Infection with Newcastle disease virus

Article 10.9.1.

General provisions

1. For the purposes of the Terrestrial Code, Newcastle disease (ND) is defined as an infection of poultry caused by Newcastle disease virus (NDV), which is an avian paramyxovirus serotype 1 (APMV-1) that meets one of the following criteria for virulence:

   1. the virus has an intracerebral pathogenicity index (ICPI) in day-old chicks (Gallusgallus) of 0.7 or greater; or

   2. multiple basic amino acids have been demonstrated in the virus (either directly or by deduction) at the C-terminus of the F2 protein and phenylalanine at residue 117, which is the N-terminus of the F1 protein. The term ‘multiple basic amino acids’ refers to at least three arginine or lysine residues between residues 113 and 116. Failure to demonstrate the characteristic pattern of amino acid residues as described above would require characterisation of the isolated virus by an ICPI test.

   In this definition, amino acid residues are numbered from the N-terminus of the amino acid sequence deduced from the nucleotide sequence of the F0 gene, 113–116 corresponds to residues –4 to –1 from the cleavage site.’

2. Poultry is defined as ‘all domesticated birds, including backyard poultry, used for the production of meat or eggs for consumption, for the production of other commercial products, for restocking supplies of game, or for breeding these categories of birds, as well as fighting cocks used for any purpose’.

   Birds that are kept in captivity for any reason other than those reasons referred to in the preceding paragraph, including those that are kept for shows, races, exhibitions, competitions, or for breeding or selling these categories of birds as well as pet birds, are not considered to be poultry.

3. For the purposes of the Terrestrial Code, the incubation period for ND shall be 21 days.

4. This chapter deals with NDV infection of poultry as defined in point 2) above, in the presence or absence of clinical signs.

5. The occurrence of infection with NDV is defined as the isolation and identification of NDV as such or the detection of viral ribonucleic acid specific for NDV.

6. A Member Country should not impose bans on the trade in poultry  commodities in response to information on the presence of any APMV-1 in birds other than poultry, including wild birds.

7. Standards for diagnostic tests, including pathogenicity testing, are described in the Terrestrial Manual. When the use of ND vaccines is appropriate, those vaccines should comply with the standards described in the Terrestrial Manual.

Article 10.9.2.

Determination of the Newcastle disease status of a country, zone or compartment

The ND status of a country, a zone or a compartment can be determined on the basis of the following criteria:

1. ND is notifiable in the whole country, an ongoing ND awareness programme is in place, and all notified suspect occurrences of ND are subjected to field and, where applicable, laboratory investigations;

2. appropriate surveillance is in place to demonstrate the presence of NDV infection in the absence of clinical signs in poultry; this may be achieved through an ND surveillance programme in accordance with Articles 10.9.22. to 10.9.26.;

3. consideration of all epidemiological factors for ND occurrence and their historical perspective.

Article 10.9.3.

Newcastle disease free country, zone or compartment

A country, zone or compartment may be considered free from ND when it has been shown that NDV infection in poultry has not been present in the country, zone or compartment for the past 12 months, based on surveillance in accordance with Articles 10.9.22. to 10.9.26.

If infection has occurred in poultry in a previously free country, zone or compartment, ND free status can be regained three months after a stamping-out policy (including disinfection of all affected establishments) is applied, providing that surveillance in accordance with Articles 10.9.22. to 10.9.26. has been carried out during that three-month period.

Article 10.9.4.

Recommendations for importation from a Newcastle disease free country, zone or compartment as defined in Article 10.9.3.

For live poultry (other than day-old poultry)

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

1. the poultry showed no clinical sign suggestive of ND on the day of shipment;

2. the poultry were kept in an ND free country, zone or compartment since they were hatched or for at least the past 21 days;

3. the poultry are transported in new or appropriately sanitized containers.

If the poultry have been vaccinated against ND, the nature of the vaccine used and the date of vaccination should be attached to the certificate.

Article 10.9.5.

Recommendations for the importation of live birds other than poultry

Regardless of the ND status of the country of origin, Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. the birds showed no clinical sign suggestive of infection by NDV on the day of shipment;

2. the birds were kept in isolation approved by the Veterinary Services since they were hatched or for at least 21 days prior to shipment and showed no clinical sign of infection during the isolation period;

3. a statistically valid sample of the birds, selected in accordance with Article 10.9.24., was subjected to a diagnostic test within 14 days prior to shipment to demonstrate freedom from infection with NDV;

4. the birds are transported in new or appropriately sanitized containers.

If the birds have been vaccinated against ND, the nature of the vaccine used and the date of vaccination should be attached to the certificate.

Article 10.9.6.

Recommendations for importation from a Newcastle disease free country, zone or compartment

For day-old live poultry

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

1. the poultry were hatched and kept in an ND free country, zone or compartment since they were hatched;

2. the poultry were derived from parent flocks which had been kept in an ND free country, zone or compartment for at least 21 days prior to and at the time of the collection of the eggs;

3. the poultry are transported in new or appropriately sanitized containers.

If the poultry or parent flocks have been vaccinated against ND, the nature of the vaccine used and the date of vaccination should be attached to the certificate.

Article 10.9.7.

Recommendations for the importation of day-old live birds other than poultry

Regardless of the ND status of the country of origin, Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. the birds showed no clinical sign suggestive of infection by NDV on the day of shipment;

2. the birds were hatched and kept in isolation approved by the Veterinary Services;

3. the parent flock birds were subjected to a diagnostic test at the time of the collection of the eggs to demonstrate freedom from infection with NDV;

4. the birds are transported in new or appropriately sanitized containers.

If the birds or parent flocks have been vaccinated against ND, the nature of the vaccine used and the date of vaccination should be attached to the certificate.

Article 10.9.8.

Recommendations for importation from a Newcastle disease free country, zone or compartment

For hatching eggs of poultry

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

1. the eggs came from an ND free country, zone or compartment;

2. the eggs were derived from parent flocks which had been kept in an ND free country, zone or compartment for at least 21 days prior to and at the time of the collection of the eggs;

3. the eggs are transported in new or appropriately sanitized packaging materials.

If the parent flocks have been vaccinated against ND, the nature of the vaccine used and the date of vaccination should be attached to the certificate.

Article 10.9.9.

Recommendations for the importation of hatching eggs from birds other than poultry

Regardless of the ND status of the country of origin, Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. the parent flock birds were subjected to a diagnostic test seven days prior to and at the time of the collection of the eggs to demonstrate freedom from infection with NDV;

2. the eggs have had their surfaces sanitized (in accordance with Chapter 6.5.);

3. the eggs are transported in new or appropriately sanitized packaging materials.

If the parent flocks have been vaccinated against ND, the nature of the vaccine used and the date of vaccination should be attached to the certificate.

Article 10.9.10.

Recommendations for importation from a Newcastle disease free country, zone or compartment

For eggs for human consumption

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

1. the eggs were produced and packed in an ND free country, zone or compartment;

2. the eggs are transported in new or appropriately sanitized packaging materials.

Article 10.9.11.

Recommendations for importation of egg products of poultry

Regardless of the ND status of the country of origin, Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. the commodity is derived from eggs which meet the requirements of Article 10.9.10.; or

2. the commodity has been processed to ensure the destruction of NDV in accordance with Article 10.9.20.;

AND

3. the necessary precautions were taken to avoid contact of the egg products with any source of NDV.

Article 10.9.12.

Recommendations for importation from a Newcastle disease free country, zone or compartment

For poultry semen

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

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

2. were kept in an ND free country, zone or compartment for at least 21 days prior to and at the time of semen collection.

Article 10.9.13.

Recommendations for the importation of semen of birds other than poultry

Regardless of the ND status of the country of origin, Veterinary Authorities should require the presentation of an international veterinary certificate attesting that the donor birds:

1. were kept in isolation approved by the Veterinary Services for at least 21 days prior to and on the day of semen collection;

2. showed no clinical sign suggestive of infection with NDV during the isolation period and on the day of semen collection;

3. were subjected to a diagnostic test within 14 days prior to semen collection to demonstrate freedom from infection with NDV.

Article 10.9.14.

Recommendations for importation from a Newcastle disease free country, zone or compartment

For fresh meat of poultry

Veterinary Authorities should require the presentation of an international veterinary certificate attesting that the entire consignment of fresh meat comes from poultry:

1. which have been kept in an ND free country, zone or compartment since they were hatched or for at least the past 21 days;

2. which have been slaughtered in an approved abattoir in an ND free country, zone or compartment and have been subjected to ante- and post-mortem inspections in accordance with Chapter 6.3. and have been found free of any sign suggestive of ND.

Article 10.9.15.

Recommendations for importation of meat products of poultry

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

1. the commodity is derived from fresh meat which meet the requirements of Article 10.9.14.; or

2. the commodity has been processed to ensure the destruction of NDV in accordance with Article 10.9.21.;

AND

3. the necessary precautions were taken to avoid contact of the commodity with any source of NDV.

Article 10.9.16.

Recommendations for the importation of products of poultry origin, other than feather meal and poultry meal, intended for use in animal feeding, or for agricultural or industrial use

Regardless of the ND status of the country of origin, Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. these commodities were processed in a ND free country, zone or compartment from poultry which were kept in a ND free country, zone or compartment from the time they were hatched until the time of slaughter or for at least the 21 days preceding slaughter; or

2. these commodities have been processed to ensure the destruction of NDV using:

   1. moist heat treatment for 30 minutes at 56°C; or

   2. any equivalent treatment which has been demonstrated to inactivate NDV;

AND

3. the necessary precautions were taken to avoid contact of the commodity with any source of NDV.

Article 10.9.17.

Recommendations for the importation of feathers and down of poultry

Regardless of the ND status of the country of origin, Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. these commodities originated from poultry as described in Article 10.9.14. and were processed in a ND free country, zone or compartment; or

2. these commodities have been processed to ensure the destruction of NDV using one of the following:

   1. washed and steam-dried at 100ºC for 30 minutes;

   2. fumigation with formalin (10% formaldehyde) for 8 hours;

   3. irradiation with a dose of 20 kilogray;

   4. any equivalent treatment which has been demonstrated to inactivate NDV;

AND

3. the necessary precautions were taken to avoid contact of the commodity with any source of NDV.

Article 10.9.18.

Recommendations for the importation of feathers and down of birds other than poultry

Regardless of the ND status of the country of origin, Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. these commodities have been processed to ensure the destruction of NDV using one of the following:

   1. washed and steam-dried at 100ºC for 30 minutes;

   2. fumigation with formalin (10% formaldehyde) for 8 hours;

   3. irradiation with a dose of 20 kilogray;

   4. any equivalent treatment which has been demonstrated to inactivate NDV;

2. the necessary precautions were taken to avoid contact of the commodity with any source of NDV.

Article 10.9.19.

Recommendations for the importation of feather meal and poultry meal

Regardless of the ND status of the country of origin, Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. these commodities were processed in a ND free country, zone or compartment from poultry which were kept in a ND free country, zone or compartment from the time they were hatched until the time of slaughter or for at least the 21 days preceding slaughter; or

2. these commodities have been processed either:

   1. with moist heat at a minimum temperature of 118ºC for minimum of 40 minutes; or

   2. with a continuous hydrolysing process under at least 3.79 bar of pressure with steam at a minimum temperature of 122ºC for a minimum of 15 minutes; or

   3. with an alternative rendering process that ensures that the internal temperature throughout the product reaches at least 74ºC for a minimum of 280 seconds;

AND

3. the necessary precautions were taken to avoid contact of the commodity with any source of ND virus.

Article 10.9.20.

Procedures for the inactivation of Newcastle disease virus in eggs and egg products

The following times and temperatures are suitable for the inactivation of ND virus present in eggs and egg products:

The listed temperatures are indicative of a range that achieves a 7-log kill. Where scientifically documented, variances from these times and temperatures may also be suitable when they achieve the inactivation of the virus.

Article 10.9.21.

Procedures for the inactivation of Newcastle disease virus in meat

The following times for industry standard temperatures are suitable for the inactivation of ND virus present in meat.

The listed temperatures are indicative of a range that achieves a 7-log kill. Where scientifically documented, variances from these times and temperatures may also be suitable when they achieve the inactivation of the virus.

Article 10.9.22.

Introduction to surveillance

Articles 10.9.22. to 10.9.26. define the principles and provide a guide on the surveillance for ND as defined in Article 10.9.1. and is complementary to Chapter 1.4. It is applicable to Member Countries seeking to determine their ND status. This may be for the entire country, zone or compartment. Guidance for Member Countries seeking free status following an outbreak and for the maintenance of ND status is also provided.

Surveillance for ND is complicated by the known occurrence of APMV-1 infections in many bird species, both domestic and wild, and the widespread utilisation of ND vaccines in domestic poultry.

The impact and epidemiology of ND differ widely in different regions of the world and therefore it is not possible to provide specific recommendations for all situations. Therefore, surveillance strategies employed for demonstrating freedom from ND at an acceptable level of confidence should be adapted to the local situation. Variables such as the frequency of contacts of poultry with wild birds, different biosecurity levels, production systems and the commingling of different susceptible species require specific surveillance strategies to address each specific situation. It is incumbent upon the Member Country to provide scientific data that explains the epidemiology of ND in the region concerned and also demonstrates how all the risk factors are managed. There is, therefore, considerable latitude available to Member Countries to provide a well-reasoned argument to prove freedom from NDV infection.

Surveillance for ND should be in the form of a continuing programme designed to establish that the country, zone or compartment, for which application is made, is free from NDV infection.

Article 10.9.23.

General conditions and methods for surveillance

1. A surveillance system in accordance with Chapter 1.4. should be under the responsibility of the Veterinary Authority. In particular there should be in place:

   1. a formal and ongoing system for detecting and investigating outbreaks of disease or NDV infection;

   2. a procedure for the rapid collection and transport of samples from suspect cases of ND to a laboratory for ND diagnosis;

   3. a system for recording, managing and analysing diagnostic and surveillance data.

2. The ND surveillance programme should:

   1. include an early warning system throughout the production, marketing and processing chain for reporting suspicious cases. Farmers and workers, who have day-to-day contact with poultry, as well as diagnosticians, should report promptly any suspicion of ND to the Veterinary Authority. They should be supported directly or indirectly (e.g. through private veterinarians or veterinary paraprofessionals) by government information programmes and the Veterinary Authority. All suspected cases of ND should be investigated immediately. As suspicion cannot be resolved by epidemiological and clinical investigation alone, samples should be taken and submitted to a laboratory for appropriate tests. This requires that sampling kits and other equipment are available to those responsible for surveillance. Personnel responsible for surveillance should be able to call for assistance from a team with expertise in ND diagnosis and control;

   2. implement, when relevant, regular and frequent clinical, virological and serological surveillance of high risk groups of poultry within the target population (e.g. those adjacent to an ND infected country, zone, compartment, places where birds and poultry of different origins are mixed, or other sources of NDV).

An effective surveillance system may identify suspicious cases that require follow-up and investigation to confirm or exclude that the cause of the condition is due to NDV infection. The rate at which such suspicious cases are likely to occur will differ between epidemiological situations and cannot therefore be predicted reliably. Applications for freedom from NDV infection should provide details of the occurrence of suspicious cases and how they were investigated and dealt with. This should include the results of laboratory testing and the control measures to which the animals concerned were subjected during the investigation (quarantine, movement stand-still orders, etc.).

Article 10.9.24.

Surveillance strategies

1. Introduction

   Any surveillance programme requires inputs from professionals competent and experienced in this field and should be thoroughly documented. The design of surveillance programmes to prove the absence of NDV infection or circulation should be carefully followed to avoid producing results that are either unreliable, or excessively costly and logistically complicated.

   If a Member Country wishes to declare freedom from NDV infection in a country, zone or compartment, the subpopulation used for the surveillance for the disease and infection should be representative of all poultry within the country, zone or compartment. Multiple surveillance methods should be used concurrently to accurately define the true ND status of poultry populations. Active and passive surveillance for ND should be ongoing with the frequency of active surveillance being appropriate to the disease situation in the country. Surveillance should be composed of random or targeted approaches, dependent on the local epidemiological situation and using clinical, virological and serological methods. If alternative tests are used they should have been validated as fit-for-purpose in accordance with OIE standards. A Member Country should justify the surveillance strategy chosen as adequate to detect the presence of NDV infection in accordance with Chapter 1.4. and the prevailing epidemiological situation.

   In surveys, the sample size selected for testing should be statistically justified to detect infection at a predetermined target prevalence. The sample size and expected prevalence determine the level of confidence in the results of the survey. The survey design and frequency of sampling should be dependent on the historical and current local epidemiological situation. The Member Country should justify the choice of survey design and confidence level based on the objectives of surveillance and the epidemiological situation, in accordance with Chapter 1.4.

   Targeted surveillance (e.g. based on the increased likelihood of infection in a population) may be an appropriate strategy.

   It may, for example, be appropriate to target clinical surveillance at particular species likely to exhibit clear clinical signs (e.g. unvaccinated chickens). Similarly, virological and serological testing could target species that may not show clinical signs (Article 10.9.2.) of ND and are not routinely vaccinated (e.g. ducks). Surveillance may also target poultry populations at specific risk, for example direct or indirect contact with wild birds, multi-age flocks, local trade patterns including live poultry markets, the presence of more than one species on the holding and poor biosecurity measures in place. In situations where wild birds have been shown to play a role in the local epidemiology of ND, surveillance of wild birds may be of value in alerting Veterinary Services to the possible exposure of poultry and, in particular, of free ranging poultry.

   The sensitivity and specificity of the diagnostic tests are key factors in the choice of survey design, which should anticipate the occurrence of false positive and false negative reactions. Ideally, the sensitivity and specificity of the tests used should be validated for the vaccination and infection history and for the different species in the target population. If the characteristics of the testing system are known, the rate at which these false reactions are likely to occur can be calculated in advance. There should be an effective procedure for following up positives to ultimately determine with a high level of confidence, whether they are indicative of infection or not. This should involve both supplementary tests and follow-up investigation to collect diagnostic material from the original sampling unit as well as flocks which may be epidemiologically linked to it.

   The results of active and passive surveillance are important in providing reliable evidence that no NDV infection is present in a country, zone or compartment.

2. Clinical surveillance

   Clinical surveillance aims to detect clinical signs suggestive of ND at the flock level and should not be underestimated as an early indication of infection. Monitoring of production parameters (e.g. a drop in feed or water consumption or egg production) is important for the early detection of NDV infection in some populations, as there may be no, or mild, clinical signs, particularly if they are vaccinated. Any sampling unit within which suspicious animals are detected should be considered as infected until evidence to the contrary is produced. Identification of infected flocks is vital to the identification of sources of NDV.

   A presumptive diagnosis of clinical ND in suspect infected populations should always be confirmed by virological testing in a laboratory. This will enable the molecular, antigenic and other biological characteristics of the virus to be determined.

   It is desirable that NDV isolates are sent promptly to an OIE Reference Laboratory for archiving and further characterisation if required.

3. Virological surveillance

   Virological surveillance should be conducted to:

   1. monitor at risk populations;

   2. confirm suspect clinical cases;

   3. follow up positive serological results in unvaccinated populations or sentinel birds;

   4. test ‘normal’ daily mortalities (if warranted by an increased risk e.g. infection in the face of vaccination or in establishments epidemiologically linked to an outbreak).

4. Serological surveillance

   Where vaccination is carried out, serological surveillance is of limited value. Serological surveillance cannot be used to discriminate between NDV and other APMV-1. Positive NDV antibody test results can have five possible causes:

   1. natural infection with APMV-1;

   2. vaccination against ND;

   3. exposure to vaccine virus;

   4. maternal antibodies derived from a vaccinated or infected parent flock are usually found in the yolk and can persist in progeny for up to four weeks;

   5. non-specific test reactions.

   It may be possible to use serum collected for other survey purposes for ND surveillance. However, the principles of survey design described in these recommendations and the requirement for a statistically valid survey for the presence of NDV should not be compromised.

   Discovery of seropositive, unvaccinated flocks should be investigated further by conducting a thorough epidemiological investigation. Since seropositive results are not necessarily indicative of infection, virological methods should be used to confirm the presence of NDV in such populations. Until validated strategies and tools to differentiate vaccinated animals from those infected with field APMV-1 are available, serological tools should not be used to identify NDV infection in vaccinated populations.

5. Use of sentinel poultry

   There are various applications of the use of sentinel poultry as a surveillance tool to detect virus circulation. They may be used to monitor vaccinated populations or species which are less susceptible to the development of clinical disease for the circulation of virus. Sentinel poultry should be immunologically naïve and may be used in vaccinated flocks. In case of the use of sentinel poultry, the structure and organisation of the poultry sector, the type of vaccine used and local epidemiological factors will determine the type of production systems where sentinels should be placed, the frequency of placement and monitoring of the sentinels.

   Sentinel poultry should be in close contact with, but should be identified to be clearly differentiated from, the target population. Sentinel poultry should be observed regularly for evidence of clinical disease and any disease incidents investigated by prompt laboratory testing. The species to be used as sentinels should be proven to be highly susceptible to infection and ideally develop clear signs of clinical disease. Where the sentinel poultry do not necessarily develop overt clinical disease a programme of regular active testing by virological and serological tests should be used (the development of clinical disease may be dependent on the sentinel species used or use of live vaccine in the target population that may infect the sentinel poultry). The testing regime and the interpretation of the results will depend on the type of vaccine used in the target population. Sentinel birds should be used only if no appropriate laboratory procedures are available.

Article 10.9.25.

Additional surveillance requirements for declaration of freedom

The requirements for a country, zone or compartment to declare freedom from ND are given in Article 10.9.3.

A Member Country declaring freedom of a country, zone or compartment (with or without vaccination) should report the results of a surveillance programme in which the ND susceptible poultry population undergoes regular surveillance planned and implemented in accordance with the general conditions and methods described in these recommendations.

1. Member Countries declaring freedom from Newcastle disease for the country, zone or compartment

   In addition to the general conditions described in the Terrestrial Code, a Member Country declaring freedom from ND for the entire country, or a zone or a compartment should provide evidence for the existence of an effective surveillance programme. The surveillance programme should be planned and implemented in accordance with general conditions and methods described in this chapter to demonstrate absence of NDV infection in poultry during the preceding 12 months.

2. Additional requirements for countries, zones or compartments that practice vaccination

   Vaccination against ND may be used as a component of a disease prevention and control programme.

   In vaccinated populations there is a need to perform surveillance to ensure the absence of NDV circulation. The use of sentinel poultry may provide further confidence of the absence of virus circulation. The surveillance should be repeated at least every six months or at shorter intervals in accordance with the risk in the country, zone or compartment, or evidence to show the effectiveness of the vaccination programme is regularly provided.

Article 10.9.26.

Additional surveillance requirements for regaining freedom

A Member Country regaining country, zone or compartment freedom from ND should show evidence of an active surveillance programme depending on the epidemiological circumstances of the outbreak to demonstrate the absence of the infection.

A Member Country declaring freedom of a country, zone or compartment after an outbreak of ND (with or without vaccination) should report the results of a surveillance programme in which the ND susceptible poultry population undergoes regular surveillance planned and implemented in accordance with the general conditions and methods described in these recommendations.

nb: first adopted in 1968; most recent update adopted in 2014.