Examination of witnesses (Questions 381-399)
WEDNESDAY 25 APRIL 2001
PROFESSOR DAVID
KING, DR
NEIL FERGUSON,
DR ALEX
DONALDSON AND
PROFESSOR MARK
WOOLHOUSE
Chairman
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.
Chairman
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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