TUESDAY 9 FEBRUARY 1999

PROFESSOR SIR JOHN R KREBS

  100. As Diana has already said, if we had the vaccine at least for cattle, a significant part of the problem would be removed. However, there would be a whole multitude of problems in trying to implement a vaccine for badgers.
  (Professor Krebs) But I think the badger vaccine is not the preferred way forward, and we said that very clearly in our report, for a whole multitude of reasons. If you look at the case of human TB where vastly more amounts of money are being spent than on cattle TB, the development of better vaccines than the ones that were developed many years ago has moved very slowly because it is an extremely complicated problem and that is why I am loath to say that if MAFF threw tens of millions of pounds at it they would crack it in a short period of time. I think they have increased the budget significantly and what we will need to do or what MAFF should do is monitor progress. We laid out some targets and milestones in our report and they should monitor progress against those targets and milestones and judge on the basis of that whether they are putting enough money into it and putting money into the right people.

  101. You mentioned actually in your report that there is a negligible risk to the human population of Great Britain from M-bovis, but that the disease has the potential to be a significant health risk. How do you define "potential"?
  (Professor Krebs) Well, the reason why there is not a health risk at the moment is because the measures that were introduced many years ago of pasteurising milk and tuberculin testing of the national herd are effective in controlling the disease to the level where it is below a human health risk. However, what we meant was that if humans get bovine tuberculosis, it can be a fatal disease and, as you know from the statistics, back in the 1930s roughly 2,500 people a year were dying of bovine tuberculosis. We document in our report one or two cases of outbreaks of bovine tuberculosis not in Britain, but in other countries and amongst immuno-compromised people where it did cause a significant amount of fatality, so it is a potential. It is a dangerous organism and not one that you can ignore.

  Mr Marsden: But if you are saying that we have taken the right steps to reduce that to an acceptable minimal risk at the moment, then what is the potential?

  102. And can I particularly ask about the risk of transmission direct from the animal to those who work with the animal, the farmers and vets?
  (Professor Krebs) I think that in a way leads to my response to Mr Marsden's question. Although, as I understand it from the data that I was provided with in writing my report, there is no current epidemiological evidence that people working in close proximity to cattle have a higher risk, if the disease became much commoner in cattle, one does not know whether that risk might not increase.

  103. So if it is not the virulence of the actual disease, is it the quantity?
  (Professor Krebs) No, what I am saying is that it is a dangerous organism, it does constitute a health risk and, therefore, if the organism became much more prevalent in the environment, then it could be through many routes of transmission.

  104. You are putting the emphasis on data collection, through experimental culling and comparing all the research, but you are also saying there is a massive potential here for the disease to threaten the human population. Can you justify not putting more emphasis on that significance, and in tackling that in a more proactive way across the country?
  (Professor Krebs) You said "massive potential" and I did not say there was a massive potential.

  105. You introduced the figures and I would have thought that was pretty massive, 2,500.
  (Professor Krebs) Well, that is a long time ago in history. What we did suggest and what MAFF is now doing is monitoring the human infection situation very closely, so I think that -

  106. Sorry to interrupt, but do you know what the trend is or is it static?
  (Professor Krebs) For human infections?

  107. Yes.
  (Professor Krebs) I do not know the numbers for the time-frame over the last three years, but, as I understand it, at the time of our report the incidence in the human population of TB attributable to M-bovis was extremely low, a few tens of people per year, and probably most of those were people who had contracted the disease much earlier in life and were showing the symptoms now, so they were relics, if you like, from the pre-pasteurisation and tuberculin testing.

  108. Would you agree that your approach is flawed, that there is a potential threat to humans, you know the disease is spreading, we agree that there is a link to the badgers, but we do not know to what extent and that surely there has got to be a greater urgency in tackling it directly?
  (Professor Krebs) There is urgency, but there is urgency in a lot of other things as well and I guess that is a resource allocation decision for MAFF to make and there are other diseases that they have got to deal with at the moment. One should always of course bear in mind that TB, although increasing and increasing quite rapidly, is still a very rare disease. It is only a very small proportion of the national herd that is affected by it.

  109. I wonder if you could give us some figures as to what sort of level of the national herd.
  (Professor Krebs) When we wrote our report, we gave the figure of 0.4 per cent of the national herd, and I am told that in 1997 there were 515 herds affected by TB and in 1998 the number is somewhat bigger, it is going up, and in the first half of 1998 there were over 300, so if you extrapolate that through the rest of the year, it might be 600.

  110. Let's look at what farmers might do themselves to control this. The other issue we have not yet discussed, and I think we should, is husbandry. I have to say from all the written evidence we have received, I am actually rather disappointed at the lack of attention which has been given to husbandry. A couple of badger groups produced some very useful notes, but, otherwise, it is quite thin. In fact your own report, although it alluded to husbandry, I think, dealt with it in a couple of pages, as far as I remember. Does this mean you actually regard it as a second-order issue or you felt you were not qualified to talk about husbandry issues for some reason?
  (Professor Krebs) We thought and I still believe that husbandry has a role to play. We did not write a great deal about it because we did not have the expertise and also we felt that it was important to complete the report rather than carry on and on exploring further avenues in detail, so we focused on our area of expertise rather than areas where we had less expertise. To go back to a comment I made earlier, I think (a) husbandry will have a role to play and (b) the industry should be taking a lead in exploring that role. I do not think really ultimately issuing leaflets from MAFF on the guidance notes is going to sort the problem. When I talked to farmers, I said, "How often do you read the guidance notes?" and the answer was, to put it in a polite way, "Not very often", so I think the industry has got to take ownership of the fact that they are responsible for looking at how husbandry can be part of the solution. Again, to refer back to an earlier comment that I made in answer to Mr Marsden's first question, I think this analysis of risk which MAFF is carrying out as a matter of urgency will help to point to ways of implementing husbandry changes.

  111. I do not quite understand how the industry can take ownership of this issue because there are some very complex issues which need to be resolved in the husbandry question and it is not just a question of putting up fences because you yourself highlighted the problems. For example, the badger groups think that one thing which would help farmers would be if the Ministry were to include records of tuberculosis testing on cattle passports and that is something for the Government to take the lead on. Do you think that is something that would help?
  (Professor Krebs) I think that having those sort of records will be important, but I guess I was distinguishing that and husbandry on the farm, the way you keep the animals.

  112. But if an individual farm is going to take a decision about how it alters its husbandry practice, that could be quite costly and it might not produce any benefit. How are individual farmers going to take the lead for that if there is a cost on them which they cannot actually foresee the benefit from? One thinks of things like slurry-spreading, for example.
  (Professor Krebs) I think some things will be more costly than others. One comment that was made to us by various people who know about badgers was that by raising feed-troughs and water-troughs up off the ground, you could keep badgers away from them and prevent them from spitting into the feed-troughs and reduce infection. Now, when I talked to farmers about that, they said, "Well, there is no evidence that it would have any effect whatsoever".

  113. My farmers are very sceptical about that. Actually, funnily enough, in the written evidence it has not actually cropped up at all as a suggestion. The suggestion has come, for example, that trace element deficiency could be at the root of the problem and that cattle lose immunity through trace element deficiency. Now, that seems to be the kind of thing that is very plausible, but would require a scientific experiment led by the Government, not by farmers, I would have thought, to establish.
  (Professor Krebs) I would put that in a separate box for a moment, if I may, and I will come back to it in a second, but just to continue about husbandry practices, precisely because, as you say, farmers are sceptical about husbandry practices is why I say the industry has got to take ownership, by which I mean they have got to recognise that husbandry may be part of the solution. As long as they are saying, "It is nothing to do with husbandry, it is up to the Government to sort it out", the Government can only issue leaflets and guidelines and you do not make any progress.

  114. Well, I do not understand this logic at all, I am afraid, because you say it is up to the industry to own the development of a vaccine.
  (Professor Krebs) No.

  115. What is the difference?
  (Professor Krebs) I am talking about husbandry in particular.

  116. But investment required in research to discover which husbandry techniques are effective --
  (Professor Krebs) It is because the husbandry has to take place on the farm and the vaccine takes place in the laboratory.

  117. But husbandry must take place on individual farms which may or may not derive a benefit from that process.
  (Professor Krebs) They do not know whether they will derive a benefit which is why they are not prepared, or I understood it from my conversation with farmers that they do not know whether it will benefit them, so they are not prepared to do anything about it.

  118. Let's look at the maize question, for example, which relates to mineral deficiency because there is a lot of anecdotal evidence that badgers love maize and that maize growing seems to attract badgers to farm, or I believe that is the case. Similarly, we have evidence here from a badger group saying that feeding cattle heavily on maize seems to have a mineral deficiency consequence. Now, here is a very interesting area for research, I would have thought, so who should be doing that?
  (Professor Krebs) If somebody thought that there was evidence, significant evidence that mineral deficiency was a contributing factor, then that would be something for MAFF to consider.

  119. Was that presented to you when you did your report, that mineral deficiency as an element is one of those other--
  (Professor Krebs) No, that was not presented to us at the time. That has cropped up more recently, but I think the immediate questions one would ask if mineral deficiency is being posited as a contributing factor are why has mineral deficiency gone up in the last five years as the disease has gone up, what has been changing, how does mineral deficiency explain the spatial variation that we referred to earlier in risk across quite local areas --