In some parts of the world, a fatal brain disease called Mad Cow Disease has infected cattle. In these locations, primarily in parts of Europe, people have been diagnosed with a new disease called variant Creutzfeld-Jacob Disease (vCJD), which is also a fatal brain disease. It is theorized that vCJD is a form of Mad Cow Disease that has been transferred to humans by eating infected beef. While there have not been any documented cases of vCJD being transmitted by blood transfusions, the Food and Drug Administration, the federal agency that regulates blood collection in the United States, has recently placed restrictions on whether an individual may donate blood based on how much time they have spent in countries where cows have been affected by Mad Cow Disease. The restrictions are based on a theoretical risk of transmitting vCJD by a blood transfusion.
Since 1996, there have been 115 cases of vCJD identified in Europe, predominantly in the United Kingdom. It is theorized that these individuals were infected by eating meat from infected cows.
No. To date there have not been any cases of vCJD reported in the US.
Extremely small, if any. As noted above, there have been very few cases identified so far. However, since there is a delay of years until an individual shows signs of the disease, no one can say for sure whether someone is infected.
No test currently exists to identify persons who are infected with vCJD.
No, the US Food and Drug Administration policy does not make any exception for this rule.