The Scottish Government

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Chapter 1
1 Principles of Disease Control

Overall Control Strategy

1.1 In the event of an outbreak of an exotic animal disease, the overall control strategy of the Scottish Government is set out in the Strategy Box below:

Prevention is better than Cure

1.2 There are a number of measures which, if implemented and practised before and after the introduction of disease, can limit the size of any outbreak of disease should it occur. The effectiveness of these measures is the responsibility of the livestock keeper and all of those that are responsible for the transport, marketing of animals and the meat sector. Effective implementation of these measures is the key planning assumption made in the preparation of this plan.

Concept Note
Incubation Period
The incubation period of a disease is the period between when an animal is first infected and when it starts to show signs of disease. This period is variable and depends on the disease and other factors. With most virus diseases it can be from one to fourteen days but is usually around 3 to 5 days. Animals may be infectious to other animals during the incubation period i.e. before they show signs of disease. If they are moved during the incubation period they may infect other animals they contact. This is one of the mechanisms of silent spread.

1.3 The eventual extent of an outbreak of exotic animal disease, in terms of the number of livestock premises infected, depends on a number of factors but the principal factor is the time from when the first animal in the country becomes infected to when disease is reported to the control authorities and the first actions can be taken to contain the disease. If disease initially goes undetected for a long period of time, as in the 2001 outbreak of foot and mouth disease, then the disease may spread extensively before action can be taken and the disease outbreak will be large and prolonged, as the control authorities will be faced with a large number of infected premises to be dealt with before the disease can be brought under control. In such circumstances the resources available initially may be overwhelmed before sufficient resource can be mobilised to deal with the situation. Prompt reporting by livestock keepers of suspicious signs of disease in their animals is therefore essential to prevent large outbreaks of disease.

1.4 Animals infected by an exotic disease may not always show visible signs of disease and disease may go undetected and could result in "silent" spread of disease following its initial hidden entry. The spread of exotic disease can be limited by livestock keepers practising good biosecurity on their premises, when animals are transported and, by obeying the legislation with respect to movement standstill controls (see concept note below on Movement Standstills) and by good movement record keeping. If these good practices are followed routinely when exotic disease is not known to be present in the country then the likelihood of an extensive outbreak of disease will be reduced.

1.5 If the presence of disease is reported promptly then the chances of limiting the outbreak to a one or a handful of premises is good. However if "silent" spread of disease has occurred or, in the case of foot and mouth disease, there has been windborne spread over a wide geographical area then the outbreak may be extensive and prolonged.

Concept Note
Movement Standstills
The objective of movement standstills, which operate even when disease is not known to be present in the country, is to limit silent spread of disease when it is introduced. The principle is if animals are moved on to a premises then no animals are moved off until an incubation period has passed giving an opportunity for disease to be seen before animals are moved off the premises with the potential for further spread. This is known as the 13 day rule. Details of the rule may be found at:
http://www.scotland.gov.uk/
Topics/Agriculture/animal-welfare/Diseases/GenControls/ MovementRestrictions/
MovementDigest

1.6 At the start of any outbreak there will always be great uncertainty about the eventual scale and outcome of any outbreak 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 prepare to ramp up resources should they be needed however in the event of a limited outbreak not all the structures, processes and controls tools may be needed.

Maintaining Readiness

1.7 The first principle of disease control is maintaining readiness to deal with an outbreak of disease with speed and certainty. This is not only for the control authorities and its operational partners but also for the industry including the meat sector, transporters and live stock hauliers, dairies, major retailers, exporters, show organisers, market operators and livestock keepers. All should have a contingency plans in place to deal with an outbreak of notifiable disease which are regularly practised and reviewed eg. Implications of a movement standstill.

1.8 The livestock keeper has a vital role in maintaining vigilance for early reporting of suspect disease and maintaining good biosecurity practices, following the rules on movements as prevention is better than cure.

Phases of an Animal Disease Outbreak

1.9 The phases of an Animal Disease Outbreak may be divided into:

• Suspicion
• Confirmation/negation of disease
• Preventing Spread
• Determining and implementing the Control Strategy
• Determining and implementing the Exit Strategy
• Returning to Normal Business

1.10 These phases are described in more detail below. Only the principles are described there will be some variations depending on the particular disease (see the relevant disease annex).

Suspicion

1.11 There is a legal duty on any person who suspects that an animal may have a statutory notifiable disease to report their suspicion to the local Divisional Veterinary Manager ( DVM) of the Animal Health agency; the web link is http://www.defra.gov.uk/animalhealth/about-us/contact-us/search .

1.12 On report of suspicion of notifiable disease the DVM will arrange an investigation by an Animal Health Veterinary Officer ( VO). There is a duty on the keeper of the livestock to facilitate the investigation by providing assistance to the VO by gathering the animals, by providing handling facilities to examine animals and take samples and providing records and other information that will assist the VO in determining whether disease may exist or not. Restrictions will be placed on the premises by serving a legal notice on the livestock keeper. This will be done either by an Officer of Animal Health or the local Authority. The Notice prohibits the movement of animals, people, vehicles and things on and off the premises except under the terms of a licence issued. Before the notice is served the livestock keeper will be instructed not to move anything off the premises.

1.13 If following the investigation the VO does not suspect disease then the restrictions will be removed. If the VO cannot rule out the possibility that disease exists then samples will be taken from one or more animals and submitted to the relevant National Reference Laboratory (see Laboratory Testing Page 163). In the case of suspected foot and mouth disease the Scottish Government will place a temporary control zone with a radius of at least 10km around the suspect premises. Within that zone Scottish Minister shall, by declaratory order, declare what movement restrictions are to be put in place. Temporary control zones 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 these zones would depend on the veterinary advice at the time but would likely be 10km radius.

1.14 While the Animal Health agency will make every effort to arrive on the premises to investigate reports of suspicious disease within two hours, if it is dark and there is inadequate light it may be necessary to postpone the investigation until first light for practical and health and safety reasons.

Confirmation of Disease

1.15 Once samples have been submitted to the laboratory it may take up to 72 hours to initially confirm or negate disease. In Scotland the CVO Scotland (on the basis of the VO report and laboratory reports) has responsibility for confirming disease. On confirmation of disease appropriate area restrictions are imposed. 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 ramp up resources if required.

Stopping Disease Spread

Concept Note
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 and other body secretions. It is capable of infecting any susceptible animal it comes in contact with.

A contagious disease is one that can be spread indirectly by the movement of people, vehicles, animal product and things that have become contaminated with the infectious material such as faeces, urine and other excretions in which the virus has survived and is capable of infecting other animals that come into contact with the contamination.

1.16 Once disease has been confirmed the primary objective is to prevent the spread of disease by taking action on the IP, imposing wider area livestock movement controls, placing controls on animal products, investigating the origin of the outbreak and determining whether there has been further spread of disease from that source and other surveillance for further spread of disease.

Actions on an Infected Premises ( IP)

Infected Place Restrictions

1.17 Infected Place ( IP) restrictions are served on the keeper of the livestock. They prevent the movement of people, animal products, feed and fodder, vehicles and things off and onto the premises except under licence. They also prevent the movement of animals susceptible to the particular disease onto and off the premises. Usually, subject to cleansing and disinfection procedures, non susceptible animals may be allowed to move off and onto the premises under licence.

1.18 The objective of the restrictions is to ensure that infection is not moved from the premises by people, vehicles, and anything else liable to be contaminated with infectious material thereby spreading disease.

1.19 The actual rules concerning the IP will be set out in the notice served on the livestock keeper and any licence conditions permitting movements onto and off the premises. It may be possible, depending on the layout of the premises to exclude the dwelling house from the restrictions.

Valuation

1.20 Once disease is confirmed all susceptible animals on the premises will humanely slaughtered. Compensation is normally paid for susceptible animals killed for control purposes on the premises. A valuation of the animals is normally carried out while preparations are made for the safe and humane slaughter of the animals. The detailed valuation procedures and any appeals process are explained to the owner of the livestock at the time.

Slaughter and Disposal

1.21 Animals infected with a notifiable infectious and contagious disease may excrete vast quantities of virus contaminating the environment and providing a potent source of infection either directly or indirectly for other susceptible animals. It is important therefore that they are killed as quickly as possible. Once an animal is killed virus production stops. The carcases of the killed animals must be destroyed, by removing them from the premises using biosecure transport to the designated disposal facility. Slaughter and disposal is the responsibility of the Animal Health agency.

1.22 While speed of slaughter and disposal is essential, the health and safety of personnel, keepers and owners is paramount and careful preparations are required by the Animal Health agency to ensure that health and safety is not compromised. This is particularly important in the case of animal diseases that are communicable to man (zoonoses) and Health Protection Scotland will advise on the precautions to be taken on the IP to protect workers. In the case of avian influenza this includes the administration of antivirals and vaccine as well as personal protective equipment to be worn.

1.23 Scottish Environment Protection Agency ( SEPA) will advise on the suitability of disposal sites in Scotland. Depending on capacity the preferred hierarchy for disposal is:

• Rendering at approved and licensed premises
• Incineration at approved and licensed premises
• Landfill
• Burial on farm
• Incineration on farm

Cleansing and Disinfection (C&D)

1.24 Infectious agents of infectious and contagious diseases can remain viable in the environment for variable periods of time depending on the disease agent and its immediate environmental conditions of 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 killed and their carcases removed, the premises and potentially contaminated transport and equipment is cleansed and disinfected to prevent indirect spread from the premises and recrudescence of disease when the premises are restocked. Animal feedstuffs and things that have been contaminated and which cannot be cleansed and disinfected may be seized, destroyed and compensation may be paid for them in some circumstances.

1.25 Approved ¹ disinfectants or biocides must be used for the cleansing and disinfection process - these are agents which have been approved by the competent authority after testing and are fit for purpose.

1.26 A list of approved disinfectants can be found at:
http://www.scotland.gov.uk/Topics/Agriculture/animal-welfare/Diseases/GenControls/15721/approveddisinfectants

1.27 SEPA provide advice on precautions to be taken on premises undergoing C&D in order to minimise environmental impacts of disinfectants or biocides.

1.28 There are two phases to C&D - preliminary and secondary - these are outlined below.

Preliminary disinfection

1.29 Preliminary disinfection is carried out immediately after slaughter and disposal has been completed. It is usually carried out by 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 levels of surface contamination. Primary disinfection is considered to be completed 24 hours after the last area on the IP has been sprayed with disinfectant.

1.30 The timing of preliminary disinfection is important because, generally, the lifting of the protection zone and surveillance zone, providing there are no other cases in those zones, can only take place after a defined number of days following completion of preliminary disinfection, depending on the disease.

Secondary (final) disinfection

1.31 In order for disinfectants or biocides to work they must be applied to clean surfaces so areas in need of disinfection must be cleaned of organic matter. This is the process of secondary disinfection. Secondary disinfection, depending on the disease, can only commence a defined number of days after preliminary disinfection.

1.32 What needs to be done on the IP in terms of cleansing, removal of slurry and dung contaminated feed and fodder etc. will be set out in the legal notice served on the owner of the premise by the competent authority and is dependent on the disease agent concerned.

1.33 The costs of secondary disinfection may fall to the owner of the premises or the competent authority depending on the disease. There is no obligation on the part of the Scottish Government to pay for the costs of cleansing and disinfection. Such costs are not normally paid by the Scottish Government for Poultry premises or slaughterhouses, nor are they paid for dilapidated, dangerous or excessively dirty premises.

1.34 The time of completion of secondary or final disinfection is important because for some diseases the earliest date of country freedom is dependent on the completion of secondary disinfection. Restocking is also dependant on the completion of secondary C&D.

1.35 In cases where secondary C&D cannot be completed (dangerous structures, for example), depending on the disease the premises may remain restricted and not allowed to restock until the competent authority is satisfied that sufficient time has elapsed for the infectious agent to have become inactivated naturally.

1.36 Completion of secondary disinfection is certified by the competent authority following inspection of the premises.

Controlled Restocking

1.37 Depending on the disease, restocking is not permitted until a defined number of days have elapsed following secondary cleansing and disinfection. With some diseases there is controlled restocking where limited numbers of animals are allowed on the premises and observed to ensure disease is no longer present. In some cases, samples are taken and undergo laboratory testing to ensure that disease no longer exists on the premises before all restrictions are lifted and the premises allowed to restock completely.

Dealing with contacts to infected animals - forward tracing

1.38 Since disease can spread from an Infected Premises by the movement of infected animals or the movement of people, vehicles and other things, such as equipment, contaminated with infectious material, Animal Health agency staff will trace potential movements of animals, people, vehicles or anything else that may have carried infection to susceptible animals elsewhere. In addition to these routes of potential infection there are also risks to animals on neighbouring premises that infection may have passed to them by direct contact, across a fence, for example, or by aerosol spread. A veterinary risk assessment will be carried out to assess the likelihood of spread of disease by these routes to other susceptible animals.

Concept Note
Dangerous Contact
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 have been in any way exposed to such a degree of infection that it 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.

1.39 If the assessment of the risk of spread of disease, or exposure, is negligible then no action will be taken.

1.40 If the assessment of 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 observed to see if they develop disease. Depending on the disease restrictions remain in place on the premises for 21 or 28 days from the date of potential contact.

1.41 If the assessment of the risk of spread of disease is high then the animals are classified as Dangerous Contacts and the animals are compulsorily slaughtered and compensation paid.

Slaughter of Animals to Prevent the Spread of Disease

1.42 Scottish Ministers have power to require the slaughter of animals in order to prevent the spread of certain specified diseases, including foot and mouth disease. These powers are contained within the Animal Health and Welfare (Scotland) Act 2006 which may be found at:
http://www.opsi.gov.uk/legislation/scotland/acts2006/asp_20060011_en_2

1.43 Before such powers were used Scottish Ministers would have to make a statement explaining the situation and why it was necessary to resort to using such powers. Compensation would be paid for any animals slaughtered under these powers.

Determining the Origin of the Outbreak - back tracing

1.44 Animal Health agency staff will investigate movement of animals, people, vehicles and anything else that could have introduced infection on to the premises. Visits will be made to premises with susceptible livestock from which the movement originated. Animals on those premises will be examined to see if they have disease and which of those animals may have been the origin of the infection. If necessary, samples may be taken for laboratory tests. 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 from it investigated to close down possible spread from it.

Area Movement Controls

1.45 In the event of an outbreak of disease there will initially be great uncertainty about the origin of the disease, how long it has been present and how far it has spread and how far it will spread. Because of this uncertainty area restrictions are imposed to stop animal movements into, from and within the restricted area. For most notifiable infectious and contagious diseases a protection zone and a surveillance zone are imposed by Statutory Order under the relevant disease control legislation. These zones are described below and in Figure 1

Figure 1 Protection and Surveillance Zones

Protection Zone ( PZ)

1.46 The protection zone has a radius of not less than 3 kilometres from the IP. It may be delineated as a circle or by roads or natural geographic boundaries. A radius of 3 kilometres is normally used because, as a rule of thumb for infectious and contagious animal diseases, 80% of new cases occur within 3 kilometres of an existing case. However it may be necessary to have a much larger PZ, for example, in the case of foot and mouth disease, if following computer modelling the disease is likely to spread by windborne spread then the PZ may be the size and shape of the wind plume under which animals are likely to have been infected. 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 will normally become part of the SZ with some relaxation in the controls equivalent to those of the SZ.

Surveillance Zone ( SZ)

1.47 The surveillance zone has a radius of not less than 10 kilometres from the infected premises. It may be delimited by a circle or by roads or natural geographic boundaries. Provided there are no further cases and all the required surveillance has been carried out, the surveillance zone will be lifted not less than 30 days after the completion of preliminary cleansing and disinfection on the last premises within the zone.

Controls in the PZ and SZ

1.48 The controls in the PZ and SZ are primarily controls on the movements of animals since these are the most potent method of spread of disease. In addition there are controls on meat, meat products, 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 on animals on the premises, carry out additional biosecurity measures and report, in certain circumstances, animals that die. In addition the Animal Health agency is required to carry out surveillance, involving clinical inspection, examination and possibly sampling for laboratory testing in the areas to demonstrate that disease has not spread. The detailed controls vary with the disease to be controlled and are set out in the legal instrument declaring the PZ and SZ.

1.49 In extensive outbreaks of disease where there may be a large number of PZ and SZ areas declared, the areas may coalesce to form very large PZ and SZ which may take a long time to carry out the required surveillance to demonstrate freedom.

Other Disease Specific Control Areas

Concept Note
Disease Strategy Group ( DSG)
The DSG plays a major role in determining the disease control strategy. Its role is to co-ordinate and manage the Scottish disease control response, taking account of local conditions, farming practices in Scotland, and other potential impacts on the Scottish economy.
See page 24 for more detail.

1.50 The Scottish Government has powers to declare wider control areas restricting movements etc. should the disease situation merit it. In the case of Foot and Mouth disease it has been agreed that when there is an outbreak there will be a GB wide animal movement ban until the likely extent of the outbreak has been established.

1.51 In the event of an outbreak of disease depending on the disease, the whole country 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

1.52 Within the EU internal market depending on the disease there may be a ban on intra community trade 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 intra community they may be traded on the domestic market with a domestic health mark (round stamp) if they cannot be EU health marked (oval stamp). In certain circumstances animal products may have to undergo certain treatments (for example, heat treatment, deboning and maturing etc.) in order to be traded on the internal EU market with an EU health mark.

1.53 In the case of trade with third countries i.e. those countries that are not members of the EU or EFTA export certificates may be withdrawn until the situation has been clarified with the importing country

Determining the Control Strategy

1.54 The Scottish Government will determine the disease control strategy in Scotland using the structures set out in Page 18 and in consultation with relevant Scottish stakeholder groups.

1.55 Determining the control strategy is complex it must take account of, amongst other things:

• the legal framework
• the requirements of the EU and the World Organisation for Animal Health ( OIE) see page 56
• the available resources, including laboratory resources
• the cost benefit of proposed measures and likely speed of application and effect
• the expert advice from the National Epidemiology Emergency Group ( NEEG)
• advice from the National Experts Group see page 21
• the size and extent of the outbreak
• the output of computer model simulations
• the requirement of other UK Governments
• minimising the effects on the rural community, the wider economy and community and other users of the countryside
• minimising any adverse effects on the environment
• the availability and efficacy of vaccine
• the availability and reliability of tests to distinguish between vaccinated animals and animals that have been infected
• whether the proposed control strategy may complicate and exacerbate the exit strategy

1.56 The Scottish Government will endeavour to decide and communicate control strategies and timeframes to those affected as quickly as possible, so that livestock keepers may plan their approach to keeping their livestock, livestock movements and maintaining the welfare of their animals and their businesses. Subject always to the uncertainties presented by disease outbreaks.

Vaccination

1.57 Whether vaccination would be in support of a control strategy is a complex decision and depends on the disease, its epidemiology, whether it is permitted under EU law, vaccine availability, the efficacy of vaccine, whether it can be administered in sufficient time to sufficient animals to be effective in control and whether there are efficient tests to distinguish between vaccinated and infected animals. Because vaccination is specific to the disease, it is covered in more detail in each disease annex.

Wildlife

1.58 Many of the 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 if it becomes infected. Strategies may have to be developed to deal with a situation of infected wildlife. Broadly wildlife disease controls may fall into the categories of:

• Wildlife vaccination
• Minimising contact between livestock and wildlife
• Wildlife destruction `

1.59 Because wildlife controls are disease specific they are dealt with in more detail in the disease specific annexes.

Pets, Rare Breeds and Hobby Farms

1.60 Pets, rare breeds and hobby farms are subject to the same control measures required under the legislation as for other livestock. Where a dangerous contact or slaughter measures taken to control the spread of disease, the status of these classes of livestock will be taken account of in the veterinary risk assessment to determine control action.

Livestock Welfare Disposal Scheme

1.61 In the event of a widespread and prolonged outbreak of disease with prolonged movement controls and limited or no intracommunity trade, there may be no outlet for meat and meat products. There may be a build up of livestock on premises because they can't be moved off as a result of movement restrictions and cannot be sold for slaughter because there is no market for them. Such a build up may adversely affect the welfare of animals on the premises. The welfare of animals is the responsibility of the keeper of the animals and where there is suffering due to overcrowding the keeper may have to humanely slaughter those animals. Humane slaughter may be a cheaper option for the keeper than maintaining them in the hope that movement restrictions may ease and the market improve. Pressures on accommodation can arise quickly and this is especially so in the pig sector. It is important therefore that all livestock keepers have contingency plans in place to deal with prolonged movement restrictions.

1.62 In exceptional circumstances the Scottish Government may consider the introduction of a welfare disposal scheme subject to a sufficient evidence base that there is a genuine need and the industry can provide no alternatives. Compensation is unlikely to be paid to keepers whose animals are disposed of under a welfare disposal scheme.

Exit Strategy

1.63 Determining the exit strategy to restore disease freedom and return to business as usual goes hand in hand with the control strategy which must be developed with a view to the final exit strategy. For example, the deployment of a vaccination campaign may significantly prolong the surveillance programme to prove freedom of disease.

1.64 Depending on the disease, the duration of the outbreak and its extent a surveillance programme must be undertaken to demonstrate that the country is free of disease and there have been no undisclosed outbreaks of disease. After this programme has been completed a certain period of time must lapse without further cases of disease before country disease free status is restored according to the OIE Code. See page 56

Regionalisation

1.65 Depending on the disease situation it may be possible following a risk assessment to divide the country into risk areas from low to high and which allow the relaxation of controls and permit movements within and from low risk areas to high risk areas. Regionalisation is dependent on the epidemiology of the disease and its geographical distribution and seasonal trade patterns. Laboratory surveillance may be required to demonstrate freedom from disease in the region. Proposals to regionalise must be acceptable to other UK Governments, the European Commission and other trading partners. Regionalisation will also impose restrictions on animal and animal product movements to maintain the region's disease status. This may have an adverse economic effect which outweighs any short term advantage of regionalisation and these economic considerations must be taken into account in coming to decisions on regionalisation. It will be dealt with in more detail in the disease specific annexes.

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