Dierziekte scrapie aangetroffen bij schapen in Frankrijk en Cyprus - vraag en antwoord (en)

What are TSEs (Transmissible Spongiform Encephalopathies)?

TSEs are a family of diseases occurring in man and animals that are characterised by a degeneration of brain tissue giving a sponge-like appearance. The family includes diseases such as Creutzfeldt Jakob Disease (CJD) in humans, Bovine Spongiform Encephalopathy (BSE) in cattle and scrapie in sheep and goats. While BSE has only recently been identified, scrapie has been known about for centuries. On the basis of the available data, scrapie is not considered to be transmissible to humans nor to pose a risk to man. However, as a precautionary measure, EU legislation in place to prevent the spread and transmission of BSE also applies to sheep and to goats.

What is the difference between BSE and Scrapie?

Both BSE and Scrapie belong to a family of TSE diseases, caused by prions. Scrapie has existed for over 200 years in sheep without ever showing any signs that it can be transmitted to humans. BSE is a disease affecting cattle which was seen for the first time in 1986. It was discovered 10 years later that it could be transmitted to humans. BSE has never been detected in sheep before.

What EU legislation applies to small ruminants with regard to TSEs?

The EU TSE Regulation 999/2001 lays down the specific testing requirements for TSEs in small ruminants, as well as eradication measures to be carried out when a TSE is detected (e.g. culling of any sheep and goats infected with scrapie). Preventive measures against BSE, such as the feed ban and the removal of specified risk materials, also apply to small ruminants. The TSE Regulation is directly applicable in all Member States.

Why are samples from three sheep now being investigated?

Through the required monitoring programme for small ruminants laid down in EU legislation, three sheep (two in France, one in Cyprus) were found positive for TSE. Any positive TSE cases must be subjected to further tests to ensure that the TSE present is not BSE. In the case of these sheep, the initial "rule-out" tests identified unusual profiles and while some data suggested that the samples may not be BSE in sheep, there was insufficient evidence to definitively rule out the presence of BSE. This means that further "rule-out" tests are required. The definitive test is a mouse bio-assay, which the Community Reference Laboratory (CRL) will now carry out on tissues from the suspected sheep.

How long until the Community Reference Laboratory (CRL) confirms whether these sheep had BSE or Scrapie?

The CRL will now submit the samples to the third level of discriminatory testing (mouse bio-assay). This requires the inoculation of specifically-bred mice with the infected tissue from the affected sheep.

This inoculation will cause disease in the mice which can then be analysed. The analysis will allow the experts to tell definitively whether the disease in the sheep was really BSE or not. However because this type of testing requires the use of mice, it takes time. Normally 12-18 months will be required to conclude the investigations.

What is the process for testing for TSEs/BSE in the EU?

Monitoring for TSEs in domestic animals in Europe is extensive. All healthy slaughtered cattle over thirty months of age are tested at the abattoir for BSE. All animals over 24 months of age that die on farm or are culled for a disease must also be tested at the rendering plant. Finally, animals that display clinical signs of BSE must also be tested.

As for cattle, all sheep that display clinical signs of TSE must be tested. In addition, the EU monitoring programme requires that random samples be taken from the brains of animals both at the abattoir and at the rendering plant. In 2005, up to 10 000 tests per Member State were carried in healthy slaughtered sheep and as many again in fallen stock, depending on the size of the sheep population (statistically-based sampling).

How extensive is TSE testing in small ruminants?

Over 1 560 000 sheep and 410 000 goats have been tested in the EU since April 2002. This testing will now be increased further, so that 800,000 healthy slaughtered sheep in abattoirs and 140,000 dead sheep in rendering plants will be tested in the next 6 months. The tables below indicate the number of samples taken in sheep and goats from 2002-2005, and the number of those which tested positive for TSE:

Table 1: Summary of TSE testing in Sheep in the EU 25 from 2002 to 2005

Table 2: Summary of TSE testing in Goats in the EU 25 from 2002 to 2005

Does this finding of an unusual profile of TSE in the 3 sheep hold any threat for the consumer?

No. It should be remembered that the animals in question were detected due to the normal surveillance measures which have been in place for many years. EU measures against BSE have been applied to all farmed ruminants (cattle, goats, and sheep) to ensure the highest possible level of public health protection. These safety measures include a ban on the use of animal proteins (meat-and-bone meal) in feedstuffs, the removal of specified risk materials (e.g. brain, spinal cord, part of the intestines) from the food and feed chain, the slaughter of sheep and goat herds affected by scrapie, and the application of a TSE surveillance/monitoring programme. So, whatever the final findings show, there is no risk to public health, as the sheep did not enter the food and feed chain and strict animal health measures are applied to all farmed ruminants.

Are mutton and lamb still safe to eat?

Yes, mutton and lamb on the EU market can be considered as safe to eat, as stringent EU animal health and food safety rules apply to all meat sold for consumption. As a precautionary measure and following scientific advice, meat from flocks and cohorts which are affected by a BSE case, cannot enter the food chain. After the detection of BSE in a goat in 2005, the European Food Safety Authority (EFSA) was asked to assess the risk from eating the meat and meat products of goats. EFSA considered the risk to be low, due to the risk management measures already in place. There is currently no reason to expect that the risk from sheep meat would be different from goats. Nonetheless, EFSA has already started a quantative risk assessment on sheep meat (which began before these suspected cases even arose), and are due to give their Opinion before autumn 2006.

Are sheep milk and milk products safe for consumption?

After the detection of BSE in a goat in 2005, the EFSA was asked to assess the risk from milk and milk derivatives from small ruminants. EFSA found that these products from sheep and goats are unlikely to present any risk of TSE contamination, provided that milk is sourced from healthy animals. EU food safety rules ensure that only products from healthy animals are allowed to enter the food chain. Therefore, consumers should not be concerned about any health risk from sheep milk and milk products.

What scientific advice has been requested in relation to BSE in sheep?

Research is ongoing on BSE in sheep. Currently EFSA is studying questions on breeding programmes for TSEs in sheep (e.g. how to breed sheep that are more resistant to TSEs). It is also looking at the issue of specified risk materials, and the level of risk different ovine tissues would pose should BSE be confirmed in sheep. EFSA is expected to report their findings on this research in the coming months.

In light of the current findings in the 3 sheep being tested, how do we know that BSE is in not widespread in sheep?

The extensive testing conducted in Europe to date has only detected 3 possible cases of BSE in sheep, which are now being examined further. This indicates a very low prevalence of the disease. Sheep are more commonly affected by scrapie, and are not considered to be a natural host for BSE.

Have there been any more cases of BSE detected in goats since the confirmed case in 2005?

No further positive cases of BSE have been found in goats since the single case detected in January 2005 (see IP/05/132). This is despite increased in testing of goats (see table above), through which 1 111 positive TSE cases have been picked up since 2002, of which 179 were sent for subsequent discriminatory testing .

For more information on TSEs, see:

http://europa.eu.int/comm/food/food/biosafety/bse/index_en.htm