France, involved for a long time in the epidemiological surveillance of transmissible spongiform encephalopathy (TSE), created a national network of surveillance in 1991, because of the description of the first cases of Creutzfeldt-Jakob disease (CJD) linked to a treatment by growth hormone of human origin and the observation of cases of cats infected with the agent of the bovine spongiform encephalopathy in the United Kingdom (UK).
The most frequent of the latter include acquired forms secondary to injections of human cadaveric pituitary-derived growth hormone and the new variant of CJD--probably related to bovine spongiform encephalopathy.