes his research will reduce the severity of the disease.

Suresh Mahalingam: This is not just for Ross River sufferers as well, it could also be extended to sufferers of other viral arthritis found in other parts of the world and also in India at the moment, there are about six million cases of virus that triggers viral arthritis called Chikungunya virus and also outbreaks in Europe and Italy and so on. So this could be extended to those patients as well.

Tony Eastley: Virologist Professor Suresh Mahalingam from the University of Canberra speaking to AM's Lindy Kerin.