Sufferers of chronic fatigue syndrome will have to wait for answers to their debilitating condition, after new research found that it is not caused by infection from certain viruses, as previously suggested.
Earlier research found a link between chronic fatigue syndrome (CFS) and the viruses XMRV (xenotropic murine leukemia virus-related virus) and pMLV (polytropic murine leukemia virus), however new research reveals there is no evidence that infection from these viruses causes 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," said study co-author Ian Lipkin from Columbia University in New York.
Sufferers of CFS experience unexplained fatigue, muscle weakness, pain, disordered sleep and many other symptoms.
For years researchers have been arguing about the causes. Two separate studies in 2009 and 2010 reported finding retroviruses in the blood of CFS patients, however subsequent studies have not been able to produce the same results.
"We went ahead and set up a study to test this thing once and for all and determine whether we could find footprints of these viruses in people with chronic fatigue syndrome or in healthy controls," Lipkin said in a media release.
The researchers tested blood from 147 people with CFS and 146 people without, looking for genes specific to the virus XMRV and pMLV.
They were very careful to ensure there was no contamination of the chemicals used for testing –– which could explain the previous study results.
"We've tested the XMRV/pMLV hypothesis and found it wanting," Lipkin said.
"But we are not abandoning the patients. We are not abandoning the science. The controversy brought a new focus that will drive efforts to understand CFS and lead to improvements in diagnosis, prevention and treatment of this syndrome."
Dr Nicole Phillips, medical adviser to ME/CFS Australia (Victoria) told ninemsn other viruses are still being investigated.
"There is research going on all over the world and there is a huge amount of evidence of biological dysfunction in people with CFS," she said.
"The problem has been tying it all together into a neat package that makes sense in terms of cause and treatment. That has not yet been done."
At the moment, treatment involves supportive and lifestyle therapies to help people manage their illness.
"Things such as pacing so they don't use up all their energy and help with sleep or pain helps," Dr Phillips said.
"You can't give a curative medication until you have a known and specific cause and that's where the problem lies."
The research was published in the journal mBio.