[prairiebreeze]

BSE prions have never been discovered to be present in muscle tissue. Only CNS tissue(brains, spinal columns).

I don't believe they've ever been detected in bone marrow either.

Prairie

[FollowingTheGrace]

Not just in CNS tissue--spleen, tonsils, corneas, and, I think,in very small quantities in muscle tissue.

[torstars]

BSE prions have never been discovered to be present in muscle tissue.

Over what time frame? I think you are just talking about sensitivities of assays. Transmission of vCJD by transfusion is quite solid. The prions are almost certainly in blood, but at lower concentrations, which may just mean a longer incubation time.