Contrary to previous findings, new research finds no link between chronic fatigue syndrome and the viruses XMRV (xenotropic murine leukemia virus-related virus) and pMLV (polytropic murine leukemia virus). A study to be published on September 18 in mBio®, the online open-access journal of the American Society for Microbiology, reveals that research that reported patients with chronic fatigue syndrome carried these two viruses was wrong and that there is still no evidence for an infectious cause behind chronic fatigue syndrome.
"The bottom line is we found no evidence of infection with XMRV and pMLV. These results refute any correlation between these agents and disease," says Ian Lipkin of Columbia University, a co-author on the study.
Chronic fatigue syndrome (CFS), also known as myalgic encephalomyelitis (ME), is a disabling condition in which sufferers experience persistent and unexplained fatigue as well as any of a host of associated problems, including muscle weakness, pain, impaired memory, and disordered sleep. Medical treatment for CFS/ME costs as much as $7 billion every year in the U.S. alone.
The possible causes of CFS/ME have been argued and researched for years with no success. Results from separate studies in 2009 and 2010 that reported finding retroviruses in the blood of patients with CFS/ME created a sensation among patients and the medical community and offered hope that a tractable cause for this disease had finally been found. Since then, other investigators have been unable to replicate the results of those studies, casting doubt on the idea that these viruses, XMRV and pMLV, could be behind CFS/ME.