Rob Sharp meets a City high-flyer whose nagging cough turned out to have a sinister cause

When hard-working City hot-shot Carl Liebel developed a cough one morning, he thought that he would work through it, like always. The last thing he expected was to take many months off work, having contracted an infectious disease more commonly associated with the developing world.

But little did he know that the number of Britons catching tuberculosis, or TB, is on the rise. Levels of the sickness, which spreads through prolonged contact with someone afflicted, have increased every year over the past two decades. Now, 8,000 people contract it every year in the UK. Last week, four people tested positive for TB after a former student at Manchester Metropolitan University became infected. In April, a British teacher died from it after being allowed to leave hospital in Hong Kong and return to Britain.

Liebel, 26, says that in his case, development of the disease happened slowly at first. In August 2005, he explains, he started to develop a cough. "I came back from a weekend away and I started coughing and then it developed and got progressively worse," he says. After six weeks, Liebel lost his voice. It was then that he began to wonder if this could be more than just a cold and, five days later, he went to see a private GP at a drop-in centre in the City. The doctor told him it was laryngitis and he was placed on a course of antibiotics, although the drugs had little effect. "I was told I might never get my voice back," he says.

At the time, Liebel, an investment banker, was working long hours, often through the weekend, and getting no more than five hours of sleep a night. Whatever the causes of his cough, doctors told him he had to slow down: the pressure was taking its toll on his immune system.

He went to a series of private doctors to get second, then third, fourth and fifth opinions. All maintained he had chronic laryngitis. They were bemused as to why treatment was having no effect. Liebel became so tired he could barely get out of bed. By November, his weight had plummeted from 85 to 61kg (he is 6ft 1in). One morning he coughed so hard that he felt a sharp crack in his chest. It later emerged that he had heard a rib breaking, just from coughing. He broke three ribs in total over the course of his illness.

It was not until his Austrian father sent him to doctors in Vienna that he was diagnosed with TB. "They figured out what it was within minutes," adds Liebel. "I had night sweats and massive fatigue. I couldn't even walk. There was clearly something wrong with me. They sent me for a variety of X-rays, which showed a massive hole in my left lung. They then put me into an isolation unit and I didn't see the light of day for three months."

By then he was coughing up blood as the condition entered its advanced stages. He was placed on a drip and it was shown that he had "drug-sensitive TB" – 93 per cent of cases are treatable with standard medicines – and so could be cured.

Liebel made contact with his bosses in London, who got in touch with some of England's most accomplished TB specialists – John Moore-Gillon and his nurse, Malcolm Cocksedge, who work at London's Barts Hospital and the London Chest Hospital – to advise Liebel in Austria via his BlackBerry. "In Austria they hadn't had a lot of experience with TB," Liebel says. "They wanted to change the drug I was on and I was told from the UK that this was a bad move. It's a stereotype, but in that part of the world the average TB patient is uneducated and they refer to doctors as 'gods in white'. I'm glad I got the advice because with the drug they were proposing there is a 50-50 chance of going deaf."

After three months, even though the contagious period of the disease had long since passed, his Austrian doctors maintained that he should stay isolated. Liebel eventually discharged himself on advice from London and went on to receive treatment from the NHS London Chest Hospital in east London, under the watchful eye of Cocksedge. Within another three months, he was back to full health.

He now says his health is "better than before", and is competing in a triathlon in three weeks. "The irony is that if I had gone to an NHS doctor in the first place, it is likely they would have diagnosed it immediately because of the amount of exposure they have to TB from their wider scope of patients," he adds. "No one knows where I got it. It came back as an anomaly when the disease was DNA fingerprinted. I might have caught it when I was a kid living in South Africa. I had been to Thailand four months earlier, and the likelihood is I contracted it on the plane on the way home."

According to TB expert Professor Peter Davies, cases such as Liebel's are on the rise because the disease is common in the wider world. "In Britain, the real problem is people from Africa and India moving here, bringing infection with them," he says. "But to put that into context, England gave TB to the rest of the world in Victorian times. We have had 200 years to get used to it, but poorer countries have had half that. Additionally, the British have had much improved living conditions, whereas they haven't."

Professor Davies says one of the main problems with TB is that often GPs and patients do not recognise it for what it is. Thankfully, it is still quite hard to contract. "You usually have to be in close frequent contact to have a chance of picking it up," he continues. "It is so common in South Africa that even if he had just climbed into a taxi for half an hour, he would have picked it up that way."

People can carry the infection for many years before getting the full-blown disease – the onset is often prompted by a weak immune system.

For Liebel it is clear what the moral of the story is. "If you really believe there's something wrong with you should trust your instincts," he concludes. "And I've also learned not to make my job my first priority."