Safe meat and healthy animals: BSE and bovine TB

Keir Waddington | 07 May 2002

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Executive Summary

• The recent crisis over BSE is not unique but was directly paralleled by an earlier crisis over Bovine TB in the late nineteenth and early twentieth centuries.
• Then as now, conflicts of opinion between veterinarians and the medical profession led to confusion and delay; scientific expertise was used to reassure the public and minimise the government's response; and pressure from the meat industry further limited the extent of public intervention.
• The record suggests that it can be unwise for governments to wait for the science to be 'correct' before responding.
• Despite the short-term costs to vested interests, any animal disease suspected of being capable of crossing the species barrier should be treated by the government as both a public health and an animal health problem.

How safe is the food we eat? E.coli in 1987, the Salmonella scare in 1988, and the furore over GM ingredients in 1999, have highlighted public anxieties over food safety. Food scares have come to dominate headlines and become caught up with wider political issues connected with the freedom of information and the role of the scientific expert. A rise in the number of food poisoning cases, epizootics, and food scares has convinced the public that something has gone seriously wrong. After more than a decade of panics and scandals, there is little trust in the food industry, farming, or government regulation of food. Bovine Spongiform Encephalopathy (BSE) has stood at the heart of this fear and distrust.

In 1986, a new form of the disease was detected in British cattle, although the condition had probably been present since the 1970s. Quickly christened 'mad cow disease' by the media, the cause was attributed to infected bone and meat meal given to cattle, prompting references to 'cannibalistic' cows. A link was made between BSE and a family of brain diseases that included Creutzfeldt-Jakob Disease (CJD) - a frightening illness affecting humans that resulted in dementia and death. Because the two diseases came from the same family, questions were immediately asked about whether BSE could be transmitted to people. Meat was feared as a possible means of contagion. As a sense of crisis developed, anxiety was voiced about whether a human epidemic of BSE was possible and who was most at risk. Three years after the disease was first detected, measures were put in place to ban the most infected parts of the carcase from entering the food chain. At the same time, the public was repeatedly reassured that it was safe to eat beef based on a belief that the 'science' the government had come to rely on was accurate. By the mid-1990s, once it had become clear that a new variant of Creutzfeldt-Jakob Disease (vCJD) was almost certainly connected with BSE, such claims were proved disastrously unfounded. As the number of cases of vCJD rose, so, too, did public alarm. Many accused the Thatcher and Major governments of misinforming the public and not acting quickly enough to stop people eating infected beef. BSE fuelled mistrust of scientists, civil servants, and the state. Agriculture came under attack for its intensive farming practices, the food industry for hampering investigations. Few institutions appeared to escape blame.

It would seem that a change of regime has not brought a fresh response. Blair's government has been seen to flounder, creating the impression that New Labour is just as insensitive to post-BSE concerns about food safety as previous Conservative governments had been. Belatedly, it established the Food Standards Agency and appointed an inquiry into BSE under Lord Phillips. The recent handling of the foot-and-mouth crisis and yet another public inquiry has suggested that the government has failed to learn any helpful lessons about how to handle a hazard or the problem of animal disease from BSE. Can any lessons be learnt from the past?

BSE and bovine TB

Blair's government would do well to see food safety and responses to zoonotic disease in a historical framework. The threat of animal diseases was all too familiar to the Victorian and Edwardian public. Rinderpest (or the cattle plague) had swept through the farming industry in the late-1860s. Outbreaks of foot and mouth, rabies, and pleuropneumonia fuelled concern, but it was bovine TB that came to stand at the heart of debates about animal disease because it was also capable of crossing the species barrier to infect humans, and in particular children. Like BSE, its nature and mode of infection were initially open to considerable speculation. Both have long incubation periods, are easily confused with other diseases, and (in the case of bovine TB before the 1890s tuberculin tests) could not be detected before the clinical signs had become established. Both were quickly assumed to be widespread, with the infective agent believed to be commonest in the cheapest products. However, unlike BSE, little attempt was made to define bovine TB as an animal-health issue, at least until after the First World War. Initially it was seen, at an administrative and scientific level, as a public-health problem.

Although now eradicated from the national herd following measures introduced from 1950 onwards, bovine TB was responsible for over 800,000 human deaths in Britain between 1850 and 1950 at a time when TB was Bunyan's 'captain of all those men of death'. Given the level of mortality and growing evidence that the disease was endemic in cattle, it became 'the most important disease of cows', attracting attention at an international level. Easier to tackle than the respiratory form of TB, bovine TB became a target for action. Between 1890 and 1911 three royal commissions were appointed into the disease and its affects on people. Although the extent of the danger proved a source of confusion, by the 1890s bovine TB had been constructed as the paradigm zoonosis, in much the same way as BSE has come to be over a century later. Conflicting claims about the threat from infected beef were made, but the main impression was that the disease represented 'a substantial risk to the... consumer' of meat. Fuelled by this anxiety, existing measures to identify and prohibit the sale of diseased meat were tightened. Import controls were introduced. Campaigns were launched for eradication and the creation of public abattoirs, whilst attention also focused on better methods of diagnosis and the possibility of a vaccine. In the light of BSE, all this sounds strangely familiar. The Victorian and Edwardian story of bovine TB might therefore be seen as a parable, if not a direct parallel, for the present government, an object lesson in the pitfalls of tackling a zoonosis.

Veterinarians and the medical profession

Reports about bovine TB had appeared in the medical and veterinary press with increasing frequency from the 1870s onwards and a link between the bovine and human forms of TB had long been suspected. As with the case of BSE, it was veterinarians who first highlighted the problem, but the medical profession disputed their interpretations of the evidence and so the formulation of effective action was hindered. A consensus that the bovine form was also dangerous to man did not become apparent until the 1880s following Robert Koch's identification of the tubercle bacillus in 1882. Koch's assertion that tubercular disease was infectious and caused by the same organism in animals and man highlighted the danger of ingesting infected meat. The identification of the tubercle bacillus gave new impetus to the efforts to restrict the sale of diseased meat. As with BSE, only once a link had been more or less scientifically proven did the state respond by significantly strengthening local authorities' systems of inspection. Consequently, there was a sharp rise in efforts to secure prosecutions for the sale of diseased meat. A successful prosecution in Glasgow in 1889 of a meat trader and wholesale butcher for sending diseased cattle to a slaughterhouse finally brought the issue into the media spotlight. This test case re-affirmed the right of local authorities to destroy tuberculous meat but left open the important practical question of how much of a carcass should be destroyed if only part of it showed infection.

Again there was division of opinion between the veterinary and medical professions. Asserting their own practical understanding of animal disease, veterinarians adopted a localized model of infection, claiming that only those parts of the carcase visibly exhibiting the tubercles were dangerous to consume. Medical Officers of Health (MOHs) were suspicious that veterinarians were too keen to defend agricultural interests and that their view was not sufficient to protect the public's health. MOHs subscribed to a more generalized view of infection, arguing that when the tubercles had become visible in a carcase it had probably already spread throughout the body, making the entire carcase dangerous. The confusion between the two schools of thought was reflected at a local government level. As one contemporary complained, 'meat which, after inspection, is pronounced fit for sale in one market [was] liable to seizure in another because the inspecting authority happens to differ in opinion as the extent of tuberculosis which may be dangerous'. The Glasgow trial highlighted these problems. Experts called to the witness stand presented conflicting evidence about the dangers of bovine TB. Under pressure, the then Conservative government moved to appoint a royal commission to inquire into the whole matter.

The use of scientific expertise

Late-Victorian ministers had already gone some way towards consulting scientific experts. The cattle plague of the 1860s saw the state commission experts to investigate, drawing on an emerging culture of epidemiological and scientific investigation in the public health administration. The veterinary and medical departments of the Privy Council subsequently commissioned studies into anthrax, rabies, and pleuropneumonia, whilst similar work into contagious and animal diseases was undertaken by the state-sponsored Brown Animal Sanatory Institute in London. At local authority level, many MOHs were using microscopic and bacteriological evidence and working with university bacteriology and public health departments to identify diseased carcases. Even before the Glasgow meat drama, Salisbury's Conservative government had made some effort to inquire into the danger presented by bovine TB. Although tentative conclusions had already been reached, in the aftermath of the Glasgow cases and the furore it generated, this was not seen as sufficient. In the same way as Thatcher's government turned to a 'safe' working party to buy time nearly a hundred years later, the Conservative government responded in 1890 by appointing a Royal Commission. This was a recognized way to be seen to be doing something whilst delaying action.

A growing confidence in medical science (and especially the new science of bacteriology) thus saw the state invoking a language of scientific investigation to determine the danger of tuberculous meat to human health. From the start, the 1890 Royal Commission adopted a model of contagion that defined bovine TB as a public health problem for humans, amenable to laboratory investigation. In doing so, any discussion of controversial and expensive moves to eradicate the disease from the national herd was simply never considered.

The commission did much to dispel confusion while incidentally revealing evidence of what should have been seen as an alarming extent of bovine TB in cattle. After conducting a lengthy programme of experimental studies, it corroborated the view that TB was the same disease in man and in the food-animals. However, like the Southwood working party of 1988, it played down the human risks from infected beef. The extent of the danger was shown to depend on 'the degree of tuberculosis of the cow'. The commissioners agreed with veterinary interpretations that the disease was a local infection of specific organs. From this, they concluded that, with proper butchering, infected meat was rendered safe, provided the diseased organs were removed. This, however, was not felt to be true in advanced cases where the entire carcase was to be condemned. (Awkward cases of disease contracted from apparently tubercle-free beef was blamed on cross contamination from sloppy butchering practices, thereby transferring blame to the meat industry, which had been under scrutiny when the commission was appointed). The commission also 'revealed' that cooking rendered tuberculous meat safe. In supporting this approach, it adopted a model of domestic and culinary reform that not only sought to check the spread of infectious disease but also to reform the habits of the urban poor. Under these conditions, better meat inspection to remove the most infected parts combined with public health education was seen as adequate. This removed the need for the most expensive solutions, which would have involved slaughter of large numbers of cattle. It took a second commission, sitting from 1896 to 1898, to put forward detailed suggestions for improved meat inspection, public slaughterhouses under local authority control, and funding for tuberculin testing.

So convinced was the state about the findings of the science it had commissioned, that when Koch announced to the 1901 London Congress on TB that the bovine and human forms of the disease were not the same after all, it responded with a further royal commission. From the start, the dice was loaded. Like the first commission, the third was carefully constructed to provide the scientific evidence that bovine TB was a risk, but that existing legislation was adequate. Although this outcome was rigged, the confidence it exuded in the objective value of science stimulated yet more increased public funding for scientific investigation, directly leading to the foundation of the Medical Research Council.

Pressure from the meat industry

From the 1890s, public-health officials, doctors, and veterinarians were all pressing for action about bovine TB, agreeing on the need for policing measures and slaughter. Both were well-tested approaches in the control of animal diseases. Compulsory slaughter measures had already been introduced through the Contagious Diseases (Animals) Act to tackle rinderpest, foot and mouth, and pleuropneumonia. Responses to the cattle plague had also seen the adoption of a policy of notification along with movement and import controls. Between 1869 and 1894 the number of animal diseases covered by the Contagious Diseases (Animals) Act was extended, but bovine TB remained excluded from this framework, largely because of pressure from the farming and meat industries.

In much the same way as the 1988 Southwood working party has been accused of delaying action, the three royal commissions of the 1890s and 1901 produced similar reassurances and were also accused of passivity by contemporaries. These commissions also ensured that what efforts were taken remained within existing public health structures, ensuring only 'a stricter and more general enforcement of the law'. Opposition from the meat trade, which, like today's food industry, played down the risks, further obstructed the state's will to act, especially when the thorny issue of compensation was raised. In addition, the Board of Agriculture was keen to minimize the human health risk of cattle diseases for fear that public panic would damage the livestock industry. It shared veterinarians' scepticism of experimental investigations, whilst it defended a construction of separate areas of competence. G. T. Brown, the then-chief government adviser, spoke disparagingly of the 'pathology of contagion' and advanced an approach that saw existing control measures as adequate. In addition, the Board did not see the human implications of bovine TB as its problem and felt that moves to include the disease under the Contagious Diseases (Animals) Acts was unworkable. It was all too keen to pass responsibility to the medical department of the Privy Council on the understanding that the problem would not be tackled in the national herd but through measures to improve meat inspection, hygiene and public education. Such an approach was relatively inexpensive and less damaging to farming. In the face of a strong farming lobby and pressure from the Board of Agriculture, the three royal commissions supported this stance. Other solutions were seen as impractical, controversial, or too expensive. Although there is evidence to suggest that ministers realized that an expensive eradication scheme was the only effective response, they balked at the cost.

The findings of the three royal commissions that tuberculous meat was rendered 'safe' by cooking, and that an extension of inspection and public slaughterhouses were sufficient control mechanisms, defused concern about meat and bovine TB. With a solution to the problem tuberculous meat apparently found, concern moved from the national to the local arena. Although the creation of public slaughterhouses proved controversial, MOHs used new systems of meat inspection to prevent the sale of diseased meat.

Reassurances about meat had not solved the problem of bovine TB. However, they had redefined it. With the role of meat minimized in the spread of the disease and with meat apparently rendered safe through cooking, the role played by milk infected with bovine TB now came to take centre stage. This transition was hardly surprising. Milk was seen as the vehicle for infection in a number of diseases, while bacteriological samples revealed that all too often milk was laden with the tubercle bacilli. Although few contemporaries could doubt that milk infected with bovine TB was a major cause of the disease in man, similar problems to controlling the sale of tuberculous meat were encountered. Opposition came from the dairy industry, which saw measures to control the spread of the bovine TB and to create disease free herds as too expensive. In government, little support was expressed for compensation at a time of financial cutbacks. This limited the arena of state action, while friction between the Ministry of Agriculture and the Ministry of Health created tensions that frustrated attempts to eradicate the disease. However, as evidence accumulated that infected milk represented a very real danger to human health - especially to children - the state found it harder to avoid introducing legislation to limit the spread of bovine TB. As in the case of tuberculous meat, identification and inspection to weed out infected cattle were initially seen as the key. By the 1930s, this policy of inspection had become linked to limited financial incentives through higher prices for milk from disease-free herds were introduced to encourage farmers to stamp out the disease. This transferred the cost to the consumer. Local eradication schemes were introduced, but there was little effort to promote national eradication programmes on the grounds of cost. Pasteurization was fitfully adopted at first in part because of differences of opinion between the Ministry of Agriculture and the Ministry of Health over its value. However, a deepening depression in farming and the high cost of compensation claims, estimated at £750,000 per annum in the early-1930s, gradually made a system of prevention and eradication more accepted, if only to save money. Effective measures to control the spread of the disease were introduced during the Second World War, but it was not until 1950 that a concerted effort was made to eradicate bovine TB from the national herd.

What had started as a concern about tuberculous meat, had become by the 1920s an issue of infected milk, child health, and anxiety about the economic cost to farming. In the process of controlling and then eliminating bovine TB in milk and from the national herd, the problem of tuberculous meat was also solved. With no effective cure for TB until the introduction of antibiotics, the only apparatus available had been prevention through inspection and eradication. The cost to human health, the farming industry and the state is impossible to gauge.

Conclusions

Although nearly a century has passed between the two food scares, they point to the common problems produced by zoonoses. The main lessons to be learned are the consequences of delay, the dangers of waiting for the science to be 'correct' before responding, and the longer-term costs in human lives which can result from excessive sensitivity over the short-term to the costs for vested interests. By conceiving bovine TB within a public health framework, measures to stamp out the disease in the national herd were delayed. By constructing BSE as an animal health problem, measures to protect the public have been delayed. So in future it would also be wise to treat all animal diseases suspected of being capable of crossing the species barrier as both a public health and an animal health problem.

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• Waddington, Keir
• Farming and food

About the author

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Keir Waddington is a Research Fellow in the School of History and Archaeology at Cardiff University. He has written on voluntarism and the hospital, the history of psychiatry, and on medical education, and is currently working on a history of bovine TB and the public's health in Victorian and Edwardian Britain.waddingtonka@cf.ac.uk

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