INDEX CASES. “The concern comes after scientists found that a small number of people who died from Creutzfeldt-Jakob disease (CJD) after being treated with growth hormone taken from cadavers, developed brain changes seen in Alzheimer’s disease.”
http://www.theguardian.com/science/2015/sep/09/protein-linked-to-alzheimers-could-be-spread-during-surgery-say-researchers