General Q&A - Animal Health Controls & Surveillance
Feed Controls
- An indepth Q&A
can be found on the Feed Ban webpage.
Notification Of TSEs / Compensation Paid
Procedures following notifications of suspicion of animals affected by either BSE or Scrapie
Q.1 What happens if the Veterinary Officer
(VO) decides that an animal is not affected with BSE or scrapie?
Q.2 What happens if the Defra vet's inspection is inconclusive?
Q.3 What if an animal recovers after an inconclusive
diagnosis?
Q.4 What happens if the Defra vet suspects that the
animal is suffering from BSE/scrapie?
Q.5 What if a BSE or a scrapie suspect animal is pregnant?
Q.6 Will reporting suspect cases place any restrictions
on the rest of the other animals on the farm?
Q.7 When do you expect to use the powers to restrict
a flock?
Q.8 Will reporting a suspect case of BSE place any restrictions
on the suspect's off-spring?
Q.9 Will reporting a suspect case of scrapie place any
restrictions on the suspect's off-spring?
Compensation
Q.10 Are owners of cattle slaughtered
as being BSE suspects eligible for compensation?
Q.11 How is the compensation calculated?
Q.12 Is compensation offered to the owners of sheep
and goats slaughtered as suspected of having SEs?
Q.13 Why is there a £400 limit on the higher
rate of compensation? Pedigree animals are frequently worth much more
than this.
Q.14 What are the slaughter and compensation schemes
expected to achieve?
Surveillance Of TSEs - EC Legislation
Q.15 What EC legislation covers surveillance of TSEs
such as BSE and scrapie?
Q.16 What does the Regulation require EC Member States
to do?
Q.17 What does the monitoring system required by the
Regulation involve?
Surveillance for Scrapie in sheep
Q.18 What is the Scrapie Postal Survey?
Q.19 Where were the findings of the postal survey published?
Q.20 How many of the farmers responded?
Q.21 Why was the survey anonymous?
Q.22 How many of the farmers in this survey reported
scrapie on their farms?
Q.23 So most sheep farmers have not seen scrapie on
their farms?
Q.24 Could farmers be confusing scrapie with other
diseases?
Q.25 What is Defra doing to encourage the identification
and reporting of scrapie?
Surveillance for TSES in other animals
Q.26 In what ways are SEs in other animals monitored?
Diagnostic Tests for BSE
Q.27 What tests are used to confirm BSE
in an animal that is reported to Defra as a BSE suspect as part of
the surveillance programme?
Q.28 What tests are used to test for BSE in animals
in the abattoir, as part of the active surveillance programme?
Q.29 What are the newer tests that that have been validated
by the European Commission, for the post-mortem diagnosis of BSE?
Q.30 Can these tests also detect TSEs in sheep
and goats?
Q.31 How do these tests work?
Q.32 Which tests are the Swiss and French governments
using?
Q.33 Which rapid tests are the VLA using?
Q.34 What are the advantages of developing tests for
use at the VLA?
Q.35 Could the other tests not just be bought in and
used straight away?
Q.36 What measures have the UK introduced to protect
public health?
Q.37 Can post-mortem testing detect infectivity in
young animals?
Q.38 Are there any live-animal tests?
Notification Of TSEs / Compensation Paid
Q.1. What happens if the Veterinary Officer (VO) decides that an animal is not affected with BSE or scrapie?
A. If the VO considers that the animal is not affected no movement restrictions will be enforced. The animal will not be slaughtered. The owner should consult his own vet about a diagnosis and treatment of the animal.
Q.2. What happens if the Defra vet's inspection is inconclusive?
A. If a diagnosis is inconclusive the VO will serve a Movement Restriction Order, and will revisit the animal within 28 days. If the diagnosis is still uncertain another Movement Restriction Order may be served. This may occur several times. Eventually, a diagnosis will be reached in that the animal will either
- recover, or
- be diagnosed as having another illness or,
- become a BSE/scrapie suspect.
If a diagnosis is inconclusive the animal may still be slaughtered if this proves necessary for welfare reasons. If after slaughter, a laboratory diagnosis confirms BSE/scrapie, compensation will be payable, on an ex-gratia basis.
Q.3. What if an animal recovers after an inconclusive diagnosis?
A. If on a revisit the Veterinary Officer is satisfied that an animal is not affected with BSE or scrapie then the Movement Restriction will be lifted.
Q.4. What happens if the Defra vet suspects that the animal is suffering from BSE/scrapie?
A. If the VO suspects that the animal is infected with BSE/scrapie, a Movement Restriction Order will be served.
In the case of BSE in cattle, most animals will be slaughtered on farm and the carcase will be taken to an incinerator for destruction at Government expense. Its brain will be sent to a Government laboratory for confirmation of the disease.
In the case of sheep and goats, the animal will be tagged and moved to a Veterinary Investigation Centre (VIC) for laboratory diagnosis. In some cases the suspect will be transported alive. However, where the suspect's welfare would be compromised by transport, it will be slaughtered and the carcase delivered to a VIC.
Q.5. What if a BSE or a scrapie suspect animal is pregnant?
A. If a suspect animal is pregnant and the VO serves a Movement Restriction Order, the following conditions will apply:
- the animal must be isolated from all other animals during labour and for 72 hours afterwards in accommodation approved by the vet;
- the placenta, discharges and bedding must be buried or burned; and
- the accommodation must be cleansed and disinfected afterwards in accordance with the guidance of the Veterinary Officer.
Q.6. Will reporting suspect cases place any restrictions on the rest of the other animals on the farm?
A. Not normally. However, in the case of SEs in sheep and goats the legislation does provide powers for a veterinary inspector to prohibit the movement of any flock, where he has reasonable grounds for believing that the movement of any animal from that flock may give rise to the spread of disease.
Q.7. When do you expect to use the powers to restrict a flock?
A. At present, there is no legal requirement to restrict additional animals while we investigate the rest of the flock. However, Commission Regulation (EC) No 260/2003 requires that, from 1 October 2003, on the detection of scrapie on a holding:
(i) either the killing and complete destruction of certain animals, embryos and ova identified as being at risk; or
(ii) the killing and complete destruction of certain animals, embryos and ova identified as being at risk, with the exception of:
- breeding rams of the ARR/ARR genotype,
- breeding ewes carrying at least 1 ARR allele and no VRQ allele, and
- sheep carrying at least one ARR allele which are intended solely for slaughter,
(iii) if the infected animal has been introduced from another holding, based on the history of the case, the same eradication measures may be applied in the holding of origin in addition to, or instead of, the holding in which the infection was confirmed. In the case of land used for common grazing by more than one flock, these measures may be applied to a single flock, based on a consideration of all the epidemiological factors.
Only the following animals may be introduced to the holding(s) where such destruction hasbeen undertaken:
(a) male sheep of the ARR/ARR genotype;
(b) female sheep carrying at least 1 ARR allele and no VRQ allele;
(c) Caprine animals, provided that:
- no ovine animals other than those of the ARR/ARR genotype are present on the holding,
- thorough cleaning and disinfection of all animal housing on the premises has been carried out following de-stocking,
- the holding shall be subjected to intensified TSE monitoring, including the testing of all culled and dead on-farm caprine animals over the age of 18 months.
During autumn 2003, Defra will consult the industry and other interested bodies ondomestic legislation to implement these new requirements. The new legislation is expected to come into effect in spring 2004.
Q.8. Will reporting a suspect case of BSE place any restrictions on the suspect's off-spring?
A. Yes. As a condition of the Date Based Export Scheme (the DBES) the UK must slaughter all offspring born on or after 1 August 1996 to dams in which BSE has been confirmed. Therefore as soon as a cow is placed under restriction as a BSE suspect a search is made on a computer database to enable all its offspring to be traced and their movements to be restricted. If BSE is subsequently confirmed in the dam, the off-spring will be slaughtered.
Q.9. Will reporting a suspect case of scrapie place any restrictions on the suspect's off-spring?
A. No.
Compensation
Q.10. Are owners of cattle slaughtered as being BSE suspects eligible for compensation?
A. . Currently, there are no approved tests for the diagnosis of BSE in live animals. However, Defra has funded a lot of research aiming to develop a test in live animals, including cattle. Further information on this research is available.
Q.11. How is the compensation calculated?
A. In England and Wales, the compensation payable for animals slaughtered because they are suspected of being affected with BSE is determined in accordance with the Transmissible Spongiform Encephalopathies (No.2) Regulations 2006 or the Bovine Spongiform Encephalopathy (BSE) Compensation (Wales) Regulations 2006 using a compensation table.
Animals are categorised on the date the notice of intention to slaughter is served. The compensation payable is determined from the valuation table for the month in which the animal is slaughtered. Further details are available. The monthly compensation tables are published on the Defra website.
In Scotland, the compensation payable for animals slaughtered because they are suspected of being affected with BSE is determined in accordance with the TSE (Scotland) Regulations 2002:
- The compensation payable for slaughtered suspects confirmed to be affected with BSE is an amount equal to either the Indicative Market Price or the market value, whichever is lower;
- The compensation payable for slaughtered suspects not confirmed to be affected with BSE is an amount equal to either 125% of the Indicative Market Price or the market value, whichever is lower.
Details of compensation payable for the slaughtered offspring of confirmed BSE cases are available.
Q.12. Is compensation offered to the owners of sheep and goats slaughtered as suspected of having SEs?
A. Yes. Under the terms of the TSE (England) Regulations 2002, owners of animals caused by the Minister to be slaughtered are eligible to receive a compensation payment.
Q.13. Why is there a £400 limit on the higher rate of compensation? Pedigree animals are frequently worth much more than this.
A. The animals were showing signs of a serious neurological disease when they were slaughtered and would very likely have died anyway. We would expect that the owners of valuable animals would have private insurance arrangements in place.
Q.14. What are the slaughter and compensation schemes expected to achieve?
A. The slaughter and compensation schemes are expected to improve the surveillance of TSEs in cattle, sheep and goats by the removal of disincentives to the farmer for reporting the disease. The scheme will improve current controls on affected animals and will also provide additional information and materials for the study of the disease.
Surveillance of TSEs - EC Legislation
Q.15. What EC legislation covers surveillance of TSEs such as BSE and scrapie?
A. Surveillance of TSEs is covered by (EC) Regulation 999/2001 as amended.
Q.16. What does the Regulation require EC Member States to do?
A. Regulation 999/2001 requires that:
- relevant personnel are familiar with the clinical signs of disease (Article 10)
- TSEs be made notifiable diseases (Article 11)
- suspect animals be placed under movement restrictions (Article 12[1])
- suspect animals be slaughtered, relevant material be used for laboratory diagnosis and that the carcase be retained under official control until a negative diagnosis has been made, or be destroyed(Article 3[2])
- Member States monitor the occurrence of TSEs (Article 6)
- Member States report annually to the Commission (Article 6[4])
Q.17. What does the monitoring system required by the Regulation involve?
A. Member States must test for TSEs:
- All bovine animals over 24 months of age slaughtered for human consumption;
- All bovine fallen stock over 24 months of age;
- All bovine casualty animals over 24 months of age;
- All OTMS animals from the 1996-97 cohort;
- A random sample of around 10,000 OTMS animals per year born before 1 August 1996;
- All OTMS animals aged over 30 months and born after 1 August 1996;
- A random sample of 10,000 ovine animals aged over 18 months and slaughtered for human consumption, per year;
- A random sample of 10,000 fallen ovine animals aged over 18 months, per year;
- All caprine animals aged over 18 months and slaughtered for human consumption, per year;
- A random sample of 1000 fallen caprine animals aged over 18 months, per year.
Completed TSE surveys carried out in previous years
Surveillance for scrapie in sheep
Q.18. What is the Scrapie Postal Survey?
A. The latest scrapie postal survey of October 2002 was a follow up to the previous survey conducted in 1998 and was carried out in order to obtain a more up to date snapshot of farmers’ experience of the disease in Great Britain. It was an anonymous survey by postal questionnaire sent to 12,800 randomly selected sheep farms.
Q.19. Where were the findings of the postal survey published?
A. The preliminary findings were presented in a paper entitled 'Occurrence of scrapie in Great Britain: results of a postal survey in 2002' published in The Veterinary Record in 2003 (vol.153, no 25, pages 782-783).
Q.20. How many of the farmers responded?
A. 53.1% of the questionnaires were returned and analaysed.
Q.21. Why was the survey anonymous?
A. The incidence of scrapie is difficult to assess in part because some farmers will be reluctant to report cases for fear of consequent loss of trade and also the symptoms can be confused with other diseases. Pilot surveys used to inform the design of this survey suggested an anonymous survey as one method to assess the incidence of scrapie and farmers' knowledge of the disease.
Q.22. How many of the farmers in this survey reported scrapie on their farms?
A. 1.0% of the farmers who responded believed that they had recently seen a case of scrapie on their farm - i.e. in the 12 months prior to the survey. This compares with 2.7% in the 1998 survey. Possible explanations for this difference include sampling variation, a change in farmers’ knowledge of the disease and their attitude to reporting and a real change in occurrence. A more detailed analysis of the results will address these issues. The 2002 survey also indicated that 2.8% of farmers believed that they have had a case of scrapie in the preceding 5 years.
Q.23. So most sheep farmers have not seen scrapie on their farms?
A. The survey shows that the vast majority of sheep farmers even if asked anonymously report that they have not seen scrapie on their farms.
Q.24. Could farmers be confusing scrapie with other diseases?
A. This is possible. Scrapie can be difficult to diagnose in
live animals. Many of the symptoms on their own could be indicative of
other diseases, but it must be appreciated that a farmer who has reason
to suspect scrapie is required to report it, whatever the eventual diagnosis.
Defra will prosecute whenever it is clear that a farmer has knowingly
refused to notify the authorities where he had grounds to suspect that
he had a case of scrapie in his flock.
Q.25. What is Defra doing to encourage the identification and reporting of scrapie?
A. Defra are very conscious of the need to take all possible steps to ensure that any suspicion of scrapie is reported. Initiatives in place are:
- Compulsory slaughter - with compensation - for sheep or goats suspected of having scrapie was introduced in July 1998 . The Sheep and Goats Spongiform Encephalopathy (England and Wales) (Compensation) (Amendment) Order 2001 , which came into force on 14 December 2001, revoked by The TSE (England) Regulations 2002, which came into force on 19 April 2002 - increased the rate of compensation for scrapie cases to £30 for cull animals and £90 for any other affected animal;
- A video on the clinical signs of scrapie has been added to the Defra publications catalogue. It was sent to State Veterinary Service Animal Health Offices for training purposes who publicised its availability to veterinary practices and sheep farmers;
- In 2004, a DVD was produced which combined the contents of both the scrapie video and a similar video on clinical signs of BSE. This was sent to SVS Animal Health Offices.
-
An Advisory Notes to Farmers
(288 KB) on scrapie was published in November 1999 and a revised edition
was published in April 2004.The note explains:
-
why it is important to report the disease;
-
that scrapie is notifiable, with severe penalties for not reporting it;
-
the symptoms;
-
the notification procedures; and
-
that compensation is paid.
Surveillance for TSEs in other animals
Q.26. In what ways are SEs in other animals monitored?
A. There is a free service, which the Veterinary Laboratories Agency of Defra offers to veterinary surgeons in GB to investigate the presence of TSEs in other species. Animals, including pets or zoo animals of any species, which a private veterinary surgeon suspects might have signs of a progressive neurological disease, can be examined for evidence of a spongiform encephalopathy without charge. This means that there is a comprehensive system for monitoring TSEs in animals. To date this service has identified 89 cases of FSEs in domestic cats, the most recent one in 2001. It has also identified 37 cases of TSEs in zoo animals, including big cats and various species of antelope. The most recent case was in a 14 year old lion in 2001.
Following the first confirmation of Feline Spongiform Encephalopathy (FSE) in a cat in 1990, a small random survey was carried out on hunting hounds to determine whether TSEs could be present in dogs. These animals were chosen because they were fed on raw material from dead cattle, which could have included parts of the carcase which contained BSE infectivity. The dogs tested were not those that had died of natural causes but those that were culled from hunting packs for other reasons. The examination was hampered by the deterioration of the brain tissue after death, but no confirmed TSE disease was found.
In preparation for a possible systematic monitoring of deer, the Veterinary Laboratories Agency has carried out some trials to evaluate testing methods. In 2002 and 2003, they examined around 400 samples from dead deer collected for tuberculosis testing. All were negative for TSEs. In 2003 a total of 249 deer (mostly fallow deer) were culled from the Royal Parks. All were negative for TSE.
Diagnostic tests for BSE
Q.27. What tests are used to confirm BSE in an animal that is reported to Defra as a BSE suspect, as part of the passive surveillance programme?
A. When BSE suspects are slaughtered, the primary test for diagnosis is histopathology. This is the gold standard against which all the other tests have to be validated, and continues to be used to ensure that any variations in the pathology of BSE during the epidemic are detected. This is also a requirement of the agreed EU Diagnostic Manual and of the OIE. The histopathology test is performed post-mortem and requires brain material which firstly has to be preserved in formalin, and is then stained and examined under the microscope for the characteristic appearance of BSE specific changes. If there is any degree of decomposition before the brain is examined then histopathology may be difficult to analyse.
Western blotting and immunohistochemistry (IHC) are
now also used routinely for all suspects born from 1996 onwards and
on suspects born before 1996, which are negative on routine histopathological
examination. The Western blot test is used to detect PrPSc protein
extracted from treated brain material. The PrPSc is separated by its
molecular weight and is detected by its reaction to specific antibodies.
IHC also relies on the detection of PrPSc using specific antibodies.
Preserved post-mortem brain material is required, but this test is
performed directly on the tissue section and does not involve any
protein purification steps. On clinically affected cattle it is considered
to be one of the most sensitive tests for confirmation. IHC can also
work on other tissues, such as the third eyelid or tonsil of sheep.
Work is under way both in Britain and abroad to determine exactly
how useful it would be to take biopsies of these tissues while the
animal is still alive, as a means of screening flocks.
Q.28. What tests are used to test for BSE in animals in the abattoir, as part of the active surveillance programme?
A. Brain samples from the animals to be tested are analysed using EU approved rapid testing procedures. These tests are quicker to perform than the conventional methods and enable larger scale testing.
Q.29. What are the newer tests that have been validated by the European Commission, for the post-mortem diagnosis of BSE
A. In total, thirteen tests that have been validated following three field trials carried out by the European Commission. All tests have only been evaluated on adult cattle showing clinical signs of BSE and confirmed to have the disease. They have not yet been proved to be effective in detecting infected animals, a long time before they develop clinical symptoms, which usually occurs at four to six years of age.
In the 1999 evaluation, three tests were approved. These were:
- Prionics Check Western;
- Enfer TSE assay;
- Bio-Rad TeSeE Bovine Western Blot.
In a subsequent evaluation in 2002, two further tests were approved. These were:
- Prionics Check LIA test;
- InPro CDI test.
Seven additional tests were approved by the European Commission in 2004. These were:
- CediTect BSE Test;
- Enfer TSE Kit version 2.0, automated sample preparation;
- IDEXX HerdChek BSE Antigen Test Kit, EIA;
- Institut Pourquier Speed´it BSE;
- Prionics Check PrioSTRIP;
- Roboscreen Beta Prion BSE EIA Test Kit;
- Roche Applied Science PrionScreen.
Finally in 2005, an additional test was approved. This was the Fujirebio FRELISA BSE post mortem rapid BSE Test.
Q.30. Can these tests also detect TSEs in sheep and goats?
A. The following eight tests were assessed and approved in 2005 by the European Commission for the diagnosis of classical scrapie and BSE in sheep: Bio-Rad TeSeE, Bio-Rad TeSeE sheep/goat, Enfer TSE Test, Idexx TSE post mortem Test, InPro CDI-5, Institut Pourquier Scrapie ELISA test, Prionics Check LIA SR, and Prionics Check Western SR. The Fujirebio FRELISA post mortem Test was not deemed suitable.
Q.31. How do these tests work?
A. All of these rapid tests operate by detecting the disease-associated form of the prion protein (PrPSc) in the central nervous system. Following slaughter of the animal, a sample of brain or spinal cord is taken to the laboratory and tested for the presence of PrPSc. The tests developed detect PrPSc by using either a Western Blot technique or an ELISA (Enzyme-Linked Immunosorbent Assay) based test. Both assays use antibodies to detect the presence of the disease-associated form of the prion protein, and the ELISA-based assays are generally considered to be more high-throughput techniques, as they allow the analysis of a larger number of samples.
Q.32. Which tests are the Swiss and French governments using?
A. The Swiss are using both tests produced by Prionics, as well as the Bio-Rad TeSeE assay. The French government are using the Prionics Western Blot in their surveillance programme along with the Bio-Rad TeSeE test. All the tests analyse brain samples taken post-mortem, and enable testing within 24 hours of collection.
Q.33. Which rapid tests are the VLA using?
A. Following successful assay optimisation steps, the VLA now has the capacity to effectively use several of the rapid tests, including the Bio-Rad TeSeE test, the Prionics Check Western, and the InPro CDI. In addition, through successful collaborations, the VLA has been instrumental in developing the IDEXX Herdchek.
Q.34. What are the advantages of developing tests for use at the VLA?
A. It is difficult to run a large surveillance programme by sending samples abroad for testing. Ideally, Defra needs a capacity to test thousands of samples in its own laboratories, so that it can give the appropriate priority to the work. Although Enfer and Prionics are testing commercially, the logistics of sending large numbers of samples internationally are considerable and indeed illegal at present for non-research purposes.
Q.35. Could the other tests not just be bought in and used straight away?
A. The EU has introduced surveillance requirements that will require member states to undertake testing programmes, using one of the EU validated tests. Even when available on a large scale, the introduction of any new test into a laboratory requires time to ensure that it is working as efficiently as it did in the laboratory where it was developed.
Q.36. What measures have the UK introduced to protect public health?
A. The primary BSE control, involves the removal of Specified Risk Material (SRM), which removes more than 99% of any infectivity that may be present. Additionally the Over Thirty Months (OTM) Rule is the BSE control, set up in 1996, that automatically bans older cattle from entering the human food chain. However, in September 2005, the Government agreed to lift the OTM Rule, following advice from the Food Standards Agency stating that the current control measures are no longer proportionate to the risk. It was recommended that the OTM Rule should be replaced with BSE testing of all cattle older than 30 months that are destined for human consumption. This is the line with other member states of the European Union, which currently test all cattle over thirty months of age intended for human consumption. Only the meat from those with negative results is allowed to enter the food chain. There are also controls on Specified Risk Materials in all member states.
Q.37. Can post-mortem testing detect infectivity in young animals?
A. We know that some of the available tests are as good as conventional diagnostic tests i.e. they detect all of the clinical cases, which are confirmed as BSE by examination of the brain. However, we do not know yet whether they can be used to detect pre-clinical disease effectively. In its OTM Rule review, the FSA considered that the BSE tests would only be able to detect clinical cases. They considered that this measure combined with the removal of SRM would ensure that the risks of infected material entering the food chain remained extremely low.
Q.38. Are there any live-animal tests?
A. Currently, there are no tests for the diagnosis of BSE in live animals. However, Defra (and previously MAFF) has funded a lot of research aiming to develop a test in live animals, especially in cattle, but none have so far progressed to the point of being better than the clinical judgement of Defra's veterinary officers.
Page last modified:
18 March, 2008