Lyme disease not a local-grown problem: pathologists
The peak body of pathologists has dismissed controversial claims that debilitating Lyme disease is endemic to Australia, and has warned patients and doctors to be wary of positive diagnoses based on tests carried out by non-accredited laboratories.
In a Position Statement bound to incense those who insist people in Australia are catching Lyme disease from native ticks, the Royal College of Pathologists of Australasia (RCPA) has declared there is no evidence that the disease-causing bacteria Borrelia spp is carried by local ticks.
“There is considerable misinformation regarding Lyme disease in Australia, sparking an ongoing debate as to whether the disease is present both here and in New Zealand,” RCPA spokesman Dr Stephen Graves said. “So far, research has failed to prove the presence of Lyme disease-causing Borrelia in ticks native to Australia and New Zealand.”
Lyme disease is the most common tick-borne disease in the northern hemisphere and is caused by Borrelia bacteria entering the body through a tick bite. Initial symptoms include headache, fever and fatigue, and around 70 per cent of those infected develop a rash.
The infection responds to antibiotics, but if left untreated it can lead to more serious problems in the heart, joints and central nervous system.
Until recently, the only diagnosed cases in Australia involved people who had returned to the country after being bitten by a tick in countries where the disease in endemic.
But several local doctors claim to have diagnosed the disease, including in patients who have never left the country.
Both Bellingen GP Dr Trevor Cheney and Melbourne GP Dr Geoffrey Kemp told ABC radio, in a show broadcast in May 2013, that they had diagnosed cases of Lyme disease in their patients.
“The bottom line is these are very sick people, they have been turned away, nothing was working, and they got better,” Dr Cheney said. “I don't have any particular commitment to the L-word, Lyme, I don't give a damn. What I do know is that I've been in general practice of 15 years and I am motivated by a deep sense of guilt and shame for failing so many people.”
Dr Cheney’s colleague Dr Gull Herzberg told the ABC he was seeing an increasing number of patients presenting with Lyme disease-like symptoms.
“I can't tell you that it's because they have Lyme,” he said. “It looks like Lyme, they've got Lyme in the laboratory, I give them a Lyme treatment and they get better. I would like someone to come and pull that apart and show me well, why else is this person getting better.”
But so far no National Association of Testing Authorities-accredited lab has diagnosed Lyme disease in patients who have never left the country.
Instead, doctors have controversially used laboratories overseas to confirm the Lyme diagnosis, and the RCPA has warned these results cannot be relied upon.
Many of the tests performed by non-NATA/RCPA-accredited laboratories have not been validated for use in diagnosing Lyme disease, as evident in consensus documents published by European and North American professional bodies, pathologists cited by the RCPA said.
“Until advised otherwise, no confidence can be attached to the results of tests undertaken by non-NATA/RCPA-accredited laboratories,” Dr Graves said. “The referring doctor and their patients must be advised that the results of these tests may result in inaccurate diagnoses.”
The ABC reported that many Australian samples have been sent to testing at California laboratory Ingenex, which claims to be able to detect Lyme disease when other laboratories cannot.
But University of Western Australia infectious diseases expert Professor Miles Beaman said he was sceptical.
“The reason why enthusiasts of Lyme disease send specimens overseas is because Australian laboratories who participate in quality assurance schemes supervised by national bodies have not been able to detect any positives,” Professor Beaman told the ABC. “So they refer the tests overseas, at great expense, to laboratories which are not subject to the same stringent licensing controls as Australian laboratories have.”
He said proven clinical cases of Lyme disease were “actually very recognisable. There are very clear primary, secondary and tertiary phases of the disease”.
“So the vague symptoms that patients who use overseas tests to diagnose their problems are not typical of Lyme disease, they are just typical of any other condition. In fact being alive really is what they are consistent with.”
Aside from the actual diagnosis of the disease itself, one of the big concerns is that often the treatment prescribed is a sustained course of antibiotics.
Infectious disease physician Professor Peter Collignon warned that prolonged use of antibiotics such as ceftriaxone, considered a ‘last-line’ antibiotic, could increase resistance in the broader population, reducing their effectiveness.
Dr Graves said such treatment was not recommended.
“Long-term antibiotic treatment for Lyme disease is considered inappropriate by expert European and North American bodies, and is not advocated in Australia and New Zealand,” he said. “Any beneficial effect a patient experiences from such treatment is unlikely to be a result of the antibacterial activity of the antibiotic.”
The nation’s Chief Medical Officer Professor Chris Baggoley has established a Clinical Advisory Committee on Lyme Disease to investigate the possibility that there is a local variant of the infection, but Dr Graves said that so far there was no evidence this was the case.
“If a definitive, endemic Australian case of Lyme disease can be confirmed by culture or PCR in a patient who has never left Australia, the issue of endemicity of Lyme disease in Australia will have been settled,” he said. “As of January 2014, there is no evidence of Lyme disease borne endemically in Australia or New Zealand.”
Published: 15 Apr 2014