Chronic fatigue syndrome: suspicion is back on virus

A leading scientist at the US National Institutes of Health (NIH) supports the theory that a retrovirus causes chronic fatigue syndrome (CFS) and says that government researchers have independently confirmed the association.

The link between xenotropic murine leukemia virus-related virus (XMRV) and CFS was reported last year by scientists at the Whitmore Peterson Institute in Reno, Nevada. But it has since come under heavy criticism after several groups failed to replicate the association with their own patients.

However, Harvey Alter, an infectious disease expert at NIH, gave a talk on protecting the blood supply from disease at a closed workshop in Zagreb, last month with a slide that called the XMRV-CFS association "extremely strong and likely true, despite the controversy", the Wall Street Journal reports.

The same slide also indicates that scientists at NIH and the Food and Drug Administration have confirmed the link between CFS and XMRV themselves. His team also estimates that XMRV and related viruses are present in 3 to 7 per cent of blood donors.

The news is generating a lot of buzz on CFS patient forums, where hopes have been high that the connection would offer a solid explanation - and potentially a treatment - for the enigmatic condition.