From Sydney, Australia: One Research Team Says Yes
Belgium's Dr. Kenny De Meirleir explained to a long-time Dutch Patient with CFIDS (PWC) that his RNase-L enzyme test showed a high level of viral activation consistent with the Chronic Fatigue Syndrome/Chronic Fatigue and Immune Dysfunction Syndrome/Myalgic Encephalopathy (CFS/CFIDS/ME). "We now understand the immunological basis of Chronic Fatigue Syndrome(CFS)," he said. "Because of your RNase-L test, it is certain that your illness has a viral basis."
Expressing his concern that CFS/CFIDS/ME might be contagious, the patient asked the doctor about the possibility of infecting others through casual contact. "I don't think so," Dr. De Meirleir answered. "But blood products can transmit it; we are sure of that. We have a rather large number of CFS patients who became ill immediately after transfusion." If supported by subsequent research, this hypothesis would obviously hold serious implications for public health.
Dr. De Meirleir shared the findings of his study on blood transfusions at the CFS Conference held in Sydney, Australia, this February. Bear in mind that these are the results of a single study and that the numbers are fairly small. Just the same, because of the possible ramifications of this study, the abstract is reproduced here more or less in its entirety:
"We analyzed...1 ,210 consecutive patients... who visited our fatigue clinic at the Vrige Universiteit Brussel [Brussels, Belgium]. In this group, 752 patients fulfilled the  CDC criteria for CFS: Of those patients, 34 (4.5%) have a common factor in their past medical history that immediately preceded the onset of their CFS. These patients had received a blood transfusion a few days to a week prior to developing a 'flulike' syndrome that later proved to be the acute onset of CFS. Another 8 patients also received a blood transfusion but their illness started at least two months later, so we cannot take these patients [into account] in our calculations.
"None of these post-transfusion patients developed hepatitis C or other types of viral hepatitis. Some had antibodies (IgG) against CMV or EBV, but [when these antibodies developed] in time in relationship to the blood transfusion could not be determined. In 9 of 34 the LMW [low molecular weight] RNase-L test was performed; in all 9 patients, the [results were consistent with those seen] in viral disorders.
"These findings point towards a transmittable cause in this subset of CFS patients in which acute onset was temporally linked to blood transfusion. As viruses and possibly other micro-organisms seem to be able to trigger an acute onset of CFS, and [because] RNase-L dysfunction seems to be preferentially related to CFS, it comes as no real surprise that receivers of a blood transfusion, often being in a weakened status, [could potentially] develop CFS. We therefore would advise CFS patients not to be blood donors and, secondly, [recommend] that the administration of blood transfusions... [should occur] only when strictly necessary and not as a standard procedure (e.g., as in after the delivery of a baby)."
(Abstract: "Blood Transfusion and Chronic Fatigue Syndrome," by K. De Meirleir, P. De Becker, and I. Campine, Human Physiology and Medicine, Vrige Universiteit Brussel. Source: CPAR Digest, V.I #401