The surveillance system for Creutzfeldt-Jakob disease, based on mandatory reporting and notifications to the RNS-CJD, makes it possible to track the progression of this disease

The emergence of the variant form of CJD and its link to bovine spongiform encephalopathy (BSE)

Following the discovery that the prion responsible for variant Creutzfeldt-Jakob disease (incorrectly referred to as the “mad cow crisis”) can be transmitted through food derived from animal products, 28 confirmed or probable cases of CJD were identified in France, with patients dying between 1992 and 2019 (table).

These included 12 men and 16 women. The median age at death or diagnosis was 36 years (ranging from 19 to 58 years). Among them, 9 people resided in the Île-de-France region and 19 in other regions. All cases identified to date were Met-Met homozygous for codon 129 of the prion protein gene (PRNP); they had no identified risk factors for other recognized forms of CJD. One case had visited the United Kingdom very regularly for about ten years starting in 1987.

Number of confirmed or probable CJD deaths in France (updated January 31, 2026)

Four iatrogenic CJD deaths caused by recombinant growth hormone occurred in 1991.

An overall increase in the incidence of Creutzfeldt-Jakob disease between 1992 and 2002

The primary explanation for the steady increase in the incidence of sporadic Creutzfeldt-Jakob disease is the implementation of active surveillance. The two “mad cow” crises (1996 and 2000) and the development of the 14.3.3 test (1997) likely also contributed to better case identification, particularly among the elderly. This increase has, in fact, been observed in all countries within the EuroCJD active surveillance network.