Scientists say they have made a dramatic breakthrough in understanding the cause of chronic fatigue syndrome. The researchers have discovered a strong link between chronic fatigue syndrome, which is sometimes known as ME or myalgic encephalomyelitis, and an obscure retrovirus related to a group of viruses found to infect mice.

The study, published in the journal Science, shows that the virus, called murine leukaemia virus-related virus (XMRV), was found in 68 of 101 patients from around the US with chronic fatigue syndrome. This compared with just eight of 218 healthy ‘controls’ drawn at random from the same parts of the US, the scientists said. But the senior author of the study, Judy Mikovits, director of research at the Whittemore Peterson Institute in Reno, Nevada, said further blood tests have revealed that more than 95 per cent of patients with the syndrome have antibodies to the virus – indicating they have been infected with XMRV, which can lie dormant within a patient’s DNA.

Dr Mikovits said that if the findings are replicated by other groups, and the XMRV virus is accepted as a cause of chronic fatigue syndrome, then it could be possible to treat patients with antivirals, just like treating HIV, or to develop a vaccine against the virus to protect people from developing the condition.

However, other researchers emphasised that the numbers published so far are too small to conclude anything about the cause of chronic fatigue syndrome. ‘It’s spectacular, but needs replication. And I hope that no one is thinking of prescribing anti-retrovirals on the basis of this,’ said Simon Wessely, professor of psychological medicine at King’s College London. ‘It’s very preliminary and there is no evidence to say this is relevant to the vast majority of people in the UK with the condition.’

The Independent