The importance of ongoing international surveillance for Creutzfeldt–Jakob disease

Abstract

Creutzfeldt–Jakob disease (CJD) is a rapidly progressive, fatal and transmissible neurodegenerative disease associated with the accumulation of misfolded prion protein in the CNS. International CJD surveillance programmes have been active since the emergence, in the mid-1990s, of variant CJD (vCJD), a disease linked to bovine spongiform encephalopathy. Control measures have now successfully contained bovine spongiform encephalopathy and the incidence of vCJD has declined, leading to questions about the requirement for ongoing surveillance. However, several lines of evidence have raised concerns that further cases of vCJD could emerge as a result of prolonged incubation and/or secondary transmission. Emerging evidence from peripheral tissue distribution studies employing high-sensitivity assays suggests that all forms of human prion disease carry a theoretical risk of iatrogenic transmission. Finally, emerging diseases, such as chronic wasting disease and camel prion disease, pose further risks to public health. In this Review, we provide an up-to-date overview of the transmission of prion diseases in human populations and argue that CJD surveillance remains vital both from a public health perspective and to support essential research into disease pathophysiology, enhanced diagnostic tests and much-needed treatments.

Abstract

Despite the declining incidence of variant Creutzfeldt–Jakob disease, prion diseases remain a threat to public health. In this Review, Suvankar Pal and colleagues provide an up-to-date overview of the transmission of prion diseases in human populations and argue that CJD surveillance is still vital.

Key points

• Creutzfeldt–Jakob disease (CJD) is a transmissible and universally fatal human prion disease; surveillance programmes exist globally to monitor trends in CJD epidemiology and mitigate public health risks.

• The variant CJD (vCJD) epidemic was a devastating consequence of the bovine spongiform encephalopathy (BSE) epizootic.

• Studies indicate the widespread prevalence of vCJD-associated prion protein in BSE-exposed populations.

• Although new diagnoses of vCJD have declined in parallel with the suppression of BSE, lessons from other prion diseases indicate the potential for highly extensive incubation phases lasting decades.

• Emerging animal prion diseases might harbour the potential for zoonotic transmission to humans.

• Continued CJD surveillance is a necessity to meet the potential for further cases of vCJD or the emergence of novel prion diseases in humans.