Lyme disease: the jury is still out
A national panel of medical experts has failed to resolve the controversy around claims Lyme disease is endemic to Australia, finding there was no conclusive evidence that Lyme disease-causing bacteria are present in Australian ticks.
In a result unlikely to douse claims Australia has Lyme disease, the Clinical Advisory Committee on Lyme Disease, convened by the Health Department, has concluded its work without being able to conclusively establish whether or not there is a local version of the debilitating North American ailment.
A progress report issued by the nation’s Chief Medical Officer, Professor Chris Baggoley, stated that “the conclusive finding of a bacterium that could cause Lyme disease-like syndrome in Australia has yet to be made”.
Great controversy surrounds the disease, which causes flu-like symptoms with associated fatigue, muscle pain and various neurological symptoms.
Several medical practitioners claim to have diagnosed the illness in patients who have never travelled to areas overseas where it is endemic, but positive laboratory tests have been disputed and its endemic presence in Australia is yet to be officially verified.
The Clinical Advisory Committee, established by Professor Baggoley in late 2012 following a request from the NSW Chief Health Officer Dr Kerry Chant has, in conjunction with the Health Department, outlined a program of research it hopes will shed further light on the issue.
In his progress report, Professor Baggoley provided a reassuring message for those convinced Lyme disease, or something like it, is present in Australia.
He said that, even though the Committee concluded its work on 15 July, “the Department’s interest in an Australian Lyme disease-like syndrome will be maintained”.
Research is being pursued in a number of areas, including continued attempts to determine if Lyme disease-causing Borrelia bacteria are present in Australian ticks, whether it might be present in other vectors including flies, sand flies and mites, determining the best laboratory test for the disease, and the appropriate form of treatment.
Professor Baggoley said the failure to identify an indigenous cause for Lyme-like syndrome was hampering efforts to develop an appropriate diagnostic test.
“The most appropriate laboratory testing algorithm has yet to be agreed,” he reported. “Doubts around the sensitivity and specificity of diagnostic tests available in Australia hinder the exploration of a potential Borrelia infection in Australian patients with no relevant travel history.”
The issue was further complicated by a lack of consensus around Lyme disease diagnosis, the Chief Medical Officer said, noting that although clinical presentation was a common basis for diagnosis there was no agreed case definition.
These issues had to be resolved in order to determine the most appropriate treatment, he added.
“Treatment of acute Lyme disease acquired from overseas endemic areas is generally agreed, and would comprise a short course of antibiotics, such as doxycycline,” Professor Baggoley said. “[But] the treatment for ‘chronic’ Lyme disease is more contentious, and the existence of this form of the disease is strongly disputed.”
The Health Department has established a Lyme disease website (http://www.health.gov.au/lyme-disease), which includes advice and assessments of the disease, as well as details of the research program mapped out by the Department and Committee and links to other reports and information.