Transmissible encephalopathies and biopharmaceutical production.

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.