Select Committee on Agriculture Minutes of Evidence

Examination of witnesses (Questions 381-399)




  381. Gentlemen, welcome to the Select Committee. I do not know what the collective noun for epidemiologists is, but whatever it is then no doubt you are illustrating it at the moment. Professor King, you have sort of appeared on our silver screen over the last three or four weeks, in direct proportion, really, to the disappearance of Jim Scudamore from it, and clearly you have been in the forefront of a large amount of persuasive work. I wonder if I could ask you, to begin with, if you have cast an eye on The Times today, with this calf called Phoenix on the front page, and you will no doubt recall The Daily Telegraph, of a week or so ago, of this lamb covered in mud, which occupied an equally prominent part of the front page, and, in the light of that, whether you think we will ever combat a future foot and mouth outbreak with a policy of slaughter?

  (Professor King) Well, Chairman, I thought you might end with that question, not begin with it. But you are raising the question about the entire procedure of a cull policy to contain the epidemic, and I am absolutely certain that, as a result of this massive epidemic in Great Britain, there will have to be lessons learned, and amongst the most important lessons to be learned is whether or not the cull policy was the right one and whether, for example, vaccination routes should be opened up. But this would be a matter for discussion with international bodies, with the European Union, not least with the OIE, with all bodies involved, and I do think that those discussions will be had and must be had.

  382. I recall the BSE epidemic, and the Government's defence of the time was always that it took the best scientific advice available, and the Government's defence of this policy, again, is that it is taking the best scientific advice available, though BSE, of course, was a new disease so there was not a large body of received wisdom out there, whereas perhaps in foot and mouth disease it is a much older-established disease. But, actually, in the modern age of instant television coverage, media interest and the sort of apocalyptic visions we have seen in this epidemic, scientific opinion may be a necessary but it is not a sufficient consideration for politicians, is it, politicians are going to have to take public perceptions and public acceptability into account as well; do you think that is a fair comment?
  (Professor King) My position, Chairman, is that of a Scientific Adviser to the Prime Minister and the Cabinet, and as Adviser I am not a policy-maker, I do not make decisions. I am in a position where I ought to be giving advice based on the best possible scientific input, and that is what I have striven to do throughout this unfortunate episode.

  383. Well, let us come to some of the substance of that advice, if we may. I am right, I think, in saying that what you insisted on, very clearly, was the importance of the contiguous cull, that people talk constantly of the need to destroy animals who have the illness very, very rapidly; if you do not think that is accurate you will no doubt tell me. But do you think that the contiguous cull will reduce the period of the epidemic, and what other actions could be taken to shorten that period?
  (Professor King) Could I take that question to be the introduction to, for me to describe what it is that my team was doing, how they informed me?

  384. Yes?
  (Professor King) Essentially, very early on, the Prime Minister asked me to form a science group to inform him on the best ways to approach the epidemic, and that science group, the membership I have distributed to you, is widely drawn. I believe it follows the Chief Scientific Adviser's advice, following the BSE outbreak, on how best to use scientific advice; so it is widely drawn, it contains groups of experts who cover different ranges of expertise. And what I would stress is that amongst those experts are epidemiological modellers, four teams of modellers, who use different modelling approaches; amongst them are, I believe, the world's experts on the disease in these animals, largely drawn from the Pirbright Laboratory, and amongst them as well are people from MAFF, of course, but also from DERA, because what we wanted to be sure of was that any proposals we made could be carried through logistically, and the people from DERA on our team, Les Ruskell in particular is a DERA modeller himself, and what he aimed to do and what he did was model the epidemic from the point of view of handling the slaughtering required and the carcasses required to disposal. So it is a broadly-based group. That group was originally drawn together, at the Food Standards Agency, as it happened, and what that group did was produce a set of models which made predictions as to how the epidemic would continue through Great Britain; these predictions were based on input data that were obtained from MAFF, in particular from John Wilesmith, so within MAFF John Wilesmith had close contact with the modelling groups and was providing them with the sort of input data that was required to produce reliable models. I can describe how the models work, if you like, but let me just proceed—

  385. I think you will find we are going to ask you to do that in a little while.
  (Professor King) The output of the models showed, initially, on around 21 March, when I first became involved, that the outbreak, as it was running at that point, was out of control, and we then asked the modellers to try various modelling parameters to see what the models indicated were required on the ground in order to achieve getting the epidemic under control. And you have asked me a question, and I have not forgotten it, about the 48-hour cull of contiguous premises. But, from that modelling, on 22 March, I drew the conclusion that the key parameter was the speed with which the premises on which the infection is reported is taken out; the speed with which that cull is achieved is absolutely crucial to bringing this under control. So we introduced this 24-hour target figure for what we call the IP, the infected premise, to be culled; that is, the 24 hours is from time of report of the animal being ill to the time when the last animal on that premise is killed. The contiguous policy was to contain the spread of the disease. Let me stress that by the time the disease is apparent, sufficiently apparent, in animals for a farmer or a vet to discern it the disease is already in its infectious state in that animal, and so the disease will have the probability of really spreading. And so the notion of culling neighbouring premises not only follows the modelling advice but also follows commonsense, around the infected premise, and here I have done, for your benefit, a very simple diagram. IP would be the infected premise at the centre of the diagram and A, B, C, D are the so-called contiguous, neighbouring premises, where there is a common boundary with the infected premise; if we take out all the lettered premises, A, B, C, D, we have created a kind of fire-break for the containment of the epidemic. Now the epidemiologists will tell you that they were working on input numbers which simply tell them the probability that the neighbouring premise, let us say premise A, will pick up the infection from the IP premise, and I believe the probabilities were in the region of 17 per cent per premise in the initial phase. And then there is a probability for the disease spreading to the next neighbour premises, which I have labelled 1 to 12 in this diagram, and that, I believe, was originally around 3 per cent per premise. Now, as you can see on the diagram, as you go away from the infected premise the number of premises increases, so although 3 per cent does not sound like a lot you have to multiply it by a larger number, in this case 12, and so it is still significant, the probability of the disease spreading into the next premise.

Mr Mitchell

  386. Does not that depend on the physical geography?
  (Professor King) Oh, yes.

  387. If you have got very hilly country, like Norfolk is portrayed in American films, then it ain't going to spread as far as if it is flat, open?
  (Professor King) Absolutely right, and I will ask the modellers to respond to that; but, certainly, geographic, terrain conditions, wind conditions, all of these are vitally important.


  388. Could I ask you then, Professor; you have explained that. Initially, of course, when there was an outbreak then MAFF drew an extraordinarily large perimeter around that as an infected area, and, in some cases, I know from my own constituency that an infected area could stretch 30 miles away from a single outbreak, and, of course, in that infected area then all normal activities came to a halt and farmers were subject to a series of very complex licensing schemes for movements. If one were to start at the beginning and apply your contiguous cull principles, would it also be necessary to draw such very large boundaries around infected areas, or could you base it, in fact, on operating around the infected outbreak and not have the requirement to designate such large areas and hence create such intensive dislocation to normal farming activity, and, for that matter, a very large cost to the Government in the Welfare Slaughter Scheme?
  (Professor King) Let me first respond briefly to your comment and then pass you to Dr Donaldson. The policy that we introduced was an add-on policy to what MAFF were already doing, which is what you have outlined briefly there. MAFF's policy is one of trace and cull dangerous contacts, so if there is an outbreak you trace backwards in time to the contacts that produced that outbreak, and this is a piece of detective work, and then you trace forward in time to what possible dangerous contacts have been made and you cull those out. You also put massive restrictions on animal movement and on people movement, and I think what you are referring to is that process. We never contradicted that as the first stage of controlling the disease; but I will ask Dr Donaldson to comment.
  (Dr Donaldson) So you would like me to comment on the more traditional MAFF approach used by the State Veterinary Service, in terms of reaction?

  389. My question was, in a nutshell, was it necessary to draw such very large excluded zones, many of which appear to have been drawn because of the convenience of natural or man-made geographical features, for definitional purposes, and which obviously showed some inconsistencies, in that in one direction you could have the line which stopped short at, say, ten miles, but in another direction it could be 30 miles wide, and even looking for wind direction it was quite difficult to trace the logic of some of these definitions? Could this have been a replacement for it, or did they necessarily have to go together?
  (Dr Donaldson) My understanding is that the traditional approach, and that, in fact, recommended by the European Union and international bodies, is that when an infected premises is diagnosed a three-kilometre area is declared around it, that is a radius out of three kilometres. If the assessment on the ground is that there is the potential that infection has gone beyond that then there is a local judgement made. That is my understanding.

  390. I do not want to pursue this too far, but, of course, it was not a local judgement at all, it was a judgement made in London, without consulting local people, as it happens, even the local MAFF experts, and it was not a three-kilometre radius, in this case it was 30 miles from a single outbreak, and that has been reproduced right across the country?
  (Dr Donaldson) May I just continue; in the first couple of premises pigs were involved, and we know that pigs are very potent disseminators of airborne virus. And so, in those circumstances, there would have been a justification for drawing a larger protection area.

  391. In fact, these are not pigs, these are sheep, as a matter of fact?
  (Dr Donaldson) No, I am sorry, I am talking about the abattoir in Essex, which was the first confirmed outbreak; the second one which was confirmed was at Heddon-on-the-Wall. Both were pig premises; pigs are very powerful emitters of airborne virus. So, potentially, the neighbouring premises were infected already, when those two premises were diagnosed, because the age of lesions seen on those premises were quite old.

  Chairman: I am not going to pursue this because we want to get on. I merely point out that the instance I was quoting was actually the outbreak in Hawes, in North Yorkshire, which was not to do with pigs, which was then followed by looking at a 30-mile distance of the infected area. We are going to move on because we are going to come to Heddon-on-the-Wall actually in the next questions. Owen.

Mr Paterson

  392. Good morning, Professor King. Last week, you said the disease was "fully under control"; what does "under control" mean?
  (Professor King) I was using the words, as I explained to the media, in a scientific sense. When an outbreak is out of control, which is what I stated to the media back in the third week of March, we have a situation where each infected premise is producing two subsequent, or more than one subsequent infected premise, so that the ratio of secondaries to primaries is greater than one; and when an epidemic is under control, in this sense, we are saying that we are getting fewer than one further outbreak from a given primary outbreak. And all of the modellers, and I have to stress that I have got four teams of modellers, who argue with each other, but all of the modellers are now showing that this so-called R factor is below one.

  393. So did you have any input into this document, which is the reply to the NFU's questions, put out by MAFF, which, in reply to question eight, says: "The epidemiologists' projections suggest that, on current policies, without vaccination, between 70 per cent and 99 per cent of livestock in northern Cumbria could be lost"? Is that how you define an epidemic that is under control?
  (Professor King) I have defined as clearly as I can what I mean by an epidemic under control. It did not state how many animals will be culled in a given area; and, certainly, the expectation from the modellers, if we look at the Cumbrian area, is that something like 30 per cent of the livestock in that area will be left standing. So when we say "under control" we are defining our statement very clearly, and you asked me what I meant by it.

  394. But your definition of "under control" still allows for 99 per cent of livestock in Cumbria to be wiped out?
  (Professor King) No. I would say that that is not under control, and I did not state that that was my definition. Perhaps I could ask Dr Ferguson to take you on.
  (Dr Ferguson) I do not quite know where the 99 per cent figure came from.

  395. It is the MAFF as well; they put it out yesterday?
  (Dr Ferguson) I do not know where MAFF got the figure from, shall I say. Certainly, from the estimates, Cumbria clearly is the most seriously affected area, and we are talking about the infected zone really, in Cumbria, not the whole of Cumbria, necessarily. And the epidemic took hold to a much greater extent there than really it did anywhere else, and, for that reason, a much smaller proportion of livestock in those heavily infected zones are expected to be surviving. Even if you just look now at the proportion of livestock which has been culled in those areas, a very large proportion of sheep have already been culled. I suppose the critical question is, how many livestock could vaccination now save, or how many could it have saved in the past (because the epidemic is going down so rapidly now)? The estimation is that it could have, two or three weeks ago, saved potentially up to 90,000 cattle. From the trends we were seeing in the epidemic at that time, up to 90,000. That would be a maximum number, you would save, would still be standing on the ground, if you put vaccination in then. That number is probably considerably smaller now, just because the epidemic, first of all, has been going down rather faster than our more conservative prediction said, and, secondly, because we are that much later on, so that many more outbreaks have occurred and so there is less scope for vaccination to have a protective effect. Maybe that helps more? But I think there will be very few sheep left, certainly in the infected zone in Cumbria, by the time this epidemic is over.

  396. Is it going down, because you will actually make it harder for a farm which is infected to qualify as an infected premise? Jim Scudamore gave us a figure of 3,500 farms which had been culled, as contiguous culls or `shoot on suspicion' culls, on top of the 1,440 cases, on Monday; on the same day, Lady Hayman gave a figure of 5,385, of which 1,435 had been defined as IP, so nearly 4,000 farms on top are SOSs or contiguous culls. Now that is a huge number of farms, and we are now getting reports, certainly in Devon and certainly on the Welsh Borders, that it is much harder to get Page Street to categorise an infected farm as an IP than it would have been two weeks ago. Page Street are now pushing for these to be categorised as SOSs, which has a double-whammy for you, two hits, which are an advantage; one, it does not count as a case in the daily figures, and, secondly, you do not have to take out the neighbouring farms in the contiguous cull and out of the carcass mountain. So have you changed the categories?
  (Professor King) Can I just say, have we changed the categories implies that we are a decision-making group, and, as I said very clearly, we are an advisory body, we are not making decisions.

  397. So who advises the vets in Page Street, which ultimately decide, down the telephone, to a local vet, "You call that an IP and you slaughter that farm and the neighbouring farms in 24 hours," or, "You call it an SOS, you slaughter that farm in 48 hours and you don't take out the contiguous farms;" because this will have a very significant impact on the disease?
  (Professor King) I am sure the question of a decision-making hierarchy in this matter should be directed somewhere else, but, if you are asking me, I would say, we do have CoBRA. I have just come from a meeting of CoBRA this morning, CoBRA meets at 8.30 every morning, and at that meeting all parties, all ministries, are represented and advice is then given. That advice goes to the Prime Minister and the Minister of Agriculture; from there, it filters down through Page Street.

  398. I will ask a strictly scientific question now. On 9 March, Dr Alex Donaldson received an e-mail from Roger Breeze, who is the Assistant to the Head of the USDA in America, Floyd Hall, asking if he could co-operate with Pirbright, using a machine which he describes as a "real-time PCR", which, as I understand it, and I am not a scientist, is a machine which will identify a virus in the saliva, or from a nasal swab, of animals that are infected with foot and mouth before they show symptoms. Now this I was told yesterday by Professor Fred Brown, from Plum Island, who was over here for a day; and, as I understand it, he received no reply. If this machine is as accurate as Professor Brown told me, he said it is 99 per cent accurate, could it not have saved this huge, vast, expensive cull of mainly healthy animals?
  (Professor King) Could I answer this, first of all, and then, of course, I will ask Dr Donaldson to deal with your specific query. The question of the so-called `smart cycler' is one that was brought to my attention in a discussion I had, very early on, with Fred Brown; so, here, I am simply telling you that, as Chief Scientist, I got on the telephone and 'phoned the experts around the world, and Fred Brown was one of those. And Fred Brown told me about the development of the `smart cycler' and also told me that he had already had somebody get in touch with Dr Donaldson. Of course, we have investigated the potential use of this instrument; it is a PCR-based instrument, which means that it is based on a polymerase chain reaction, where the virus contains RNA, you multiply the RNA through this chain reaction and it becomes very readily detectable, so it is a means of detecting the virus. The world's experts in this application of foot and mouth are Dr Donaldson and his team at Pirbright; they did not develop this in-field machine, that was developed in the United States for the use of the military. Now it is commercially available, but it is an untested machine and there are very serious questions to be asked about the use of that machine in the field, in particular the problem of cross-contamination. Now I have to stress that, if you are under laboratory conditions, Chairman, and you carry out these tests, you do get very accurate results. In the field, it is considerably more difficult to achieve this type of accuracy, particularly if you are going, as you want to do, to analyse a large number of animals, from animal to animal. And that cross-contamination problem has not been answered. We would like to see very distinct field tests on this instrument; but my final conclusion, from talking to all the experts, including Fred Brown, is that, unfortunately, it will not be available to us for this epidemic.
  (Dr Donaldson) I will give you the background. I have not got the correspondence with me, but I have copied it to OST and I am quite happy to make the correspondence available to anyone else who might want it. I have known Roger Breeze for many years, he was a former Director of the Plum Island Animal Health Laboratory in the United States, where Dr Fred Brown is also based at the moment. In March, Dr Roger Breeze contacted me and said that he, working with the US military, had this `smart cycler' equipment available, and he and his team would like to come to the United Kingdom and to test the equipment under field conditions to validate it during an outbreak situation; he was optimistic that it would be very helpful. He did say, in his correspondence, that the machine had not been validated for work with foot and mouth disease. I approached Jim Scudamore, Chief Veterinary Officer, and asked if this could be facilitated. Jim Scudamore's response was that he was very interested in the equipment and he would be very willing to collaborate with the USDA, but he suggested that this should be done after the epidemic had declined because there would be logistic problems in taking such equipment into the field. I sent a reply back to Roger Breeze, saying that the Chief Veterinary Officer was not willing to accommodate him at this particular point in time but would be willing to do so at a future date. I said, meantime, I would be willing to accommodate a scientist from the USDA at the Laboratory in Pirbright to test his equipment under standardised conditions, alongside PCR equipment which we already had and which is up and running and functioning. The particular attraction of what the USDA have been offering is that their equipment is portable; it is a small device, operated by a battery, which can link to a lap-top computer, and that, in turn, can convey the output of the test result through the Internet. I should point out that the piece of equipment costs in the region of £22,000, and there was no indication of what would happen to the equipment once it had been taken onto an affected farm, in other words, how it will be decontaminated. So I expressed that view, that we would be willing to collaborate, sent that back to Roger Breeze. The next communication I had was on a Thursday, saying that he, Roger Breeze, and his team would be arriving the following weekend to test out the equipment. I said that would not be convenient, that we would have to arrange a time to accommodate him in the Laboratory when we could find space and to do it properly. He, in turn, offered to show the equipment to us over the Internet. It was pointed out to me by colleagues that one of my scientific staff was about to make a visit to Plum Island and it would be an opportunity for him to see the equipment, which we understood had been developed in collaboration with Plum Island. That scientist went to Plum Island, he was hosted by Dr Peter Mason, who is the foremost molecular biologist at Plum Island, he asked to see the equipment; the response he got from Dr Peter Mason was that he had heard about the equipment but he had not seen it nor had he been involved in any validation of it. Subsequent to that there have been the pressures from Dr Fred Brown, I believe, through different channels, to have the `smart cycler' tested. Since that time, I believe, Jim Scudamore has offered the services of MAFF. We had a visit last weekend from a Mr Mike Tass, I believe, who offered to take some of our equipment, which is portable, into the field and to test it alongside anything else that might be forthcoming, from whatever source; because I should add that the `smart cycler' and other offers from the United States are not the only ones we have had. The normal scientific approach when pieces of equipment like this are represented is that data is provided to show that they do operate, and when that data is available through the scientific press then one can start looking at that data in relation to well-established, gold standard methods. That is the normal scientific approach. I would add and emphasise that we have no data from the Americans about the performance of their equipment for foot and mouth disease - they may have used it for other agents, I am not sure; and, I would repeat again, I have no indication that their equipment has been validated. So, I think, there we are, we are still willing to accommodate the Americans. Mr Jim Scudamore has offered, I think, to accommodate them in the field, and, well, we are willing to help if we can.

Mr Todd

  399. Professor King, when were you first invited by the Prime Minister to advise on the epidemiology of this outbreak; you said "early on", I think, at one stage?
  (Professor King) Yes. On 21 March, I attended a meeting at the Food Standards Agency, which was organised by John Krebs, and at that meeting groups of epidemiologists, people from MAFF, and so on, were invited to discuss the state of the epidemic. On 22 March, I wrote a letter to the Prime Minister, but before I had even posted it I had an invitation from Sir Richard Wilson to attend a meeting of the Permanent Secretaries, which was called to discuss the handling of the foot and mouth disease, and it was at that meeting, on 23 March, which could be said to be the first meeting of CoBRA in this crisis, that I first put forward the 24-hour/48-hour cull policy. At the first meeting the Prime Minister attended, he was in Stockholm at that time, on 24 March, he asked me to set up a science group on foot and mouth disease.

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