Lyme disease seems to have become the illness du jour. The condition - which is contracted primarily from a tick bite and is claimed to cause a range of serious and even lethal illnesses - made headlines recently when telecoms billionaire John Caudwell revealed he and several of his family members have been diagnosed with 'the insidious infection'.

Fear of this sometimes long-term condition has been spiralling among people who are suffering vague symptoms of illness, such as muscle and joint pain (which can be caused by Lyme disease). But is there really such a thing as 'chronic' Lyme disease?

The conventional scientific wisdom is that the infection is contracted from a tick carrying the Borrelia burgdorferi bacterium. The first symptom is a bull's-eye shaped rash, called erythema migrans, around the bite. The vast majority of cases can be cured by prompt treatment with antibiotics.

Phones 4u's John Caudwell revealed he and several of his family members have Lyme disease

The NHS says the short-term infection afflicts only 2,000 to 3,000 sufferers every year in Britain. However, campaigners claim that the condition can go undiagnosed by NHS tests, leaving hundreds of thousands at risk of a chronic form with crippling and terrifying effects.

John Caudwell, founder of Phones 4u, believes chronic Lyme disease is behind the host of health problems his son Rufus has suffered with for the past nine years.

Rufus, 20, is malnourished and vitamin-deficient. He has also been diagnosed with generalised anxiety disorder, agoraphobia, emetophobia (fear of vomiting) and has suffered bouts of psychosis.

As well as his son's health problems, Caudwell, 63, who first heard of Lyme disease in February, blames it for the fact that he now needs six hours' sleep, rather than the four hours to which he was accustomed in his younger years.

More alarmingly, he claims that chronic Lyme disease could be the root cause of major diseases such as Alzheimer's, motor neurone disease, Parkinson's, multiple sclerosis and chronic fatigue syndrome (also known as ME).

Other members of his family so far diagnosed include his ex-wife Kathryn McFarlane and their daughters, Rebekah, 35, and Rhiannon, 27. His two younger children from two other relationships - Scarlett, 13, and 11-year-old Jacobi - are also due to be tested.

(L-R) John with daughters Libby (left), Rebekah (centre) - who have Lyme disease - and his ex Claire Johnson

John Caudwell and son Rufus, who has Lyme disease and suffers anxiety, agoraphobia and psychosis

Caudwell is 'certain' they were not all bitten by ticks. 'It's almost impossible. And we haven't lived together for 20 years.'

Instead, he claims that chronic Lyme disease may be spread by sexual intercourse and from mother to baby in the womb. He says that since going public, he has been contacted by hundreds of worried people.

'I believe Lyme disease is one of the greatest threats to public health in our time,' he has said.

The Health Protection Agency is not convinced, maintaining: 'There is no scientific evidence to support the suggestion that Lyme disease is caused by anything other than ticks.

'There is no scientific evidence that Lyme disease causes ME, Alzheimer's or Parkinson's disease.'

I believe Lyme disease is one of the greatest threats to public health in our time

But the starkly troubling fact is that with our currently limited medical knowledge, no one can definitively quell such fears. Experts admit there are no tests yet that can definitely rule out Lyme disease. Indeed, standard antibody tests for the condition can give false negative results if a patient has recently taken antibiotics or steroids, as these medications reduce the number of antibodies in the blood.

Caudwell's family's infections were not confirmed by NHS testing - their blood samples were sent to a private clinic in Germany. 'I'm hearing stories all the time of people who tested negative here, then positive in German labs,' he has said.

This is a concern for medics, who worry that people with vague and often harmless symptoms of mild pain could be gulled into believing they have chronic Lyme disease by alternative health practitioners who then charge them for treatment with unproved therapies.

In May, a study in the journal Clinical Infectious Diseases (CID) identified more than 30 unproven alternative treatments for chronic Lyme disease being marketed over the internet.

These included oxygen therapy, radiation therapy, stem cell transplants and dosing people with heavy metals and drug regimens 'without recognised therapeutic effects', says the study.

It concludes that 'in most cases, there is no medical rationale for the advertised treatments'. There are also questions over whether some cases of chronic Lyme disease may in fact be the result of psychosomatic problems - a view supported by the Mail's psychiatrist Dr Max Pemberton in his column last Saturday.

Bella Hadid (pictured) and her brother Anwar, have Lyme disease, like their mother Yolanda

This month, researchers writing in CID said patients with chronic Lyme disease bear remarkably strong similarities to patients with chronic fatigue syndrome - a condition some researchers argue has a strong psychological element.

The lead researcher, David Patrick, a professor of infectious diseases and epidemiology at Canada's University of British Columbia, says patients given negative results by conventional tests then go to alternative clinics that falsely give them positive results.

This persuades them that they have the disease and exacerbates their psychosomatic symptoms.

Other medical experts are adamant that chronic Lyme disease simply does not exist. For example, Dr Paul Lantos, an infectious disease specialist at Duke University in North Carolina, has declared that research findings 'do not support the proposition that chronic, treatment-resistant infection with Borrelia burgdorferi is responsible for the many conditions that get labelled as chronic Lyme disease'.

Writing in the journal Infectious Disease Clinics of North America, Dr Lantos added that giving such patients prolonged courses of antibiotics (as recommended by many chronic Lyme disease campaigners) 'neither prevents nor ameliorates these symptoms and is associated with considerable harm'.

This view has long been held by British officialdom.

Susan O'Connell, retired head of the Lyme Borreliosis Unit at the Health Protection Agency Microbiology Laboratory, wrote last year in the journal Medicine: 'Controlled trials in patients with post-Lyme symptoms have shown no evidence of persistent infection and no sustained benefit from prolonged antibiotic treatment.'

But there has recently been a significant change of tack. Dr Matthew Dryden, a consultant at Public Health England's rare and imported pathogens department, told Good Health the organisation now recognises that some people who contract Lyme disease may eventually develop 'complicated disease with damage to the nervous system, joints, or, rarely, heart tissue'.

John's two younger children - Scarlett, 13, and 11-year-old Jacobi - are due to be tested

For these people, he says, specialist care is necessary.

Dr Dryden explains: 'The majority of patients respond to simple treatment, but a few have long-lasting symptoms or disabilities.

'Public Health England and the NHS are considering the possible causes of this, and better treatment regimens, as the available scientific information is beginning to open up new possibilities.' He says Public Health England is conducting research to improve the accuracy of lab tests.

But Dr Dryden stresses that heading abroad for alternative testing is a mistake. 'Tests done in foreign, private laboratories are misleading,' he says. 'Many entirely healthy people have positive results by these tests. The value of many of these tests has not been published or verified.' He adds that very few of those who develop persistent symptoms have the chronic form of Lyme disease.

Public Health England is working with the patient charity Lyme Disease Action to increase awareness of the complex issues emerging around the infection.

The charity's chair, Stella Huyshe-Shires, was diagnosed with Lyme Disease three years after being bitten by a tick. NHS tests revealed she had the bacteria in her spinal fluid.

Antibiotic treatment helped, but six months later she relapsed and had to take early retirement from her job as an IT analyst in the NHS.

8% The proportion of Lyme disease patients who will develop facial palsy Advertisement

'Twelve years on, I suffer from pain in my spine that wakes me up during the night,' she says.

'Pain relief takes the edge off it, but it sedates you in the daytime. I also experience appalling itching. I have swollen lymph glands and burning pain in my legs.'

But such is the current confusion surrounding diagnosis and testing that she says: 'I can't say whether I have chronic Lyme disease, or something else that they can't find.'

She believes the publicity surrounding John Caudwell's claims has only helped fuel concern and confusion. 'It has raised the spectre of possible sexual infection.

'It is theoretically possible, but there are no recorded cases and animal tests have failed to prove that it could occur,' she says.

'However, the danger of infection through transmission from mother to baby in the womb is a real possibility. And blood transfusions need to be checked out.'

To speed up action to improve the identification and treatment of this condition, on Thursday, the Liberal Democrat Lord Greaves will lead a House of Lords debate 'to ask Her Majesty's Government what action they are taking to combat Lyme disease and other tick-related illnesses'. The debate is supported by Lyme Disease Action.

'We have no idea about how many people have chronic Lyme disease in the UK,' says Stella Huyshe-Shires. 'Many probably remain undiagnosed. It is also possible that some have been misdiagnosed. Realistically, it is going to take a long time before we get definitive tests.'

The situation leaves her in a painful state of limbo. 'Although antibiotics have helped, they have not cured me,' she says.