Infection with high pathogenicity avian influenza viruses

Article 10.4.1.

General provisions

1. This chapter deals with the listed disease, infection with high pathogenicity avian influenza viruses.

2. For the purposes of the Terrestrial Code:

   1. High pathogenicity avian influenza means an infection of poultry by any influenza A virus that has been determined as high pathogenicity in accordance with the Terrestrial Manual.

   2. An occurrence of infection with a high pathogenicity avian influenza virus is defined by the isolation and identification of the virus or the detection of specific viral ribonucleic acid, in one or more samples from poultry.

   3. The incubation period at the flock-level for high pathogenicity avian influenza is 14 days.

3. Although the objective of this chapter is to mitigate animal and public health risks posed by infection with high pathogenicity avian influenza viruses, other influenza A viruses of avian host origin (i.e. low pathogenicity avian influenza viruses) may have the potential to exert a negative impact on animal and public health. A sudden and unexpected increase in virulence of low pathogenicity avian influenza viruses in poultry is notifiable as an emerging disease in accordance with Article 1.1.4. Infection of domestic and captive wild birds with low pathogenicity avian influenza viruses having proven natural transmission to humans associated with severe consequences, and infection of birds other than poultry, including wild birds, with influenza A viruses of high pathogenicity, are notifiable in accordance with Article 1.3.3.

4. A notification of infection of birds other than poultry, including wild birds, with influenza A viruses of high pathogenicity, or of infection of domestic or captive wild birds with low pathogenicity avian influenza viruses does not affect the high pathogenicity avian influenza status of the country or zone. A Member Country should not impose bans on the international trade of poultrycommodities in response to such notifications, or to other information on the presence of any non-notifiable influenza A virus in birds.

5. This chapter includes monitoring considerations for low pathogenicity avian influenza viruses because some, especially H5 and H7 subtypes, have the potential to mutate into high pathogenicity avian influenza viruses.

6. The use of vaccination against avian influenza may be recommended under specific conditions. Any vaccine used should comply with the standards described in the Terrestrial Manual. Vaccination will not affect the high pathogenicity avian influenza status of a free country or zone if surveillance supports the absence of infection, in accordance with Article 10.4.28., in particular point 2. Vaccination can be used as an effective complementary control tool when a stamping-out policy alone is not sufficient. Whether to vaccinate or not should be decided by the Veterinary Authority on the basis of the avian influenza situation as well as the ability of the Veterinary Services to implement the vaccination strategy, as described in Chapter 4.18.

7. Standards for diagnostic tests and vaccines, including pathogenicity testing, are described in the Terrestrial Manual.

Article 10.4.2.

Safe commodities

When authorising importation or transit of the following commodities, Veterinary Authorities should not require any conditions related to high pathogenicity avian influenza, regardless of the high pathogenicity avian influenza status of the exporting country or zone:

1. heat-treated poultry meat products in a hermetically sealed container with an F₀ value of 3 or above;

2. extruded dry pet food and coated ingredients after extrusion;

3. rendered protein meal, blood meal, feather meal, and poultry oil;

4. washed and steam-dried feathers and down from poultry and other birds.

Other commodities of poultry and other birds can be traded safely if in accordance with the relevant articles of this chapter.

Article 10.4.3.

Country or zone free from high pathogenicity avian influenza

A country or zone may be considered free from high pathogenicity avian influenza when:

• infection with high pathogenicity avian influenza viruses is a notifiable disease in the entire country;

• an ongoing awareness programme is in place to encourage reporting of suspicions of high pathogenicity avian influenza;

• absence of infection with high pathogenicity avian influenza viruses, based on surveillance, in accordance with Chapter 1.4. and Articles 10.4.26. to 10.4.30., has been demonstrated in the country or zone for the past 12 months;

• an awareness programme is in place related to avian influenza viruses risks and the specific biosecurity and management measures to address them;

• commodities are imported in accordance with Articles 10.4.7. to 10.4.22.

Surveillance should be adapted to parts of the country or existing zones depending on historical or geographical factors, industry structure, population data and proximity to recent outbreaks or the use of vaccination.

Article 10.4.4.

Compartment free from high pathogenicity avian influenza

The establishment of a compartment free from high pathogenicity avian influenza should be in accordance with relevant requirements of this chapter and the principles described in Chapters 4.4. and 4.5.

Article 10.4.5.

Establishment of a containment zone within a country or zone free from high pathogenicity avian influenza

In the event of outbreaks of high pathogenicity avian influenza within a previously free country or zone, a containment zone, which includes all epidemiologically linked outbreaks, may be established for the purpose of minimising the impact on the rest of the country or zone.

In addition to the requirements for the establishment of a containment zone outlined in Article 4.4.7., the surveillance programme should take into account the density of poultry production, types of poultry, local management practices (including inter-premises movement patterns of poultry, people and equipment), relevant biosecurity, the presence and potential role of birds other than poultry, including wild birds, and the proximity of poultry establishments to permanent and seasonal water bodies.

The free status of the areas outside the containment zone is suspended while the containment zone is being established. It may be reinstated, irrespective of the provisions of Article 10.4.6., once the containment zone is established. It should be demonstrated that commodities for international trade have originated from outside the containment zone or comply with the relevant articles of this chapter.

Article 10.4.6.

Recovery of free status

If infection with high pathogenicity avian influenza virus has occurred in poultry in a previously free country or zone, the free status may be regained after a minimum period of 28 days (i.e. two flock-level incubation periods) after a stamping-out policy has been completed (i.e. after the disinfection of the last affected establishment), provided that surveillance in accordance with Articles 10.4.26. to 10.4.30., in particular point 3 of Article 10.4.28., has been carried out during that period and has demonstrated the absence of infection.

If a stamping-out policy is not implemented, Article 10.4.3. applies.

Article 10.4.7.

Recommendations for importation from a country, zone or compartment free from high pathogenicity avian influenza

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 signs of avian influenza on the day of shipment;

2. the poultry originated from a country, zone or compartment free from high pathogenicity avian influenza;

3. the poultry originated from a flock that was monitored for avian influenza viruses and was found to be negative;

4. the poultry are transported in new or appropriately sanitised containers.

If the poultry have been vaccinated against avian influenza viruses, the nature of the vaccine used and the date of vaccination should be stated in the international veterinary certificate.

Article 10.4.8.

Recommendations for the importation of live birds other than poultry

Regardless of the high pathogenicity avian influenza status of the country of origin, Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. on the day of shipment, the birds showed no clinical signs of avian influenza;

2. the birds had been kept in isolation facilities approved by the Veterinary Services since they were hatched or for at least 28 days (i.e. two flock-level incubation periods) prior to shipment and showed no clinical signs of avian influenza during the isolation period;

3. a statistically appropriate sample of the birds was subjected, with negative results, to a diagnostic test for avian influenza within 14 days prior to shipment;

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

If the birds have been vaccinated against avian influenza, the nature of the vaccine used and the date of vaccination should be stated in the international veterinary certificate.

Article 10.4.9.

Recommendations for importation from a country, zone or compartment free from high pathogenicity avian influenza

For day-old live poultry

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

1. the day-old live poultry had been kept in a country, zone or compartment free from high pathogenicity avian influenza since they were hatched;

   and

   1. the day-old live poultry were derived from parent flocks that were monitored for avian influenza viruses and were found to be negative at the time of collection of the eggs from which the day-old poultry hatched; or

   2. the day-old live poultry that hatched from eggs that had had their surfaces sanitised in accordance with point 4 d) of Article 1.1.5.;

AND

2. the day-old live poultry were transported in new or appropriately sanitised containers.

If the day-old live poultry or the parent flocks have been vaccinated against avian influenza, the nature of the vaccine used and the date of vaccination should be stated in the international veterinary certificate.

Article 10.4.10.

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

Regardless of the high pathogenicity avian influenza status of the country of origin, Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. on the day of shipment, the birds showed no clinical signs of avian influenza;

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

3. a statistically appropriate sample of the parent flock birds were subjected, with negative results, to a diagnostic test for avian influenza at the time of collection of the eggs;

4. the birds were transported in new or appropriately sanitised containers.

If the birds or parent flocks have been vaccinated against avian influenza, the nature of the vaccine used and the date of vaccination should be stated in the international veterinary certificate.

Article 10.4.11.

Recommendations for importation from a country, zone or compartment free from high pathogenicity avian influenza

For hatching eggs of poultry

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

1. the hatching eggs came from a country, zone or compartment free from high pathogenicity avian influenza;

2. 1. the hatching eggs were derived from parent flocks that were monitored for avian influenza viruses and were found to be negative at the time of collection of the hatching eggs; or

   2. the hatching eggs have had their surfaces sanitised in accordance with point 4 d) of Article 1.1.5.;

3. the hatching eggs are transported in new or appropriately sanitised packaging materials and containers.

If the parent flocks have been vaccinated against avian influenza, the nature of the vaccine used and the date of vaccination should be stated in the international veterinary certificate.

Article 10.4.12.

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

Regardless of the high pathogenicity avian influenza status of the country of origin, Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. a statistically appropriate sample of the parent flock birds was subjected, with negative results, to a diagnostic test for avian influenza 14 days prior to and at the time of collection of the hatching eggs;

2. the hatching eggs have had their surfaces sanitised in accordance with point 4 d) of Article 1.1.5.;

3. the hatching eggs are transported in new or appropriately sanitised packaging materials and containers.

If the parent flocks have been vaccinated against avian influenza, the nature of the vaccine used and the date of vaccination should be stated in the international veterinary certificate.

Article 10.4.13.

Recommendations for importation from a country, zone or compartment free from high pathogenicity avian influenza

For poultry semen

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

1. showed no clinical signs of avian influenza on the day of semen collection;

2. were kept in a country, zone or compartment free from high pathogenicity avian influenza.

Article 10.4.14.

Recommendations for the importation of semen from birds other than poultry

Regardless of the high pathogenicity avian influenza 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 facilities approved by the Veterinary Services for at least 28 days (i.e. two flock-level incubation periods) prior to semen collection;

2. showed no clinical signs of avian influenza during the isolation period;

3. were subjected, with negative results, to a diagnostic test for avian influenza within 14 days prior to semen collection.

Article 10.4.15.

Recommendations for importation from a country, zone or compartment free from high pathogenicity avian influenza

For eggs for human consumption

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

1. the eggs for human consumption were produced and packed in a country, zone or compartment free from high pathogenicity avian influenza;

2. the eggs for human consumption were transported in new or appropriately sanitised packaging materials and containers.

Article 10.4.16.

Recommendations for the importation of egg products from poultry

Regardless of the high pathogenicity avian influenza status of the country of origin, Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. the egg products are derived from eggs which meet the requirements of Article 10.4.15.; or

2. the egg products have been processed to ensure the inactivation of high pathogenicity avian influenza viruses, in accordance with Article 10.4.23.;

AND

3. the necessary precautions were taken to avoid contact of the egg products with any source of high pathogenicity avian influenza viruses.

Article 10.4.17.

Recommendations for importation from a country, zone or compartment free from high pathogenicity avian influenza

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 originated from a country, zone or compartment free from high pathogenicity avian influenza;

2. which were slaughtered in an approved slaughterhouse/abattoir in a country, zone or compartment free from high pathogenicity avian influenza and were subjected to ante- and post-mortem inspections in accordance with Chapter 6.3., with favourable results.

Article 10.4.18.

Recommendations for the importation of meat products from poultry

Regardless of the high pathogenicity avian influenza status of the country of origin, Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. the meat products from poultry are derived from fresh meat which meets the requirements of Article 10.4.17.; or

2. the meat products from poultry have been processed to ensure the inactivation of high pathogenicity avian influenza viruses in accordance with Article 10.4.24.;

AND

3. the necessary precautions were taken to avoid contact of the meat products from poultry with any source of high pathogenicity avian influenza viruses.

Article 10.4.19.

Recommendations for the importation of poultry products not listed in Article 10.4.2. and intended for use in animal feeding, or for agricultural or industrial use

Regardless of the high pathogenicity avian influenza status of the country of origin, Veterinary Authorities should require the presentation of an international veterinary certificate attesting that:

1. these commodities were obtained from poultry which originated in a country, zone or compartment free from high pathogenicity avian influenza and that the necessary precautions were taken to avoid contamination during processing with any source of high pathogenicity avian influenza viruses;

OR

2. these commodities have been processed to ensure the inactivation of high pathogenicity avian influenza viruses using:

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

   2. heat treatment where the internal temperature throughout the product reached at least 74°C; or

   3. any equivalent treatment that has been demonstrated to inactivate avian influenza viruses;

AND

3. the necessary precautions were taken to avoid contact of the commodity with any source of high pathogenicity avian influenza viruses.

Article 10.4.20.

Recommendations for the importation of feathers and down from poultry not listed in Article 10.4.2.

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

1. these commodities originated from poultry as described in Article 10.4.17. and were processed in a country, zone or compartment free from high pathogenicity avian influenza; or

2. these commodities have been processed to ensure the inactivation of high pathogenicity avian influenza viruses using one of the following:

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

   2. irradiation with a dose of 20 kGy;

   3. any equivalent treatment which has been demonstrated to inactivate avian influenza viruses;

AND

3. the necessary precautions were taken to avoid contact of the commodity with any source of high pathogenicity avian influenza viruses.

Article 10.4.21.

Recommendations for the importation of feathers and down of birds other than poultry not listed in Article 10.4.2.

Regardless of the high pathogenicity avian influenza 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 inactivation of high pathogenicity avian influenza viruses using one of the following:

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

   2. irradiation with a dose of 20 kGy;

   3. any equivalent treatment which has been demonstrated to inactivate avian influenza viruses;

2. the necessary precautions were taken to avoid contact of the commodity with any source of high pathogenicity avian influenza viruses.

Article 10.4.22.

Recommendations for the importation of collection specimens, skins and trophies of birds other than poultry

Regardless of the high pathogenicity avian influenza 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 inactivation of high pathogenicity avian influenza viruses in accordance with Article 10.4.25.;

AND

2. the necessary precautions were taken to avoid contact of the commodity with any source of high pathogenicity avian influenza viruses.

Article 10.4.23.

Procedures for the inactivation of high pathogenicity avian influenza viruses in egg products from poultry

The following time/temperature combinations are suitable for the inactivation of high pathogenicity avian influenza viruses present in egg products:

These time/temperature combinations are indicative of a range that achieves a 7-log₁₀ reduction of avian influenza virus infectivity. These are examples for a variety of egg products but, when supported by scientific evidence, variations of these time/temperature combinations may be used, and they may be used for other egg products, if they achieve equivalent inactivation of the virus.

Article 10.4.24.

Procedures for the inactivation of high pathogenicity avian influenza viruses in meat products from poultry

The following time/temperature combinations are suitable for the inactivation of high pathogenicity avian influenza viruses in meat products.

These time/temperature combinations are indicative of a range that achieves a 7-log₁₀ reduction of avian influenza virus infectivity. When supported by scientific evidence, variations of these time/temperature combinations may be used if they achieve equivalent inactivation of the virus.

Article 10.4.25.

Procedures for the inactivation of high pathogenicity avian influenza viruses in collection specimens and in skins and trophies

For the inactivation of high pathogenicity avian influenza viruses in collection specimens and in skins and trophies, one of the following procedures should be used:

1. boiling in water for an appropriate time to ensure that any material other than bone, claws or beaks is removed; or

2. soaking, with agitation, in a 4% (w/v) solution of washing soda (sodium carbonate-Na₂CO₃) maintained at pH 11.5 or above for at least 48 hours; or

3. soaking, with agitation, in a formic acid solution (100 kg salt [NaCl] and 12 kg formic acid per 1,000 litres water) maintained below pH 3.0 for at least 48 hours; wetting and dressing agents may be added; or

4. in the case of raw hides, treatment for at least 28 days with salt (NaCl) containing 2% washing soda (sodium carbonate-Na₂CO₃); or

5. treatment with 1% formalin for a minimum of six days; or

6. any equivalent treatment which has been demonstrated to inactivate the virus.

Article 10.4.26.

Principles of surveillance for avian influenza

The following are complementary to Chapter 1.4. and should be applied by Member Countries seeking to determine their high pathogenicity avian influenza status.

These principles are also necessary to support vaccination programmes, to monitor low pathogenicity avian influenza viruses, especially H5 and H7, in poultry and to detect high pathogenicity avian influenza in wild birds.

The impact and epidemiology of avian influenza differ widely among different regions of the world and therefore it is impossible to provide detailed recommendations for all situations. Variables such as the frequency of contacts between poultry and wild birds, different biosecurity levels and production systems, and the commingling of different susceptible species including domestic waterfowl, may require different surveillance strategies to address each situation. Furthermore, domestic waterfowl typically do not show clinical signs and have longer infective periods than gallinaceous poultry. It is therefore incumbent upon the Member Country to provide scientific data that explain the epidemiology of avian influenza in the region of concern and also to demonstrate how all the risk factors have been taken into account. Member Countries have flexibility to provide a science-based approach to demonstrate absence of infection with high pathogenicity avian influenza viruses at an appropriate level of confidence, as described in Chapter 1.4.

There is an increased recognition of the value of the application of sequencing technologies and phylogenetic analyses to determine routes of introduction, transmission pathways and epidemiological patterns of infection. When avian influenza viruses are detected, Member Countries should apply these technologies, when possible, to enhance the evidence used to develop specific surveillance strategies and control activities.

A monitoring system for low pathogenicity avian influenza viruses in poultry should be in place for the following reasons:

1. H5 and H7 low pathogenicity avian influenza viruses have the potential to mutate into high pathogenicity avian influenza viruses, but it is not possible to predict which viruses will mutate or when these mutations will occur.

2. The detection of sudden and unexpected increases in virulence of low pathogenicity avian influenza viruses in poultry is notifiable as an emerging disease in accordance with Article 1.1.4.

3. The detection, in domestic or captive wild birds, of low pathogenicity avian influenza viruses that have been proven to be transmitted naturally to humans with severe consequences is notifiable in accordance with Article 1.1.3.

Article 10.4.27.

Surveillance for early warning of high pathogenicity avian influenza

1. An ongoing surveillance programme for avian influenza should be in place and be designed to detect the presence of infection with high pathogenicity avian influenza viruses in the country or zone in a timely manner.

2. The high pathogenicity avian influenza surveillance programme should include the following.

   1. An early warning system for reporting suspected cases, in accordance with Article 1.4.5. throughout the production, marketing and processing chain. Farmers and workers who have day-to-day contact with poultry, as well as diagnosticians, should report promptly any suspicion of avian influenza to the Veterinary Services. All suspected cases of high pathogenicity avian influenza should be investigated immediately and samples should be collected and submitted to a laboratory for appropriate tests.

   2. Implementation, as relevant, of regular and frequent clinical inspection, or serological and virological testing of high-risk groups of animals, such as those adjacent to a country or zone infected with high pathogenicity avian influenza, places where birds and poultry of different origins are mixed, such as live bird markets, and poultry in close proximity to waterfowl or other potential sources of influenza A viruses. This activity is particularly applicable to domestic waterfowl, where detection of high pathogenicity avian influenza via clinical suspicion can be of low sensitivity.

   3. Immediate investigation of the presence of antibodies against influenza A viruses that have been detected in poultry and are not a consequence of vaccination. In the case of single or isolated serological positive results, infection with high pathogenicity avian influenza viruses may be ruled out on the basis of a thorough epidemiological and laboratory investigation that does not demonstrate further evidence of such an infection.

Article 10.4.28.

Surveillance for demonstrating freedom from infection with high pathogenicity avian influenza

1. A Member Country declaring freedom of the entire country, a zone or a compartment from high pathogenicity avian influenza in poultry should provide evidence of an effective surveillance programme.

   Transparency in the application of different methodologies is essential to ensure consistency in decision-making, ease of understanding, fairness and rationality. The assumptions made, the uncertainties, and the effect of these on the interpretation of the results, should be documented.

   The design of the surveillance programme will depend on the epidemiological circumstances and it should be planned and implemented in accordance with this chapter and Article 1.4.6.This requires the availability of demographic data on the poultry population and the support of a laboratory able to undertake identification of infection with avian influenza viruses through virus detection and antibody tests.

   The surveillance programme should demonstrate absence of infection with high pathogenicity avian influenza viruses during the preceding 12 months in susceptible poultry populations (vaccinated and non-vaccinated).

   The design of the sampling strategy should include an epidemiologically appropriate design prevalence. The design prevalence and desired level of confidence in the results will determine the sample size. The Member Country should justify the choice of design prevalence and confidence level used on the basis of the stated objectives of the surveillance and the epidemiological situation.

   The sampling strategy may be risk-based if scientific evidence is available, and provided, for the quantification of risk factors. Specific risks could include those linked to the types of production, possible direct or indirect contact with wild birds, multi-age flocks, local trade patterns including live bird markets, use of possibly contaminated surface water, the presence of more than one species at the establishment and poor biosecurity in place.

   Data from different surveillance activities can be included to increase the sensitivity of the surveillance system. If this is to be done, data from structured (e.g. surveys and active surveillance) and non-structured (e.g. passive surveillance) sources should be combined and the sensitivity of each activity should be quantified in order to be able to quantify the sensitivity of the overall surveillance system.

   The surveillance programme should include surveillance for high pathogenicity avian influenza viruses in birds other than poultry, including wild birds, and monitoring of low pathogenicity avian influenza viruses in poultry, in order to ensure that biosecurity and control measures are fit for purpose.

   Documentation of freedom from infection with high pathogenicity avian influenza should provide details of the poultry population, the occurrence of suspected cases and how they were investigated and dealt with. This should include the results of laboratory testing and the biosecurity and control measures to which the animals concerned were subjected during the investigation.

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

   Vaccination to prevent the transmission of high pathogenicity avian influenza virus may be part of a disease control programme. The level of flock immunity required to prevent transmission depends on the flock size, composition (e.g. species) and density of the susceptible poultry population. Based on the epidemiology of avian influenza in the country, zone or compartment, a decision may be reached to vaccinate only certain species or other poultry  subpopulations.

   In all vaccinated flocks tests should be performed to ensure the absence of virus circulation. The tests should be repeated at a frequency that is proportionate to the risk in the country, zone or compartment. The use of sentinel poultry may provide further confidence in the absence of virus circulation.

   Member Countries seeking the demonstration of freedom from high pathogenicity avian influenza in vaccinated population should refer to the chapter on avian influenza (infection with avian influenza viruses) in the Terrestrial Manual.

   Evidence to show the effectiveness of the vaccination programme should also be provided.

3. Additional requirements for recovery of free status

   In addition to the conditions described in the point above, a Member Country declaring that it has regained country, zone or compartment freedom after an outbreak of high pathogenicity avian influenza in poultry should show evidence of an active surveillance programme, depending on the epidemiological circumstances of the outbreak, to demonstrate the absence of the infection. This will require surveillance incorporating virus detection and antibody tests. The Member Country should report the results of an active surveillance programme in which the susceptible poultry population undergoes regular clinical examination and active surveillance planned and implemented according to the general conditions and methods described in these recommendations. The surveillance samples should be representative of poultry  populations at risk. The use of sentinel birds may facilitate the interpretation of surveillance results.

   Populations under this surveillance programme should include:

   1. establishments in the proximity of the outbreaks;

   2. establishments epidemiologically linked to the outbreaks;

   3. poultry used to re-populate affected establishments;

   4. any establishments where preventive depopulation has been carried out.

Article 10.4.29.

Surveillance of wild bird populations

Passive surveillance, i.e. sampling of birds found dead, is an appropriate method of surveillance in wild birds because infection with high pathogenicity avian influenza can be associated with mortality in some species. Mortality events, or clusters of birds found dead should be reported to the Veterinary Services and investigated, including through the collection and submission of samples to a laboratory for appropriate tests.

Active surveillance, i.e. sampling of live wild birds, may be necessary for detection of some strains of high pathogenicity avian influenza viruses that produce infection without mortality in wild birds. Furthermore, it increases knowledge of the ecology and evolution of avian influenza viruses.

Surveillance in wild birds should be targeted towards times of year, species and locations in which infection is more likely.

Surveillance in wild birds should be enhanced by raising awareness, and by active searching and monitoring for dead or moribund wild birds when high pathogenicity avian influenza has been detected in the region. The movements of migratory water birds, in particular ducks, geese and swans, should be taken into account as a potential pathway for introduction of virus to uninfected areas.

Article 10.4.30.

Monitoring of low pathogenicity avian influenza in poultry populations

Outbreaks of low pathogenicity avian influenza viruses can be managed at the establishment level; however, spread to other poultryestablishments increases the risk of virus mutation, particularly if it is not detected and managed. Therefore, a monitoring system should be in place.

Monitoring the presence and types of low pathogenicity avian influenza viruses can be achieved through a combination of clinical investigation when infection is suspected because of changes in production parameters, such as reductions in egg production or feed and water intake, and active serological and virological surveillance, which can be supported by the information obtained by the surveillance system for high pathogenicity avian influenza.

Serological and virological monitoring should aim at detecting clusters of infected flocks to identify spread between establishments. Epidemiological follow-up (tracing forward and back) of serologically positive flocks should be carried out to determine whether there is clustering of infected flocks regardless of whether the seropositive birds are still present at the establishment or whether active virus infection has been detected. Hence, monitoring of low pathogenicity avian influenza will also enhance early detection of high pathogenicity avian influenza.

nb: first adopted in 1998; most recent update adopted in 2024.