Select Committee on Environment, Food and Rural Affairs Minutes of Evidence


Examination of Witnesses (Questions 60-79)

DR PETER NASH, MR PETER SOUL AND DR MANDY BAILEY

WEDNESDAY 22 MAY 2002

David Taylor

  60. You are talking about research experiments into BSE in sheep. What impact on the approach that was adopted was there from the alleged use in October 2001 in the Institute of Animal Health of non-sheep brains in this research? What effect did that have? What lessons were learned and what changes were made, and what was the overall cost of those unfortunate events, would you estimate? I think the results were described as uninterpretable, were they not?
  (Dr Bailey) The results were uninterpretable, yes. I should make it clear at the outset that, irrespective of whether or not the unfortunate occurrence that did occur had occurred, there would have still been some difficulty with the interpretation of the results from that experiment, in so far as there is still a lot unknown with respect to strain typing in this kind of way; and what BSE might look like if it goes through different populations of sheep, sub passage, from one sheep to another. There are still a lot of things that we do not know from the science which would have made it quite difficult to interpret the work anyway. Obviously, that was not the reason in the end that we had the problems with it. I am afraid on costs I do not recall off the top of my head the total cost of that experiment so I will have to let you know that. In terms of lessons that are learned, one of the things that the department has done as a consequence of this is to commission an external review of procedures for quality control and the position with respect to the organisations where we contract research. This is a fairly new thing. We have not as yet fully considered the report and how we are going to develop it and take it further. We are looking at ways of improving quality assurance and the standards that are required in our contractual organisations, where we fund research. We are learning lessons and taking it forward.

Chairman

  61. Has DEFRA decided whether it is going to try and recover the grant which it gave to the institute for this experiment which went AWOL?
  (Dr Bailey) Yes. It has been agreed that we will not recover the money, but there has been an agreement in relation to other work related to quality assurance which BBSRC are undertaking in lieu.

  62. If I can quote another piece of my bedside reading which is about bovine spongiform encephalopathy in Great Britain: "A Progress Report, December 2001", "One of the key areas for research is the development of a sensitive diagnostic test for TSE infection. The ideal test would be one that could be performed on the live animal." Are we getting there?
  (Mr Soul) There are some developments. I do not know whether we are getting there yet, but, for example, there is a test being developed in sheep to look at prions in sheep blood which was originally developed in America and is being evaluated at our central laboratory. There is a possibility of a urine test again with workers in Israel, collaborating with our central laboratory, and they have found a form of the prion protein in urine of infected animals.

  63. This is animal urine we are talking about?
  (Mr Soul) And human urine. They are looking at seeing if that can be developed into a test and other people have looked at various tissues which can be taken from live animals such as tonsils, and lymphoid tissue from the third eyelid and cerebrospinal fluid. We know in the case of the third eyelid and tonsils you can detect the prion protein. The difficulty with these tests is that, due to the nature of the pathogenesis of the disease, you may get positive results at certain times but not at other times. It may be that these will not be particularly useful as individual tests, but they might be useful on a flock or herd basis.

  64. Do you think it is a priority to try and develop some reliable test? The impression you give is that you think it is all terribly interesting but, at the end of the day, it might not turn out to be terribly useful.
  (Mr Soul) Because of the nature of the pathogenesis of the disease, it is something which could be quite difficult to be confident about in the results that you are getting.

  65. In terms of cost benefit analysis, the pursuit of a test which is carried out on a live animal you would regard as (a) unlikely to be possible and (b) not really a priority?
  (Mr Soul) It is a question of balance of priorities and there are other areas which have much higher priority.

  66. Your conclusions of the tests in other countries are that what they tend to do is to demonstrate just how difficult it is to develop the test.
  (Mr Soul) That is right.

  67. None of them gives the level of reliability which one wants.
  (Mr Soul) It is extraordinarily difficult to develop a test that you can be confident in.

  68. If I can ask you about the tests carried on out in the continent for BSE, I know that Professor Prusiner has said that they are rather poor quality tests and the European Union might be foolish to draw too many conclusions from them because they are taken in a particular stage in the animal's development. What is your conclusion about how reliable the information about the prevalence of the disease on the continent is, based on the tests carried out?
  (Mr Soul) The difficulty there is that these are post mortem tests. Animals can be incubating this disease for long periods of time and we are fairly confident that you will only get positive results in these post mortem tests in animals that are very close to developing clinical signs. You are potentially missing a large number of animals which are incubating the disease that have not reached that end point of the incubation period.

  69. If one drew the conclusion from that that it may be the animals have a lot more of this disease than they are letting on, on the continent, how would you respond to that if somebody bounced that at you?
  (Mr Soul) I do not think that would be fair because no test is available for them to tell us how extensive their epidemic is.

  70. As that statement is made almost universally in the United Kingdom at every auction mart and every farmer you meet states it is a matter of absolute rubbish; the continent has far more of this than they let on and somehow they are all conniving, making sure it does not come out, you would say what?
  (Mr Soul) That was based on the relative lack of reporting of clinical disease. We are very good in this country at reporting clinical disease and they were not so good in other Member States. Now, of course, they have this active surveillance programme. They are testing hundreds of thousands of animals and they are finding cases through that mechanism.

  71. We are not testing enough?
  (Mr Soul) They are testing huge numbers, and relatively young animals as well.

Mr Mitchell

  72. Is it correct that scrapie does not exist in New Zealand sheep and, if it is correct, why is that?
  (Dr Nash) As far as we know, that is correct.

  73. Why?
  (Dr Nash) We do not know but it is possible that the infectivity has never got there to start with so that you have not had the initiation of a scrapie outbreak.

  74. Sheep went out from Britain and the USA and some of it was maintained in the flock so why did they not start out with it?
  (Dr Nash) It would seem to be the case that the flocks that went to New Zealand happily did not have the disease and therefore it was not established there because the New Zealand flock does include susceptible genotypes. They do include some sheep that, when exposed to the agent, do go down with scrapie.

  75. Why is it that French scientists and advisers to the Food Safety Agency are accustomed to thinking of French scientists as brilliant, intuitive and clever and British scientists as plodding, sincere and hard working? Why is it that they have never come to different conclusions?
  (Dr Nash) It is difficult for us to comment on that because we see absolutely no scientific justification whatsoever for the ban. If you look at the reasons given by AFFSA in 1999, there were a number of arguments which were put forward which have not really stood the test of time. There are other arguments which you could still follow but which do not seem very strong. They include arguments like the fact that, at that time in mid-1999, it seemed as though temporarily the UK epidemic had stopped or that the decline had slowed down. We have obviously seen since then that the decline has continued . One of the arguments used was linked to testing and there was uncertainty about the scope of the epidemic in the United Kingdom. New tests were coming along that might show that there was more BSE around. Ironically, those tests have shown that there was more BSE around than thought, including in France. There are a number of reasons, none of which we would accept.

  76. You have assessed the evidence offered by the French Food and Safety Agency?
  (Dr Nash) We have assessed it but, more particularly, it was assessed by the EU Scientific Steering Committee which includes independent scientists from a number of Member States. They have assessed the AFFSA opinion and have not agreed with its findings.

  77. Your assessment is that most of the limitations are chronological or out of date?
  (Dr Nash) Yes.

Paddy Tipping

  78. Whilst we are talking about other countries, it has been suggested that imported meat like pâté and sausages that have not been subject to stringent controls could be a potential source of the import of BSE. Do you accept that suggestion?
  (Dr Nash) This is a 100 per cent area for the Food Standards Agency and I would be on very dangerous ground if I commented. There is an over 30-month rule in the United Kingdom that does apply to imports with one or two exceptions. One of the exceptions is processed products but, as to the risk that presents, the FSA has reviewed the position and is not proposing any change to the current arrangements.

  79. Fairly recently?
  (Dr Nash) Yes.


 
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