Supplementary memorandum by the Department
for Environment, Food and Rural Affairs (DEFRA)
Avian influenza is a highly contagious viral
disease affecting the respiratory, digestive and/or nervous system
of many species of birds. It is caused by a Type A influenza virus.
There are two types of avian influenza virus, low pathogenicity
(LPAI) and high pathogenicity (HPAI). The last outbreak of avian
influenza in Great Britain was in 1992.
2. Contingency Plans
Great Britain has in place high level contingency
plans to deal with any future outbreaks of this disease, as required
by European Union legislation (Council Directive 92/40). The Plan
allows access to the facilities, equipment, personnel and all
other appropriate measures necessary for the rapid and efficient
eradication of an outbreak of avian influenza. These plans were
approved by the EU Commission in 2000.
The Contingency Plan for FMD, laid before Parliament
on 28 March, will provide the detailed framework for any response.
Appropriate sections of the plan will apply to inform the establishment
of Local and National Disease Control Centres, the notification
process, the involvement of stakeholders and operational partners,
the ramping up of staff and other resources and the management
Operational Instructions are contained within
Chapter 4 of VIPER (Veterinary Instructions, Procedures and Emergency
Routines). This is currently undergoing review but existing instructions
are sufficient for the field to respond to suspicion, investigation,
confirmation and control of disease. A necessary update to reflect
changes in disposal hierarchy, valuation and contact details was
issued to the field in early March 2003.
3. Control Strategy
The Diseases of Poultry (England) Order 2003
came into force on 30 April. It updates and replaces earlier similar
legislation to enact European Union Council Directive 92/40/EEC
introducing control measures for avian influenza. The new Order
also contains powers to check that disease is not present. Similar
updating legislation is being made for Scotland and Wales. Instructions
to field staff are contained in State Veterinary Service Chapter
The main aspects of disease control are:
(i) Compulsory notification of suspected
cases of avian influenza
The legislation requires that any suspicion
of disease must without delay be notified to the Divisional Veterinary
Manager. It empowers veterinary inspectors to enter any premises,
conduct all necessary inquiries and take samples to ascertain
whether disease exists.
(ii) Declaration of infected premises
This includes prohibition on movements of animals,
litter and vehicles into or out of an infected place. Vehicles
must be cleansed and disinfected. There is compulsory slaughter
of diseased poultry and poultry suspected of being infected or
which has been exposed to infection. Eggs on the infected premises
must also be destroyed.
During the recent outbreak of avian influenza
in the Netherlands, Belgium and Germany, those member states used
preventive culls to stop the spread of disease. We do not have
these powers here automatically for avian influenzaHouse
of Lords' amendments during the passage of the Animal Health Act
2002 restricted such automatic powers to Foot and Mouth Diseasethough
we will be seeking them through an Order requiring Affirmative
Resolution to ensure we have the flexibility of response to an
(iii) Declaration of an infected area
This includes movement restrictions on poultry
and hatching eggs within a protection zone of at least 3 kilometres
around the infected premises, and in a surveillance zone of at
least 10 kilometres. Within these zones, poultry must be kept
in their living quarters. They must not be moved unless authorised
by a veterinary inspector. Meat and eggs produced during the incubation
period of the disease shall be traced and destroyed. Markets,
shows and fairs in the infected area are prohibited. Waste disposal
contractors must not remove or spread used poultry manure or litter.
Hauliers must cleanse and disinfect any vehicle used for the conveyance
of poultry, carcases, offal, feathers or eggs.
In addition, the Secretary of State may order
the vaccination of any species of poultry in a vaccination area.
However, vaccination is not considered practical for avian influenza.
The only vaccines available for this disease are inactivated,
which means that birds must be dosed individually by injection.
It can take up to three weeks for birds to develop protective
immunity following vaccination and some poultry require two doses.
Vaccination does not prevent birds from becoming infected and
shedding virus. Vaccination can help suppress the clinical signs
of disease and reduce the amount of virus shed by infected birds.
Currently no avian influenza vaccines have marketing authority
in Great Britain.
4. TABLE TOP
A table top exercise is being held on 27 June,
with representatives of other Government departments and agencies,
devolved administrations, and Defra staff responsible for policy,
operations, legal issues, communications, procurement to check
overall readiness to deal with an outbreak, improve awareness
of existing plans, roles and responsibilities and to identify
gaps requiring further work. Already much work has been done to
access the best methods of rapid and effective poultry slaughter,
in particular learning from those who were involved in the outbreak
in the Netherlands.
If the strain is identified as avian or other
animal Defra would be involved in licensing viral cultures into
the country for research purposes and vaccine development. Human
laboratories that are likely to be involved are already licensed
under SAPO to work with avian flu viruses. Defra is in a position
to process requirements quickly should new import licenses be
As shown with SARS the Veterinary Laboratories
Agency are in a position to provide reagents and sera quickly,
where they have them in stock, to assist with ongoing investigations
both in the UK and abroad.
The Veterinary Laboratory Agency is the World
Reference Laboratory for Avian Influenza. They receive samples
from around the world and routinely sequence the viruses and categorise
them according to pathogenicity. The genetic basis for avian influenza
virulence is fairly well understood and VLA are undertaking work
to enable them to better predict what mutations are associated
with changes in virulence. VLA is also looking at the possible
reassortment that can occur when human and animal viruses infect
the same host. With human influenza viruses we do not understand
as much about which mutations increase human pathogenicity. Human
virus are sequenced by the HPA and WHO Reference Laboratory at
Mill Hill. VLA works closely with these laboratories.
DEFRA LINKS WITH OUTSIDE BODIES
Defra policy is one of close liaison with other
Government Departments, Agencies and other organisations.
There are procedural mechanisms for working
with the Department of Health (DH) and the Food Standards Agency
(FSA) within the remits of the Surveillance Group on Diseases
and Infections in Animals (SGDIA) and the United Kingdom Zoonoses
Group (UKZG). There is a concordat with the FSA and there is a
Memorandum of Understanding between the Veterinary Laboratories
Agency (VLA) and the Health Protection Agency (HPAformerly
the Public Health Laboratory Service). Identified new infections
in animals are referred to DH and FSA. DH is advised by the Advisory
Committee on Dangerous Pathogens (ACDP) and FSA are advised by
the Advisory Committee on Microbiological Safety of Food (ACMSF).
It is the responsibility of the UKZG and the SGDIA to ensure that
the mechanisms work properly in the matter of collaboration and
co-operation between these bodies on new and emerging zoonotic
Defra has close contact with and takes note
of advice from independent groups such as the ACMSF, the ACDP
and independent review groups on Defra or Agency work.
Defra produces a wide range of annual reports
and other literature, much of which is on the Internet, including:
Annual UK Zoonoses Report;
Annual Report on Trends and Sources
of Zoonotic Agents in Feedingstuffs, Animals, Food and Man, Annual;
Annual Salmonella in Livestock Report;
Annual Report on Antimicrobial Resistance
Annual Salmonella in Feedingstuffs
Veterinary Investigation Diagnosis
Analysis Report; and
Quarterly Reports of Species Groups.
Defra implements EU policy in the area of zoonoses,
and is fully compliant with Zoonoses regulations. Defra takes
the precautionary view that an animal disease is zoonotic until
it has evidence that it is not.
HPA has indicated that there has been a 50 per
cent cut in indigenous foodborne disease incidents, particularly
in the area of Salmonella. This is encouraging since this
is the only area in which Defra has indicated that controls at
primary production level, in view of current knowledge, are likely
to be successful. All evidence suggests that the controls in breeding
flocks of poultry, improvements in hygiene, pest control and vaccination
have been very beneficial and this is shown in the results of
monitoring in broiler chickens for Salmonella enteriditis and
Salmonella typhimurium. (Further information/background
at Annex 4).
3. VTEC 0157 AND
Until outputs from research indicate clear new
methods for control of VTEC 0157 and Campylobacter it may
be very difficult to make substantial progress at primary production
level with these organisms.