There is no blood test for vCJD. ---------- In 2004 a new report published in the Lancet medical journal showed that vCJD can be transmitted by blood transfusions (Peden, 2004). The finding alarmed healthcare officials because a large epidemic of the disease might arise in the near future. There is no test to determine if a blood donor is infected and is in the latent phase of vCJD. In reaction to this report, the British government banned anyone who had received a blood transfusion since January 1980 from donating blood. On May 28, 2002, the United States Food and Drug Administration instituted a policy that excludes from donation anyone who lived in high-risk areas of Europe from 1980 to the mid-1990s. Given the large number of U.S. military personnel residing in Europe, it was expected that over 7% of donors would be deferred due to the policy [citation needed]. A similar policy applies to potential donors to the Australian Red Cross' Blood Service, procluding people who have spent a cumulative time of six months or more in the United Kingdom between 1980 and 1996. http://en.wikipedia.org/wiki/Creutzfeldt-Jakob_disease#Blood_donor_restrictions Are patients receiving blood transfusions at risk of contracting the disease through blood? There have been no known cases of humans receiving vCJD through a blood transfusion. However, there is some risk the disease may be transmissible through blood, so the Red Cross is applying its best judgment by tightening the restrictions to exclude some blood donors who have lived in Europe. The cause of this new vCJD, which has now killed more than 100 people in Europe (mostly Great Britain), has now been traced to the consumption of meat and meat products infected with BSE. Vulnerable patients' lives depend on the safest possible blood available. The American Red Cross must be prudent and cautious to implement a more strict deferral in the face of scientific uncertainty, because there is a long latency period with this disease, evidence in animal models that the disease may be contracted through blood and currently no blood test exists. American Red Cross. http://www.redcross.org/services/biomed/blood/supply/tse/tsefaqtop10.html Creutzfeldt-Jakob Disease (CJD) - A degenerative and fatal nervous system disorder. Affected individuals can remain asymptomatic for decades after infection and then progress rapidly to dementia, severe loss of coordination and death. The Blood establishment claims the risk of CJD being transmitted through Blood products is 'theoretical.' The infectious agent has (yes, has) been found in Blood products. from the net.

As of 2014 there is test being developed. https://www.healthline.com/health-news/blood-test-detects-human-form-of-mad-cow-disease-061214#1