WASHINGTON — A U.S. government study has uncovered a family of mouse viruses in some people with chronic fatigue syndrome, raising still more questions about whether infection may play a role in the complicated illness.
The study reported Monday does not prove that having any of these viruses causes harm, said co-author Dr. Harvey Alter of the National Institutes of Health. The government has additional research underway.
The virus connection made headlines last fall when Nevada researchers reported finding a specific type, named XMRV, in the blood of two-thirds of the 101 chronic-fatigue patients they tested. Several other studies failed to find XMRV in patients, making researchers wonder whether this was a false alarm.
This time, NIH and FDA scientists examined the blood of 37 chronic-fatigue patients and again didn’t find XMRV — but they did find closely related bugs, named MLV-related viruses, in 86 percent of the cases. Testing of 44 healthy blood donors, in contrast, found evidence of those viruses in nearly 7 percent.
Various viruses have been linked to chronic fatigue over the years only to fall by the wayside as potential culprits in the illness thought to afflict about 1 million Americans.
