Defines the number of recorded cases of Bovine SpongiformEncephalopathy (BSE) in the UK as comprising those reported to theMinistry of Agriculture, Fisheries and Food…
Defines the number of recorded cases of Bovine Spongiform Encephalopathy (BSE) in the UK as comprising those reported to the Ministry of Agriculture, Fisheries and Food (MAFF) and checked by them using histopathological techniques. Proposes that, if it is assumed that BSE is a similar condition to other mammalian transmissible spongiform encephalopathies (TSEs), and if other specific assumptions are made, it is possible to estimate the true number of cases of BSE and, hence, the number of human beings who have been infected in the UK. States that approximately 6.87 per cent of cattle born in 1988 became infected with BSE, with lower numbers in antecedent years, and that BSE cases reported in the UK represent approximately 23 per cent of the cattle which have become infected and are hence potentially infective to other animals, including man. Discloses the fact that TSEs of animals, of which BSE is one, can be transmitted to a mean of at least 70 per cent of other species and that oral transmission has been successful. Uses the potential levels of infectivity of the bovine products present in human food in the UK from 1984 to 1997, together with data as to individual diets within the population, to assess the number of people who would be expected to have eaten the minimum potentially infective dose or more. Discusses the possible effects on human health.
Outlines the scientific evidence surrounding the occurrences of bovine spongiform encephalopathy (BSE) and Creutzfeldt‐Jakob Disease (CJD) in the UK. Examines the background to and development of the recent outbreaks and their possible causes. Looks in detail at the role of prions, the encephalopathy infective agent, the origins of the disease and its transmission in cattle and the controls which have been introduced to minimize the impact of the disease. Examines the evidence as to whether BSE can be transmitted to humans in the form of V‐CJD (variant Creutzfeldt‐Jakob Disease), in the light of the UK government announcement of 20 March 1996 that eating infected beef products was the most likely cause. Briefly discusses which parts of BSE‐infected cattle carry the infective agent, measures taken which affect the food chain and research which is being undertaken in the field. Concludes that muscle meat, milk and milk products and tallow from British beef are safe within the normal meaning of the term.
Considers recent developments in bovine spongiform encephalopathy (BSE)and their relation to Creutzfeldt Jakob disease (CJD). Sheep scrapie isnow known to be irrelevant to…
Considers recent developments in bovine spongiform encephalopathy (BSE) and their relation to Creutzfeldt Jakob disease (CJD). Sheep scrapie is now known to be irrelevant to the cause of both BSE and CJD. The range of species of animals acquiring novel spongiform encephalopathies continues to broaden. The failure to find infectivity in many tissues of BSE cattle has been due to the use of an inappropriate and insensitive assay method. The occurrence of vertical transfer of BSE from dam to calf is now accepted by the Ministry of Agriculture, Fisheries and Food (MAFF), as shown by the recent removal from the human food chain of intestines and the thymus from young calves. During the last year, the probability that CJD is caused by BSE has increased.
Evidence for the spread of the agent responsible for Bovine Spongiform Encephalopathy (BSE) continues to accrue. Hopes that the ban on feeding concentrates to cattle in July 1988 would result in the resolution of the epidemic have not been fulfilled, since the number of BSE cases continues to rise. It is proposed that the infective agent of BSE is primarily a cattle pathogen, perhaps initially spread by contaminated feed, but in recent years propagated chiefly by maternal (vertical) transmission with variable manifestation of the clinical disease. If this is correct, the implications for farming, and possibly also for human health, are grave.
Bovine spongiform encephalopathy (BSE), widely known as “mad cow disease”, has virtually crippled the British livestock industry. Even though, no cases of BSE have been…
Bovine spongiform encephalopathy (BSE), widely known as “mad cow disease”, has virtually crippled the British livestock industry. Even though, no cases of BSE have been reported in the United States (US), a similar epidemic in the US would be catastrophic. The added concern for the risk of introduction of the human disease called variant Creutzfeldt‐Jacob disease that has been linked to eating meat of BSE infected cattle compounds the risk of BSE. Systems dynamics models based on the underlying transmission pathways of BSE can help to anticipate the spread of this disease in different cattle populations and assist in the evaluation of potential risk mitigations for preventing its introduction or controlling its spread if it was introduced. With this in mind, an age and health status structured systems dynamics model was developed. By making assumptions and setting up feasible scenarios, the model can be used to examine potential prevalence and incidences rates of BSE; the effect of mitigations including changes in feeding habits or rendering processes and/or other policies and regulations designed to prevent the introduction of BSE. The systems dynamics simulation model enabled us to create virtual experiments whose real‐world analogues would otherwise be expensive, dangerous, or even impossible to carryout.
Transmissible degenerative encephalopathy agents are relatively resistant to standard decontamination procedures. Bovine spongiform encephalopathy (BSE) agent was inactivated by sodium hypochlorite but not sodium dichloroisocyanurate; 1M or 2M sodium hydroxide was unreliable for BSE and scrapie agents. BSE infectivity survived a two‐year exposure to formol saline. Porous‐load autoclaving at 134‐138°C was ineffective with BSE and scrapie agents, and resistance to porous‐load autoclaving was enhanced by prior exposure to ethanol. Gravity displacement autoclaving at 132°C was also ineffective with BSE agent. Gravity displacement autoclaving at 121°C was effective with scrapie agent if it was exposed to 2M sodium hydroxide during autoclaving. After BSE‐spiked material was processed through facsimiles of EC rendering processes, infectivity was recoverable in the meat and bonemeal produced by four of these processes. Using scrapie‐spiked material, infectivity was recoverable in all meat and bonemeal samples except those derived from processes which used steam under pressure.
BSE has now been transmitted orally to 16 species, and appears to have infected over 50 per cent of UK dairy herds, these representing over 85 per cent of UK dairy cattle. It now seems that BSE may be passed from cow to calf and hence the banning of infected feed in 1988 has only had a minor effect in stopping infection of calves, which, as they reach the age of three to six years are the cattle we see with clinical symptoms. Presents evidence that BSE is not derived from scrapie. Approximately 1,800,000 infected cattle will be eaten by humans by 2001. Discusses the human risk.
Pricing densities implied from options on live cattle futures show a persistent and negative skew. The purpose is to examine whether the skew can be explained, in part, by…
Pricing densities implied from options on live cattle futures show a persistent and negative skew. The purpose is to examine whether the skew can be explained, in part, by peso-type problems.
Two announcements of bovine spongiform encephalopathy (BSE) provide a natural setting within which to examine the validity of the peso-problem explanation. These announcements represent the first documented cases of BSE in North America. Prior to the announcements, the potential for BSE would have been known by market participants as the disease had been found among cattle in the British Isles, Europe and Asia. The paper uses options market data to compute implied moments of the pricing distribution for live cattle futures. The paper then analyzes these moments around BSE announcements.
The first Canadian BSE announcement impacted the mean and volatility but not the implied skew. Later in the year, BSE was found in a US cow and the paper finds a statistically significant change in the implied skew. The distribution showed a pronounced leftward skew prior to the US announcement but was nearly symmetric during the days afterwards. This finding is consistent with the market having priced the possibility of a BSE discovery into deep out-of-the-money put options.
Peso problems have been documented in other financial markets. The results are important because they suggest that they may also be important to agricultural markets and that agricultural options markets do account for low probability but highly important events.
The purpose of this paper is to examine the organizational antecedents and management of the bovine spongiform encephalopathy (BSE) epidemic in the UK in the 1990s in…
The purpose of this paper is to examine the organizational antecedents and management of the bovine spongiform encephalopathy (BSE) epidemic in the UK in the 1990s in order to answer the following questions. What organizational factors contributed to the development of the epidemic? How did they do so? What can we learn from the management of BSE that can help us in tackling future epidemics?
The research involved content analysis of the most extensive documentation of the crisis, the Philips Report, and other official and non‐official sources, to gain a phenomenological understanding of the organizational/departmental/financial contexts in which key decisions were taken.
The organization of the institutions charged with managing BSE ensured slow, shortsighted and atomized decision‐making, inappropriate to the management of an epidemic. Organization‐ and department‐specific priorities, budgets and boundaries ensured piecemeal, “locally rational” responses to BSE, which cumulatively exacerbated the crisis.
The research is limited by the fact that it is based upon the Philips Report, and other official and non‐official sources. Further studies could assess these research findings through direct interviews with those involved. The implications of the study are that rapid and appropriate responses to epidemics do not necessarily arise spontaneously from co‐operation between bureaucratic institutions.
Through identifying the organizational reasons for the inadequate responses to BSE, this research clearly shows the need for pan‐ or super‐institutional emergency teams, able to address future epidemics unhindered by localized bureaucratic imperatives.
The phenomenological analysis is new and significant in that it highlights the localized rationality of decision‐making before and during the crisis, and shows how locally rational decisions cumulatively exacerbated the epidemic. The research will be of interest to those involved in the prevention and management of epidemics.