Chronic Fatigue Syndrome Not Caused by a Virus… or Is It?

Corot at Big news for people suffering from chronic fatigue syndrome (CFS), which affects an estimated one million Americans. Besides profound exhaustion, CFS symptoms include sleep disorders, cognitive problems, muscle and joint pain, sore throat and headaches. Patients show signs of abnormalities that affect immune and endocrine systems and neurological functioning. These symptoms are frequently diagnosed as a mind-body illness, perhaps related to stress, trauma, or other “non-medical” causes. There is often a veiled dismissal that can accompany these tentative diagnoses. Their suffering has just not been taken seriously enough, CFS patients complain, because nothing specific could be found through accepted diagnostic procedures… until now—maybe.

Two studies have just been published that report on evidence that CFS may be triggered by an acute viral illness. Both studies were conducted by impeccably reputable sources. Both targeted the connection between CFS and a viral cause. Neither is conclusive, because the studies’ results contradict each other.

The study that supports a viral cause for CFS was conducted by researchers from the National Institutes of Health, the Food and Drug Administration, and Harvard Medical School, and was published in May. The study discovered the presence of DNA from a xenotropic murine leukemia virus (XMRV) in the blood of 67% of CFS patients, as compared with 3.7% found in testing a control group of healthy individuals. Another test on  patients meeting accepted diagnostic criteria for CFS found traces of a similar virus (MRV) in 86%, compared with only 7% among healthy volunteer blood donors. The researchers concluded that there appears to be a strong association between CFS and these viruses, although they stopped short of saying whether these viruses play a causative role in the development of CFS, and whether they represent a threat to the blood supply.

But in July, researchers from another federal agency, the Centers for Disease Control and Prevention, published a study finding no XMRV or other MRV-related viruses in patients with CFS. This study tested 51 persons with CFS and 56 healthy persons for evidence of XMRV and the results were consistently negative. Thus, researchers from this study concluded that there is no trace of XMRV in the blood of CFS patients or healthy controls and  therefore there is no evidence to support an association of CFS with XMRV.

News of the conflicting findings has led some patients to express alarm that important scientific information about CFS might be suppressed. People with a diagnosis of chronic fatigue syndrome are used to hearing scientists, doctors, employers, friends and family members dismiss the condition as psychosomatic or related to stress or trauma, despite mounting anecdotal evidence that CFS often follows an acute viral illness.

The CFIDS Association of America, the advocacy group for CFS patients, expressed the hope that these studies will help “shape immediate and longer term priorities for research and will build consensus about these agents, the conditions with which they may be associated and the exact nature of those relationships, one to another,” and that “few will question whether CFS is real or not,” as this research may help “lay that controversy to rest, at long last.”