Present: Dr Alex Donaldson - Institute for Animal Health (IAH) Pirbright
Laboratory
1. Dr Anderson welcomed Dr Donaldson and introduced the Inquiry. Dr
Donaldson had prepared a presentation which he used to illustrate
some of his remarks. During discussion the following points were
made:
2. Pirbright’s mission related to major livestock diseases (as classified by
OIE) that had potential for great economic impact. Its main function
was research into 11 out of the 16 OIE List A diseases. There were
eight Reference Laboratories at Pirbright including the World
Reference Laboratories for FMD and Rinderpest. Through its contacts
throughout the world, Pirbright maintained its expertise and with its
biosecure facilities, it had provided an emergency diagnostic service for
FMD since 1924.
Slide 1 illustrated the main elements of Dr
Donaldson’s involvement during the crisis.
Experiments on the precise characteristics of the causal virus.
MAFF had insisted that the work done at Pirbright on their behalf duing
the emergency should be under an accreditation system and that the
diagnostic tests used should be only fully validated. They also required
that there should be a full audit trail. In all some 200 extra staff were
recruited during the crisis.
8. Asked about the mission of Pirbright, Dr Donaldson said that since it
was part of the Biotechnology and Biological Sciences Research
Council (BBSRC), the mission of Pirbright was research on exotic
viruses - to understand their basic properties and their interaction with
host species including their maintenance and transmission. The
mission was decided by the Director of the Institute for Animal Health
(of which Pirbright was a part) and the Governing Body, which included
the CVO.
9. Pirbright’s funding of £29 million per year was about 30-35% from
BBSRC, about 30-35% from DEFRA and the rest from other contracts,
such as from the Department for International Development, selling
reagents and test kits.
10. Dr Anderson commented that, as a semi-independent institute, it was
not clear how such a vital resource was tied into the national priorities.
Dr Donaldson pointed out that one of the reasons for the establishment
of the research councils had been to give scientific activities
independence from political issues. The BBSRC reported eventually to
the Department of Trade and Industry.
11. No other institute in the UK matched Pirbright’s expertise. Its
possession of an FMD reference collection dating back to 1924 gave
the laboratory the unique capability to compare samples of virus from
the field with those in the reference collection and thereby to determine
their origin in many cases. The only other laboratory licensed to work
with live FMD virus in the UK was Merial, the vaccine producer, which
was located next to the Pirbright site. During the outbreak five other
laboratories had been licensed to perform serological tests.
12. MAFF/DEFRA was aware of Pirbright’s capabilities since the Chief
Scientist was on the council of the BBSRC. However, Pirbright had not
been consulted in the drawing up contingency plans and Dr Donaldson
was concerned that their only mention in the interim contingency plan
produced recently by DEFRA related to training.
13. Responding to a suggestion that the country would not have coped
without Pirbright, Dr Donaldson agreed that laboratory confirmation of
the first suspected cases was essential, following which disease control
required efficient management and resources to stamp it out. That, in
turn, depended on the scale of the outbreak and whether serological
surveillance was required to confirm freedom. Many outbreaks had
consisted of just one outbreak. The epidemics of 2001, 1967/8 and
1952 were unusual in that respect and may therefore have reflected
lack of resources to tackle them. There were examples of countries
that had dealt with the disease without reliance on the World Reference
Laboratory – such as Greece, Bulgaria, and Italy – who instead relied
on their own national FMD Laboratories during emergencies.
14. Pirbright had been contracted by DEFRA during (not before) the
epidemic. During “peacetime”, MAFF/DEFRA usually funded service
projects on an annual basis, and it had an arrangement for the
processing of 300 samples a year.
15. Pirbright did not have a written contingency plan for managing largescale
epidemics. Experience had shown how resources should be redeployed
and they had tested their ability to ramp up vaccine supplies,
as necessary. That said, the scale of the epidemic had been much
greater than expected.
16. The volume of media enquiries had increased such that after about two
weeks, they were dealt with by another part of IAH to allow Dr
Donaldson to concentrate on other priorities. Specific enquiries
directed to Dr Donaldson were, however, addressed as soon as
possible. During the crisis IAH logged over 2,000 enquiries from the
media and public.
17. Resources at Pirbright had been, and still were, an issue, with retention
and recruitment difficulties at all levels. Consultants, ex-PhD students
and scientists working in the private sector had volunteered to help
Pirbright during the epidemic. In 1983 there had been 13 vets but now
there were only four.
18. Research for DEFRA was funded through DEFRA’s Science
Directorate, but Page Street (formerly Tolworth) funded monitoring and
surveillance services. Pirbright was assessed on the quality of its
scientific research. The BBSRC assessed the totality of the research
via Visiting Group assessments every four years. Pirbright received
high ratings because its science was recognised as being of
international standard. DEFRA assessed the DEFRA-funded science
in separate reviews, the last of which had been in June 1999. The
following one, scheduled for February 2001 had been postponed due
to the FMD emergency. Whilst the contracts for services were
reviewed twice every year, the services themselves were not reviewed
regarding quality and efficiency. Dr Donaldson agreed that the
services should be reviewed in the future.
19. Turning to the characteristics of the Pan Asia O strain, Dr Donaldson
said that the virus had been identified as a serotype O virus on 20 Feb,
confirmed as a Pan Asian strain within 24 hours. There had been three
considerations:
- Nucleotide sequencing had previously shown that members of
the Pan Asia group of strains had been present in many
countries
- Some strains had differed in their virulence for various species
but the UK strain had been found to be virulent for cattle, sheep
and pigs
- The UK strain had, surprisingly, been found to be emitted as
airborne virus in lower amounts than other strains and therefore
the distance of spread by this means was likely to be less than
for other strains of the virus.
20. It had been found, in 1997, that the strain of virus which caused a large
epidemic in Taiwan was very virulent for pigs but not for cattle or
sheep. Therefore, Dr Donaldson had been cautious about making
assumptions about the properties of the UK strain both in terms of its
virulence and the amounts emitted as aerosols. He had suspected
from studies on the airborne excretion of a Pan Asia strain from South
Korea that the UK strain would have lower excretion.
21. Airborne spread was not only influenced by levels of excretion, but also
by climatic effects such as humidity and wind speed. Topography was
also important. For example, the spread in the Ribble valley could
have been affected by the wind direction and humidity. Windborne
spread was especially likely to cattle which were very susceptible to
infection by inhalation.
22. The evidence for the airborne spread from the farm at Heddon-on-the-
Wall had been strong. Pirbright’s collaboration with the Met Office
pointed to a period when plumes over Ponteland had clearly been
possible. However, other than during the early stages, airborne spread
had not been a major mechanism of spread during the epidemic.
MAFF/DEFRA had estimated that some 80% of transmission of virus
had been by local spread. Dr Donaldson suggested that this could
have been due either to breaches of biosecurity or short distance
airborne spread by atmospheric prediction models were estimates and
not absolutes.
23. Other possibilities such as the following had been considered but were
unlikely to have played large roles:
- Water in streams: unlikely – since virus would be quickly diluted
and livestock were relatively resistant to infection by ingestion,
probably because virus was inactivated by the low pH of
gastrointestinal tract
- Aerosol transmission between pigs kept physically separated –
unlikely since experimental results had shown that pigs were
difficult to infect by aerosols of virus and direct contact was
usually necessary.
24. That the Heddon-on-the-Wall case had arisen from feeding illegally
imported meat to pigs was credible since pigs were relatively
susceptible to infection by the oral route.
25. Asked whether walkers could have spread FMD from footpaths, Dr
Donaldson replied that he was not aware of any evidence of such
spread. There were reports in the literature for other epidemics of
stockmen and vets spreading disease by handling animals. Animals
could be easily infected when they were handled around the mouth by
people contaminate with the virus but mechanical spread by other
means did not readily occur.
26. The disease was unlikely to have been spread by infected deer. No
evidence had been found for their involvement. The 400 serological
samples (300 of which from a herd in Cumbria) had all tested negative.
About 100 virological tests (some of which had been repeated by PCR)
had also been negative. All five species of deer had been shown to be
capable of transmitting the virus to livestock, but since they were
solitary animals, they were unlikely to have had direct contact with
infected animals (e.g. on farm).
27. Dr Donaldson had realised that the outbreak would not be easily dealt
with once he had heard about the dealer in Devon who had been linked
to cases in the north of the country and had been the owner of ten
other farms. The seriousness of the outbreak had become evident
when the CVO had phoned Dr Donaldson and informed him about the
use of a 3 km cull in Cumbria. He had never known such a policy to
have been used before on a sustained basis.
28. Dr Donaldson had criticisms of the scientific basis of the mathematical
models and the influence they had had on disease control policy. He
strongly disagreed with the conclusions of the modellers about their
forecasts for the development of the epidemic. The predicted epidemic
curves had been based on parameters from the 1967/8 epidemic which
had been cattle-driven; they had taken no account of the wide
difference between FMD in various species and between farming
systems. The influence of spatial factors on the rate of disease spread
had not been included in the models. An average infection to
confirmation period of 8 days had been used by the modellers but this
had been a gross over-simplification since several cycles of infection
with incubation periods ranging from 2 to 14 days had been possible.
The epidemic had been in decline by the time of the introduction of the
contiguous cull policy on 29 March. (In a publication by Keeling and
co-authors, it was stated that the epidemic peaked on 26 March with 54
outbreaks per day.)
29. The disease could be controlled and the virus eradicated if control
measures were implemented quickly and effectively. The priority
should have been to concentrate the resources on the infected
premises (IP) rather than diluting the scarce resources to contiguous
premises where it had been believed, without any proof, that animals
had been incubating the disease. As a result, many negative cases
had been slaughtered – on average four to five contiguous farms for
every IP. At one stage of the epidemic it had been estimated that fifty
per cent of cases on contiguous premises (CPs), dangerous contacts
(DCs) and slaughters on suspicion (SoSs), as well as 20% of infected
premises (IPs), had tested negative.
30. It was impossible to determine whether the contiguous culling was
scientifically tenable since samples had not been routinely taken on
CPs, despite his requests for a properly conducted trial to collect the
data. DEFRA may have taken samples. However, if the animals had
been incubating disease, serological samples would not have been
useful since they might have been viraemic and not yet have
seroconverted.
31. The contiguous cull policy had been a reasonable policy to pursue at
the start of the epidemic, especially in Cumbria, where nearly all of the
CPs were, in practice, actually DCs (due to uncontrolled movement).
This was not necessarily the case in other areas. Indeed, the
contiguous cull itself may even have contributed to the long tail of the
epidemic in England.
32. Scotland had not seen a long tail, possibly because they had been
better organised to deal with emergencies as a result of the experience
of the Lockerbie crisis and had the co-operation of the farmers through
greater involvement of the farmers’ union. The 3 km sheep cull there
was claimed to have been justified because the resources had not
been available to carry out the traditional methods of epidemiological
investigation of IPs and patrols in the 3 km areas.
33. Pirbright had contributed to the scientific advice provided to the
Minister, Prime Minister and COBR, but Dr Donaldson was not certain
where the policy decisions had been taken. He and Paul Kitching had
had regular communications with the CVO. He had held frequent
discussions with the MAFF epidemiology group (headed by Hugh
Morris). The CSA’s Science Group from 26 March (of which he, Paul
Kitching and Paul Barnett had been members) discussed and made
points that the CSA had taken to COBR, where the CVO had had also
been present.
34. The majority of the CSA’s Science Group had known very little about
FMD. This was a matter of concern and Dr Donaldson and his
colleagues had had to spend much time explaining FMD to them,
especially when the Group first met.
35. Discussions about vaccination had continued for months and the issue
had been considered very carefully. Ring vaccination around the
Essex cases would have been a waste of effort since the disease had
soon appeared elsewhere and the stock of vaccine would already have
been exhausted. Mass vaccination would not have eradicated the
virus without continued stamping out and other measures. Dr
Donaldson gave the examples of Argentina and Uruguay in 2001
where large epidemics (over 2000 outbreaks in each country) had been
controlled by mass vaccination of the cattle populations. However,
Argentina still had the disease after 50 million doses of vaccine had
been used and Uruguay was expecting to vaccinate, probably for five
years). The only unanimous decision in support of vaccination by the
CSA Group had been to vaccinate the cattle which had been about to
be released from sheds to spring pasture in Cumbria, but it had met
resistance. Overall, the case for vaccination had been marginal and it
could have gone for or against.
36. Pirbright had concluded that the SmartCycler portable RT-PCR
equipment had potential once the reagents used for tests had been
optimised – the first trial had given unsatisfactory results. The results
had been comparable to other real-time PCR tests. However, the
SmartCycler system for FMD diagnosis had not been validated and its
use in the field, untested, could have been unreliable. In addition,
before the DNA could be amplified, the nucleic acid had to be extracted
from the tissue and the RNA converted into cDNA. These two stages
added time. A farm environment would bring added risks of
contamination of the sensitive PCR technique. Furthermore, operation
would require trained expert. Future use in the field could be in mobile
or regional laboratories.
37. Field tests had been an attractive possibility because diagnosis had to
be rapid to meet the 24 hour target to slaughter. Pirbright had often
been testing samples from dead animals. On average the samples
had taken a day to arrive and, in future, the use of helicopters to deliver
samples should be considered to reduce the transport time and ensure
the fastest possible diagnosis.
38. The management of samples had been poor. Much greater use should
be made of electronic information collection and transmission systems.
Pirbright had been frustrated by the time spent in trying to decipher the
information and inconsistency of forms accompanying samples.
Indeed, forms and samples had often not been co-ordinated.
39. Compatible computer systems between Pirbright and DEFRA were
essential and these should include computer-based mapping and
management systems. Problems had arisen from incompatibility and
also from the DEFRA firewall. An email could take 12 to 18 hours to
get to DEFRA.
40. Turning to issues associated with other animal diseases and general
principles for disease control, Dr Donaldson referred to slides listing
diseases which posed a risk (slide 2), and routes of likely entry (slide
3). He suggested that alongside the continuing risk of FMD, Classical
Swine Fever (CSF) was the disease that currently posted the greatest
risk.
41. International surveillance was important, but currently inadequate. The
decision for action on the ground lay with individual countries and the
FAO. The EU also had a role to play. The OIE only collected
information – it was not operationally involved in surveillance.
Globalisation was a continuously increasing risk. Intensified checks
were needed at borders, ports and airports.
42. Swill feeding of waste food to pigs had already been banned. This ban
should continue.
43. All pigs, sheep, goat and cattle should be subject to movement
restrictions for 28 days, rather than 21 days, subsequent to trade (since
28 days was equivalent to two incubation periods). Including poultry in
the movement ban restrictions after trade would be sensible.
44. Training and awareness of exotic diseased and their control needed to
be improved among, for example, vets, farmers and abattoir staff.
45. Exotic disease outbreaks should continue to be managed through the
SVS. On the ground, the Police and Army should be involved in
controlling movements and disinfection.
MOST LIKELY ROUTES OF ENTRY OF FMD,
SVD AND CSF VIRUSES TO THE UK: