Comment by macbr

Creutzfeldt-Jacob can be tested for using the RT-QuIC test[1] where a positive result guarantees with near certainty that misfolded prions are present. But as the disease is defined via the physical changes in brain tissue only obtainable via autopsy a definite diagnosis is often only made after death.

[1]: https://en.wikipedia.org/wiki/Real-time_quaking-induced_conv...