A new study has found that a virus called xenotropic murine leukemia virus (XMRC) may be linked to chronic fatigue syndrome (CFS). The XMRC is part of a family of viruses known as murine leukemia viruses (MLV). The MLV is a type of retrovirus and it causes cancer in mice. The new study was published in the Proceedings of the National Academy of Sciences and its findings conflict with some earlier studies, which had claimed that XMRV or other viruses in this family are not found in the blood of people with CFS.
But the new research claimed that 86.5% of 37 people with CFS had evidence of this virus in their blood. "There is a dramatic association with CFS, [but] we have not determined causality for this agent," said Harvey Alter, MD, chief of clinical studies and associate director for research in the department of transfusion medicine at the National Institutes of Health (NIH) Clinical Center in Bethesda, Md., at a news conference. "Other labs have not found this virus, so a dilemma at present is how to reconcile that some labs find the association and others do not," added Alter.
"We think it is in the patient populations, not the lab testing [contamination causing a false-positive lab result], but the latter has not been completely ruled out," noted Alter.
Talking to WebMD, Steve Monroe, PhD, director of the division of high-consequence pathogens and pathology at the CDC, said that the new study "raises as many questions as it answers and there are still a lot of things about this virus that we don't know."
