The following memorandum by Professor David King really should be subjected to proper scrutiny. 
 I copy the PQ and PA (King incorrectly refers to is as House of Commons Debate). Out of 680 Premises tested only one was positive.
King tries to underplay the significance of this by implying that the Pirbright tests were inaccurate.
However, as we have said on warmwell many times already,  the high level of accuracy of the tests was made quite clear by Donaldson in his evidence to the Select Committee on 25 April 2001 (also copied below)
Professor King was actually present and heard the reply since he also was being questioned at that session.

Supplementary memorandum submitted by Professor David King, Chief Scientific Adviser, Office of Science and Technology

7 November 2001
The Committee's third request was for my comments on a written answer given by Elliot Morley (HC Deb, 6 November 2001, 146W) relating to the number of premises culled out as Dangerous Contacts and Slaughter on Suspicion cases which were found subsequently to have Foot and Mouth Disease. I understand that DEFRA will shortly be issuing a corrected answer and that the relevant figures are: 284 premises currently classified as Slaughter on Suspicion and 396 premises currently classified as Dangerous Contact had laboratory tests conducted for the presence of Foot and Mouth Disease. Of these, one returned an initial positive result.

  The fact that all but one of the premises have tested negative does not mean that the policy of culling out Dangerous Contacts and Slaughter on Suspicion cases is too stringent. FMD is an extremely infectious disease and, in order to bring the epidemic under control, it was necessary to get ahead of the infection by removing animals that were potentially already incubating the virus and, if not slaughtered, would themselves pass the infection on. Currently available diagnostic tests are not fast or sensitive enough to spot incubating infection quickly enough to prevent it becoming a risk to surrounding farms.

13 December 2001


Commons Written Answers  (6 Nov 2001)
Foot and Mouth
Mr. Morley : As at 22 October a total of 7,294 Dangerous Contacts (DC) and 255 Slaughter on Suspicion (SOS) cases, which had not been recognised as Infected Premises, had laboratory tests conducted. .....
Speaker: Mr. Morley  [holding answer 25 June 2001]

updated: 01/05/2002 matching: morley

Mr. Yeo: To ask the Secretary of State for Environment, Food and Rural Affairs how many farms included in the foot and mouth cull but not recognised as

6 Nov 2001 : Column: 146W

infected premises have had laboratory tests conducted for the presence of foot and mouth; and what proportion of these recorded positive results. [286]

Mr. Morley [holding answer 25 June 2001]: As at 22 October a total of 7,294 Dangerous Contacts (DC) and 255 Slaughter on Suspicion (SOS) cases, which had not been recognised as Infected Premises, had laboratory tests conducted. Of these, five yielded positive results and subsequently became IPs and were recorded as such.


    In addition to IPs and SOS cases, contiguous premises and DC premises have had samples taken from sheep at slaughter to further inform the Department as to origin and spread of disease. Some of these were subsequently recorded as IPs as they yielded positive laboratory results. A negative result does not necessarily mean that disease was not present. In the main, testing was for antibody, ie looking for evidence of origin (older disease).


    DEFRA Disease Control System database as at 22 October—these figures may be subject to change as quality assurance of the data are carried out.


Examination of witnesses (Questions 420-439)



418. Thank you for that. Just one, very short, other question. We were informed, on Monday, in our Select Committee, that the laboratory tests were not necessarily very reliable; how reliable are the laboratory tests that you are using currently to determine whether the infection, in fact, was present in a sample?
  (Professor King) These are serology tests that you are now asking about, as distinct from the PCR tests?

  419. Correct; yes.
  (Professor King) PCR tests for the virus, the serology tests for the antibody, and the serology tests are performed at the Pirbright Laboratory, so it is back to Alex.
  (Dr Donaldson) There is no doubt in my mind that we are using the most appropriate, sophisticated, sensitive and specific tests which are available. We have something like 70 years' experience of developing and improving on tests for foot and mouth disease. I am not sure what the basis of your question is.

420. To conclude on this question, Chair; explicitly, what we were told was that, if a vet judged that the disease was present and slaughter also went ahead, even if the result was negative in a laboratory, that negative result was not necessarily reliable, and I am just wondering what percentage of confidence do you have in the outcome of those tests?
  (Dr Donaldson) I have to qualify what I have said by saying that we are dependent on both the quality and the suitability of the samples which are collected. We are the recipient laboratory, we would expect anyone investigating a suspected case to take the appropriate samples, to put them in the appropriate transport medium and to send them to us by optimal means. If that is done and we get the appropriate material, in an optimal condition, then the tests should identify whether the virus is present, whether the viral RNA is present, or, in the case of serum, whether there is antibody present.

  421. With greater than, say, 90 per cent confidence?
  (Dr Donaldson) Absolutely.