Bovine spongiform encephalopathy (BSE)
Bovine Spongiform Encephalopathy (BSE) is a disease in cattle. It belongs to a group of diseases called Transmissible Spongiform Encephalopathies (TSEs) 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.
BSE was first diagnosed in 1986. Since 1989, the European Commission and the EU Member States have put in place a comprehensive series of measures to manage the risk of BSE in the European Union (EU).
BSE can be divided into Classical BSE and Atypical BSE. At present only the infectious agent causing Classical BSE has been demonstrated to be transmissible to humans.
Classical BSE was first diagnosed in the United Kingdom in 1986. It was first a European and later became a global problem affecting cattle. Epidemiological studies suggest that the source of this disease was cattle feed prepared from BSE-infected animal tissues, such as brain and spinal cord.
The common symptoms of Classical BSE in cattle include behavioural changes, lack of coordination, difficulty in walking or standing up, decreased milk production and weight loss. However, the disease has also been detected in animals showing no symptoms.
The infectious agent – a prion – which causes BSE in cattle can be transmitted to humans through consumption of contaminated meat causing variant Creuzfeldt-Jakob disease, which was first diagnosed in 1996. A prion is an abnormal form of a protein(known as PrPc).
EFSA’s role is to provide independent scientific advice to risk managers on all animal and public health-related aspects of BSE in the EU. Most of EFSA’s work is based on requests from the European Commission.
EFSA has carried out comprehensive scientific work regarding BSE. The Panel on Biological Hazards (BIOHAZ) has provided scientific advice on different aspects related to BSE such as:
- The EU monitoring regime
- Risks associated with certain animal tissues (specified risk materials)
- Risks associated with the use of animal proteins in animal feed
In addition to BSE in cattle, EFSA has also carried out assessments on the BSE infectivity in the tissues of small ruminants (sheep and goats). Based on available scientific evidence only one natural case of BSE (in a goat) has been found so far worldwide. The BIOHAZ Panel concluded that the likely prevalence of BSE in the wider EU small ruminant population is very low.
Previously, EFSA was also responsible for assessing the geographical BSE risk of countries. Given the global impact of BSE, the World Organisation for Animal Health (OIE) has since 2007 advised on the classification of BSE risks in different countries.
In the EU, a large body of legislation is in place to protect humans and animals from BSE and other animal TSEs.
The main measures for BSE include:
- A ban on using animal protein in feed given to animals farmed for food production.
- A comprehensive monitoring system, including post-mortem testing of healthy and at-risk animals over certain ages. Annually around 10 million cattle are tested for BSE in the EU.
- Compulsory removal and destruction of tissues containing the highest risk of BSE infectivity, such as the brain and spinal cord (Specified Risk Material, SRM) from bovine animals over a certain age.
- Following the detection of a positive BSE case, destruction of the carcass and culling strategies for herds with confirmed BSE cases.
The Commission has adopted a strategic document – the TSE Roadmap- which outlines possible future changes to EU measures on animal TSEs, including BSE, in the short, medium and long term until the year 2015. Due to the EU progress made in the battle against BSE changes to the main measures, such as the feed ban are expected.
- Information on risk management measures regarding BSE and TSEs - European Commission, DG Health and Consumers
- TSE Roadmap - European Commission, DG Health and Consumers