United Kingdom BSE outbreak

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
United Kingdom BSE outbreak
A plaque with gold letters on a black background saying "In loving memory of the victims of Human BSE (vCJD) – Always in our thoughts – Human BSE Foundation"
A plaque memorializing those who died of vCJD.
LocationUnited Kingdom
TypeDisease outbreak
Deaths177
InquiriesThe BSE Inquiry

The United Kingdom was afflicted with an outbreak of Bovine spongiform encephalopathy (BSE, also known as "mad cow disease"), and its human equivalent variant Creutzfeldt–Jakob disease (vCJD), in the 1980s and 1990s. Over four million head of cattle were slaughtered in an effort to contain the outbreak, and 177 people died after contracting vCJD through eating infected beef. A political and public health crisis resulted, and British beef was banned from export to numerous countries around the world, with some bans remaining in place until as late as 2019.[1]

The outbreak is believed to have originated in the practice of supplementing protein in cattle feed by meat-and-bone meal (MBM), which used the remains of other animals. BSE is a disease involving infectious misfolded proteins known as prions in the nervous system; the remains of an infected animal could spread the disease to animals fed on such a diet.

Background[edit]

A cow slumped forward in a stable facing the left of the photograph
A cow with BSE which has lost its ability to stand.

Bovine spongiform encephalopathy (BSE) is a neurodegenerative disease of cattle caused by misfolded proteins known as prions. Symptoms include abnormal behaviour, trouble walking, weight loss, and eventual paralysis.[2] Prion diseases such as BSE are universally fatal; the time between infection and onset of symptoms is generally four to five years and time from onset of symptoms to death is typically weeks to months.[3]

At the time of the outbreak, cattle farming was the largest sector of British agriculture, comprising up to 38 per cent of the United Kingdom's entire agricultural product, and was capable of providing the vast majority of domestic demand for beef and dairy.[4] This was due to policies enacted after World War II to reduce reliance on food imports and sustain rural areas, and strengthened after the United Kingdom's 1973 entrance to the European Economic Area provided the Common Agricultural Policy and a larger export market for farmers.[5] The cattle industry had produced a breed of dairy cattle that had high milk yields when fed a high-protein diet.[6] Feeds derived from animal sources, such as meat-and-bone meal (MBM), had been used since the early 20th century and were found to increase milk yields more than those derived from non-animal sources such as soybeans.[7] That dairy herds were fed such feeds more than beef herds ultimately proved immaterial since most British beef came from cattle in dairy herds.[8]

British cattle are believed to have become infected in large numbers in the 1980s through the use of MBM, which contained the remains of other animals.[9] This included the remains of cattle which had spontaneously developed the disease as well as sheep infected with scrapie, a similar disease in sheep, while the inclusion of brain and spinal cord tissue in MBM increased the likelihood of infection.[10]

Timeline of outbreak[edit]

1980s: First cases of BSE in cattle[edit]

Evolution of the Bovine spongiform encephalopathy (BSE) epidemic in the UK.

The earliest suspicions of BSE were on a farm in Sussex in December 1984,[11] and the earliest confirmed case was by a post-mortem examination of a cow from the same farm in September 1985, although it was not confirmed as such until June 1987.[12]

By November 1987, the British Ministry of Agriculture accepted it had a new disease on its hands.[13][14] In 1989, high-risk foodstuffs like offal were banned for human consumption and widespread fear about beef led many British consumers to stop purchasing it.[15]

1990–1994: Spread to other animals[edit]

A crucial basis for the government's assurances that British beef was safe was the belief that BSE-infected meat products would not be able to infect other animals. This was founded on their experience with scrapie-infected sheep, which had proven unable to cause any illness in humans.[16][17]

However, scientists studying BSE were already questioning this assumption and, on 10 May 1990, it was widely reported that a Siamese cat named Max had become infected with BSE, providing the first confirmation outside the laboratory that BSE could in fact be transmitted between species through eating infected meat.[18] Despite this, the government maintained that British beef was safe and, later that month, the then-Secretary of State for Environment, Food and Rural Affairs, John Gummer, appeared on TV encouraging his daughter to eat a beef burger, and declared British beef to be 'completely safe'.[19] Many more cats would go on to develop the disease, as would numerous other animals including at least one tiger in a UK zoo.[20]

Cases of the disease in cattle continued to rise despite bans on feeding offal to cows, and peaked with 100,000 confirmed cases in 1992-1993. In an attempt to stop the spread of the disease, a total of 4.4 million cattle were slaughtered during the outbreak.[15]

1994–1996: Spread to humans[edit]

In late 1994, a number of people began to show symptoms of a neurological disease similar to CJD, a fatal disorder that occurs naturally in a small percentage of people, though usually only later in life. This new form of the disease would go on to be identified as variant CJD (vCJD), occurring primarily in younger people and caused through eating BSE-infected meat.[21] The first known death from vCJD occurred on 21 May 1995, when the 19-year old Stephen Churchill died[21] although the UK government continued to emphasise the safety of British beef and, in September 1995, concluded that there was 'insufficient evidence' to link BSE and vCJD.[22] It was not until 20 March 1996 that Stephen Dorrell, the Secretary of State for Health announced that vCJD was caused by eating BSE-infected meat.[23]

177 people (as of June 2014) would go on to contract and die of the disease.[24][25]

Regulations and bans of British beef[edit]

When BSE was identified, the United States banned the importation of British cattle in 1989, and 499 cows who had been recently imported from the United Kingdom were destroyed. The United States slaughtered an additional 116 British cows in 1996.[26]

Between December 1997 and November 1999, the British government banned the sale of beef on the bone.[27]

A week after Dorrell's announcement, on 27 March 1996, the European Union (EU) imposed a worldwide ban on exports of British beef.[27] The ban would go on to last for 10 years before it was finally lifted on 1 May 2006, although restrictions remained on British beef containing vertebral material and beef sold on the bone.[28] The ban, which led to much controversy in Parliament and to the incineration of over one million cattle from at least March 1996, resulted in trade controversies between the UK and other EU states, dubbed a "beef war" by media.[29] France continued to impose a ban on British beef illegally long after the European Court of Justice had ordered it to lift its blockade, although it has never paid any fine for doing so.[30]

The BSE inquiry[edit]

During the height of the crisis, as well as after cases began to decline, the UK government came under criticism for its response, and in particular for how slow it was to acknowledge the problem, to inform the public, and to take steps to deal with the outbreak.[31]

On 22 December 1997, an inquiry was announced in parliament to investigate the history of the outbreak and the actions taken in response. The inquiry was conducted by a committee consisting of Lord Phillips of Worth Matravers, June Bridgeman, and Malcolm Ferguson-Smith. It provided its report in October 2000, and the report was published in full by Nick Brown, the secretary for agriculture at the time.[31]The inquiry report was critical of the government, the Ministry of Agriculture, Fisheries and Food, and Sir Donald Acheson the chief medical officer.[32]

Future risk[edit]

The original outbreak of vCJD only affected individuals with a particular genetic makeup; those who only make an M form of a particular protein. Studies of similar diseases in other parts of the world have shown that individuals with the M form tend to become ill quickly in a first wave, while individuals with the other, V form can be infected but asymptomatic for years or even decades.[33] This has led some researchers including Graham Jackson of the University College London to warn that there could be a second wave of vCJD infections years later.[33][34]

In late 2014, the first case was reported in an individual with the V form of the protein.[33]

See also[edit]

References[edit]

  1. ^ "Japan to scrap UK beef ban imposed after BSE crisis". BBC News. 10 January 2019. Retrieved 5 November 2019.
  2. ^ Casalone, C; Hope, J (2018). Atypical and classic bovine spongiform encephalopathy. Handbook of Clinical Neurology. 153. pp. 121–134. doi:10.1016/B978-0-444-63945-5.00007-6. ISBN 9780444639455. PMID 29887132.
  3. ^ "Bovine spongiform encephalopathy". WHO. November 2002. Archived from the original on 2012-12-18. Retrieved 27 October 2018.
  4. ^ Inquiry Report, Vol. 1 §119
  5. ^ Inquiry Report, Vol. 1 §120
  6. ^ Inquiry Report, Vol. 1 §121
  7. ^ Inquiry Report, Vol. 1 §122
  8. ^ Inquiry Report, Vol. 1 §123
  9. ^ Nathanson, Neal; Wilesmith, John; Griot, Christian (1997). "Bovine Spongiform Encephalopathy (BSE): Causes and Consequences of a Common Source Epidemic" (PDF). American Journal of Epidemiology. 145 (11): 959–69. doi:10.1093/oxfordjournals.aje.a009064. PMID 9169904.
  10. ^ "BSE in North America BSE (Bovine Spongiform Encephalopathy) Prion Diseases". CDC. 2 October 2018. Retrieved 26 October 2018.
  11. ^ Inquiry Report, Vol. 3 §1.9
  12. ^ Inquiry Report, Vol. 3 §1.7
  13. ^ Pain, Stephanie (5 November 1987). "Brain disease drives cows wild". NewScientist. Retrieved 7 December 2018.
  14. ^ "Mad Cow Disease Fast Facts". CNN. Retrieved 12 July 2019.
  15. ^ a b "'Mad cow disease': What is BSE?". BBC. 18 October 2018. Retrieved 12 July 2019.
  16. ^ Ridley, RM; Baker, HF (21 June 1999). "Big decisions based on small numbers: lessons from BSE". The veterinary quarterly (3): 86–92.
  17. ^ Sample, Ian (10 January 2007). "Should we still be worried?". The Guardian. Retrieved 15 July 2019.
  18. ^ Ainsworth, Claire; Carrington, Damian (25 October 2000). "BSE disaster: the history". New Scientist.
  19. ^ Nelson, Sarah (11 July 2019). "'Mad Cow Disease': Symptoms, Outbreaks And Everything You Need To Know". Huffington Post. Retrieved 12 July 2019.
  20. ^ Pattison, James (1998). "The emergence of bovine spongiform encephalopathy and related diseases". Emerging Infectious Diseases. 4 (3): 390–394. doi:10.3201/eid0403.980311. PMC 2640268. PMID 9716952.
  21. ^ a b Meikle, James (27 October 2000). "Sad and painful decline of a daughter". The Guardian. Retrieved 12 July 2019.
  22. ^ Beck, Matthias; Kewell, Beth; Asenova, Darinka (2007). "BSE crisis and food safety regulation: a comparison of the UK and Germany" (PDF). Archived from the original (PDF) on 20 February 2019. Retrieved 12 July 2019.
  23. ^ "The government acknowledged the possible link between BSE in cows and CJD in humans". Policy Navigator. Retrieved 12 July 2019.
  24. ^ "Variant Creutzfeldt–Jakob Disease, Current Data (October 2009)". The National Creutzfeldt–Jakob Disease Surveillance Unit (NCJDSU), University of Edinburgh. October 2009. Archived from the original on 21 July 2012. Retrieved 14 October 2009.;
  25. ^ "Variant Creutzfeldt-Jakob Disease Current Data" (PDF). June 2014. Archived from the original (PDF) on 26 February 2015. Retrieved 11 February 2015.
  26. ^ Sheen, p. 65
  27. ^ a b "BSE crisis: timeline". The Guardian. 26 October 2000. Retrieved 12 July 2019.
  28. ^ "End to 10-year British beef ban". BBC News. 3 May 2006.
  29. ^ "EU beef war escalates". CNNfn. 22 October 1999. Retrieved 4 June 2018.
  30. ^ Sparks, Ian (6 November 2008). "Yes, we had mad cow disease too, France confesses". Evening Standard. Retrieved 23 September 2017.
  31. ^ a b Ahmed, Kamal; Barnett, Anthony; Millar, Stuart (29 October 2000). "Madness". The Observer. Retrieved 12 July 2019.
  32. ^ "From nannyism to public disclosure: the BSE Inquiry report". Canadian Medical Association Journal. 164 (2): 165. 23 Jan 2001. PMC 80663. PMID 11332300.
  33. ^ a b c MacKenzie, Debora (18 January 2017). "Many more people could still die from mad cow disease in the UK". New Scientist. Retrieved 16 July 2019.
  34. ^ Toolis, Kevin (22 September 2001). "Epidemic in waiting". The Guardian. Retrieved 16 July 2019.

Works cited[edit]