• Scientists study ticks to determine what pathogens they can transmit to humans. (AFP)
As debate rages in Australia about tick-borne illnesses, Insight asks: how much can a bite from one of these critters affect our health?
By
Madeleine King

Source:
Insight
24 Oct 2016 - 3:21 PM  UPDATED 6 DAYS AGO

In September 2015, Vivianne Vandenberg went bushwalking with friends on the picturesque NSW South Coast. When they returned back to the house they were renting, she found a tick had lodged itself into her upper leg. The women debated what to do, before settling on a method of extraction and pulling the critter fully free from Vivianne’s body.

“Julie got the whole tick out and we were very pleased with that because we thought great, we've got the head out, fine,” recalls Vivianne.

But three minutes later, she began to feel oddly warm. Her vision went next, and the last thing she remembers is falling to the ground and vomiting. Her friends, two of whom were nurses, briefly lost her pulse before Vivianne came to with slurred speech waiting for an ambulance to arrive.

She’d been bitten by a paralysis tick: a species responsible for 95 per cent of all human tick bites on Australia’s eastern seaboard and thought to be the most likely vector of illness-causing pathogens. Of the 70 – 75 tick species in the country – 65 of which are uniquely Australian – only 10 are thought to bite humans.

The bite to Vivianne had triggered an anaphylactic reaction and now even a nibble from a baby tick is potentially fatal to the 58 year-old. So extreme is her reaction, she is concerned about living on Australia’s east coast where the paralysis tick is endemic. 

Vivianne is part of a growing number of Australians whose health has been severely impacted by the humble bite of a tick. Around 1000 people in Sydney’s Northern Beaches currently suffer from a mammalian meat allergy, brought about by the bite of a tick in their leafy surrounds. Others, meanwhile, have developed what appears to be a tick-borne illness whose symptoms resemble Lyme disease found overseas.

The latter’s experience can be crippling. Elite Australian tennis player Samantha Stosur knows the full effect of Classical Lyme disease, when she was bitten by a tick, in Paris she suspects, around the time she was training for Wimbledon in 2007. Her glands swelled, a rash spread across her body, and she developed extreme tiredness, headaches and body aches. A few weeks later and back in the US, she had developed viral meningitis.

Many weeks and four doctors later, Stosur was finally diagnosed with Lyme disease. With two months of oral and IV antibiotics she was on her way to recover, but it would be a long journey.

“Eventually when the doctors told me it was okay for me to come home, I came home and started really slowly with my training again which was about a twenty minute walk,” she tells Insight’s Jenny Brockie. “So that was quite, you know, a different scope of what I was used to.”

If Stosur had sought diagnosis in Australia, she may have run into some scepticism. While doctors here do recognise the existence of Lyme disease from tick bites contracted overseas, such a diagnosis does not extend to Australians who present with symptoms resembling Lyme disease from a bite in the country.

A couple of years ago, Jesse Chadwick was on the NSW Central Coast with his family bushwalking among sand dunes and marshland. Bugs and sand flies were everywhere, but they brushed them away without much notice. After flying to New Zealand for a holiday not long after, Jesse was hit with a wave of illness: fevers, chills, fatigue. “They started subsiding after about ten days,” says Jesse, “and then when I got back to Australia, I could never actually really shake it. It was just always something coming towards me.”

The fatigue increased and he developed headaches, muscle and joint pains, and digestion problems. He thinks he visited more than 16 doctors before finally finding one who specialised in chronic fatigue syndrome willing to see him.

“The chronic fatigue doctor said: ‘I don't think you've got chronic fatigue, I think you've got a Lyme-like illness.”

According to the CSIRO, there are only three tick-borne illnesses in Australia: Queensland tick typhus, Flinders Island spotted fever and Q fever. The difficulty in diagnosing Lyme disease in Australia comes down to the fact that species of the Borrelia bacteria that causes Lyme have never been detected in native ticks, despite extensive studies.

“There's now been four large studies done over the last twenty years looking at many, many ticks in Australia, thousands of ticks, and none of them have found Lyme disease bacteria in the ticks,” says Professor Stephen Graves, a medical microbiologist.

There's now been four large studies done over the last twenty years ... and none of them have found Lyme disease bacteria in the ticks.

In addition to this, methodologically reliable and accredited testing is difficult to come by. Australian Biologics, for example, offers services testing for Lyme disease in Australia, but is not recognised by the National Association of Testing Authorities (NATA) which ensures transparency.

Australian researchers in this field don’t deny that there may indeed be an as-yet undetermined illness spreading via tick bites in the country.

“There may be in fact be other illnesses that have not yet been diagnosed that are associated with ticks,” says Professor Graves. “So all the scientists and the medical professionals are saying at this point in time [is that] there's no good evidence Lyme disease exists in Australia.”

“We're not saying you're not sick, we're not saying you haven't got something from the tick bite because that hasn't been adequately investigated yet, but we're saying you almost certainly haven't got Lyme disease.”

In a recent breakthrough, Dr Charlotte Oskam and her team from Murdoch University have found a strain of Borrelia unique to Australia. But many health professionals reject the comparison of these unidentified illnesses to Lyme disease, and the use of the term ‘Lyme-like’, arguing it may bias future research into what might be causing Jesse’s and fellow sufferer’s sickness.

“I don't think anybody really cares what we call it,” counters Jesse. “Like you can call it whatever you want but you need to study it and you need to hurry up about it.”

Call it whatever you want but you need to study it and you need to hurry up about it.

The presence of this unknown illness borne by Australian ticks is a rare area of common ground, but it presents a conundrum for victims and scientists: sufferers are increasingly isolated and sitgmatised for seeking treatment similar to that prescribed for Lyme disease, and researchers cannot swiftly present an alternative diagnosis and treatment options, without adequate funding and in the face of something all good research needs: time.

In the meantime, tick-bite prevention remains a reliable method to stop the spread of such illnesses. If you’re planning to be in an area where ticks are common, wear long trousers that can be tucked into thick socks, keep your shirt tucked in an apply DEET-containing insect repellent.  

If you do find yourself bitten by a tick, don’t remove it with tweezers (or at all), recommends Dr Sheryl van Nunen, a senior specialist in immunology and allergies. Disturbing the tick will only encourage it to release its saliva into the body and transmit any pathogens it contains. Seek assistance from a doctor or hospital immediately, where they will be able to remove it using fine surgical tweezers.