Terrestrial Animal Health Code
Terrestrial Animal Health Code |
Zoning and compartmentalisation
Introduction
The purpose of this chapter is to provide recommendations on the principles of zoning and compartmentalisation to Member Countries wishing to establish and maintain different subpopulations with specific health status within their territory. These principles should be applied in accordance with the relevant chapters of the Terrestrial Code. This chapter also outlines a process by which trading partners may recognise such subpopulations.
Establishing and maintaining a disease-free status throughout the country should be the final goal for Member Countries. However, given the difficulty of achieving this goal, there may be benefits to a Member Country in establishing and maintaining a subpopulation with a specific health status within its territory for the purposes of international trade or disease prevention or control. Subpopulations may be separated by natural or artificial geographical barriers or by the application of appropriate biosecurity management.
While zoning applies to an animal subpopulation defined primarily on a geographical basis, compartmentalisation applies to an animal subpopulation defined primarily by management and husbandry practices related to biosecurity. In practice, spatial considerations and appropriate management, including biosecurity plans, play important roles in the application of both concepts.
Zoning may encourage the more efficient use of resources within certain parts of a country. Compartmentalisation may allow the functional separation of a subpopulation from other domestic or wild animals through biosecurity, which would not be achieved through geographical separation. In a country where a disease is endemic, establishment of free zones may assist in the progressive control and eradication of the disease. To facilitate disease control and the continuation of trade following a disease outbreak in a previously free country or zone, zoning may allow a Member Country to limit the extension of the disease to a defined restricted area, while preserving the status of the remaining territory. For the same reasons, the use of compartmentalisation may allow a Member Country to take advantage of epidemiological links among subpopulations or common practices relating to biosecurity, despite diverse geographical locations.
A Member Country may thus have more than one zone or compartment within its territory.
General considerations
The Veterinary Services of a Member Country that is establishing a zone or compartment within its territory should clearly define the subpopulation in accordance with the recommendations in the relevant chapters of the Terrestrial Code, including those on surveillance, on animal identification and animal traceability and on official control programmes.
The procedures used to establish and maintain the specific animal health status of a zone or compartment depend on the epidemiology of the disease, including the presence and role of vectors and susceptible wildlife and environmental factors, on the animal production systems as well as on the application of biosecurity and sanitary measures, including movement control.
Biosecurity and surveillance are essential components of zoning and compartmentalisation, and should be developed through active cooperation between industry and Veterinary Services.
The Veterinary Services, including laboratories, should be established and should operate in accordance with Chapters 3.1. and 3.2., to provide confidence in the integrity of the zone or compartment. The final authority over the zone or compartment, for the purposes of domestic and international trade, lies with the Veterinary Authority. The Veterinary Authority should conduct an assessment of the resources needed and available to establish and maintain a zone or compartment. These include the human and financial resources and the technical capability of the Veterinary Services and of the relevant industry and production system (especially in the case of a compartment), including for surveillance, diagnosis and, when appropriate, vaccination, treatment and protection against vectors.
In the context of maintaining the animal health status of a population or subpopulation of a country, zone or compartment, importations into the country as well as movements of animals and their products, and fomites, into the zones or compartments should be the subject of appropriate sanitary measures and biosecurity.
The Veterinary Services should provide movement certification, when necessary, and carry out documented periodic inspections of facilities, biosecurity, records and surveillance procedures. Veterinary Services should conduct or audit surveillance, reporting, laboratory diagnostic examinations and, when relevant, vaccination.
The production sector's responsibilities include, in consultation with the Veterinary Services if appropriate, the application of biosecurity, documenting and recording movements of commodities and personnel, managing quality assurance schemes, documenting the implementation of corrective actions, conducting surveillance, rapid reporting and maintenance of records in a readily accessible form.
Principles for defining and establishing a zone or compartment
The following principles apply when Member Countries define a zone or a compartment.
The extent of a zone and its geographical limits should be established by the Veterinary Authority on the basis of natural, artificial or legal boundaries, and made public through official channels.
The factors defining a compartment should be established by the Veterinary Authority on the basis of relevant criteria such as management and husbandry practices related to biosecurity, and communicated to the relevant operators through official channels.
Animals and herds or flocks belonging to subpopulations of zones or compartments should be recognisable as such through a clear epidemiological separation from other animals and all factors presenting a risk. The measures taken to ensure the identification of the subpopulation and to establish and maintain its health status through a biosecurity plan should be documented in detail. These measures should be appropriate to the particular circumstances, and depend on the epidemiology of the disease, environmental factors, the health status of animals in adjacent areas, applicable biosecurity (including movement controls, use of natural, artificial or legal boundaries, spatial separation of animals, control of fomites, and commercial management and husbandry practices), and surveillance.
Relevant commodities within the zone or compartment should be identified in such a way that their movements are traceable. Depending on the system of production, identification may be done at the herd or flock or individual animal level. Relevant movements of commodities into and out of the zone or compartment should be well documented and controlled. The existence of an animal identification system is a prerequisite to assess the integrity of the zone or compartment.
For a compartment, the biosecurity plan should describe the partnership between the relevant industry and the Veterinary Authority, and their respective responsibilities. It should also describe the standard operating procedures to provide clear evidence that the surveillance conducted, the animal identification and traceability system, and the management and husbandry practices are adequate to meet the definition of the compartment. In addition to information on controls of movements of relevant commodities, the plan should include herd or flock production records, feed, water and bedding sources, surveillance results, birth and death records, visitor logbook, morbidity and mortality history and investigations, medications, vaccinations, documentation of training of relevant personnel and any other criteria necessary for evaluation of risk management. The information required may vary in accordance with the species and diseases under consideration. The biosecurity plan should also describe how the measures will be audited to ensure that the risks are being managed and regularly reassessed, and the measures adjusted accordingly.
Articles 4.3.4. to 4.3.7. describe different types of zones that
can be established by Member Countries. However, other types of zones may
be established for the purposes of disease control or trade.
Free zone
A free zone is one in which the absence of a specific infection or infestation in an animalpopulation has been demonstrated in accordance with the relevant requirements of the Terrestrial Code.
In conjunction with Articles 4.3.2. and 4.3.3., and depending on the prevailing epidemiological situation, the attainment or maintenance of free status may require past or ongoing specific surveillance and vectorsurveillance, as well as appropriate biosecurity and sanitary measures, within the zone and at its borders. The surveillance should be conducted in accordance with Chapter 1.4. and the relevant chapters of the Terrestrial Code.
The free status can apply to one or more susceptible animal species populations, domestic or wild.
So long as an ongoing surveillance demonstrates there is no occurrence of the specific infection or infestation, and principles determined for its definition and establishment are respected, the zone maintains its free status.
Infected zone
An infected zone is one either in which an infection or infestation has been confirmed, or that is defined as such in the relevant chapters of the Terrestrial Code.
An infected zone in which an infection or infestation has been confirmed may be:
a zone of a country where the infection or infestation is present and has not yet been eradicated, while other zones of the country may be free; or
a zone of a previously free country or zone, in which the infection or infestation has been introduced or reintroduced, while the rest of the country or zone remains unaffected.
To gain free status in an infected zone, or regain free status following an outbreak in a previously free zone, Member Countries should follow the recommendations in the relevant chapters of the Terrestrial Code.
Protection zone
A protection zone may be established to preserve the animal health status of an animalpopulation in a free country or a free zone by preventing the introduction of a pathogenic agent of a specific infection or infestation from neighbouring countries or zones of different animal health status to that animalpopulation. A protection zone can be established within or outside the free zone or within the free country.
Biosecurity and sanitary measures should be implemented in the protection zone based on the animal management systems, the epidemiology of the disease under consideration and the epidemiological situation prevailing in the neighbouring infected countries or zones.
These measures should include intensified movement control and surveillance and specific animal identification and animal traceability to ensure that animals in the protection zone are clearly distinguishable from other populations, and may also include:
vaccination of all or at risk susceptible animals;
testing or vaccination of animals moved;
specific procedures for sample handling, dispatching and testing;
enhanced biosecurity including disinfection and disinsection procedures for vehicles/vessels and vehicles used for transportation of animal products, feed or fodder, and possible compulsory routes for their movements within, to or from the zone;
specific surveillance of susceptible wildlife and relevant vectors;
awareness campaigns aimed at the public or targeted at breeders, traders, hunters or veterinarians.
Anytime the status of the protection zone changes, the status of the country or zone in which it was established should be redetermined in accordance with the relevant listed disease-specific chapters.
Containment zone
In the event of outbreaks in a country or zone previously free from a disease, a containment zone, which includes all epidemiologically linked outbreaks may be established to minimise the impact on the rest of the country or zone.
A containment zone is an infected zone that should be managed in such a way that commodities for international trade can be shown to have originated either from inside or outside the containment zone.
Establishment of a containment zone should be based on a rapid response, prepared in a contingency plan, and that includes:
appropriate control of movement of animals and other commodities upon declaration of suspicion of the specified disease;
epidemiological investigation (trace-back, trace-forward) after confirmation of infection or infestation, demonstrating that the outbreaks are epidemiologically related and all contained within the defined boundaries of the containment zone;
a stamping-out policy or another effective emergency control strategy aimed at eradicating the disease;
animal identification of the susceptible population within the containment zone enabling its recognition as belonging to the containment zone;
increased passive and targeted surveillance in accordance with Chapter 1.4. in the rest of the country or zone demonstrating no occurrence of infection or infestation;
biosecurity and sanitary measures, including ongoing surveillance and control of the movement of animals, other commodities and fomites within and from the containment zone, consistent with the listed disease-specific chapter, when there is one, to prevent spread of the infection or infestation from the containment zone to the rest of the country or zone.
A containment zone is considered as effectively established when the following is demonstrated:
EITHER
there have been no new cases in the containment zone within a minimum of two incubation periods from the disposal of the last detected case;
OR
the containment zone comprises an infected zone where cases may continue to occur and a protection zone, where no outbreaks have occurred for at least two incubation periods after the control measures above are in place, and that separates the infected zone from the rest of the country or zone.
The free status of the areas outside the containment zone is suspended pending the effective establishment of the containment zone. Once the containment zone has been established, the areas outside the containment zone regain free status.
The free status of the containment zone should be regained in accordance with the relevant listed disease-specific chapters or, if there are none, with Article 1.4.6.
In the event of an occurrence of a case of the infection or infestation for which the containment zone was established, either in the containment zone defined in point a) or in the protection zone defined in point b), the rest of the country or zone is considered infected.
Bilateral recognition of country or zone status by trading countries
While the OIE has procedures for official recognition of status for a number of infections (refer to Chapter 1.6.), for other infections or infestations, countries may recognise each other's status through a bilateral process. Trading partners should exchange information allowing the recognition of different subpopulations within their respective territories. This recognition process is best implemented through establishing parameters and gaining agreement on the necessary measures prior to outbreaks of disease.
The Veterinary Services of an exporting country should be able to explain to the Veterinary Services of an importing country the basis for claiming a specific animal health status for a given zone or compartment under consideration.
The exporting country should be able to demonstrate, through detailed documentation provided to the importing country, that it has implemented the recommendations in the Terrestrial Code for establishing and maintaining such a zone or compartment.
In accordance with Chapter 5.3., an importing country should recognise the existence of this zone or compartment when the appropriate measures recommended in the Terrestrial Code are applied and the Veterinary Authority of the exporting country is able to demonstrate that this is the case.
nb: first adopted in 1998; most recent update adopted in 2018.
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