Murdoch team heads tick bite disease link

16/01/2019 - 12:07


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Researchers from Murdoch University have been granted $1.9 million, as they aim to demystify tick-related diseases in Australia.

Peter Irwin (left), Una Ryan and Charlotte Oskam are using their research on ticks to better understand diseases that are transferred to humans.

Researchers from Murdoch University have been granted $1.9 million, as they aim to demystify tick-related diseases in Australia.

A team of researchers at Murdoch University is leading a national initiative to help the thousands of Australians suffering from a poorly defined illness contracted from tick bites.

The National Health and Medical Research Council has announced a grant of $1.9 million to fund a four-year project based at Murdoch University, to be carried out in collaboration with the Australian Rickettsial Reference Laboratory in Geelong, the University of Queensland, Monash University, several hospitals in Sydney’s north, and the Australian Red Cross Blood Service.

The research team at Murdoch’s Vector and Waterborne Pathogens Research Group will aim to identify the causes of an illness currently known as DSCATT (Debilitating Symptom Complexes Attributed to Ticks).

Led by Peter Irwin, Una Ryan and Charlotte Oskam, the team has been studying Australian tick-associated infections since 2013. Their work has found no evidence of the bacteria causing Lyme disease in Australian ticks, meaning DSCATT is most likely caused by microorganisms unrelated to those causing Lyme disease.

However, thousands of Australians have reported chronic bite-related symptoms including skin issues, muscle and bone pain, fatigue, neurological, and cardiac abnormalities, leaving researchers in the dark about the cause of these symptoms.

Professor Irwin said the true scale of the issue was difficult to estimate, due to the lack of accurate information.

“Our goals are to characterise the symptoms that people may or may not develop, to search for the causes, search for the triggers, search for those infectious organisms in the people now, instead of the ticks,” Professor Irwin told Business News.

“At the moment there’s not even a good case definition in Australia as to what tick illness really is.”

Professor Irwin’s team has been supported for the past four years by grants from the Australian Research Council, unearthing organisms, viruses, and parasites present in ticks.

The NHMRC grant will allow researchers to transfer this knowledge into human trials, identifying whether the microorganisms they have found in ticks are the cause of human diseases.

“Our analyses over the last four years strongly suggest there are organisms in ticks that might cause tick-borne disease in Australia,” Professor Irwin said.

“If infectious disease contributes to DSCATT, this project will identify the tick-transmitted organisms responsible.

“However, we are keeping an open mind about its possible cause.

“Most importantly for the many thousands of sufferers around Australia, understanding the cause or causes is the first step towards informing management and treatment decisions in the future.”

Professor Irwin will work closely with hospitals in the Northern Sydney Local Health District, after finding a record number of patients presenting with tick bites in the area.

“We’re going to be relying on and requiring doctors all around the country to be sampling patients who present to them with acute tick bites, that’s the starting point for this research,” Professor Irwin said.

“In Sydney, the northern beaches area is a high tick area, and those hospitals, which include Manly, Mona Vale and Hornsby, see about 1,500 tick presentations in a 20-month period – that’s a huge number.”

The team will study the blood samples, skin biopsies and ticks collected from patients who present to emergency departments and GP clinics with tick bites, providing evidence to assist with correct diagnosis of patients presenting with DSCATT, and data on the range of symptoms.

Professor Irwin hopes the research will also identify the financial impact of the disease, noting it could not be estimated in Australia until more information was known.

In the US, treatment of tick-transferred Lyme disease was estimated to cost the healthcare system between US$712 million and US$1.3 billion a year, according to research by the Johns Hopkins Bloomberg School of Public Health.

“It really is very difficult to say what the economic burden is at the moment,” Professor Irwin said.

“Case definitions are not well understood, and many people who get ill from tick bites might not recognise it’s to do with the tick in the first place; they put it down to another illness.

“This is the first time this type of research has been conducted in Australia, so really it’s a clean slate.”


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