Infection with Aujeszky's disease virus

Article 8.2.1.

General provisions

Pigs are the natural host for Aujeszky’s disease (AD) virus, although it can infect cattle, sheep, cats, dogs and rats causing fatal disease. The definition of pig includes all varieties of Sus scrofa, both domestic and wild.

For the purposes of the Terrestrial Code, AD is defined as an infection of domestic pigs or captive wild pigs, which are under direct human supervision or control.

For the purposes of this chapter, a distinction is made between domestic pig and captive wild pig populations on the one hand, and wild pig and feral pig populations on the other hand.

A Member Country should not impose trade bans in response to a notification of with AD virus in wild and feral pigs in accordance with Article 1.1.3.

When authorising import or transit of the commodities covered in the chapter, with the exception of those listed in Article 8.2.3., Veterinary Authorities should require the conditions prescribed in this chapter relevant to the AD status of the exporting country or zone.

Standards for diagnostic tests and vaccines are described in the Terrestrial Manual.

Article 8.2.2.

Determination of the AD status of a country or zone

The AD free or provisionally free status of a country or zone can only be determined after considering the following criteria, as applicable:

1. AD is notifiable in the whole country, and all clinical signs suggestive of AD are subjected to field and laboratory investigations;

2. an ongoing awareness programme is in place to encourage reporting of all cases suggestive of AD;

3. the Veterinary Authority has current knowledge of, and authority over, all domestic and captive wild pig establishments in the country or zone;

4. the Veterinary Authority has current knowledge about the population and habitat of wild and feral pigs in the country or zone;

5. appropriate surveillance, capable of detecting the presence of infection even in the absence of clinical signs, is in place; this may be achieved through a surveillance programme in accordance with Chapter 1.4.

Article 8.2.3.

Safe commodities

When authorising import or transit of the following commodities and any products made from these, Veterinary Authorities should not require any AD-related conditions, regardless of the AD status of the exporting country or zone:

1. fresh meat of domestic and wild pigs not containing offal (head, and thoracic and abdominal viscera);

2. meat products of domestic and wild pigs not containing offal (head, and thoracic and abdominal viscera);

3. products of animal origin not containing offal (head, and thoracic and abdominal viscera).

Article 8.2.4.

AD free country or zone

1. Qualification

   1. A country or zone may be considered free from the disease without formally applying a specific surveillance programme (historical freedom) if the disease has not been reported for at least 25 years, and if for at least the past 10 years:

      1. it has been a notifiable disease;

      2. an early detection system has been in place;

      3. measures to prevent the introduction of the AD virus into the country or zone have been in place;

      4. no vaccination against the disease has been carried out;

      5. infection is not known to be established in wild and feral pigs, or appropriate measures have been implemented to prevent any transmission of the AD virus from wild and feral pigs to domestic and captive wild pigs.

   2. A country or zone which does not meet the conditions of the above paragraph may be considered free from AD when:

      1. animal health regulations to control the movement of commodities with the exception of those listed in Article 8.2.3. in order to prevent the introduction of infection into the establishments of the country or zone have been in place for at least two years;

      2. vaccination against AD has been banned for all domestic and captive wild pigs in the country or zone for at least two years unless there are means, validated to OIE standards (Chapter 2.1.2. of the Terrestrial Manual), of distinguishing between vaccinated and infected pigs;

      3. if AD has never been reported in the country or zone, serological surveys, with negative results, have been conducted on a representative sample of all pig establishments in accordance with the recommendations in Chapter 1.4. at an acceptable level of confidence, no more than three years prior to qualification; the serological surveys should be directed at the detection of antibodies to the whole virus, and based on the breeding pig population or, for establishments that contain no breeding pigs, on a comparable number of fattening pigs; or

      4. if AD has been reported in the country or zone, a surveillance and control programme has been in place to detect every infected establishment and eradicate AD from it; the surveillance programme should be carried out in accordance with the recommendations in Chapter 1.4. and demonstrate that no establishments within the country or zone have had any clinical, virological or serological evidence of AD for at least two years.

      In countries or zones with wild and feral pigs, measures should be implemented to prevent any transmission of the AD virus from wild and feral pigs to domestic and captive wild pigs.

2. Maintenance of free status

   In order to maintain its free status, a country or zone should comply with the following requirements:

   1. periodic serological surveys directed at the detection of antibodies to the whole AD virus should be carried out on a statistically significant number of breeding pigs in accordance with the recommendations in Chapter 1.4.;

   2. the importation of the commodities with the exception of those listed in Article 8.2.3. into the country or zone is carried out in accordance with the import conditions contained in the relevant articles of the present chapter;

   3. the ban on AD vaccination remains in force;

   4. appropriate measures aimed at preventing the transmission of the AD virus from wild and feral pigs to domestic and captive wild pigs remain in force.

3. Recovery of free status

   Should an AD outbreak occur in an establishment of a free country or zone, the status of the country or zone may be restored if either:

   1. all the pigs in the infected epidemiological units have been slaughtered; and, during and after the application of this measure, an epidemiological investigation including clinical examination, and serological or virological testing has been carried out in all pig establishments which have been directly or indirectly in contact with the infected establishment and in all pig establishments located within a prescribed radius from the infected epidemiological units, demonstrating that these establishments are not infected; or

   2. vaccination with gE- deleted vaccines has been applied and:

      1. a serological testing procedure (differential ELISA) has been implemented in the establishments where vaccination has been applied to demonstrate the absence of infection;

      2. the movement of pigs from these establishments has been banned, except for immediate slaughter, until the above procedure has demonstrated the absence of infection;

      3. during and after the application of the measures described in points i) to ii) above, a thorough epidemiological investigation including clinical examination and serological or virological testing has been carried out in all pig establishments which have been directly or indirectly in contact with the infected establishment and in all pig establishments located within a prescribed radius from the outbreak, demonstrating that these establishments are not infected.

Article 8.2.5.

AD provisionally free country or zone

1. Qualification

   A country or zone may be considered as provisionally free from AD if the following conditions are complied with:

   1. animal health regulations to control the movement of commodities with the exception of those listed in Article 8.2.3. in order to prevent the introduction of infection into the establishments of the country or zone have been in place for at least two years;

   2. if AD has never been reported in the country or zone, a serological survey, with negative results, has been conducted on a representative sample of all pig establishments in accordance with the recommendations in Chapter 1.4. (but not at an acceptable level of confidence); the serological survey should be directed at the detection of antibodies to the whole virus, and based on the breeding pig population or, for establishments that contain no breeding pigs, on a comparable number of fattening pigs; or

   3. if AD has been reported in the country or zone, a surveillance and control programme has been in place to detect infected establishments and eradicate AD from these establishments, the herd prevalence rate in the country or zone has not exceeded 1% for at least three years (the sampling procedure described in point 1 e) of the definition of ‘AD free establishment’ should be applied within the establishments of the country or zone), and at least 90% of the establishments in the country or zone are qualified free;

   4. in countries or zones with wild and feral pigs, appropriate measures should be taken to prevent any transmission of the AD virus between wild and feral pigs and domestic and captive wild pigs.

2. Maintenance of provisionally free status

   In order to maintain its provisionally free status, a country or zone should comply with the following requirements:

   1. the measures described in points 1 b) and 1 d) above should be continued;

   2. the percentage of infected establishments remains < 1%;

   3. the importation of the commodities with the exception of those listed in Article 8.2.3. into the country or zone is carried out in accordance with the import conditions contained in the relevant articles of the present chapter.

3. Recovery of provisionally free status

   Should the percentage of infected establishments exceed 1% in a provisionally free country or zone, the status of the country or zone is cancelled and may be restored only once the percentage of infected establishments has remained < 1% for at least six months, and this result is confirmed by a serological survey conducted in accordance with point 1 c) above.

Article 8.2.6.

AD infected country or zone

For the purposes of this chapter, countries and zones which do not fulfil the conditions to be considered free or provisionally free of AD should be considered as infected.

Article 8.2.7.

AD free establishment

1. Qualification

   To qualify as free from AD, an establishment should satisfy the following conditions:

   1. it is under the control of the Veterinary Authority;

   2. no clinical, virological or serological evidence of AD has been found for at least one year;

   3. the introduction of pigs, semen, oocytes and embryos into the establishment is carried out in accordance with the import conditions for these commodities contained in the relevant articles of the present chapter;

   4. vaccination against AD has not been carried out in the establishment for at least 12 months, and any previously vaccinated pigs are free from gE antibodies;

   5. a representative sample of breeding pigs from the establishment has been subjected, with negative results, to serological tests to the whole AD virus, applying a sampling procedure set out in accordance with the recommendations in Chapter 1.4.; these tests should have been carried out on two occasions, at an interval of two months; for establishments that contain no breeding pigs, the tests should be carried out only once on a comparable number of fattening or weaning pigs;

   6. a surveillance and control programme has been in place to detect infected establishments located within a prescribed radius from the establishment and no establishment is known to be infected within this zone.

2. Maintenance of free status

   For establishments located in an infected country or zone, the testing procedure described in point 1 e) above should be carried out every four months.

   For establishments located in a provisionally free country or zone, the testing procedure described in point 1 e) above should be carried out every year.

3. Recovery of free status

   Should a free establishment become infected, or should an outbreak occur within a prescribed radius from a free establishment, the free status of the establishment should be suspended until the following conditions are met:

   1. in the infected establishment:

      1. all the pigs in the establishment have been slaughtered; or

      2. at least 30 days after removal of all infected animals, all breeding animals have been subjected to a serological test to the whole AD virus, with negative results, on two occasions, at an interval of 2 months;

   2. in other establishments located within the prescribed radius: a number of breeding pigs from each establishment has been subjected, with negative results, to serological tests to the whole AD virus (non-vaccinated establishments) or to gE antibodies (vaccinated establishments), applying the sampling procedure described in point 1 e) above.

Article 8.2.8.

Recommendations for importation from AD free countries or zones

For domestic and captive wild pigs

Veterinary Authorities should require the presentation of an international veterinary certificate attesting that the animals:

1. showed no clinical sign of AD on the day of shipment;

2. come from an establishment located in an AD free country or zone;

3. have not been vaccinated against AD.

Article 8.2.9.

Recommendations for importation from AD provisionally free countries or zones

For domestic and captive wild pigs for breeding or rearing

Veterinary Authorities should require the presentation of an international veterinary certificate attesting that the animals:

1. showed no clinical sign of AD on the day of shipment;

2. have been kept exclusively in AD free establishments since birth;

3. have not been vaccinated against AD;

4. were subjected to a serological test to the whole AD virus, with negative results, within 15 days prior to shipment.

Article 8.2.10.

Recommendations for importation from AD infected countries or zones

For domestic and captive wild pigs for breeding or rearing

Veterinary Authorities should require the presentation of an international veterinary certificate attesting that the animals:

1. showed no clinical sign of AD on the day of shipment;

2. were kept exclusively in AD free establishments since birth;

3. have not been vaccinated against AD;

4. were isolated in the establishment of origin or a quarantine station, and were subjected to a serological test to the whole AD virus, with negative results, on two occasions, at an interval of not less than 30 days between each test, the second test being performed during the 15 days prior to shipment.

Article 8.2.11.

Recommendations for importation from AD provisionally free countries or zones or AD infected countries or zones

For domestic and captive wild pigs for slaughter

The pigs should be transported directly from the place of shipment to the slaughterhouse/abattoir from immediate slaughter.

Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. a surveillance and control programme is in place in the country or zone to detect infected establishments and eradicate AD;

2. the animals:

   1. are not being eliminated as part of an eradication programme;

   2. showed no clinical sign of AD on the day of shipment; and

      1. have been kept exclusively in AD free establishments since birth; or

      2. have been vaccinated against AD at least 15 days prior to shipment.

Article 8.2.12.

Recommendations for importation from AD free countries or zones

For wild and feral swine

Veterinary Authorities should require the presentation of an international veterinary certificate attesting that the animals:

1. showed no clinical sign of AD on the day of shipment;

2. were captured in an AD free country or zone;

3. have not been vaccinated against the disease;

4. were isolated in a quarantine station, and were subjected to a serological test to the whole AD virus, with negative results, on two occasions, at an interval of not less than 30 days between each test, the second test being performed during the 15 days prior to shipment.

Article 8.2.13.

Recommendations for importation from AD free countries or zones

For semen of pigs

Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. the donor animals:

   1. showed no clinical sign of AD on the day of collection of the semen;

   2. were kept in an establishment or artificial insemination centre located in an AD free country or zone at the time of semen collection;

2. the semen was collected, processed and stored in accordance with Chapters 4.5. and 4.6.

Article 8.2.14.

Recommendations for importation from AD provisionally free countries or zones

For semen of pigs

Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. the donor animals:

   1. have been kept for at least four months prior to semen collection in an artificial insemination centre which has the status of AD free establishment, and where all boars are subjected to a serological test to the whole AD virus, with negative results, every four months;

   2. showed no clinical sign of AD on the day of collection;

2. the semen was collected, processed and stored in accordance with Chapters 4.5. and 4.6.

Article 8.2.15.

Recommendations for importation from AD infected countries or zones

For semen of pigs

Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. the donor animals:

   1. were kept in an AD free establishment for at least six months prior to entering the artificial insemination centre;

   2. have been kept for at least four months prior to semen collection in the artificial insemination centre which has the status of AD free establishment, and where all boars are subjected to a serological test to the whole AD virus, with negative results, every four months;

   3. were subjected to a serological test to the whole AD virus, with negative results, within 10 days prior to or 21 days after semen collection;

   4. showed no clinical sign of AD on the day of collection;

2. the semen was collected, processed and stored in accordance with Chapters 4.5. and 4.6.

Article 8.2.16.

Recommendations for importation from AD free countries or zones

For in vivo derived embryos of pigs

Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. the donor females:

   1. showed no clinical sign of AD on the day of collection of the embryos;

   2. were kept in an establishment located in an AD free country or zone prior to collection;

2. the embryos were collected, processed and stored in accordance with Chapters 4.7. and 4.9., as relevant.

Article 8.2.17.

Recommendations for importation from AD provisionally free countries or zones

For in vivo derived embryos of pigs

Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. the donor females:

   1. showed no clinical sign of AD on the day of collection of the embryos;

   2. were kept in an AD free establishment for at least three months prior to collection;

2. the embryos were collected, processed and stored in accordance with Chapters 4.7. and 4.9., as relevant.

Article 8.2.18.

Recommendations for importation from AD infected countries or zones

For in vivo derived embryos of pigs

Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. the donor females:

   1. showed no clinical sign of AD on the day of collection of the embryos;

   2. were kept in an AD free establishment for at least three months prior to collection;

   3. were subjected to a serological test to the whole AD virus, with negative results, within ten days prior to collection;

2. the embryos were collected, processed and stored in accordance with Chapters 4.7. and 4.9., as relevant.

Article 8.2.19.

Recommendations for importation from AD free countries or zones

For offal (head, and thoracic and abdominal viscera) of pigs or products containing pig offal

Veterinary Authorities should require the presentation of an international veterinary certificate attesting that the entire consignment of offal or products containing pig offal comes from animals which come from establishments located in an AD free country or zone.

Article 8.2.20.

Recommendations for importation from AD provisionally free countries or zones or from AD infected countries or zones

For offal (head, and thoracic and abdominal viscera) of pigs

Veterinary Authorities should require the presentation of an international veterinary certificate attesting that the entire consignment of offal comes from animals:

1. which have been kept in an AD free establishment since birth;

2. which have not been in contact with animals from establishments not considered free from AD during their transport to the approved slaughterhouse/abattoir and therein.

Article 8.2.21.

Recommendations for importation from AD provisionally free countries or zones or from AD infected countries or zones

For products containing pig offal (head, and thoracic and abdominal viscera)

Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. either the entire consignment of offal used to prepare the products complied with the conditions referred to in Article 8.2.20.; or

2. the products have been processed to ensure the destruction of the AD virus; and

3. the necessary precautions were taken after processing to avoid contact of the products with any source of AD virus.

nb: first adopted in 1986; most recent update adopted in 2012.