Transmissible spongiform encephalopathies (TSEs)


Transmissible Spongiform Encephalopathies (TSEs) are a group of diseases that affect the brain and nervous system of humans and animals. The diseases are characterised by a degeneration of brain tissue giving it a sponge-like appearance.

TSEs are caused by a prion (also known as PrPres), which is an abnormal form of a protein (known as PrPc).

TSEs include, among others:

  • Bovine Spongiform Encephalopathy (BSE) in cattle, including Atypical BSE
  • Scrapie in sheep and goats, including Atypical Scrapie
  • Chronic wasting disease (CWD) in deer, elk and moose
  • Transmissible mink encephalopathy (TME) in mink
  • Feline spongiform encephalopathy (FSE) in cats
  • variant Creutzfeldt-Jakob disease (vCJD) in humans

With the exception of the infectious agent causing BSE, which can be transmitted to humans through consumption of contaminated meat causing variant Creuzfeldt-Jakob disease, there is no scientific evidence that other TSE diseases can be transmitted to humans.  


EFSA’s role is to provide independent scientific advice to risk managers on all animal and public health related aspects of TSEs in the European Union (EU). Most of EFSA’s work is based on requests from the European Commission.

EFSA’s advice provide the scientific basis for EU measures to reduce the risks from TSEs and to maintain a high level of consumer protection in Europe.

Risk assessments and recommendations

EFSA has carried out comprehensive scientific work on different TSEs, especially on BSE, scrapie and CWD.

EFSA’s scientific work on TSEs is managed by the Panel on Biological Hazards (BIOHAZ), relying on the advice of leading experts in all aspects of TSEs, ranging from epidemiologists, pathologists and neuropathologists to experts in TSE diagnostic testing.

This work has included a review of the scientific evidence on possible links between TSEs in animals and humans prepared jointly by EFSA and the European Centre for Disease Prevention and Control. EFSA has also carried out several risk assessments on TSEs in small ruminants evaluating among others the risks of TSE transmission through milk or milk products and the TSE infectivity of small ruminant tissues.

Evaluation of TSE rapid tests

EFSA is also involved in preparing protocols for evaluating new rapid tests used to detect TSEs in animals, including ante- and post-mortem tests, as well as in the different steps of the test evaluation procedure.

EU framework

The European Commission and EU Member States have taken a series of measures to manage the risk of TSEs in the EU. There is a large body of legislation in place to protect humans and animals from these diseases. All EU measures on animal TSEs are gathered together in one main Regulation (No 999/2001).