Chapter 1: Principles of Disease Control
Overall Disease Control Strategy
1.1. In the event of an outbreak of exotic animal disease, the Scottish Government will act swiftly and decisively to:
- protect public health
- safeguard the health and safety of those involved directly in controlling the outbreak
- eradicate the disease and regain disease free status
- minimise the economic impact of the outbreak on industry
1.2. The Scottish Government will try to:
- keep to a minimum the number of animals that have to be destroyed
- ensure that if animals do have to be destroyed, it is carried out humanely
- minimise adverse impacts on animal welfare, the rural and wider economy, the public, rural communities and the environment
1.3. The Scottish Government will achieve its objectives by working with the other UK administrations, national and local operational partners, those directly affected by the outbreak through their representative groups and, where appropriate, international organisations.
Prevention is better than Cure
1.4. A notifiable disease outbreak can have long term impacts for businesses and communities. There are a number of measures that can limit the size of any outbreak if implemented and practised before, during and after the introduction of disease. Some of those measures have been summarised in the biosecurity leaflet attached at Appendix 1. The effectiveness of those measures depends on the animal keeper and those responsible for the marketing and transport of animals (including meat products, eggs, milk and milk products), animal feed, animal waste, equipment, and animal by-products.
1.5. One of the first measures is the routine inspection of stock in compliance with welfare Codes of Practice. Another is good biosecurity by visitors. Scotland's Environmental and Rural Services partnership (SEARS), which brought together nine public bodies, produced biosecurity guidance that can be applied by anyone visiting rural land, including contractors and utility companies. This biosecurity guidance, which includes a handy reference guide, is an important tool in the prevention of disease and can be found on the SEARS website..
The importance of vigilance
1.6. The number of livestock premises affected by an outbreak of exotic animal disease depends on a number of factors, but the principal one is the time between the first animal in the country becoming infected and the disease being reported to the control authorities so that action can be taken to contain the outbreak. Another important factor is the incubation period (see concept note 1).
1.7. If disease initially goes undetected for a long time then it may spread extensively before action can be taken. The resulting outbreak can be large and prolonged as control authorities need to deal with many infected premises before the disease can be brought under control. This can mean that the available resources are overwhelmed and need to be boosted before they can deal with the outbreak. Prompt reporting (see concept note 2) by livestock keepers of suspicious signs of disease in their animals is therefore essential to prevent widespread outbreaks of disease.
Concept Note 1
Incubation Period The incubation period of a disease is the time between an animal becoming infected and the time it starts to show signs of disease. This period varies and depends on the disease and other factors. Animals may be infectious to other animals during the incubation period i.e. before they show signs of disease. Animals moved during the incubation period may be one of the mechanisms of undetected spread.
Concept Note 2
The livestock keeper has a crucial role in maintaining vigilance for early signs of disease. Prompt reporting of suspect disease to their local APHA Office, or local vet who will notify APHA, will help control authorities identify the source of disease before it has a chance to spread, thus reducing the impact on the wider community
1.8. Animals infected by an exotic disease may not always show visible signs which can result in undetected or silent spread. The spread of disease can be limited by livestock keepers practising good biosecurity (see Appendix 1) on their premises and when animals are transported, by obeying the legislation with respect to movement standstill controls (see concept note 3) and by good movement record keeping. If good biosecurity practices are followed routinely when exotic disease is not known to be present in the country the likelihood of an extensive outbreak of disease can be significantly reduced.
Concept Note 3
Movement standstills operate even when disease is not known to be present in the country. They limit undetected (“silent”) spread of disease. The principle is that if animals are moved on to a premises, then an incubation period must pass before any animals are moved off. This gives an opportunity for any disease to be identified and limits the potential for further spread. This is known as the 13 day rule (20 day rule for pigs). Details of the rule may be found at: http://www.gov.scot/MovementStandstills
1.9. If the presence of disease is reported promptly to the local APHA Office then there is a greater likelihood of limiting the number of premises affected. Even where undetected spread of disease has occurred, the opportunities for identifying potential routes of spread improve the earlier it is reported. The contact details for the APHA are listed at Appendix 2 and are also available on the APHA website.
1.10. At the start of any outbreak there may be uncertainty about the eventual scale until the likely origin of the disease has been established and an estimate has been made of the length of time disease has been present in the country. The Scottish Government and its operational partners will increase resources if needed. However, in the event of a limited outbreak, not all the structures, processes and control tools identified within this plan may be needed.
1.11. Maintaining readiness to deal with an outbreak of disease is an essential aspect of effective disease control. This is not only the case for the control authority and their operational partners, but also applies to industry, including the meat sector, hauliers, dairies, major retailers, exporters, show organisers, market operators and livestock keepers. All should have rehearsed and regularly reviewed contingency plans in place to deal with a notifiable disease outbreak. Industry should, for example, know how to deal with the implications of a movement standstill, including accommodation of increasing numbers of animals particularly on pig and poultry farms. The plans should also cover the consequences of becoming an infected premises, e.g. consideration of where to dispose of any litter slurry or waste water used in the cleansing and disinfection process.
1.12. At the request of industry, SEARS partnership produced a template to assist farmers develop site specific contingency plans for the outbreak of a notifiable disease. The document is designed to:
- inform operators of the likely consequences of an outbreak of disease on their premises
- encourage operators to improve biosecurity measures
- help businesses prepare for an outbreak on their premises, or the imposition of movement controls
- provide a single source of information to allow the operator and APHA to deal with a disease outbreak and return the unit to productivity in the shortest time possible without compromising animal welfare
- assist operators in putting measures in place to prevent pollution of the environment or harm to animal or human health
- encourage operators to think through potentially polluting actions and establish appropriate mitigation strategies.
1.13. The use of the template is entirely at the discretion of individual operators and it is designed so that operators can add or subtract elements to suit their own needs, although there is a requirement under Pollution Prevention and Control regulations for operators to consider disease outbreak in their incident prevention and mitigation plans.
1.14. Livestock keepers have a responsibility to be prepared for a disease outbreak. To help farmers plan the action they would take to maintain biosecurity following the outbreak of a notifiable disease Scotland's Rural College (SRuC) has produced an on farm biosecurity strategy for a notifiable disease outbreak.
Phases of an Animal Disease Outbreak
1.15. The phases of an animal disease outbreak may be divided into:
- Preventing potential disease spread
- Confirmation (or negation of disease)
- Preventing disease spread
- Control strategy
- Exit strategy
1.16. These phases and the disease management actions associated with each phase (with the exception of 'Returning to Normal Business') are described in more detail later in this chapter. There will be some variations in practice depending on the particular disease (see the relevant disease Annex).
1.17. There is a legal duty on any person who suspects that an animal may have a statutory notifiable disease to report their suspicion to their local APHA Duty Vet. The contact details for APHA are listed at Appendix 2 and are also available on the APHA website.
1.18. On report of suspicion of notifiable disease the Duty Vet will arrange an investigation by an APHA Veterinary Inspector (VI). There is a duty on the keeper of the livestock to facilitate the investigation by:
- gathering the animals
- providing handling facilities for the VI to examine animals and take samples providing records and other information that will assist the VI in determining whether or not disease exists.
Preventing potential disease spread
1.19. If the VI cannot rule out the possibility of disease then samples will be taken from one or more animals and submitted to the relevant National Reference Laboratory (see paragraph 2.93).
1.20. Restrictions will be imposed on a suspect premises by serving a legal notice on the livestock keeper. This will be done either by an APHA official or the local authority. The notice will prohibit the movement of animals, people, vehicles and things onto and off the premises except under the terms of a licence. Before the notice is served, the livestock keeper may be instructed verbally not to move anything off the premises.
1.21. The restrictions will be removed if following investigation, the VI does not suspect disease.
Temporary Control Zone
1.22. In the case of certain diseases Scottish Ministers may impose a Temporary Control Zone (TCZ) around the suspect premises. In the case of foot and mouth disease, Scottish Ministers will impose a TCZ. The location and size of the TCZ will be such as is considered necessary to prevent the spread of disease. Within that zone Scottish Ministers shall, by declaratory order, declare what movement restrictions are to be put in place. A TCZ may also be declared under certain circumstances to control the movement of animals where other exotic notifiable animal diseases are suspected and their presence in Great Britain has already been confirmed. The size of a TCZ will depend on the veterinary advice at the time and legislation but would likely have a radius of at least 10 km.
Actions if disease cannot be ruled out
1.23. If disease cannot be ruled out from either clinical inspection or preliminary test results there may be a case conference between all four UK Chief Veterinary Officers (CVOs) supported by key policy and veterinary officials from each administration to consider the known circumstances and to determine the next steps. In particular this meeting would determine whether the circumstances warrant triggering an Amber Teleconference.
1.24. If suspicion of disease is strong and cannot be ruled out on clinical grounds, an Amber Teleconference will be organised and supported by Defra's Animal Health Policy and Implementation Team. Scottish Government will be responsible for ensuring Scottish operational partner agencies/organisations such as Health Protection Scotland (HPS), Scottish Environment Protection Agency (SEPA), Police Scotland and Local Authorities are able to participate in the Amber teleconference. Its purpose to apprise all concerned of the situation, assess the risks, and to agree future action and communication accordingly. Participants include all four UK CVOs and senior officials from SG, Defra, Welsh Government (WG), Department for Agriculture, Environment and Rural Affairs in Northern Ireland (DAERA), APHA, the relevant UK reference laboratory for the disease under investigation, APHA Scotland Outbreak Director and relevant representatives from other government departments and Health Agencies.
1.25. At the Amber Teleconference, for disease in Scotland, CVO Scotland would either agree to confirm disease or specify what further evidence, such as test results, would be needed. In the latter circumstance, the Amber Teleconference would be reconvened when further information was available.
1.26. Communication channels on suspicion of disease are outlined in more detail in the Scottish Government's Exotic Diseases of Animals Communications Strategy.
Confirmation of Disease
1.27. Once samples have been submitted to the reference laboratory it may take up to 72 hours to confirm or negate disease and it can take longer depending on which tests are carried out. CVO Scotland has responsibility for confirming disease in Scotland on the basis of the APHA Veterinary Inspector report and laboratory reports. On confirmation of disease, appropriate area restrictions are imposed in accordance with EU and domestic legislation. The period between the initial report of disease and final confirmation will be used by the Scottish Government to activate the contingency plan and make initial preparations to increase disease management resources if required. CVO UK will be responsible for notifying confirmation to the European Commission and the World Organisation for Animal Health (OIE).
Preventing Disease Spread
1.28. Once disease has been confirmed, the primary objective is to prevent the spread of disease by:
- taking action on the infected premises (IP)
- imposing wider area livestock movement controls
- placing controls on animal products and activities
- investigating the origin of the outbreak and determining whether there has been further spread of disease from that source
- other surveillance to detect further spread of disease.
Actions on Infected Premises (IP)
A) Movement Restrictions
1.29. IP restrictions are served on the owner in line with the relevant legislation, and if appropriate, the keeper of the livestock. These restrict the movement of people, animal products, feed and fodder, vehicles and items off and onto the IP except under licence. They also prevent the movement of animals susceptible to the particular disease off and onto the IP. In some circumstances non-susceptible animals may, however, be allowed to move off and onto the IP under licence issued by APHA (see paragraphs 1.72 and 1.73).
1.30. The objective of the restrictions is to ensure that infection is not moved from the IP.
1.31. The actual rules concerning the IP will be set out in the notice served on the livestock keeper and any licence conditions permitting movements off and onto the premises. It may be possible, depending on the layout of the IP, to exclude the dwelling house from the restrictions.
1.32. Once disease is confirmed, all susceptible animals on the IP will be humanely culled. For some diseases culling is not required and it may be possible to exclude some animals in certain circumstances [see section 1.86: Breeds at Risk]. Compensation may be paid for susceptible animals culled for control purposes as determined in legislation. The detailed valuation procedures and any appeals process are explained to the owner of the livestock at the time.
1.33. Animals infected with a notifiable infectious and contagious disease (see concept note 4) may excrete virus contaminating the environment and provide a potent source of infection either directly or indirectly for other susceptible animals. It is important therefore that they are culled as quickly as possible. Once an animal is culled new virus production stops.
Concept Note 4
Infectious and Contagious Disease
An infectious animal is an animal that has become infected and is excreting the infectious agent in its urine, faeces, breath, saliva, milk or other body secretions. It is capable of infecting any susceptible animal and contaminating the environment.
A contagious disease is an infectious disease that can be spread by a susceptible animal coming into very close contact with an infected animal or with people, vehicles, animal product or can be spread by things that have become contaminated with infectious material e.g. faeces, urine and other excretions in which the virus has survived.
1.34. The welfare of the animals to be culled is given careful consideration and is taken into account when selecting the most suitable depopulation method as outlined in annex 1 of 1099/2009. The depopulation method deployed will depend on the type of incident, species, age, number of animals, and any other site-specific conditions or resource constraints. For domestic pets, it is likely that lethal injection would be used (this is common method used by veterinarians when "putting an animal to sleep").
1.35. The following are the main depopulation methods for livestock that APHA will consider:
- Lethal injection
- Electrical stun/kill
- Captive bolt followed by pithing
- Free bullet
Depending on the circumstances it may be necessary to sedate the animal before using one of the above methods. It is considered unlikely that there would be a need to seek any derogation to the approved methods outlined in annex 1 of 1099/2009 for depopulating livestock premises.
1.36. In the event of a notifiable avian disease being confirmed, APHA has 26 Containerised Gassing Units (CGU) for immediate deployment, as well as a number of poultry transport modules and specialist percussion killers. Depopulation activities by CGU are also supported by contractor's personnel and kit. A pair of CGUs working in tandem can process approximately 4,000 birds per hour, dependent on size of bird and catcher throughput. Depending on the suitability of the premises, APHA may also consider the use of whole house gassing for depopulation of housed poultry. The use of gas-filled foam (wet foam) has been validated and is also being investigated. APHA hold framework agreements with various sectors of the poultry industry, for example poultry catching gangs and depopulation contractors to assist in the operations.
1.37. It is possible that a derogation may be made on a case-by-case basis under EU regulation (EC) 1099/2009 (protection of animals at the time of killing) seeking alternative means of depopulating poultry premises. An example of when this may occur is when highly pathogenic AI has been confirmed in multiple premises in poultry dense areas of Scotland and all of the following apply:
- there is a significant threat to public health through animal to human transmission
- all other depopulation methods from the list above have been investigated and ruled out
- where delays in depopulating the premises would lead to further animal welfare issues such as prolonged pain and suffering
- where delays to the depopulation operation would significantly slow down the process of eradication of disease
D) Health and Safety at Infected Premises
1.38. APHA are responsible for arranging the culling and disposal of livestock. Although speed of culling and disposal is important, the health and safety of individuals is paramount and careful preparations are required by APHA to ensure that it is not compromised. This is particularly important in the case of animal diseases that are communicable to humans (zoonoses) and Health Protection Scotland will advise on the precautions to be taken on the IP to protect workers. APHA will provide Personal Protective Equipment (PPE) and for their staff and contractors working on the IP.
E) Avian Influenza incidents – Prophylaxis
1.39. APHA are responsible for the provision of antivirals to APHA staff and any contractors brought in by APHA to deal with an Avian Influenza (AI) incident (local NHS boards are responsible for provision of antivirals to farm workers and other individuals as required – see para 3.36).
1.40. Scottish Environment Protection Agency (SEPA) will advise on the suitability of disposal sites in Scotland. The NDCC (National Disease Control Centre) (see para 2.18) will co-ordinate the task of finding sufficient disposal capacity but the decision on which disposal facility to use rests with the DSG (Disease Strategy Group) (see para 2.49). The decision on disposal site and method will involve consideration of environmental and health risks and other constraints such as available capacity, the desire to limit transport of contaminated wastes, and the legislative controls for environmental protection and animal health.
1.41. The preferred hierarchy for disposal in Scotland is:
- rendering/ Incineration at approved and licensed premises
- permitted commercial landfill
- incineration on farm
- burial on farm.
1.42. However, particular areas in Scotland (especially those areas in the Highlands and Islands covered by the remote area derogation) may have logistical difficulties moving the carcases off farm for rendering and incineration because of their geography. Depending on the individual situation and the disease, consideration would be given to the hierarchy of preferred options for disposal in Scotland at the time of any outbreak. Any decisions on disposal methods will be taken in consultation with key stakeholders and appropriate environmental and public health assessments will be undertaken at each disposal location prior to use.
G) Cleansing and Disinfection (C&D)
1.43. Infectious agents of infectious and contagious diseases can remain viable in the environment for different lengths of time depending on the disease agent and environmental conditions such as temperature, humidity, acidity, alkalinity and light. In certain conditions the agent may survive many weeks or months. It is important therefore, that after susceptible animals have been culled and their carcases removed, the premises and transport and equipment at risk of contamination is cleansed and disinfected to prevent indirect spread and re‑emergence (recrudescence) of disease when the premises are restocked. Animal feedstuffs and things that have been contaminated but cannot be cleansed and disinfected may be seized and destroyed.
1.44. Approved disinfectants or biocides must be used at the approved concentration for the cleansing and disinfection process. A list of Scottish Ministers approved disinfectants is held on a GB basis and is available from the DEFRA website.
1.45. SEPA provides advice on precautions to be taken on premises undergoing C&D in order to minimise environmental impacts of disinfectants or biocides.
1.46. There are two phases to C&D of an IP, preliminary and secondary. These are outlined below.
1.47. Preliminary disinfection is carried out immediately after culling and disposal has been completed. It is usually carried out, under the direction and control of APHA, on behalf of the competent authority, and consists of spraying contaminated and potentially contaminated areas of the IP with an approved disinfectant or biocide. The objective is to reduce the level of surface contamination. Primary disinfection is considered to be completed 24 hours after spraying of the IP with the approved disinfectant.
1.48. The timing of preliminary disinfection is important because, generally, the lifting of the Protection Zone and Surveillance Zone (see paragraphs 1.65 and 1.66) can only take place after a number of days (which may vary depending on the disease) has passed since completion of preliminary disinfection on the last IP within the zone.
Concept Note 5
Slurry and Manure
Manure is a solid mixture of faeces, urine and used bedding material (e.g. straw, wood shavings, paper). It is generated on any farm where animals are housed on bedding, i.e. premises with pigs, cattle, sheep or poultry.
Slurry is a liquid made up of faeces, urine and wash water. Only certain types of pig and cattle management systems will produce slurry. Even though caged laying hens do not have bedding, they do not produce slurry (poultry droppings do not have sufficient liquid content to become slurry).
A single premises can produce both slurry and manure.
1.49. In order for disinfectants or biocides to work they must be applied to clean surfaces. Areas in need of disinfection must be cleaned of organic matter before the disinfectant is applied. This is the process of secondary disinfection. Secondary disinfection, depending on the disease, can only commence after a number of days (which may vary depending on the disease) have passed since preliminary disinfection.
1.50. The legal notice served on the owner/keeper of the premises by the competent authority will set out what cleansing needs to be done on the IP, such as removal of slurry and dung, contaminated feed and fodder etc. The exact terms will depend on the disease agent concerned. IP restrictions will remain in effect until C&D is completed and re-stocking carried out, with no evidence of the recurrence of disease.
1.51. The costs of secondary C&D will fall to the owner of the premises. There is no obligation on Scottish Ministers to pay these costs. Owners are responsible for undertaking and paying for secondary C&D, irrespective of whether or not they intend to restock the premises.
1.52. The time of completion of secondary or final disinfection is important because for some diseases the earliest date a country can be declared free of a disease depends on completion of secondary disinfection. Similarly, restocking will also only be permitted after secondary disinfection has been completed (see para 1.56).
1.53. In cases where secondary C&D cannot be completed (because of dangerous structures, for example) the premises may remain restricted and not available for restocking until the competent authority is satisfied that sufficient time has elapsed for the infectious agent to have become inactivated naturally.
Disinfection of slurry and manure
1.54. Disinfection of slurry and manure requires particular attention during the secondary C&D of an IP because both substances can harbour disease-causing organisms, including viruses. In the case of slurry, some viruses can survive for several months.
1.55. In the event of an outbreak, of most diseases covered by this framework, European legislation requires that the manure from all livestock buildings on the IP is removed from the buildings and stacked, sprayed with disinfectant and left for at least 42 days. This allows the manure to compost, thereby destroying viruses. In the case of foot and mouth disease, any manure must be mixed with granulated quick lime (100 kg/m3) prior to composting, must reach at least 70°C during composting, and must be covered during the composting period or restacked (to ensure even heating throughout the material). In the case of Newcastle Disease, the stack must be covered during composting to prevent access by vermin or birds.
1.56. In the event of an outbreak of most diseases covered by this framework, European legislation requires that slurry is decontaminated according to the specific disease (please see individual Annexes for more information). The slurry can be stored for a specified period of time or can be treated to destroy the virus in accordance with official instructions. In most cases, tanks or lagoons on farms for storing slurry are large enough to accommodate several months of slurry production. It is important to note that when treating large volumes of slurry with chemicals, it can be difficult to achieve uniform mixing.
1.57. In addition, SEPA must be consulted before any treated slurry is spread on land. SEPA can also advise on the selection of an appropriate chemical prior to slurry treatment.
1.58. Viruses are efficiently deactivated by heat therefore heating slurry is an effective method of decontamination. However, given the processes and equipment required to heat a large volume of slurry, it is unlikely to be practical on most premises.
1.59. Completion of secondary disinfection is certified by the competent authority following inspection of the premises.
H) Controlled Restocking
1.60. The controlled restocking of premises that have had infected or susceptible animals culled and disposed of is an integral part of the recovery phase. Depending on the disease, restocking is not permitted until a defined number of days has elapsed following secondary cleansing and disinfection. With some diseases there is controlled restocking where limited numbers of animals are allowed on the premises (sentinel animals) and observed to ensure disease is no longer present. In some cases, samples from these animals may be tested to ensure that disease no longer exists on the premises before all restrictions are lifted and the premises allowed to restock completely. During extensive outbreaks, where the movement of animals can be restricted for prolonged periods, or if final cleansing and disinfection is delayed or not possible the restocking of a premises may take many months.
I) Dealing with contacts to infected animals – forward tracing
1.61. Since disease can spread from an IP by, for example, the movement of infected animals, people, vehicles or contaminated equipment, APHA staff will trace any movements that may have carried infection to susceptible animals elsewhere. In addition to these routes of potential infection, neighbouring premises may be at risk from infection by direct contact across a fence, for example, or through the air (aerosol spread). A veterinary risk assessment will be carried out to assess the likelihood of spread of disease.
1.62. If the assessment is that the risk of spread of disease, or exposure, is negligible no action will be taken.
1.63. If the assessment is that risk is low then the contact animals and other susceptible animals on the premises will be confined to the premises by the service of a Statutory Notice on the livestock keeper. The animals will then be monitored and may be tested to see if they develop disease. Restrictions remain in place on the premises for a minimum of 21 or 28 days, depending on the disease, from the date of potential contact.
1.64. If the assessment is that risk of spread of disease is high then the animals may be classified as Dangerous Contacts (see concept note 6) and the animals compulsorily culled.
Concept Note 6
A Dangerous Contact is an animal, group of animals or an entire herd or flock which, on the basis of a veterinary risk assessment, is believed to have been exposed to infection and is likely to develop disease.
It is a legal requirement in many EU Directives that dangerous contacts, once declared, must be culled to prevent propagation of the infectious agent and further spread of disease.
J) Determining the Origin of the Outbreak – back tracing
1.65. APHA staff will trace any movements that could have introduced infection by visiting the premises where the movement originated if there are susceptible livestock. Those animals will be examined for signs of disease and, if necessary, may be tested. The objective will be to try to find the origin of infection. If disease is found on the premises it will become an IP and routes of spread to and from the IP will be investigated to close down possible onward spread of disease and continue investigation into its source.
Culling of Animals to Prevent the Spread of Disease (pre-emptive cull)
1.66. Scottish Ministers have powers to require the culling of animals in order to prevent the spread of certain specified diseases. These powers are contained within the Animal Health and Welfare (Scotland) Act 2006.
1.67. Before such powers are used Scottish Ministers would have to make a statement explaining the situation and why it is necessary to resort to using such powers. Compensation would be paid for any animals culled under these powers.
Area Movement Controls
1.68. In the initial stages of a disease outbreak there will be uncertainty about the origin of the disease, how long it has been present, how far it has spread and how far it will spread. As a result, area restrictions are imposed to stop animal movements into, from and within specified areas. For most notifiable infectious and contagious diseases a Protection Zone (PZ) and a Surveillance Zone (SZ) are imposed by statutory order under relevant disease control legislation (for more detail on specific area restrictions refer to the individual Annexes). These zones may be a circle around the IP or may follow roads or natural geographic boundaries. In the case of multiple IPs, zones may overlap. Where this occurs the overlapping zones would be combined to form a single PZ and SZ. The PZ and SZ for non-vector and vector linked disease are shown below and in Figures 1a and 1b.
Figure 1a: Non-vector linked disease
Figure 1b: Vector linked disease
(Vector linked diseases generally require larger area based restriction zones. The example provided here is for bluetongue virus)
A) Protection Zone (PZ)
1.69. For diseases that are not spread principally by vectors such as biting insects, a PZ has a radius of at least 3 kilometres centred on the part of the IP considered appropriate for disease control purposes (see figure 1a). A radius of 3 kilometres is normally used because, as a rule of thumb, approximately 80% of new cases of infectious and contagious animal disease occur within 3 kilometres of an existing case. However, in some circumstances it may be necessary to extend the PZ to ensure that the area is representative of the risk of spread. If there are no further cases and all the required surveillance has been carried out within the PZ, normally after 21 days following completion of preliminary C&D, the PZ would normally become part of the SZ with some controls relaxed to match those of the SZ. For diseases that are spread by vectors, such as bluetongue, any zones put in place would likely be much larger (see figure 1b) and would be in place for a much longer period.
B) Surveillance Zone (SZ)
1.70. For diseases that are not spread principally by vectors, a SZ has a radius of at least 10 kilometres centred on the part of the IP considered appropriate for disease control purposes. Provided there are no further cases, and all the required surveillance has been carried out, the SZ will be lifted; usually not less than 30 days after the completion of preliminary cleansing and disinfection on the last IP within the PZ. For diseases that are spread by vectors, any zones put in place would likely be much larger.
C) Controls in the PZ and SZ
1.71. Detailed controls vary and are set out in the relevant legal instrument declaring the PZ and SZ. The controls will focus on enhanced biosecurity including restrictions on the movement of susceptible animals as these are the most potent method of spreading disease. In addition there are controls on meat (including meat products, eggs, hides and in some cases milk and milk products) derived from animals in the zones and on the carcases of animals that die. Livestock keepers are required to carry out a census of animals on the premises, carry out additional biosecurity measures and report, in certain circumstances, animals that die.
1.72. As investigations into an outbreak or incident progress, it will become clearer where the risks of disease spread lie. Depending on the circumstances, and subject to veterinary risk assessment and statutory requirements, movements of animals or other controlled activities in the PZ and SZ may be allowed under specific or general licence. These licences will set out certain criteria, such as cleansing and disinfection requirements, that would need to be met either before or during the move. As each administration within the UK operates its own licensing regime, co-ordination is needed to ensure a coherent approach to moves across administrative borders.
1.73. Area movement restrictions and the licensing conditions are enforced by local authorities.
1.74. While the PZ and SZ are in place APHA is also required to carry out surveillance, involving visits to premises, carrying out clinical inspections, examination and possibly sampling to demonstrate that disease has not spread.
1.75. If a number of overlapping PZ and SZ areas have been combined to form a very large PZ and SZ, more time may be necessary to carry out the surveillance required to demonstrate freedom.
D) Other Disease Specific Control Areas
1.76. Scottish Ministers have powers to declare wider control areas if needed. In the case of FMD it has been agreed that if there is an outbreak, a GB wide animal movement ban will be imposed until the likely extent of the outbreak has been established.
1.77. Every effort will be made to keep access to the countryside open but land may need to be closed for specific diseases (most notably FMD). The risks of disease being spread by recreational access to the countryside are very small, and can be eliminated by avoiding direct contact between people and livestock and by not taking vehicles (including bicycles) onto land where livestock are, or have been kept. The Scottish Government has published a list of veterinary risk assessments (VRAs) in relation to FMD, which assess the risk of specified activities, including recreational access to agricultural areas that are being used or have been used for keeping livestock or other FMD susceptible animals.
1.78. There is no reason to close access to land in areas outwith a FMD protection zone. Current advice on access is provided in the Scottish Outdoor Access Code.
1.79. Guidance on restrictions and procedures for official closures will be issued to all major access bodies and stakeholders. Official signage would also be displayed. People visiting areas of the countryside outside a restricted area may be asked to follow specific biosecurity advice.
1.80. In the event of an outbreak of some diseases, the UK may lose its OIE international disease free status which may prevent the export of livestock and their products until disease freedom status is recovered. Other specific disease control areas are dealt with in the relevant disease Annex.
Controls on Animal Products
1.81. There may also be a ban on trade within the EU of susceptible animals and meat, meat products and milk and dairy products from the whole country or parts of it. Although these products may not be traded within the EU they may be traded on the domestic market with a domestic health mark (round stamp).
1.82. In the case of trade with third countries, i.e. those countries that are not members of the EU or European Free TradeAssociation (EFTA), export certificates may be withdrawn until the situation has been clarified.
1.83. The Scottish Government will determine the disease control strategy in Scotland using the structures set out in Chapter 2 in line with control measures for specific diseases (outlined in the relevant disease annex) and in consultation with relevant stakeholder groups.
1.84. The control strategy is complex and must take account, amongst other things, of the:
- need to minimise the impact on the livestock industry, the rural community, the wider economy and community and other users of the countryside
- need to minimise any damage to the environment
- legal framework
- requirements of the EU and the OIE. (see section headed 'International' in Chapter 4)
- requirements of other UK administrations
- availability and efficacy of vaccine
- availability and reliability of tests to distinguish between vaccinated animals and animals that have been infected
- available resources, including laboratory resources
- costs and benefits of proposed measures and likely speed of application and effect
- expert advice from the National Emergency Epidemiology Group (NEEG)
- advice from the National Experts Group (NEG)
- size and extent of the outbreak
- output from computer model simulations
- interrelation between the proposed control strategy and the exit strategy.
1.85. The Scottish Government will decide and communicate control strategies and timeframes to those affected as quickly as possible, so that livestock keepers may plan their approach to livestock management, livestock movements and maintaining the welfare of their animals and their businesses.
1.86. Use of vaccination to support a control strategy depends on a number of factors, including:
- the disease and its epidemiology
- whether vaccination is permitted under EU law
- vaccine availability and efficacy
- impact on trade
- whether or not the vaccine can be administered in sufficient time and quantity to be effective in control
- whether or not there are tests to distinguish between vaccinated and infected animals.
1.88. Many exotic notifiable infectious and contagious diseases of domestic livestock are transmissible to wildlife. Wildlife may therefore provide a reservoir of infection for disease for domestic animals. Strategies may have to be developed to deal with infected wildlife. Broadly, wildlife disease controls may fall into the categories of:
- wildlife vaccination
- minimising contact between livestock and wildlife
- wildlife destruction.
Breeds at Risk and other specialist animals
1.90. Diverse genetic resources are important for maintaining an efficient and sustainable livestock industry. Similarly animals bred for scientific, research, display or educational purposes (such as zoos or wildlife parks) are important resources. Breeds at Risk and other specialist animals are subject to the same control measures as other livestock but where dangerous contact (see concept note 5 above) or wider cull measures are being implemented alternatives to culling may be considered for these animals. However, alternatives will only be allowed if permitted by legislation and CVO Scotland is assured, by means of a veterinary risk assessment, that sparing the animals will not jeopardise efforts to prevent the disease from spreading further. Owners of breeds at risk who wish Government to consider sparing their animals from a cull should alert government, ideally in advance of any disease outbreak by completing an animal breeds at risk registration form. Further information about breeds at risk, which breeds are on that list and how to apply is available from the Scottish Government website. 
Welfare of Livestock
1.91. In the event of prolonged movement controls and limited or no intra‑Community trade, there may be no outlet for meat and meat products. As a result there may be a build-up of livestock on premises because they cannot be moved or sold for slaughter. This may have an adverse effect on the welfare of animals and to avoid suffering due to overcrowding the keeper may be required to humanely cull animals. Pressures on accommodation can arise quickly and this is especially so in the pig and poultry sectors. It is important therefore that all livestock keepers have contingency plans in place to deal with prolonged movement restrictions (See paragraphs 1.11 to 1.14 'Maintaining Readiness' for information on contingency planning).
1.92. In exceptional circumstances and if it is considered appropriate to prevent widespread deterioration in welfare standards, the Scottish Government may introduce a welfare disposal scheme and arrange the culling and disposal of animals. A welfare disposal scheme would be subject to there being evidence of need and the inability of industry to provide alternatives. Animals will either be culled in abattoirs or purpose built killing plants and, where this is not possible, on farms. On farm culling will only take place where:
- animals cannot be licensed to leave the farm
- the animals cannot be transported because of welfare concerns e.g. heavily pregnant females or very young animals
- slaughterhouse/disposal plant capacity cannot cope with the volume
1.93. Each case will be considered on its merits. In line with the policy set out in the Government's response to the FMD Inquiries (November 2002) no compensation will be paid to farmers for animals culled under a welfare scheme. To ensure appropriate controls are in place to ensure food safety the Food Standards Scotland (FSS) should be consulted where premises approved under food hygiene legislation (e.g. slaughterhouses) are to be used for such a scheme.
Designation of premises
1.94. During a disease outbreak there may be circumstances in which premises such as egg packing centres, hatcheries, slaughter houses etc. can be designated to operate either in areas under movement restrictions or receive products from areas under movement restrictions, if allowed under legislation. Designation usually requires an application, official inspection and a formal official approval. To become designated there are requirements for enhanced biosecurity and in some cases additional requirements for special marking of products, separation of restricted products, and record keeping/traceability. Premises such as egg packing centres, slaughter houses and hatcheries are advised to discuss with APHA the possibility of pre-designating their premises in advance of an outbreak. This could provide an advantage to getting the business designated and operating as quickly and as normal as possible during a disease outbreak.
1.95. The control strategy must be developed in tandem with an exit strategy that will restore disease freedom and return to business as usual. For example, the deployment of a vaccination campaign may significantly prolong the surveillance programme to prove freedom from disease. EC decisions may also determine the timing and extent of any exit strategy.
1.96. During the exit phase, and in certain circumstances, animal products that could be exported may have to undergo specific treatment e.g. heat treatment, deboning and maturing and will be marked with the EU oval health stamp. Depending on the disease, the duration of the outbreak and its extent, a surveillance programme may be undertaken to demonstrate that the country is free from disease and there have been no undisclosed outbreaks of disease. After completion, a certain period must lapse without further cases of disease before country disease free status is restored according to the OIE Code (see section headed 'International' in Chapter 4).
1.97. It may be possible, following a risk assessment, to divide the UK into regions with differing levels of risk. This may allow the relaxation of some controls, and permit movements within an area of the same status and from low to high risk areas. This regionalisation is dependent on the epidemiology of the disease, its geographical distribution and seasonal trade patterns. Laboratory surveillance may be required to demonstrate freedom from disease in a region. Proposals to regionalise must be acceptable to the other UK administrations, the European Commission and other trading partners and be permitted under the relevant legislation. Regionalisation will also require restrictions on animal and animal product movements to maintain a region's disease status. As this may have an adverse economic effect that outweighs any short term advantage, economic considerations will be taken into account in decisions on regionalisation.
1.98. EU rules enable intra-Community trade to resume relatively quickly once a disease is under control. However the resumption of trade with third country trading partners can take longer. This is because most third country trading partners require the UK to be disease free according to the OIE definition of disease freedom, which requires completion of final C&D. In GB, final C&D is the responsibility of the owner of the affected premises.
1.99. Compartmentalisation is a concept that allows companies, in the event of a disease outbreak, to resume trade quickly with third countries who have signed up to the scheme. Companies must meet the conditions of EC Regulation 616/2009 which include strict bio-security measures and the requirement for premises to be approved by Government. APHA carries out the inspections required for any company wishing to consider use of compartmentalisation.
Scaling Down the Disease Control Response
1.100. As part of the exit strategy, tactical and operational resources will be scaled back once parts of the outbreak or incident management response are complete. This scaling back will be agreed between the relevant CVOs and APHA.
1.101. In line with the reducing disease control response, CVO Scotland will decide when it is appropriate to scale back and, ultimately, cease the Scottish Government's disease response activities.