Select Committee on Agriculture Minutes of Evidence

Examination of witnesses (Questions 460-463)



Mr Drew

  460. Clearly, where we are at now, if the figures are to be believed, is, the issue is becoming concentrated around disposal, and safe ways of disposal of the animals. As you said earlier, you have to face the media and hope that they get it right; how do you convince constituents that I have who have burning, we have not had burial, although that is always a possibility, how do you convince them that they have not been affected, healthwise? I know it is an open-ended question, but that is the sort of question that people want to have answered. What level of risk are we really dealing with?
  (Professor King) If we take the question of pyres then the Environment Agency and the Department of Health standards have been operated very consistently, which is, for example, that pyres should be set on the top of hills, that pyres should be lit only when we know what the wind conditions are going to be and that the wind is going to carry the smoke from the pyres away from a neighbouring village, and this has been carried through in practice. In addition, monitoring is being done of the output from those fires. But I would not want to understate the potential hazards from these fires. Chairman, the fires are not only producing dioxins, the fires produce PM10 particles, and, of course, these do pose a risk to people who are asthmatic or have a potential for asthma. And advice is also clearly going out to people, if they are in the neighbourhood of a fire, to stay indoors, where possible, and so on. But we have also to keep it in perspective. It is not the same as having a fire burning continuously in your neighbourhood, over a long period of time; if these fires are burnt out over a few days then, again, the risk to human health is relatively small. But I am not trying to say that this is not a problem, it is a problem.


  461. Gentlemen, a final point. We now appear to have got the first case of a man contracting the disease; does that make any difference at all to your calculations? For example, you said that there were issues about the acceptability of products from vaccinated animals, one thinks immediately that this might have some impact upon human perception of the acceptability of product. I realise that you are not responsible for human health, but, insofar as your responsibilities do embrace this, what conclusions have you drawn and what impact might it make?
  (Professor King) Can I try to clarify the position with vaccinated animals first, in response to your question. A vaccinated animal has antibodies produced which will kill off the virus, and a vaccinated cow, for example, will not pass the virus through into the milk, and the virus is not sustained in the beef, in the meat, in the blood system. The only place where the virus can exist as a carrier state is in the mucus in the throat and in the mouth region, so that there is no possibility, with a vaccinated animal, of posing any kind of health risk from foot and mouth disease. In the case of the 1967 outbreak, there was one reported case, which was fully established, of a person contracting foot and mouth disease as a virus. As you know, we are now examining whether or not the case currently reported very widely in the newspapers is a case of foot and mouth or not, we do not know. But, in that instance, there is a very vivid description of how this individual was splashed by the outpourings of an animal that was infected; this is not quite the same as drinking milk or eating meat. But what I would say is that, in terms of human contact with animals, for example, it is known that somebody who works with animals that are infectious will get the virus into their own mucus system, and for four or five hours the breath will contain the virus which will operate as a challenge to other animals. So a person coming into contact with an infectious animal will take on the virus, the virus can replicate for a while, and that person then poses a threat; which is precisely why the advice to our vets is that if you have been on an infectious premise you cannot go to another farm premise until an overnight stay at least.

  462. I was reflecting merely on the perceptions of safety, because you will recall the wholly different debate on GM food, in which, of course, public perception has played an enormous role, quite separate from any scientific evidence about threats to safety of that product. But that is a comment not requiring an answer.
  (Professor King) Can I make just one comment, as a different kind of health warning, and that is, over reading the output from our modellers, I heard somebody mention June 7, other dates have been looked at very carefully. The model, and I am sure that Dr Ferguson will not mind me saying this, the mean-field model becomes a little problematic when the number of cases gets small, and in that case the farm-scale models, of the kind that John Wilesmith is using, do rather better; and John Wilesmith's models are currently indicating that the outbreak will continue to bump along until about mid July to early August.
  (Dr Ferguson) It is notoriously difficult to predict the end of an epidemic, because of these random outbreaks.
  (Professor Woolhouse) I did want to say one thing, Mr Chairman, which brings me right back to your opening comments about the contiguous cull, and just one observation for you, because you were obviously concerned about this. The estimations we have done at the moment is the contiguous culling would have removed hundreds, almost certainly, of incubating foot and mouth disease outbreaks, and if those had been allowed to come through to normal reporting, diagnosis and slaughter they would have infected hundreds more, by our estimation. So that must be included, of course, in your evaluation of the effectiveness of contiguous culling.

Mr Paterson

  463. How many of the contiguous cull farms have you tested?
  (Professor Woolhouse) That information is still being analysed, is it not?
  (Professor King) Can I suggest, Chairman, that the question may be a little misleading, for the following reasons. We have put forward a policy, a cull policy, that is based on the models but based not on bringing the epidemic under control most quickly but bringing the epidemic under control in such a way that we minimise the number of animals that would be culled at the end of the epidemic. So this cull policy, with the contiguous farm removal, may remove healthy animals that are not incubating the disease, but it is absolutely clear to us that this is the policy for reducing the overall number of healthy animals that would be culled, or healthy animals that would become infected and then have to be culled.

  Chairman: We must get on. Gentlemen, thank you. Our preoccupation with June 7 was due entirely to the anniversaries of the battles on the Normandy beaches, as you can imagine. Thank you very much indeed for coming here today, it has been very illuminating, on the whole, I think; and we wish you well of the worm, as Enobarbus said to Cleopatra.

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