The 18-year-old says she can only walk a little and uses a wheelchair much of the time after she says she caught the Australian strain of Lyme disease.

According to the family, it was her mother, Nikki, a Uniting Church minister, who gave Hannah her last rights in 2010 when the family thought Hannah was going to die.

''Doctors would suggest, 'it's all in your head','' Hannah said. ''Others said 'it's a mystery illness, we don't know what it is'.''

There appears to be no clear cure for what Hannah says she suffers from.

Her mum, Nikki, now the president of the Lyme Disease Association of Australia, says she also caught the tick-borne infection, although hers was contracted overseas.

Nikki said the disease confined her to a wheelchair for eight years. She hopes her daughter's symptoms will, like hers, gradually fade with the help of antibiotics. Until then the Coleman family says it retains faith in the power of staying upbeat in the face of adversity.

Hannah will be talking at the upcoming TEDxCanberra conference in September, a gathering of speakers who tackle big ideas.

The major challenge, Hannah says, has been convincing the doctors she has Lyme disease.

Lyme disease, caused by the bacterium Borrelia burgdorferi includes symptoms such as fever, headache, fatigue, sore muscles and joints, and a characteristic skin rash.

A small number of medical practitioners, such as Dr Bernie Hudson from the Royal North Shore Hospital, have argued for years an Australian version of the disease exists.

An article published in The Lancet Infectious Diseases in September last year, however, said advocates of Lyme disease are part of the anti-science movement, incorrectly spreading information about a condition which is geographically and seasonally limited and wrongly advocating the use of antibiotics.

Dr Ashley Watson, senior specialist at Canberra Hospital's Infectious Diseases Unit, could not talk about Hannah's case.

Dr Watson said he knew of about a dozen people a year who thought they had Lyme disease. According to him, whatever symptoms they think they have, it is not Lyme disease, unless on the rare occasion they have brought it back from overseas.

''I'm in the camp 99 per cent of my colleagues are in - there's no evidence it exists in Australia,'' Dr Watson said.

''There's a hell of a lot of ticks on the eastern seaboard of Australia. If there was Lyme disease in Australia, you'd think we'd know about it.

''Maybe they've got some fatigue syndrome, maybe they've got arthritis, but it's not Lyme disease.''

Dr Watson said there were unaccredited laboratories operating which were handing out Lyme disease diagnoses.