Mouse Virus Linked To Chronic Fatigue Syndrome: MLV and CFS?

The new study shows that 86.5% of 37 people with CFS had evidence of this virus in their blood, as did 6.8% healthy blood donors. These findings back up a recent report by researchers at the Whitemore Peterson Institute in Reno, Nev., which showed similar results.

"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."

1. ave severe chronic fatigue for at least 6 months or longer that is not relieved by rest and not due to medical or psychiatric conditions associated with fatigue as excluded by clinical diagnosis; and
2. Concurrently have four or more of the following symptoms:
   • self-reported impairment in short-term memory or concentration severe enough to cause substantial reduction in previous levels of occupational, educational, social, or personal activities
   • sore throat that's frequent or recurring
   • tender cervical or axillary lymph nodes
   • muscle pain
   • multi-joint pain without swelling or redness
   • headaches of a new type, pattern, or severity
   • unrefreshing sleep and
   • post-exertional malaise (extreme, prolonged exhaustion and sickness following physical or mental activity) lasting more than 24 hours.