The use of post-mortem tissues as sources for the production of
biologicals,
vaccines and feedstuffs has led to the transmission or generation of transmissible
encephalopathies in some recipients. For example, the use of pituitary-derived
human growth hormone and
gonadotropins has resulted in the transmission of
Creutzfeldt-Jakob disease to other humans [1], the use of
formalin-inactivated sheep brain as a source for
louping ill vaccine led to the transmission of
scrapie to over 1,000 sheep from one
vaccine lot [2], and the use of rendered products from ruminant carcasses in the domestic animal food chain led to the emergence and epizootic of bovine spongifrom
encephalopathy in the United Kingdom [3].
Infection with transmissible
encephalopathies by iatrogenic or other mechanisms is difficult to predict or control. The characteristics of these pathogens do not permit easy detection, clearance, or inactivation in routine
biopharmaceutical production environments.