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Study finds key to easing symptoms of Ross River
AUSTRALIAN researchers believe they have made a major breakthrough in combating the debilitating arthritic effects of Ross River virus after pinpointing the cells and proteins that cause the symptoms.
Virologist Suresh Mahalingam and his University of Canberra team have identified the immune cells, called macrophages, that cause arthritis in Ross River virus sufferers and have found drugs to combat the symptoms.
"This is a world-first in terms of identifying the mechanism of the disease, simply because we have an animal model to do this research," Professor Mahalingam said. "By using this model, we have identified a drug to ameliorate the symptoms."
The drug, sulfasalazine, is already commercially available to treat other illnesses, such as Crohn's disease.
While it could not eliminate the chance of contracting the virus, the treatment could "greatly reduce its severity", Professor Mahalingam said.
The virus is Australia's most common mosquito-borne disease and is closely linked to the viral disease chikungunya.
Chikungunya has recently infected six million people in India, more than 300,000 people in French territories of the western Indian Ocean and about 200 people in Italy.
It was the first epidemic of a tropical disease in a developed European country.
"In the past three years, there has been a massive outbreak of this virus in Asia as well as Europe," Professor Mahalingam said. "As a result, there is a global interest in how these groups of viruses actually cause disease."
In the UC study, sulfasalazine helped mice injected with Ross River virus recover from disease by inhibiting the proteins secreted by macrophages in response to the viral attack.
That immune response can cause arthritic inflammation lasting between three and six months in people with the virus.
"The immune system is activated as a result of infection to counteract the virus, but while it is trying to do that, there's a thing that's called friendly fire," Professor Mahalingam said.
Another drug, under development in collaboration with an Italian company, was also tested and proved even more effective, knocking out one key protein without affecting the others fighting the virus.