From the Daily Mail, 21 June 2011 (story by Sophie Borland)
Now doctors say M.E. is NOT caused by virus but is found in the blood
M.E. is definitely not caused by a virus despite past claims, leading scientists say.
They have ruled out a theory that the illness, also known as chronic fatigue syndrome, is triggered by little-known bugs found in blood.
Two years ago researchers claimed to have made a breakthrough when they discovered a virus in blood samples of those with the condition that was not present in healthy people.
But now scientists who have looked at numerous other studies published since the discovery have dismissed the idea as ‘another false claim'.
M.E., which stands for myalgic encephalomyelitis, affects 250,000 Britons and is slightly more common in women than men.
Symptoms include extreme tiredness and muscle ache, and those severely affected spend most of the day in bed or are confined to a wheelchair. Experts do not know what causes it.
The condition was once dismissed as ‘yuppie flu', and sceptical doctors thought it was all in the mind.
In 2009 U.S. researchers discovered a little-known virus called XMRV in blood samples in nearly 70 per cent of sufferers.
It was not found in the vast majority of healthy people.
But writing in The Lancet, disease experts Dr Frank van Kuppevald and Jos van der Meer said recent findings ‘raise huge scepticism' about the idea that M.E. is caused by a virus.
And they added that three new pieces of research ‘provide the nail in the coffin'.
‘Sadly, we have to conclude that the world has witnessed another false claim that gave new hope to patients with chronic fatigue syndrome, who are desperately seeking a cause for their suffering,' the scientists from the University of Nijmegen in the Netherlands concluded.
M.E. usually develops in the early 20s to mid-40s but teenagers can also be affected.
There is no cure so patients are given treatments including painkillers for muscle ache and behavioural therapy and exercise therapy for fatigue.
They are often advised to avoid alcohol, caffeine, sugar and sweeteners in case they make symptoms worse.
Although scientists do not know exactly what causes M.E., they believe it may be triggered by a combination of factors such as exhaustion, a traumatic event and an infection which weakens the immune system.
Experts also believe there may be a genetic link, with some families more prone than others.
Surveys have suggested that three quarters of M.E. sufferers have lost their job because of the condition and 2 per cent cannot leave their homes.
But it was only properly recognised as a medical condition in 2002, when the then chief medical officer Sir Liam Donaldson classified it as a ‘debilitating and distressing condition'.
In 2005, a study by University College London found the physical symptoms of the disease were often exacerbated by psychological ones.
The condition is notoriously difficult to diagnose, and doctors usually classify it as sudden tiredness lasting more than six months that is not explained by another illness, exercise or hard work.