Virus possibly linked to chronic fatigue sufferers

October 28, 2009

The virus known as XMRV which is already linked to prostate cancer may also play a role in chronic fatigue syndrome, according to research for a mysterious disorder that affects 17 million people worldwide. Researchers from the Whittemore Peterson Institute in Nevada , at the National Cancer Institute, and at the Cleveland Clinic found the virus in the blood of 68 out of 101 chronic fatigue syndrome patients. The same virus showed up in only 8 of 218 healthy people according to the report which appears in the journal Science.

The researchers emphasize that the finding only shows a link between the virus and chronic fatigue syndrome (CFS) and does not prove that the pathogen causes the disorder.

CFS impairs the immune system and causes incapacitating fatigue, according to the U.S. Centers for Disease Control and Prevention. Sufferers can also experience memory loss, problems with concentration, joint and muscle pain, headaches, tender lymph nodes and sore throats. Symptoms last at least six months and can be as disabling as multiple sclerosis or rheumatoid arthritis, the CDC said.

There is currently no medical treatment for CFS aside from cognitive behavioral therapy to help patients cope with the disorder's crippling effects. The XMRV virus is a retrovirus like the HIV virus that causes AIDS. Known formally as xenotropic murine leukemia virus-related virus, XMRV has also been found in some prostate tumors and is also known to cause leukemia and tumors in animals.

The research team said further research must now determine whether XMRV directly causes CFS, is just a passenger virus in the suppressed immune systems of sufferers or a pathogen that acts in concert with other viruses that have been implicated in the disorder by previous research.

"Conceivably these viruses could be co-factors in pathogenesis, as is the case for HIV-mediated disease, where co-infecting pathogens play an important role," the report said.

Because 3.7 percent of the healthy test population tested positive for XMRV, the researchers said several million otherwise healthy people in the United States could be infected with it.