Comments by "" (@DanielSMatthews) on "Body found at Brisbane train station" video.

@Wutang 4eva Prions are proteins with two geometric conformations, one that is functional and one that is not and causes functional ones to deform into the non-functional form. They are a form of self propagating toxin that causes a buildup of the non-functional proteins while disrupting the parts of the metabolism that rely on the functional form of the protein. Other than that they can be any protein that has those characteristics that your body does not have a detection and cleanup mechanism for dealing with. In theory a single prion in one of your nerve cells is enough to eventually kill you so weight for weight they are the most toxic substance in existence.
1