Infectious fatigue

Chronic fatigue syndrome has eluded a specific molecular definition for decades, leading many clinicians to dismiss the ailment as psychosomatic or fictitious. Now, a study in Science points to a potential culprit in CFS-a recently discovered retrovirus that also has been implicated in prostate cancer.¹

The challenge will be proving that infection by xenotropic murine leukemia virus-related virus (XMRV) indeed causes CFS. In the absence of a workable animal model, confirmation of the Science report will require larger epidemiological studies...