There is no preclinical test after a possible exposure to determine if infection actually took place. CJD usually affects people between the ages of 50 and 75 years. A number of victims are younger. The officially stated mortality rate is one death per one million population per year. However, this figure appears to be an understatement as CJD frequently escapes detection.
Blood transfusions are one way.
Vaccines are another way. There are immune globulin vaccines given after exposure to such diseases as hepatitis and tetanus and for Rh Factor. In addition, blood products such as albumin are used in diagnostic tests and in In Vitro Fertilization cultures. The jury is still not in on whether CJD is transmitted to humans by blood. The infectious agent has been found in blood, but there have been no documented cases of blood transmission in humans.