General Q&A
Section 1: BSE Epidemic
BSE Statistics
Q.1. How many cases of BSE have been confirmed in the UK?
Q.2. What is the percentage change in incidence?
Q.3. How many cases of BSE have been confirmed in UK by active surveillance?
Q.4. How many dairy cattle have been affected?
Q.5. How many suckler cattle have been affected?
Q.6. How many herds have only had one case?
Q.7. What is the current trend in BSE cases?
Q.8. Is there any under-reporting of BSE suspects?
Q.9. At what age does BSE affect cattle?Born After the Ban cases
Q.10. What are 'Born After the Ban' (BAB) cases?
Q.11. What is the reason for these cases?
Q.12. How many BAB cases have there been?Born After the Reinforced Ban Cases
Q.13. What are 'Born After the Reinforced ban' (BARB) cases?
Q.14. What is the Significance of cases born after 1 August 1996?
Q.15. Why are we still getting BARB cases?
Q.16. Are there any public health implications?
Q 17. How does the Government follow up BARB cases?
Q.18. How many BARB cases have been confirmed in the UK?
Q.19. How many BARB cases have been confirmed in UK in the 12 months to 31 January 2006?
BSE Epidemic
Q.1. How many cases of BSE have been confirmed in the UK?
A. Current total: Information available.
Breakdown by passive and active surveillance: Information available.
Q.2. What is the percentage change in incidence?
Q.3. How many cases of BSE have been confirmed in the UK by active surveillance?
Q.4. How many dairy cattle have been affected in the UK?
Q.5. How many suckler cattle have been affected in the UK?
Q.6. How many herds have only had one case?
Q.7. What is the current trend in BSE cases?
A. restricted each week is now 6 times lower than when the disease was made notifiable in 1988. There are now fewer than 4 suspected clinical cases restricted per week, compared to more than 850 per week in 1992. Fewer than 25% suspects slaughtered are now confirmed to have BSE.
Q.8. Is there any under-reporting of BSE suspects?
A.The low confirmation rate indicates over-reporting of clinical suspects. Some of the cases detected by active surveillance are retrospectively discovered to have exhibited at least one of the signs of BSE (e.g. recumbency). Farmers are compensated for slaughtered BSE suspects according to fixed monthly values for standard categories (based on current market values) so there is little incentive for breaking the law by not reporting BSE suspects.
Q.9. At what age does BSE affect cattle?
Born After the Ban cases (BABs)
Q.10. What are 'Born After the Ban" (BAB) cases?
A.These are cattle which were born after the ban on the feeding of ruminant protein to ruminants, which was introduced in July 1988.
Q.11. What is the reason for these cases?
A.While the 1988 feed ban greatly reduced the number of BSE cases that occurred, it was not totally effective. There was some carry-over of infected feed produced before the ban. There was also continued cross-contamination of cattle feed with mammalian meat and bone meal used legitimately at that time, in pig and poultry rations.
Q.12. How many BAB cases have there been in the UK?
Q.13 What are ‘Born After the Reinforced Ban” (BARB) cases?
A.These are BSE cases in cattle born after 31 July 1996 when the ban on feeding of mammalian meat and bone meal (MMBM) to farmed livestock is considered effective.
Q.14. What is the significance of BARB cases?
A.Additional controls have been in place since 1 August 1996 to prohibit the feeding of MMBM to all farmed livestock, in order to prevent any possibility of it being fed ruminants. Fewer than 0.1% of BSE cases in UK were born after July 1996. Experts predicted a small number of BARB cases.
In November 2004,Defra commissioned an independent review
of BARB cases by Professor William Hill. The review
,
published in July 2005, concluded that elimination of feed borne sources
of infection is the key to the elimination of BSE, and that Defra's
controls in place to eliminate BSE, are soundly based.
Q.15. Why are we still getting BARB cases?
A.In his 2005 review, Professor Hill recommended that Defra continues to operate on the basis that BSE transmission via feed is the major route of infection in BARB cases. Current scientific evidence indicates that as little as 1 milligram of BSE-infected brain tissue is sufficient to infect a calf.
Importation of contaminated feed is a possible source of infection since total feed controls in some parts of Europe were not introduced until 2001 or later. Other sources of feed contamination, including carry-over of feed produced either before the UK or the EU feed bans, cannot be ruled out in some cases.
The probability of maternal transmission is now estimated to be approximately 1% in the last six months of the maternal incubation period. Maternal transmission is not implicated in the majority of BARB cases. The Spongiform Encephalopathy Advisory Committee has advised that maternal transmission would not sustain the BSE epidemic in cattle.
Q.16. Are there any public health implications?
A.The public health implications are negligible. All carcases of BSE suspects are incinerated. All cattle are subject to ante-mortem veterinary inspection before slaughter for human consumption. For any animal incubating BSE, the specified risk material (SRM) controls are estimated to remove over 99% of any infectivity present. In addition all healthy cattle aged over 30 months of age and all emergency slaughtered cattle aged over 24 months of age must first test negative for BSE before their carcases are released for human consumption. Any such carcase which is not tested, or tests positive for BSE mustbe disposed of, in addition to the carcase before and the two carcases after it, on the slaughter line.
The UK culls and incinerates the cohorts of all BSE cases where cohort animals are born after July 1996. A cohort is defined a group of bovine animals which were:
(i) born in the same herd as the affected bovine animal, and within 12 months preceding or following the birth of the affected animal; or
(ii) reared together with the affected bovine animal at any time during the first year of their life and which may have consumed the same feed as that which the affected bovine animal consumed during the first year of its life.
In summary, cohorts are cattle potentially exposed to the same feed as a BSE case at the age when they are most likely to be infected with BSE. The UK also culls the offspring of female BSE cases, where those offspring are born within two years prior to, or any time after, the onset of clinical disease. Both cohorts and offspring are restricted on suspicion of disease in the index case.
See also the Food Standards Agency and SEAC.
Q.17. How does the Government follow up BARB cases?
A. The State Veterinary Service carries out detailed investigations into the background of BARB cases in order to study the possible origins of the infection. In most cases it is not possible to determine the precise source of infection. Results of these investigations are used in epidemiological analysis. The cohorts and offspring of the affected animals are laughtered as detailed above. All cohorts are tested for BSE.
Q.19. How many BARB cases have been confirmed in UK in the 12 months to 31 July 2006?
Page last modified:
18 June, 2007
Page last reviewed: 20 October, 2006