[Legal obligation to inform the patient on the theoretical risk of CJD transmission by blood].

Legal obligation to inform the patient does not include theoretical risks. However, due to the very sensitive situation of blood transfusion in France, following the tainted-blood affair, a circular was issued to extend this obligation (1998) to inform the theoretical risk of CJD transmission by blood. Ethically speaking, this raises three questions: Is it beneficial to the patient to be informed on theoretical risk? Is the use of a "circular", less legally binding, appropriate? Finally, what is the situation in other countries? The evolution of the law tends to be more positive in that it no longer involves any theoretical risk.