Blog post as part of a series by Maria Amvrosiou for her fourth-year public engagement project.
Bovine Spongiform Encephalopathy (BSE) epidemic has been one of most important events in the history of UK. Thousands of cattle had been slaughtered and decades of people had died when the devastating disease spread to people. Following the previous post, some of the most important events of the BSE Epidemic will be discussed.
1986 – BSE firstly identified in the UK
After the first reported case of a cow featuring an aberrant mental status and novel clinical symptoms, more cases followed. BSE was first characterised as a slowly progressing encephalopathy in cattle with clinical symptoms of aggressive behaviour and altered mental status. Examination of the affected cattle revealed the characteristic formation of small pores in the brain and the accumulation of small fibres, resembling those found in the sheep equivalent disease, Scrapie.
Origin and cause of BSE epidemic
Early studies revealed that the use of meat-and-bone-meal (MBM) in cattle-feeding might have spread the BSE agent that led to the epidemic. MBM was manufactured using domestic animal waste tissue and converted into useful animal feed.
A very early hypothesis for the origin of BSE stated that it first emerged from cattle consuming scrapie-infected MBM. The BSE Inquiry report, however, concluded that the first BSE case originated as a result of a mutation (an alteration in the genetic code) in a cow that led to the development of the disease. The disease was then propagated through MBM feeding.
Malcolm Ferguson-Smith has been one of the greatest supporters of the latest hypothesis. The material in Archives and Special Collections reflects his continuing interest in following any updates related to BSE and also his interest in finding supporting evidence for his hypothesis. Specifically, in one of his correspondence it is stated that a novel mutation has been identified in a BSE case in USA, suggesting that such mutations are rare but should be expected. As he mentions in a Letter in Times, this observation provides evidence that it is possible for BSE to have originated from a novel mutation in a cattle.
1988 – Ruminant feed ban and BABs (born after the ruminant ban)
A feed ban that excluded the use of ruminant-derived tissues in MBM destined for cattle-feed was introduced as a response to the emerging epidemic. The dramatic reduction of cases shortly after, verified that MBM was indeed the vector of transmission, however it did not completely eliminate the disease.
1989 – Specified Bovine Offal (SBO) ban
The SBO ban prohibited tissues from cattle, which were proved to possess a risk in human health, from entering the human food chain.
1990 – Public announcements that beef is safe
Former Agriculture Minister, Mr John Gummer and Chief Medical Officer, Sir Donald Acheson made public statements that beef is safe to eat. It was quite remarkable at that time, that Mr John Gummer, in an effort to reassure that beef is safe to consume, fed his daughter a beef burger in public.
1995 – First victims of Variant Creutzfeldt-Jakob disease (vCJD)
A 19-year old was the first of several, to die of CJD, a human spongiform encephalopathy, with novel pathological features that had never been encountered before. A study reported that the cases identified were probably a new form of CJD, called variant CJD.
1996 – A possible link between BSE and vCJD
A possible association between BSE and vCJD cases was announced by the UK Government. The most probable route of infection was through the consumption of beef meat. Later studies in mice revealed that the diseases had various similarities, thus providing further evidence linking the diseases.
1998 – BSE Inquiry
The BSE Inquiry committee was set up by the UK Government with Professor Malcolm Ferguson-Smith being one of the three members of the committee. The aim of the inquiry was to review the events, up to 1996, leading to the BSE epidemic and the response of the UK government, taking into account the scientific knowledge of the time.
BARBS – born after the reinforced ban cases
A number of BSE cases continued to be born after a reinforced feed ban in 1996, raising particular concerns. Possible explanations included transmission of the disease from the mother and contamination of cattle feed with the infective agent.
Ferguson-Smith suggested that a remote although possible explanation is that BARB cases infected with BSE are the offspring of cattle which initially carried a mutation and initiated the BSE epidemic, as revealed in his correspondence with the Spongiform Encephalopathy Committee. He continued to say that such possibility could easily be tested via the DNA route by testing for any mutations in the prion gene.
Twenty years ago the UK had faced the challenge of a new devastating disease that cost several lives of both humans and cattle, while seeing its livestock completely decimating in the name of the new epidemic. With only a few BSE cases confirmed and no vCJD cases recorded in the UK since 2012, it can be argued that BSE epidemic has finally settled down.
You can view the catalogue for the Malcolm Ferguson-Smith collection here.
Maria would really appreciate some feedback on this blog-post for her project and if you would like to help her gather some statistics, please answer the questions in this questionnaire– your answers are anonymous and greatly appreciated. Thank you!
Bruce, M., Will, R., Ironside, J., McConnell, I., Drummond, D., Suttie, A., McCardle, L., Chree, A., Hope, J., Birkett, C., Cousens, S., Fraser, H. and Bostock, C. (1997). Transmissions to mice indicate that ‘new variant’ CJD is caused by the BSE agent. Nature, 389(6650), pp.498-501.
Bseinfo.org. (2016). BSE Info – BSE Origin. [online] Available at: http://www.bseinfo.org/bseorigin.aspx [Accessed 4 Dec. 2016].
Hill, A., Desbruslais, M., Joiner, S., Sidle, K., Gowland, I., Collinge, J., Doey, L. and Lantos, P. (1997). The same prion strain causes vCJD and BSE. Nature, 389(6650), pp.448-450.
Smith, P. and Bradley, R. (2003). Bovine spongiform encephalopathy (BSE) and its epidemiology. British Medical Bulletin, 66(1), pp.185-198.
Wells, G., Scott, A., Johnson, C., Gunning, R., Hancock, R., Jeffrey, M., Dawson, M. and Bradley, R. (1987). A novel progressive spongiform encephalopathy in cattle. Veterinary Record, 121(18), pp.419-420.
Wilesmith, J., Ryan, J. and Atkinson, M. (1991). Bovine spongiform encephalopathy: epidemiological studies on the origin. Veterinary Record, 128(9), pp.199-203.
Wilesmith, J., Wells, G., Cranwell, M. and Ryan, J. (1988). Bovine spongiform encephalopathy: epidemiological studies. Veterinary Record, 123(25), pp.638-644.
Will, R., Ironside, J., Zeidler, M., Estibeiro, K., Cousens, S., Smith, P., Alperovitch, A., Poser, S., Pocchiari, M. and Hofman, A. (1996). A new variant of Creutzfeldt-Jakob disease in the UK. The Lancet, 347(9006), pp.921-925.
Department of Health archive within The National Archives website
Debate about BSE health in the UK Parliament website
BSE Inquiry Report within the National Archives website
CJD figures within The National CJD Research & Surveillance Unit website
Cattle: TSE surveillance statistics in UK government page