TB in Cattle and Badgers: Zuckerman Report (1980) Revisited

Dr James Irvine FRSE, DSc, FRCPEd, FRCPath, FInstBiol

Teviot Scientific Consultancy, Edinburgh

©Teviot Scientific Consultancy

(Filed 10 March 2003)

In 1979 the then Minister for Agriculture, Fisheries and Food issued a Press Notice on 25 September in which he stated his concern about criticisms of his Department’s policy “for dealing with badgers infected with bovine tuberculosis”. He particularly referred to criticism which focused on “the extent to which infected badgers are likely to pass on the disease to cattle and the methods used to eradicate the disease”.

The notice went on to say that he had asked Lord Zuckerman OM, MA, MD, DSc, FRCP, FRS, President of the Zoological Society of London and President of the Fauna Preservation Society, “to take an objective look at the problem” and to give him advice about “the way it should be tackled in the future”. The Minister stated that he proposed to make the findings of Lord Zuckerman public.

Lord Zuckerman presented his report in August 1980, entitled “Badgers, Cattle and Tuberculosis” (1).

I obtained a copy of the report from Her Majesty’s Stationery Office. I was very glad that I did. It is a model of how such a report should be written. As testimony to such an accolade, it can be said that Zuckerman’s report in 1980 is as relevant today as it was more than 22 years ago. Rather, I should say that the report is of the highest intellectual and scientific quality, but sadly it has not been implemented.

Zuckerman describes himself as a “dedicated scientific conservationist”, and his report reads that he has conducted himself in precisely that manner. Seldom have I read a report prepared for Government with such ease, in terms of following the logic, of his reaction to a wide range of views, to the explanation of scientific method, for clarity in distinguishing the possible from the impractical, and for the quality of the writing. What is also impressive about this report is his readiness to seek the views of other scientists in related fields (such as medicine) and to explain them to the reader. When I came across reference to this report in the letter published on Warmwell and also on Land-Care (2) by Paddy Swan (a dairy farmer), the name Zuckerman took me back to my training in scientific research, when he was revered as an icon by the scientific community. From reading (in the year 2003) his report to the Minister of the day for MAFF in 1980, he justly deserves that reputation.

Whilst it was a dairy farmer who drew my attention to the Zuckerman Report, Zuckerman relates:

“It so happened that just as the team (from MAFF) was completing its work, an observant Gloucestershire farmer, frustrated at repeated failures to trace the source of breakdown in his cattle, and concerned about consequential financial losses, had got the idea that badgers with setts on his land might be a source of infection. In 1971 he (the farmer) took one that had died in the open to the MAFF Animal Health Office in Gloucester, where a post-mortem examination revealed that the animal was riddled with tuberculous lesions. Cultures made at MAFF’s Central Veterinary Laboratory showed that the particular bacillus by which the animal had been infected was the same strain of tubercle bacillus as is found in cattle. Soon more tuberculous badgers were found, and in the spring of 1972 a systematic survey was carried out to determine the extent to which Gloucestershire badgers were affected. In one particular area, one in three of the creatures was found to have the disease, while in the rest of Gloucestershire the infection rate was one in six. Cultures were also made from badger droppings, and a variety of other wild mammals were collected for laboratory examination, with tuberculous lesions being found in a few specimens. Badger carcasses collected in other parts of the country were also examined, but in general it was only in the South West (of England), where the badger population is particularly dense, that significant numbers of tuberculous specimens were recovered. In one case, every member of a social group, including young, was found to be infected.

“While all these enquiries were going on, a series of important complementary studies were started. These showed that healthy badgers can be made tuberculous by inoculating them intravenously with a culture of the tubercle bacillus isolated from cattle; and that healthy badgers can contract the disease when housed with experimentally infected badgers; and that calves penned with experimentally or naturally infected tuberculous badgers will contract the disease.”

Zuckerman goes on to describe the correlations that emerged from field studies of the geographical relationships of herds in which breakdown of tuberculosis free status had occurred to setts containing badgers that turned out to be tuberculous. He also described another common observation that herds that had been subject to breakdown of tuberculosis-free status over many years become clean and healthy when all the badgers which previously roamed their pastures have been removed.

A comparable situation has been described in New Zealand where the secondary reservoir of tuberculous infection was the possum rather than the badger. A policy of the New Zealand Government to eradicate cattle that gave a positive tuberculin test, and at the same time as the affected areas are rid of possums, has been effective. He noted that the New Zealand authorities were quick to note that the susceptibility of possums to bovine TB was similar to what was being reported about the badger of the South West of England. And it could justifiably be said that the very large part farming plays in the economy of New Zealand encouraged a more vigorous enquiry into the place of the possum in the epidemiology of the disease than has been carried out so far in the case of the badger. The New Zealand authorities have not had to contend with a lobby organised to contest what is being done, he wrote.

On page 27 para 87 Zuckerman rightly comments:

"the world would be in a sorry state if measures that have been taken over the past century to eradicate other diseases had not been embarked upon without a prior assurance that they would be 100 per cent successful."

Earlier, on pages 30-31 he discusses the ‘demand’ by some of the badger protection groups that a method to diagnose tuberculosis in the living badger ‘must’ be devised. Sadly it has not been possible, even to this date in 2003, for such test to be available. The tuberculin test used in cattle does not work successfully in badgers. Indeed BCG vaccination used in man has also been shown to be ineffective in badgers. That is a fact of science. The possibility that new types of test based on gamma interferon will be discussed when I come to review the recent reports of the Independent Scientific Group on cattle TB (ISG) (3, 4, 5). Unfortunately, while science has indeed made great contributions to the health of both man and animals in the past, and will continue to do so in the future, it is not always possible for it to deliver such advances on demand.

What was also refreshing to read in his report was his obvious awareness of the practicalities or otherwise of whatever was being discussed. How different from some of the edicts that currently emanate from Brussels in relation to such matters as advocating that all sheep in the United Kingdom (and indeed throughout the EU) should at all times have two tags in their ears each carrying a fourteen digit number, and have an individual passport, with penalties for non-compliance (6). Even although the bureaucrats from Brussels had visited the Scottish Highlands, they still do not seem to either understand or to care just how impractical that would be in such a situation.

Lord Zuckerman ended his report with a summing up and a list of recommendations which appear eminently sensible and practical. To quote:

“The basic and incontrovertible fact is that TB in badgers is now (1980) a significant secondary reservoir of the disease in parts of the South West, dangerous for badgers and cattle alike. Given the policy of the Government to suppress bovine TB, the disease cannot be allowed to spread in the badger population. Short of a fundamental change in the Government’s policy for the suppression of bovine and human TB, I cannot therefore see any reason for continuing the moratorium on the campaign to eliminate tuberculous badgers. As I have already said, I am confident that the Ministry’s policy does not constitute a threat to the survival of the species in the United Kingdom. Indeed, the very high prevalence of tuberculosis in badgers of the South West seems to me to be a far greater threat, for if disease were to take hold in badgers in other areas of the country, there is no saying what the consequences would be, not only so far as the transmission of TB to cattle is concerned, but also as they relate to the survival of the badger in our country.”

In carrying out his enquires in preparation for writing his report Zuckerman encountered fierce lobbying from focus groups dedicated to the welfare of badgers, just as there are today. Clearly he listened patiently and tried to explain the relevant fundamental science. To quote:

“Even when they are adamant in rejecting what to any informed scientist would be irrefutable fact, the groups hostile to MAFF’s policy are insistent that they are not ‘crackpot extremists’. The fact is that opposition costs protesters little or nothing - any price that has to be paid is exacted in time by officials, in pounds and pence by the farmer and taxpayer, and in health by the badger. Moreover, concern for the animal - whether healthy or tuberculous - is matched by what could be regarded as a cynical attitude to matters which concern the public health, as well as by a general belief that whatever Government officials do is necessarily misguided.

This kind of reaction also constitutes a fact, as much a fact as does the existence of TB in the badger."

The report then stresses the importance of communication with the public in relation to the scientific realities, in order to counter ignorance and thereby the misunderstandings that poor information can cause.

It is ironic that on the same day (8th March 2003) as I write this critique of the Zuckerman (1980) report, I also write a page for the Land-Care website entitled:

“TB in Cattle and Badgers: DEFRA in no hurry to review strategy” (7).

This in the face of the seriously escalating numbers of incidents of TB in UK cattle, spreading from the South West of England (8) and now into the South West of Scotland (9).

A future article in this series on Bovine TB and Badgers will attempt to understand what on earth has happened between the 1980 report by Lord Zuckerman and the present alarming state of affairs. The official reports to Government by Professor Krebs (10) and the ISG (11), set up to study the relationship between bovine TB and badgers in 1998, are currently available on this website, together with publications emanating from the ISG (11). Land-Care has approached HMSO for permission to put the full version of the Zuckerman (1980) report on the Land-Care website, complete with the supporting evidence in the Appendices, so that it is more readily available to the public.

The question to be asked is: why has it not been possible to make better progress since 1980 in improving the health of UK livestock with particular regard to tuberculosis?

Dr James Irvine
10th March 2003

References

1. Lord Zuckerman (1980). Badgers, Cattle and Tuberculosis. Report to the Right Honorable Peter Walker, Minister of State, Ministry of Agriculture, Fisheries and Food. Her Majesty's Stationary Office, London.

2. Badgers and TB in Cattle: the view of a dairy farmer.
(Filed 27 February 2003, www.land-care.org.uk, click here to view).

3. The Independent Scientific Review Group on Cattle TB (1998). First Report to the Rt Hon Dr Jack Cunningham MP from the Independent Scientific Group on Cattle TB - July 1998. (Click here to view).

4. The Independent Scientific Review Group on Cattle TB (1999). Second Report of the Independent Scientific Group on Cattle TB. (Click here to view).

5. An Epidemiological Investigation into Bovine Tuberculosis. Third Report of the Independent Scientific Group on Cattle TB. July 2001. (Download PDF).

6. Proposal for a Council Regulation establishing a system for the identification and registration of ovine and caprine animals and amending Regulation (EEC) No 3508/92. (Click here to view).

7. Tuberculosis in Cattle: DEFRA in no hurry to review Strategy.
(Filed 10 March 2003, www.land-care.org.uk, click here to view).

8.Irvine, W. J. (2003). Just how bad is the TB problem in UK Cattle?
(Filed 25 February 2003, www.land-care.org.uk, click here to view).

9. Incidents of TB in Cattle in Scotland, 1995-2002.
(Filed 26 February 2003, www.land-care.org.uk, click here to view).

10. The Krebs Report (1997) and the Independent Scientific Review Group.
(Filed 27 February 2003, www.land-care.org.uk, click here to view).

11. Independent Scientific Group (ISG) on Cattle TB (1998-current).
(Filed 27 February 2003, www.land-care.org.uk, click here to view).

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10 March 2003

TB in Cattle and Badgers: Zuckerman Report (1980) Revisited

Dr James Irvine FRSE, DSc, FRCPEd, FRCPath, FInstBiol

Teviot Scientific Consultancy, Edinburgh

(Filed 10 March 2003)

References

Further Reading Recommended by Land-Care