Avian influenza overview September – December 2022

Cornelia Adlhoch, Alice Fusaro, José L Gonzales, Thijs Kuiken, Stefano Marangon, Éric Niqueux, Christoph Staubach, Calogero Terregino, Inma Aznar, Irene Muñoz Guajardo, et al.

<figure><img src="image_1.png" /></figure>

To cite this version:

Cornelia Adlhoch, Alice Fusaro, José L Gonzales, Thijs Kuiken, Stefano Marangon, et al. Avian influenza overview September – December 2022. EFSA Journal, 2023, 21 (1), pp.e07786. 10.2903/j.efsa.2023.7786. anses-04456900

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# Avian influenza overview September – December 2022

Cornelia Adlhoch, Alice Fusaro, José L Gonzales, Thijs Kuiken, Stefano Marangon, Éric Niqueux, Christoph Staubach, Calogero Terregino, Inma Aznar, Irene Muñoz Guajardo, et al.

<figure><img src="image_1.png" /></figure>

## To cite this version:

Cornelia Adlhoch, Alice Fusaro, José L Gonzales, Thijs Kuiken, Stefano Marangon, et al. Avian influenza overview September – December 2022. EFSA Journal, 2023, 21 (1), pp.e07786. 10.2903/j.efsa.2023.7786. anses-04456900

HAL Id: anses-04456900

https://anses.hal.science/anses-04456900v1

Submitted on 14 Feb 2024

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_2.png" /></figure>
<figure><img src="image_3.png" /></figure>

APPROVED: 15 December 2022

doi:10.2903/j.efsa.2023.7786

# Avian influenza overview September – December 2022

European Food Safety Authority,
European Centre for Disease Prevention and Control,
European Union Reference Laboratory for Avian Influenza,
Cornelia Adlhoch, Alice Fusaro, José L Gonzales, Thijs Kuiken, Stefano Marangon, Éric
Niqueux, Christoph Staubach, Calogero Terregino, Inma Aznar, Irene Muñoz Guajardo and
Francesca Baldinelli

## Abstract

Between October 2021 and September 2022 Europe has suffered the most devastatingly highly pathogenic avian influenza (HPAI) epidemic with a total of 2,520 outbreaks in poultry, 227 outbreaks in captive birds, and 3,867 HPAI virus detections in wild birds. The unprecedented geographical extent (37 European countries affected) resulted in 50 million birds culled in affected establishments. In the current reporting period, between 10 September and 2 December 2022, 1,163 HPAI virus detections were reported in 27 European countries in poultry (398), captive (151) and wild birds (613). A decrease in HPAI virus detections in colony-breeding seabirds species and an increase in the number of detections in waterfowl has been observed. The continuous circulation of the virus in the wild reservoir has led to the frequent introduction of the virus into poultry populations. It is suspected that waterfowl might be more involved than seabirds in the incursion of HPAI virus into poultry establishments. In the coming months, the increasing infection pressure on poultry establishments might increase the risk of incursions in poultry, with potential further spread, primarily in areas with high poultry densities. The viruses detected since September 2022 (clade 2.3.4.4b) belong to eleven genotypes, three of which have circulated in Europe during the summer months, while eight represent new genotypes. HPAI viruses were also detected in wild and farmed mammal species in Europe and North America, showing genetic markers of adaptation to replication in mammals. Since the last report, two A(H5N1) detections in humans in Spain, one A(H5N1), one A(H5N6) and one A(H9N2) human infection in China as well as one A(H5) infection without NA-type result in Vietnam were reported, respectively. The risk of infection is assessed as low for the general population in the EU/EEA, and low to medium for occupationally exposed people.

© 2023 European Food Safety Authority. *EFSA Journal* published by Wiley-VCH GmbH on behalf of European Food Safety Authority.

**Key words:** avian influenza, captive birds, HPAI/LPAI, humans, monitoring, poultry, wild birds

**Requestor:** European Commission

**Question number:** EFSA-Q-2022-00747

**Correspondence:** biohaw@efsa.europa.eu
<figure><img src="image_3.png" /></figure>

APPROVED: 15 December 2022

doi:10.2903/j.efsa.2023.7786

# Avian influenza overview September – December 2022

European Food Safety Authority,
European Centre for Disease Prevention and Control,
European Union Reference Laboratory for Avian Influenza,
Cornelia Adlhoch, Alice Fusaro, José L Gonzales, Thijs Kuiken, Stefano Marangon, Éric
Niqueux, Christoph Staubach, Calogero Terregino, Inma Aznar, Irene Muñoz Guajardo and
Francesca Baldinelli

## Abstract

Between October 2021 and September 2022 Europe has suffered the most devastatingly highly pathogenic avian influenza (HPAI) epidemic with a total of 2,520 outbreaks in poultry, 227 outbreaks in captive birds, and 3,867 HPAI virus detections in wild birds. The unprecedented geographical extent (37 European countries affected) resulted in 50 million birds culled in affected establishments. In the current reporting period, between 10 September and 2 December 2022, 1,163 HPAI virus detections were reported in 27 European countries in poultry (398), captive (151) and wild birds (613). A decrease in HPAI virus detections in colony-breeding seabirds species and an increase in the number of detections in waterfowl has been observed. The continuous circulation of the virus in the wild reservoir has led to the frequent introduction of the virus into poultry populations. It is suspected that waterfowl might be more involved than seabirds in the incursion of HPAI virus into poultry establishments. In the coming months, the increasing infection pressure on poultry establishments might increase the risk of incursions in poultry, with potential further spread, primarily in areas with high poultry densities. The viruses detected since September 2022 (clade 2.3.4.4b) belong to eleven genotypes, three of which have circulated in Europe during the summer months, while eight represent new genotypes. HPAI viruses were also detected in wild and farmed mammal species in Europe and North America, showing genetic markers of adaptation to replication in mammals. Since the last report, two A(H5N1) detections in humans in Spain, one A(H5N1), one A(H5N6) and one A(H9N2) human infection in China as well as one A(H5) infection without NA-type result in Vietnam were reported, respectively. The risk of infection is assessed as low for the general population in the EU/EEA, and low to medium for occupationally exposed people.

© 2023 European Food Safety Authority. *EFSA Journal* published by Wiley-VCH GmbH on behalf of European Food Safety Authority.

**Key words:** avian influenza, captive birds, HPAI/LPAI, humans, monitoring, poultry, wild birds

**Requestor:** European Commission

**Question number:** EFSA-Q-2022-00747

**Correspondence:** biohaw@efsa.europa.eu
**Acknowledgements:** In addition to the listed authors, EFSA, ECDC and the EURL wish to thank the following: Member State representatives who provided epidemiological data on avian influenza outbreaks or shared sequence data: Sandra Revilla-Fernandez (Austria), Mieke Steensels, Ingeborg Mertens and Steven Van Borm (Belgium), Aleksandra Miteva (Bulgaria), Tihana Miškić, Vladimir Savic (Croatia), Michelle Fischer Carlsen and Charlotte Kristiane Hjulsager (Denmark), Béatrice Grasland, Audrey Schmitz, Karen Bucher, Elisa Bohin, François-Xavier Briand, Célia Locquet (France), Carola Sauter-Louis, Christoph Staubach and Timm Harder (Germany), Georgina Helyes, (Hungary), Audrey Jenkinson, Katherine Harrison (Ireland), Francesca Scolamacchia, Bianca Zecchin, Isabella Monne and Paolo Mulatti (Italy), Vitalie Caraus and Oxana Popa (Moldova), Michael McMenamy (United Kingdom (Northern Ireland)), Britt Gjerset and Siri Margrete Løtvedt (Norway), Aleksandra Podražka, Krzysztof Śmietanka and Edyta Swieton (Poland), Renata Carvalho, Ana Caria Nunes, Yolanda Vaz and Susana Pombo (Portugal), Marcel Spierenburg, Dennis Bol and Nancy Beerens (the Netherlands), Elena García Villacieros, Luis José Romero Gonzalez, Germán Cáceres Garrido, Monserrat Agüero García and Azucena Sánchez (Spain), Siamak Zohari, (Sweden); Ian Brown from the Animal and Plant Health Agency (United Kingdom); Camille Delavenne from AUSVET Europe for conducting the data analysis under the contract OC/EFSA/ALPHA/2021/02; Paolo Calistri and Karl Stahl from the EFSA AHAW Panel for reviewing the report; Grazina Mirinaviciute from ECDC, Linnea Lindgren Kero, Lisa Kohnle and Gina Cioacata from EFSA, Elke Schneider from OSHA, for the support provided to this scientific output; we gratefully acknowledge the authors, originating and submitting laboratories of the sequences from GISAID's EpiFlu™ Database, which is used for this assessment.

**Suggested citation:** EFSA (European Food Safety Authority), ECDC (European Centre for Disease Prevention and Control), EURL (European Reference Laboratory for Avian Influenza), Adlhoch C, Fusaro A, Gonzales JL, Kuiken T, Marangon S, Niqueux É, Staubach C, Terregino C, Aznar I, Muñoz Guajardo I and Baldinelli F, 2023. Scientific report: Avian influenza overview September–December 2022. EFSA Journal 2023;21(1):7786, 63 pp. https://doi.org/10.2903/j.efsa.2023.7786

ISSN: 1831-4732

© 2023 European Food Safety Authority. *EFSA Journal* published by Wiley-VCH GmbH on behalf of European Food Safety Authority.

This is an open access article under the terms of the Creative Commons Attribution-NoDerivs Licence, which permits use and distribution in any medium, provided the original work is properly cited and no modifications or adaptations are made.

Figures 1–14, 16 and Tables 1–3 and 6 © EFSA; Figures 15, 17–19 and Table 4 © ECDC; Table 5 © EURL
**Acknowledgements:** In addition to the listed authors, EFSA, ECDC and the EURL wish to thank the following: Member State representatives who provided epidemiological data on avian influenza outbreaks or shared sequence data: Sandra Revilla-Fernandez (Austria), Mieke Steensels, Ingeborg Mertens and Steven Van Borm (Belgium), Aleksandra Miteva (Bulgaria), Tihana Miškić, Vladimir Savic (Croatia), Michelle Fischer Carlsen and Charlotte Kristiane Hjulsager (Denmark), Béatrice Grasland, Audrey Schmitz, Karen Bucher, Elisa Bohin, François-Xavier Briand, Célia Locquet (France), Carola Sauter-Louis, Christoph Staubach and Timm Harder (Germany), Georgina Helyes, (Hungary), Audrey Jenkinson, Katherine Harrison (Ireland), Francesca Scolamacchia, Bianca Zecchin, Isabella Monne and Paolo Mulatti (Italy), Vitalie Caraus and Oxana Popa (Moldova), Michael McMenamy (United Kingdom (Northern Ireland)), Britt Gjerset and Siri Margrete Løtvedt (Norway), Aleksandra Podražka, Krzysztof Śmietanka and Edyta Swieton (Poland), Renata Carvalho, Ana Caria Nunes, Yolanda Vaz and Susana Pombo (Portugal), Marcel Spierenburg, Dennis Bol and Nancy Beerens (the Netherlands), Elena García Villacieros, Luis José Romero Gonzalez, Germán Cáceres Garrido, Monserrat Agüero García and Azucena Sánchez (Spain), Siamak Zohari, (Sweden); Ian Brown from the Animal and Plant Health Agency (United Kingdom); Camille Delavenne from AUSVET Europe for conducting the data analysis under the contract OC/EFSA/ALPHA/2021/02; Paolo Calistri and Karl Stahl from the EFSA AHAW Panel for reviewing the report; Grazina Mirinaviciute from ECDC, Linnea Lindgren Kero, Lisa Kohnle and Gina Cioacata from EFSA, Elke Schneider from OSHA, for the support provided to this scientific output; we gratefully acknowledge the authors, originating and submitting laboratories of the sequences from GISAID's EpiFlu™ Database, which is used for this assessment.

**Suggested citation:** EFSA (European Food Safety Authority), ECDC (European Centre for Disease Prevention and Control), EURL (European Reference Laboratory for Avian Influenza), Adlhoch C, Fusaro A, Gonzales JL, Kuiken T, Marangon S, Niqueux É, Staubach C, Terregino C, Aznar I, Muñoz Guajardo I and Baldinelli F, 2023. Scientific report: Avian influenza overview September–December 2022. EFSA Journal 2023;21(1):7786, 63 pp. https://doi.org/10.2903/j.efsa.2023.7786

ISSN: 1831-4732

© 2023 European Food Safety Authority. *EFSA Journal* published by Wiley-VCH GmbH on behalf of European Food Safety Authority.

This is an open access article under the terms of the Creative Commons Attribution-NoDerivs Licence, which permits use and distribution in any medium, provided the original work is properly cited and no modifications or adaptations are made.

Figures 1–14, 16 and Tables 1–3 and 6 © EFSA; Figures 15, 17–19 and Table 4 © ECDC; Table 5 © EURL
Table of contents

<table><tr><td>1.</td><td>Introduction</td><td>4</td></tr><tr><td>2.</td><td>Main observations and conclusions</td><td>4</td></tr><tr><td>2.1.</td><td>Main observations</td><td>4</td></tr><tr><td>2.2.</td><td>Conclusions</td><td>5</td></tr><tr><td>3.</td><td>Options for response</td><td>6</td></tr><tr><td>4.</td><td>Results</td><td>7</td></tr><tr><td>4.1.</td><td>Overview of HPAI outbreaks in Europe during the previous and current seasons</td><td>7</td></tr><tr><td>4.2.</td><td>HPAI and LPAI detections in Europe, 10 September to 2 December 2022 (ToR 1 and ToR 2)</td><td>16</td></tr><tr><td>4.2.1.</td><td>HPAI detections in poultry, other captive birds and wild birds</td><td>16</td></tr><tr><td>4.2.2.</td><td>Genetic characterisation of avian influenza viruses</td><td>29</td></tr><tr><td>4.3.</td><td>Human cases reported and transmission to other mammal species due to clade 2.3.4.4b A(H5Nx) avian influenza viruses detected in birds in Europe</td><td>30</td></tr><tr><td>4.4.</td><td>Prevention and control measures applied in Europe, 3 September to 18 November 2022 (ToR 3)</td><td>35</td></tr><tr><td>4.5.</td><td>The avian influenza situation in other countries not reporting via ADIS, 10 September to 2 December 2022 (ToR 4)</td><td>35</td></tr><tr><td>4.5.1.</td><td>Avian influenza A(H3N8)</td><td>36</td></tr><tr><td>4.5.2.</td><td>HPAI A(H5)</td><td>36</td></tr><tr><td>4.5.3.</td><td>HPAI A(H5N1)</td><td>36</td></tr><tr><td>4.5.4.</td><td>HPAI A(H5N2) and A(H5N5)</td><td>39</td></tr><tr><td>4.5.5.</td><td>HPAI A(H5N6)</td><td>40</td></tr><tr><td>4.5.6.</td><td>HPAI A(H5N8)</td><td>41</td></tr><tr><td>4.5.7.</td><td>HPAI-LPAI A(H7N9)</td><td>41</td></tr><tr><td>4.5.8.</td><td>LPAI A(H9N2)</td><td>42</td></tr><tr><td>4.5.9.</td><td>Human infections due to A(H10N3) and A(H10N8)</td><td>43</td></tr><tr><td>4.6.</td><td>Scientific analysis of avian influenza spread from non-EU/EEA countries and within the EU/EEA</td><td>43</td></tr><tr><td>4.7.</td><td>Monitoring, diagnosis of human infections and public health, occupational health and safety measures for infection prevention and control in the EU/EEA</td><td>45</td></tr><tr><td>4.7.1.</td><td>Occupational health and safety measures</td><td>45</td></tr><tr><td>4.7.2.</td><td>Monitoring and options for public health measures</td><td>46</td></tr><tr><td>4.7.3.</td><td>Diagnosis</td><td>46</td></tr><tr><td>4.7.4.</td><td>Reporting</td><td>47</td></tr><tr><td>4.7.5.</td><td>Sharing of sequences</td><td>47</td></tr><tr><td>4.7.6.</td><td>Candidate vaccine viruses</td><td>47</td></tr><tr><td>4.8.</td><td>ECDC risk assessment for the general public in the EU/EEA</td><td>47</td></tr><tr><td colspan="2">References</td><td>49</td></tr><tr><td colspan="2">Abbreviations</td><td>55</td></tr><tr><td colspan="2">Appendix A – Terms of Reference</td><td>56</td></tr><tr><td colspan="2">Appendix B – Data and Methodologies</td><td>58</td></tr><tr><td colspan="2">Annex A – Characteristics of the HPAI A(H5Nx)-positive poultry establishments</td><td>63</td></tr><tr><td colspan="2">Annex B – Applied prevention and control measures on avian influenza</td><td>63</td></tr><tr><td colspan="2">Annex C – Data on wild birds</td><td>63</td></tr></table>
Table of contents

<table><tr><td>1.</td><td>Introduction</td><td>4</td></tr><tr><td>2.</td><td>Main observations and conclusions</td><td>4</td></tr><tr><td>2.1.</td><td>Main observations</td><td>4</td></tr><tr><td>2.2.</td><td>Conclusions</td><td>5</td></tr><tr><td>3.</td><td>Options for response</td><td>6</td></tr><tr><td>4.</td><td>Results</td><td>7</td></tr><tr><td>4.1.</td><td>Overview of HPAI outbreaks in Europe during the previous and current seasons</td><td>7</td></tr><tr><td>4.2.</td><td>HPAI and LPAI detections in Europe, 10 September to 2 December 2022 (ToR 1 and ToR 2)</td><td>16</td></tr><tr><td>4.2.1.</td><td>HPAI detections in poultry, other captive birds and wild birds</td><td>16</td></tr><tr><td>4.2.2.</td><td>Genetic characterisation of avian influenza viruses</td><td>29</td></tr><tr><td>4.3.</td><td>Human cases reported and transmission to other mammal species due to clade 2.3.4.4b A(H5Nx) avian influenza viruses detected in birds in Europe</td><td>30</td></tr><tr><td>4.4.</td><td>Prevention and control measures applied in Europe, 3 September to 18 November 2022 (ToR 3)</td><td>35</td></tr><tr><td>4.5.</td><td>The avian influenza situation in other countries not reporting via ADIS, 10 September to 2 December 2022 (ToR 4)</td><td>35</td></tr><tr><td>4.5.1.</td><td>Avian influenza A(H3N8)</td><td>36</td></tr><tr><td>4.5.2.</td><td>HPAI A(H5)</td><td>36</td></tr><tr><td>4.5.3.</td><td>HPAI A(H5N1)</td><td>36</td></tr><tr><td>4.5.4.</td><td>HPAI A(H5N2) and A(H5N5)</td><td>39</td></tr><tr><td>4.5.5.</td><td>HPAI A(H5N6)</td><td>40</td></tr><tr><td>4.5.6.</td><td>HPAI A(H5N8)</td><td>41</td></tr><tr><td>4.5.7.</td><td>HPAI-LPAI A(H7N9)</td><td>41</td></tr><tr><td>4.5.8.</td><td>LPAI A(H9N2)</td><td>42</td></tr><tr><td>4.5.9.</td><td>Human infections due to A(H10N3) and A(H10N8)</td><td>43</td></tr><tr><td>4.6.</td><td>Scientific analysis of avian influenza spread from non-EU/EEA countries and within the EU/EEA</td><td>43</td></tr><tr><td>4.7.</td><td>Monitoring, diagnosis of human infections and public health, occupational health and safety measures for infection prevention and control in the EU/EEA</td><td>45</td></tr><tr><td>4.7.1.</td><td>Occupational health and safety measures</td><td>45</td></tr><tr><td>4.7.2.</td><td>Monitoring and options for public health measures</td><td>46</td></tr><tr><td>4.7.3.</td><td>Diagnosis</td><td>46</td></tr><tr><td>4.7.4.</td><td>Reporting</td><td>47</td></tr><tr><td>4.7.5.</td><td>Sharing of sequences</td><td>47</td></tr><tr><td>4.7.6.</td><td>Candidate vaccine viruses</td><td>47</td></tr><tr><td>4.8.</td><td>ECDC risk assessment for the general public in the EU/EEA</td><td>47</td></tr><tr><td colspan="2">References</td><td>49</td></tr><tr><td colspan="2">Abbreviations</td><td>55</td></tr><tr><td colspan="2">Appendix A – Terms of Reference</td><td>56</td></tr><tr><td colspan="2">Appendix B – Data and Methodologies</td><td>58</td></tr><tr><td colspan="2">Annex A – Characteristics of the HPAI A(H5Nx)-positive poultry establishments</td><td>63</td></tr><tr><td colspan="2">Annex B – Applied prevention and control measures on avian influenza</td><td>63</td></tr><tr><td colspan="2">Annex C – Data on wild birds</td><td>63</td></tr></table>
**1. Introduction**

This scientific report provides an overview of highly pathogenic avian influenza (HPAI) virus detections in poultry<fnref n="1" />, captive<fnref n="2" /> and wild birds as well as noteworthy outbreaks of low pathogenic avian influenza (LPAI) virus in poultry and captive birds, and human cases due to avian influenza virus that occurred in and outside Europe between 10 September and 2 December 2022.

The background, Terms of Reference and their interpretation are described in Appendix A, and the data and methodologies are reported in Appendix B.

**2. Main observations and conclusions**

A description of the avian influenza outbreaks in European countries and in other countries of interest taking place between 10 September and 2 December 2022, is presented below.

**2.1. Main observations**

* In Europe, between 10 September and 2 December 2022 (based on the Animal Disease Information System (ADIS), WOAH World Animal Health Information System (WOAH-WAHIS), and information provided by affected countries) 1,162 HPAI A(H5) detections<fnref n="3" /> were reported in poultry, captive and wild birds:

- 398 outbreaks in poultry in the United Kingdom (115), France (98), Hungary (69), Germany (42), Italy (28), the Netherlands (25), Belgium (8), Norway (2), Ireland (2), Bulgaria, Czechia, Croatia, Cyprus, Denmark, Moldova, Poland, Portugal, and Spain (1 each);

- 613 virus detections in wild birds in the United Kingdom (160), the Netherlands (97), Germany (86), France (62), Belgium (59), Spain (46), Italy (35), Denmark (20), Norway (9), Iceland (7), Romania (7), Ireland (4), Sweden (4), Serbia (3), Slovenia (3), Portugal (3), Croatia (2), Poland (2), Switzerland (2), Cyprus and Finland (1 each);

- 151 outbreaks in captive birds in France (52), Germany (32), the United Kingdom (29), Netherlands (18), Belgium (11), Ireland (2), Denmark (2), Austria, Cyprus, Italy, North Macedonia and Switzerland (1 each).

* During this reporting period, HPAI virus has been detected in at least 64 wild bird species in Europe: at least 18 waterfowl species (407 detections), 10 colony-breeding seabird species (117 detections), 12 raptor species (65 detections), and 24 other wild bird species (82 detections).

* The overall temporal pattern has shown a decrease in HPAI virus detections in wild birds since the previous reporting period (613 versus 844 detections), which is mainly due to the decreased number of detections in colony-breeding seabird species (109 versus 581 detections); conversely, the number of detections in waterfowl increased since the previous reporting period (372 versus 129 detections).

* In the current reporting period, the number of outbreaks in domestic birds continued to increase (from its lowest point in June in the previous reporting period) to a peak in October 2022. From 2 September and 10 December 2022, 35% more infected poultry establishments were observed than those observed during the same period in the previous year.

* The high infection pressure due to the continuous circulation of HPAI A(H5N1) virus in the wild reservoir has led to frequent introductions of the virus into poultry populations across Europe. Primary HPAI poultry outbreaks frequently occurred in several EU countries (e.g., France,

<footnote n="1">¹ According to Regulation (EU) 2016/429 of the European Parliament and of the Council of 9 March 2016, point (9), 'poultry' means birds that are reared or kept in captivity for: (a) the production of: (i) meat; (ii) eggs for consumption; (iii) other products; (b) restocking supplies of game birds; (c) the purpose of breeding of birds used for the types of production referred to in points (a) and (b).</footnote>

<footnote n="2">² According to Regulation (EU) 2016/429 of the European Parliament and of the Council of 9 March 2016, point (10), 'captive birds' means any birds other than poultry that are kept in captivity for any reason other than those referred to in point (9), including those that are kept for shows, races, exhibitions, competitions, breeding or selling</footnote>

<footnote n="3">³ The date of suspicion was used as the reference date, when the date of suspicion was not available then the date of confirmation was used as the reference date.</footnote>
**1. Introduction**

This scientific report provides an overview of highly pathogenic avian influenza (HPAI) virus detections in poultry<fnref n="1" />, captive<fnref n="2" /> and wild birds as well as noteworthy outbreaks of low pathogenic avian influenza (LPAI) virus in poultry and captive birds, and human cases due to avian influenza virus that occurred in and outside Europe between 10 September and 2 December 2022.

The background, Terms of Reference and their interpretation are described in Appendix A, and the data and methodologies are reported in Appendix B.

**2. Main observations and conclusions**

A description of the avian influenza outbreaks in European countries and in other countries of interest taking place between 10 September and 2 December 2022, is presented below.

**2.1. Main observations**

* In Europe, between 10 September and 2 December 2022 (based on the Animal Disease Information System (ADIS), WOAH World Animal Health Information System (WOAH-WAHIS), and information provided by affected countries) 1,162 HPAI A(H5) detections<fnref n="3" /> were reported in poultry, captive and wild birds:

- 398 outbreaks in poultry in the United Kingdom (115), France (98), Hungary (69), Germany (42), Italy (28), the Netherlands (25), Belgium (8), Norway (2), Ireland (2), Bulgaria, Czechia, Croatia, Cyprus, Denmark, Moldova, Poland, Portugal, and Spain (1 each);

- 613 virus detections in wild birds in the United Kingdom (160), the Netherlands (97), Germany (86), France (62), Belgium (59), Spain (46), Italy (35), Denmark (20), Norway (9), Iceland (7), Romania (7), Ireland (4), Sweden (4), Serbia (3), Slovenia (3), Portugal (3), Croatia (2), Poland (2), Switzerland (2), Cyprus and Finland (1 each);

- 151 outbreaks in captive birds in France (52), Germany (32), the United Kingdom (29), Netherlands (18), Belgium (11), Ireland (2), Denmark (2), Austria, Cyprus, Italy, North Macedonia and Switzerland (1 each).

* During this reporting period, HPAI virus has been detected in at least 64 wild bird species in Europe: at least 18 waterfowl species (407 detections), 10 colony-breeding seabird species (117 detections), 12 raptor species (65 detections), and 24 other wild bird species (82 detections).

* The overall temporal pattern has shown a decrease in HPAI virus detections in wild birds since the previous reporting period (613 versus 844 detections), which is mainly due to the decreased number of detections in colony-breeding seabird species (109 versus 581 detections); conversely, the number of detections in waterfowl increased since the previous reporting period (372 versus 129 detections).

* In the current reporting period, the number of outbreaks in domestic birds continued to increase (from its lowest point in June in the previous reporting period) to a peak in October 2022. From 2 September and 10 December 2022, 35% more infected poultry establishments were observed than those observed during the same period in the previous year.

* The high infection pressure due to the continuous circulation of HPAI A(H5N1) virus in the wild reservoir has led to frequent introductions of the virus into poultry populations across Europe. Primary HPAI poultry outbreaks frequently occurred in several EU countries (e.g., France,

<footnote n="1">¹ According to Regulation (EU) 2016/429 of the European Parliament and of the Council of 9 March 2016, point (9), 'poultry' means birds that are reared or kept in captivity for: (a) the production of: (i) meat; (ii) eggs for consumption; (iii) other products; (b) restocking supplies of game birds; (c) the purpose of breeding of birds used for the types of production referred to in points (a) and (b).</footnote>

<footnote n="2">² According to Regulation (EU) 2016/429 of the European Parliament and of the Council of 9 March 2016, point (10), 'captive birds' means any birds other than poultry that are kept in captivity for any reason other than those referred to in point (9), including those that are kept for shows, races, exhibitions, competitions, breeding or selling</footnote>

<footnote n="3">³ The date of suspicion was used as the reference date, when the date of suspicion was not available then the date of confirmation was used as the reference date.</footnote>
Germany, Italy, the Netherlands), without extensive secondary spread of the virus. Indeed, these countries reported, until now, only a limited number of secondary outbreaks, whereas numerous secondary outbreaks were detected in poultry in Hungary. Primary outbreaks often occurred in establishments without outdoor access, and poultry production systems (e.g. breeders) with high biosecurity standards were also affected.

* All the HPAI A(H5Nx) viruses characterised since October 2020 in Europe belong to clade 2.3.4.4b. Based on the available genetic information, the A(H5N1) viruses detected since September 2022 belong to eleven genotypes, three of which have circulated in Europe during the summer months, while eight represent new genotypes, likely evolved through reassortment events, most likely occurred locally.

* In October 2022 a mink farm in Spain was affected by an A(H5N1) virus belonging to a genotype generated through reassortment events with the gull-adapted H13 subtype. Viruses with this gene constellation have been circulating mainly in wild birds in Northern Europe since May 2022, and were detected in one fox in Belgium. The strain responsible of the outbreak in mink contained a mutation in the PB2 protein that has been demonstrated to enhance the polymerase activity of influenza A viruses in mammals.

* For the first time HPAI A(H5N1) virus infections were reported in an Amur leopard (Panthera pardus orientalis) in the USA.

* In comparison to the previous report (EFSA et al., 2022b), in the current reporting period the avian influenza situation in Africa, Asia and Russia showed a comparable level of reported outbreaks in poultry and detections in wild birds. However, the number of notifications to WOAH and of affected countries increased in the Americas by four times, particularly due to the spread of HPAI A(H5N1) to Central (Mexico) and South America (Colombia, Ecuador, Peru and Venezuela). These introductions in South American countries in both wild birds and poultry have been reported for the first time ever.

* During this reporting period six new detections of avian influenza in humans have been reported from three countries: Spain: two A(H5N1); China: one A(H5N1), one A(H5N6), and one A(H9N2); Vietnam: one A(H5) without NA-type.

* The HPAI A(H5N1) virus collected from one human sample in Spain, likely originating from an environmental contamination, clusters with the viruses collected from the infected laying hens' farm where the person was involved in culling activities. No mutation associated with increased zoonotic potential was identified.

## 2.2. Conclusions

* The HPAI epidemic observed in the 2021-2022 epidemiological year in Europe is the largest in history, involving 37 countries and with a total of 2,520 HPAI outbreaks in poultry and 50 million birds dead or culled in the affected establishments, 227 detections in captive birds, and 3,867 detections in wild birds. The overall number of detections was 1.7 times higher than in the 2020-2021 epidemiological year, and 2.4 times higher than in the 2016-2017 epidemiological year. The epidemic didn't stop during the summer and continued into the 2022-2023 epidemiological year.

* The viruses characterised to date retain a preference for avian-type receptors; mutations associated with mammalian adaptation have only been sporadically identified in the analysed viruses from avian species, but they are frequently acquired upon transmission to mammals.

* Detections of A(H5) clade 2.3.4.4b viruses in humans together with the increasing number of transmission events of A(H5) viruses to wild mammals reported from different European countries, underline the continuous risk of avian influenza virus transmission to humans, also in Europe, and that these viruses may adapt further to mammals.

* The risk of infection for the general population in the EU/EEA is assessed as low, and for occupationally exposed people low to medium with high uncertainty due to the high diversity of circulating avian influenza viruses in bird populations.
Germany, Italy, the Netherlands), without extensive secondary spread of the virus. Indeed, these countries reported, until now, only a limited number of secondary outbreaks, whereas numerous secondary outbreaks were detected in poultry in Hungary. Primary outbreaks often occurred in establishments without outdoor access, and poultry production systems (e.g. breeders) with high biosecurity standards were also affected.

* All the HPAI A(H5Nx) viruses characterised since October 2020 in Europe belong to clade 2.3.4.4b. Based on the available genetic information, the A(H5N1) viruses detected since September 2022 belong to eleven genotypes, three of which have circulated in Europe during the summer months, while eight represent new genotypes, likely evolved through reassortment events, most likely occurred locally.

* In October 2022 a mink farm in Spain was affected by an A(H5N1) virus belonging to a genotype generated through reassortment events with the gull-adapted H13 subtype. Viruses with this gene constellation have been circulating mainly in wild birds in Northern Europe since May 2022, and were detected in one fox in Belgium. The strain responsible of the outbreak in mink contained a mutation in the PB2 protein that has been demonstrated to enhance the polymerase activity of influenza A viruses in mammals.

* For the first time HPAI A(H5N1) virus infections were reported in an Amur leopard (Panthera pardus orientalis) in the USA.

* In comparison to the previous report (EFSA et al., 2022b), in the current reporting period the avian influenza situation in Africa, Asia and Russia showed a comparable level of reported outbreaks in poultry and detections in wild birds. However, the number of notifications to WOAH and of affected countries increased in the Americas by four times, particularly due to the spread of HPAI A(H5N1) to Central (Mexico) and South America (Colombia, Ecuador, Peru and Venezuela). These introductions in South American countries in both wild birds and poultry have been reported for the first time ever.

* During this reporting period six new detections of avian influenza in humans have been reported from three countries: Spain: two A(H5N1); China: one A(H5N1), one A(H5N6), and one A(H9N2); Vietnam: one A(H5) without NA-type.

* The HPAI A(H5N1) virus collected from one human sample in Spain, likely originating from an environmental contamination, clusters with the viruses collected from the infected laying hens' farm where the person was involved in culling activities. No mutation associated with increased zoonotic potential was identified.

## 2.2. Conclusions

* The HPAI epidemic observed in the 2021-2022 epidemiological year in Europe is the largest in history, involving 37 countries and with a total of 2,520 HPAI outbreaks in poultry and 50 million birds dead or culled in the affected establishments, 227 detections in captive birds, and 3,867 detections in wild birds. The overall number of detections was 1.7 times higher than in the 2020-2021 epidemiological year, and 2.4 times higher than in the 2016-2017 epidemiological year. The epidemic didn't stop during the summer and continued into the 2022-2023 epidemiological year.

* The viruses characterised to date retain a preference for avian-type receptors; mutations associated with mammalian adaptation have only been sporadically identified in the analysed viruses from avian species, but they are frequently acquired upon transmission to mammals.

* Detections of A(H5) clade 2.3.4.4b viruses in humans together with the increasing number of transmission events of A(H5) viruses to wild mammals reported from different European countries, underline the continuous risk of avian influenza virus transmission to humans, also in Europe, and that these viruses may adapt further to mammals.

* The risk of infection for the general population in the EU/EEA is assessed as low, and for occupationally exposed people low to medium with high uncertainty due to the high diversity of circulating avian influenza viruses in bird populations.
* The risk of transmission to humans by exposure to contaminated poultry products is considered negligible as also outlined in a previous EFSA assessment (EFSA AHAW Panel, 2017).

* In contrast to previous epidemiological years, there was no clear start of the HPAI epidemic in October in the epidemiological year 2022-2023, neither in wild nor in domestic birds. This is due to the persistence of the virus in wild birds along the summer months and indicates a continuous risk for HPAI virus to spread among wild birds and mammals, as well as for virus entry into poultry establishments.

* From the previous reporting period (June-September) to the current reporting period (September-December), waterfowl replaced colony-breeding seabirds as the main wild birds in which HPAI virus detection was reported. This switch is likely due to a combination of the post-breeding dispersal of colony-breeding seabirds after their breeding periods in the summer, and the increased number of waterfowl present in Europe as a result of autumn migration. It cannot be excluded that these waterfowl will be at higher risk of HPAI virus infection than in previous years due to the observed persistence of HPAI virus in wild birds in Europe.

* The shape of the epidemic curve in poultry in 2021-2022 resembled that in waterfowl, but not that in seabirds (Figure 5C). This suggests that waterfowl might be more involved than seabirds in the incursion of HPAI virus into poultry establishments, likely because the habitat of waterfowl is more likely to overlap with the location of poultry establishments than seabird colony sites.

* The biosecurity measures implemented along the poultry production chain do not seem effective in preventing all introductions of the HPAI A(H5N1) virus into poultry establishments. In the coming months, the sustained and increasing infection pressure on poultry establishments will further challenge the effectiveness of the applied biosecurity measures.

* The prolonged avian influenza risk period represents a challenge for the sustainability of the reinforced biosecurity measures implemented along the poultry chain in high-risk areas or production sectors. The persistent presence of HPAI A(H5) viruses in wild birds and in the environment and the continuous occurrence of primary outbreaks in several countries, and the possible reduction of biosecurity compliance might increase the risk of avian influenza incursions with the potential further spread between establishments, primarily in areas with high poultry densities.

### 3. Options for response

* Considering the significant negative impact of these HPAI epidemics in the last years, and the ongoing HPAI risk posed by the sustained virus circulation in wild birds, short-term preparedness and medium- and long-term prevention strategies should be identified and implemented, primarily in densely populated poultry areas and poultry production systems that are highly susceptible to avian influenza exposure. These have been described in detail in the Avian influenza overview September - December 2021 (EFSA et al., 2021).

* Given the substantial mortality of wild birds associated with the detection of HPAI A(H5) virus, it is important for the relevant authorities to enhance the surveillance and to ensure accurate documentation of the number of wild birds dead or ill during these HPAI-associated die-offs. Such information would enhance understanding of these phenomena and provides a factual basis for assessing the ecological impact and coming up with policy decisions to avert future HPAI outbreaks not only in poultry and humans but also in wild birds, both migratory and resident. On the short-term, timely removal of wild bird carcasses in certain situations, e.g. seabird breeding colonies, may reduce virus spread and subsequent mortality of wild birds during the current HPAI outbreak.

* Testing for avian influenza virus should be strongly considered in wild and farmed mammals showing neurological symptoms but also respiratory symptoms, particularly in highly susceptible species for influenza virus, in high risk period and high risk areas, when increased mortality is observed, e.g. at mink farms.

* Surveillance in mammals and humans that could potentially be exposed to infected birds should be strengthened to facilitate the early detection of virus transmission events from birds to wild
* The risk of transmission to humans by exposure to contaminated poultry products is considered negligible as also outlined in a previous EFSA assessment (EFSA AHAW Panel, 2017).

* In contrast to previous epidemiological years, there was no clear start of the HPAI epidemic in October in the epidemiological year 2022-2023, neither in wild nor in domestic birds. This is due to the persistence of the virus in wild birds along the summer months and indicates a continuous risk for HPAI virus to spread among wild birds and mammals, as well as for virus entry into poultry establishments.

* From the previous reporting period (June-September) to the current reporting period (September-December), waterfowl replaced colony-breeding seabirds as the main wild birds in which HPAI virus detection was reported. This switch is likely due to a combination of the post-breeding dispersal of colony-breeding seabirds after their breeding periods in the summer, and the increased number of waterfowl present in Europe as a result of autumn migration. It cannot be excluded that these waterfowl will be at higher risk of HPAI virus infection than in previous years due to the observed persistence of HPAI virus in wild birds in Europe.

* The shape of the epidemic curve in poultry in 2021-2022 resembled that in waterfowl, but not that in seabirds (Figure 5C). This suggests that waterfowl might be more involved than seabirds in the incursion of HPAI virus into poultry establishments, likely because the habitat of waterfowl is more likely to overlap with the location of poultry establishments than seabird colony sites.

* The biosecurity measures implemented along the poultry production chain do not seem effective in preventing all introductions of the HPAI A(H5N1) virus into poultry establishments. In the coming months, the sustained and increasing infection pressure on poultry establishments will further challenge the effectiveness of the applied biosecurity measures.

* The prolonged avian influenza risk period represents a challenge for the sustainability of the reinforced biosecurity measures implemented along the poultry chain in high-risk areas or production sectors. The persistent presence of HPAI A(H5) viruses in wild birds and in the environment and the continuous occurrence of primary outbreaks in several countries, and the possible reduction of biosecurity compliance might increase the risk of avian influenza incursions with the potential further spread between establishments, primarily in areas with high poultry densities.

### 3. Options for response

* Considering the significant negative impact of these HPAI epidemics in the last years, and the ongoing HPAI risk posed by the sustained virus circulation in wild birds, short-term preparedness and medium- and long-term prevention strategies should be identified and implemented, primarily in densely populated poultry areas and poultry production systems that are highly susceptible to avian influenza exposure. These have been described in detail in the Avian influenza overview September - December 2021 (EFSA et al., 2021).

* Given the substantial mortality of wild birds associated with the detection of HPAI A(H5) virus, it is important for the relevant authorities to enhance the surveillance and to ensure accurate documentation of the number of wild birds dead or ill during these HPAI-associated die-offs. Such information would enhance understanding of these phenomena and provides a factual basis for assessing the ecological impact and coming up with policy decisions to avert future HPAI outbreaks not only in poultry and humans but also in wild birds, both migratory and resident. On the short-term, timely removal of wild bird carcasses in certain situations, e.g. seabird breeding colonies, may reduce virus spread and subsequent mortality of wild birds during the current HPAI outbreak.

* Testing for avian influenza virus should be strongly considered in wild and farmed mammals showing neurological symptoms but also respiratory symptoms, particularly in highly susceptible species for influenza virus, in high risk period and high risk areas, when increased mortality is observed, e.g. at mink farms.

* Surveillance in mammals and humans that could potentially be exposed to infected birds should be strengthened to facilitate the early detection of virus transmission events from birds to wild
or domestic mammals and/or humans, and subsequently between humans. Cross-sectoral cooperation and communication between animal and public health and occupational safety and health (OSH) authorities are recommended (One Health approach) to initiate rapid response, follow-up, and control measures. Especially, the inclusion of avian influenza viruses in the differential diagnosis of neurological disease in wild mammals as well as in humans with exposure to potentially infected birds needs to be more widely implemented.

* Occupational health and safety measures should be set according to national legislation. Health surveillance should be offered according to national requirements (please refer to Section 4.7.1 for more detail).

* People potentially exposed to infected poultry or captive birds, for example during culling operations, or workers in close contact to potentially infected mammals such as foxes or other wildlife, for example at rehabilitation centres, should be adequately protected and actively monitored or at least self-monitor for respiratory symptoms, neurological symptoms or conjunctivitis for at least 10 days following exposure, and immediately inform the local health and occupational safety and health authorities and preventive services to initiate testing and follow-up in case of symptoms. Antiviral pre-exposure or post-exposure prophylaxis should be considered for exposed people according to national recommendations.

* Reference viruses and sera against avian influenza reference viruses need to be developed, constantly updated and provided to the countries to investigate transmission events from animals to humans and to confirm serological evidence of infections with a zoonotic virus.

* Timely generation and sharing of complete viral genome sequences from wild birds, poultry, captive birds and mammals are crucial to promptly detect the emergence in or introduction into the EU of viruses relevant for animal and public health. More efforts should be made by reporting countries to monitor and genetically characterise a significant number of samples based on the size, duration, and relevant features of the epidemic in each country or of subtypes of concern for public health.

* Should avian influenza outbreaks in mammalian species involve multiple animals, the genetic characterization of several samples obtained from diverse animals is of utmost importance to shed light on the virus origin, evolution and possible transmission among individuals.

# 4. Results

## 4.1. Overview of HPAI outbreaks in Europe during the previous and current seasons

Figures 1, 2 and 3 show the HPAI outbreaks in domestic birds (poultry and captive birds) and HPAI virus detections in wild birds that were reported in Europe via ADIS or WOAH-WAHIS for the epidemiological years 2016–2017, 2017–2018, 2018–2019, 2019–2020, 2020–2021, 2021–2022 and 2022–2023 by month of suspicion (Figures 1 and 2) and geographical location (Figure 3). In this document an ‘epidemiological year’ refers to the period starting on week 40 (the beginning of October) and ending on week 39 (the end of September) of the following year, based on the dates on which the first HPAI virus detections were observed in wild birds in Europe in 2016–2017, 2020–2021 and 2021–2022. For the current epidemiological year 2022–2023 that starts on 1 October 2022, data reported are truncated on 2 December 2022. An overview of the epidemiological year 2021–2022, in which before this epidemiological year the largest HPAI epidemic was recorded in the EU/EEA and United Kingdom in terms of number of poultry outbreaks, geographical spread and number of dead wild birds and that conventionally ended on 30 September 2022 is given in Table 1. Figure 4 shows the comparison between the monthly geographical distribution of HPAI virus detections from September to December 2022 and the same period during the 2021–2022 epidemiological year.

The analysis of the characteristics of the previous 2020–2021, 2021–2022 and current 2022–2023 avian influenza epidemiological years, from October 2020 to 2 December 2022, is reported in Figure 5 by week of suspicion, virus subtype and host population. On poultry, the information reported in Figure 5b
or domestic mammals and/or humans, and subsequently between humans. Cross-sectoral cooperation and communication between animal and public health and occupational safety and health (OSH) authorities are recommended (One Health approach) to initiate rapid response, follow-up, and control measures. Especially, the inclusion of avian influenza viruses in the differential diagnosis of neurological disease in wild mammals as well as in humans with exposure to potentially infected birds needs to be more widely implemented.

* Occupational health and safety measures should be set according to national legislation. Health surveillance should be offered according to national requirements (please refer to Section 4.7.1 for more detail).

* People potentially exposed to infected poultry or captive birds, for example during culling operations, or workers in close contact to potentially infected mammals such as foxes or other wildlife, for example at rehabilitation centres, should be adequately protected and actively monitored or at least self-monitor for respiratory symptoms, neurological symptoms or conjunctivitis for at least 10 days following exposure, and immediately inform the local health and occupational safety and health authorities and preventive services to initiate testing and follow-up in case of symptoms. Antiviral pre-exposure or post-exposure prophylaxis should be considered for exposed people according to national recommendations.

* Reference viruses and sera against avian influenza reference viruses need to be developed, constantly updated and provided to the countries to investigate transmission events from animals to humans and to confirm serological evidence of infections with a zoonotic virus.

* Timely generation and sharing of complete viral genome sequences from wild birds, poultry, captive birds and mammals are crucial to promptly detect the emergence in or introduction into the EU of viruses relevant for animal and public health. More efforts should be made by reporting countries to monitor and genetically characterise a significant number of samples based on the size, duration, and relevant features of the epidemic in each country or of subtypes of concern for public health.

* Should avian influenza outbreaks in mammalian species involve multiple animals, the genetic characterization of several samples obtained from diverse animals is of utmost importance to shed light on the virus origin, evolution and possible transmission among individuals.

# 4. Results

## 4.1. Overview of HPAI outbreaks in Europe during the previous and current seasons

Figures 1, 2 and 3 show the HPAI outbreaks in domestic birds (poultry and captive birds) and HPAI virus detections in wild birds that were reported in Europe via ADIS or WOAH-WAHIS for the epidemiological years 2016–2017, 2017–2018, 2018–2019, 2019–2020, 2020–2021, 2021–2022 and 2022–2023 by month of suspicion (Figures 1 and 2) and geographical location (Figure 3). In this document an ‘epidemiological year’ refers to the period starting on week 40 (the beginning of October) and ending on week 39 (the end of September) of the following year, based on the dates on which the first HPAI virus detections were observed in wild birds in Europe in 2016–2017, 2020–2021 and 2021–2022. For the current epidemiological year 2022–2023 that starts on 1 October 2022, data reported are truncated on 2 December 2022. An overview of the epidemiological year 2021–2022, in which before this epidemiological year the largest HPAI epidemic was recorded in the EU/EEA and United Kingdom in terms of number of poultry outbreaks, geographical spread and number of dead wild birds and that conventionally ended on 30 September 2022 is given in Table 1. Figure 4 shows the comparison between the monthly geographical distribution of HPAI virus detections from September to December 2022 and the same period during the 2021–2022 epidemiological year.

The analysis of the characteristics of the previous 2020–2021, 2021–2022 and current 2022–2023 avian influenza epidemiological years, from October 2020 to 2 December 2022, is reported in Figure 5 by week of suspicion, virus subtype and host population. On poultry, the information reported in Figure 5b
have been collected from the affected countries up to outbreaks occurred by 18 November 2022; the outbreaks that occurred later were too close to the publishing of this report to collect the data, therefore, for those poultry outbreaks the information presented in Figure 5b was unknown at the time of publication and will be included in the next report.

The start of the HPAI epidemics in the 2016–2017, 2020–2021, and 2021–2022 epidemiological years, all fell within the period between the end of September and beginning of October. There were no evident epidemics in 2017–2018 and 2018–2019, while the end of December 2019 was the start of the smaller 2019–2020 epidemic that affected only poultry (Figures 1 and 2).

In contrast to previous epidemiological years, there was no clear start of the HPAI epidemic in the epidemiological year 2022–2023 expected in October, in neither wild nor domestic birds (Figures 1 and 2). The previously interepidemic pause observed from June to September in 2020 and 2021, was absent in 2022 in wild birds, and restricted to June 2022 in domestic birds (Figure 2).

The HPAI epidemic observed in the 2021–2022 epidemiological year was so far the largest observed in Europe, with a total of 6,614 HPAI virus detections in 37 countries (Figure 1 and Table 1). This is 1.7 times more detections than in the 2020–2021 epidemiological year, and 2.4 times more detections than in the 2016–2017 epidemiological year. Regarding wild birds, the 3,867 detections in the 2021–2022 epidemiological year were 1.6 times more than in the 2020–2021 epidemiological year and 2.5 times more than in the 2016–2017 epidemiological year. Regarding poultry and captive birds, the 2,747 detections in the 2021–2022 epidemiological year were 2.0 times more than in the 2020–2021 epidemiological year and 2.3 times more than in the 2016–2017 epidemiological year (Figure 2). It should be noted that as captive birds also wild birds that are kept in captivity are included.

The higher numbers of HPAI virus detections reported in the 2021–2022 epidemiological year compared to the HPAI detections reported in the previous years can be assumed to reflect the higher level of virus circulation in wild birds, resulting in an increased risk of virus transmission from wild birds to poultry, and therefore in a higher number of primary introductions into poultry farms and higher risk of further farm-to-farm spread of HPAI virus.

The epidemic observed in the 2021–2022 epidemiological year was widespread in Europe, extending from Iceland, Ireland, and Portugal in the west to Finland, the Baltic states, Ukraine, Romania and Bulgaria to the east; from northern Norway (including the Norwegian islands Svalbard and Jan Mayen) to the north to southern Spain, Italy and Greece to the south. Compared to the 2020–2021 epidemiological year, HPAI virus detections in the 2021–2022 epidemiological year were reported further north, west and south, with a higher number of detections in both wild and domestic birds than in previous years; most of the virus detections were concentrated along the western coasts of continental Europe and in the British Isles.

In poultry, large epidemics in the 2021–2022 epidemiological year occurred in France (1,395 poultry outbreaks), Italy (318), and Hungary (290), but also United Kingdom (105), Poland (99), Germany (98) and the Netherlands (70) were severely affected (Table 1). After the two peaks of infection observed in winter 2021–2022 (Figure 2b), the number of poultry outbreaks decreased from April to June. From July onwards, however, a third minor peak of infection occurred and continued into the 2022–2023 epidemiological year peaking in October 2022. Since October 2022 HPAI poultry outbreaks have been also detected in inland areas in Hungary, Italy, Czechia, Serbia, Moldova, however in a lower number than those detected in the same period the previous year (Figure 4). Considering the period from 10 September to 2 December 2022, 35% more HPAI virus outbreaks were reported in poultry compared to those reported in the same period in the previous year (398 vs 294) and occurred primarily in the proximity to coastal areas (Figures 3c and Table 2). In wild birds, HPAI virus in the 2021–2022 epidemiological year was detected predominantly in waterfowl until the first half of April 2022. From the second half of April to the middle of August, HPAI virus was detected mainly in colony-breeding seabird species, a category of wild birds that were only affected at a low scale in previous years. The species included in this seabird category are provided in Appendix B, Table B.1. The high frequency of HPAI virus detections in colony-breeding seabird species lasted from May to August, with a peak in June; this roughly corresponds to the breeding season of seabirds in Europe. As a result, there was an unprecedented high level of HPAI virus detections in wild birds during the summer 2022, which was
have been collected from the affected countries up to outbreaks occurred by 18 November 2022; the outbreaks that occurred later were too close to the publishing of this report to collect the data, therefore, for those poultry outbreaks the information presented in Figure 5b was unknown at the time of publication and will be included in the next report.

The start of the HPAI epidemics in the 2016–2017, 2020–2021, and 2021–2022 epidemiological years, all fell within the period between the end of September and beginning of October. There were no evident epidemics in 2017–2018 and 2018–2019, while the end of December 2019 was the start of the smaller 2019–2020 epidemic that affected only poultry (Figures 1 and 2).

In contrast to previous epidemiological years, there was no clear start of the HPAI epidemic in the epidemiological year 2022–2023 expected in October, in neither wild nor domestic birds (Figures 1 and 2). The previously interepidemic pause observed from June to September in 2020 and 2021, was absent in 2022 in wild birds, and restricted to June 2022 in domestic birds (Figure 2).

The HPAI epidemic observed in the 2021–2022 epidemiological year was so far the largest observed in Europe, with a total of 6,614 HPAI virus detections in 37 countries (Figure 1 and Table 1). This is 1.7 times more detections than in the 2020–2021 epidemiological year, and 2.4 times more detections than in the 2016–2017 epidemiological year. Regarding wild birds, the 3,867 detections in the 2021–2022 epidemiological year were 1.6 times more than in the 2020–2021 epidemiological year and 2.5 times more than in the 2016–2017 epidemiological year. Regarding poultry and captive birds, the 2,747 detections in the 2021–2022 epidemiological year were 2.0 times more than in the 2020–2021 epidemiological year and 2.3 times more than in the 2016–2017 epidemiological year (Figure 2). It should be noted that as captive birds also wild birds that are kept in captivity are included.

The higher numbers of HPAI virus detections reported in the 2021–2022 epidemiological year compared to the HPAI detections reported in the previous years can be assumed to reflect the higher level of virus circulation in wild birds, resulting in an increased risk of virus transmission from wild birds to poultry, and therefore in a higher number of primary introductions into poultry farms and higher risk of further farm-to-farm spread of HPAI virus.

The epidemic observed in the 2021–2022 epidemiological year was widespread in Europe, extending from Iceland, Ireland, and Portugal in the west to Finland, the Baltic states, Ukraine, Romania and Bulgaria to the east; from northern Norway (including the Norwegian islands Svalbard and Jan Mayen) to the north to southern Spain, Italy and Greece to the south. Compared to the 2020–2021 epidemiological year, HPAI virus detections in the 2021–2022 epidemiological year were reported further north, west and south, with a higher number of detections in both wild and domestic birds than in previous years; most of the virus detections were concentrated along the western coasts of continental Europe and in the British Isles.

In poultry, large epidemics in the 2021–2022 epidemiological year occurred in France (1,395 poultry outbreaks), Italy (318), and Hungary (290), but also United Kingdom (105), Poland (99), Germany (98) and the Netherlands (70) were severely affected (Table 1). After the two peaks of infection observed in winter 2021–2022 (Figure 2b), the number of poultry outbreaks decreased from April to June. From July onwards, however, a third minor peak of infection occurred and continued into the 2022–2023 epidemiological year peaking in October 2022. Since October 2022 HPAI poultry outbreaks have been also detected in inland areas in Hungary, Italy, Czechia, Serbia, Moldova, however in a lower number than those detected in the same period the previous year (Figure 4). Considering the period from 10 September to 2 December 2022, 35% more HPAI virus outbreaks were reported in poultry compared to those reported in the same period in the previous year (398 vs 294) and occurred primarily in the proximity to coastal areas (Figures 3c and Table 2). In wild birds, HPAI virus in the 2021–2022 epidemiological year was detected predominantly in waterfowl until the first half of April 2022. From the second half of April to the middle of August, HPAI virus was detected mainly in colony-breeding seabird species, a category of wild birds that were only affected at a low scale in previous years. The species included in this seabird category are provided in Appendix B, Table B.1. The high frequency of HPAI virus detections in colony-breeding seabird species lasted from May to August, with a peak in June; this roughly corresponds to the breeding season of seabirds in Europe. As a result, there was an unprecedented high level of HPAI virus detections in wild birds during the summer 2022, which was
associated with an again unprecedented high number of HPAI virus detections in domestic birds during this period (Figure 5). From September to December 2022, the number of detections in seabirds continued to decline, while the number of detections in waterbirds started to increase, likely in association with the higher number of waterfowl arriving in Europe due to the autumn migration (Figure 5). Interestingly, the increase of the number of HPAI virus detections in waterfowl roughly corresponds to the increase in the number of poultry outbreaks (Figure 5c).

Considering only HPAI outbreaks in poultry, so far ~58.3 million of birds have been died or culled in the HPAI-affected establishments since October 2021.

Information on the HPAI virus detections that have been reported in Europe since October 2016 are available in a new interactive dashboard published by EFSA.

<figure><img src="image_4.png" /></figure>

Source: ADIS and WOAH (data extraction carried out on 2 December 2022).

**Figure 1:** Distribution of the number of HPAI virus detections reported in Europe in the epidemiological years 2016–2017, 2017–2018, 2018–2019, 2019–2020, 2020–2021, and 2021-2022 by month of suspicion, from 1 October 2016 to 2 December 2022 (14,629)

<footnote>*When the date of suspicion is not available then the date of confirmation is used to assign the week of suspicion.
United Kingdom data are from ADNS up to 31 December 2020. From 1 January 2021 onwards, the data source was the World
Animal Health Information System (WOAH-WAHIS) for United Kingdom (excluding Northern Ireland), and ADNS/ADIS for the
United Kingdom (Northern Ireland)⁴.</footnote>

<footnote n="4">⁴ In accordance with the Agreement on the Withdrawal of the United Kingdom from the EU, and in particular with the Protocol on IE/NI, the EU requirements on data sampling are also applicable to the United Kingdom (Northern Ireland).</footnote>
associated with an again unprecedented high number of HPAI virus detections in domestic birds during this period (Figure 5). From September to December 2022, the number of detections in seabirds continued to decline, while the number of detections in waterbirds started to increase, likely in association with the higher number of waterfowl arriving in Europe due to the autumn migration (Figure 5). Interestingly, the increase of the number of HPAI virus detections in waterfowl roughly corresponds to the increase in the number of poultry outbreaks (Figure 5c).

Considering only HPAI outbreaks in poultry, so far ~58.3 million of birds have been died or culled in the HPAI-affected establishments since October 2021.

Information on the HPAI virus detections that have been reported in Europe since October 2016 are available in a new interactive dashboard published by EFSA.

<figure><img src="image_4.png" /></figure>

Source: ADIS and WOAH (data extraction carried out on 2 December 2022).

**Figure 1:** Distribution of the number of HPAI virus detections reported in Europe in the epidemiological years 2016–2017, 2017–2018, 2018–2019, 2019–2020, 2020–2021, and 2021-2022 by month of suspicion, from 1 October 2016 to 2 December 2022 (14,629)

<footnote>*When the date of suspicion is not available then the date of confirmation is used to assign the week of suspicion.
United Kingdom data are from ADNS up to 31 December 2020. From 1 January 2021 onwards, the data source was the World Animal Health Information System (WOAH-WAHIS) for United Kingdom (excluding Northern Ireland), and ADNS/ADIS for the United Kingdom (Northern Ireland)⁴.</footnote>

<footnote n="4">⁴ In accordance with the Agreement on the Withdrawal of the United Kingdom from the EU, and in particular with the Protocol on IE/NI, the EU requirements on data sampling are also applicable to the United Kingdom (Northern Ireland).</footnote>
<figure><img src="image_5.png" /></figure>

*When the date of suspicion is not available then the date of confirmation is used to assign the week of suspicion.
United Kingdom data are from ADNS up to 31 December 2020. From 1 January 2021 onwards, the data source was the World Animal Health Information System (WOAH-WAHIS) for United Kingdom (excluding Northern Ireland), and ADNS/ADIS for the United Kingdom (Northern Ireland)⁴.

Source: ADIS and WOAH (data extraction carried out on 2 December 2022).

Note that the scale of the vertical axes is specific to each bird population.

**Figure 2:** Distribution of number of HPAI virus detections reported in Europe in the epidemiological years 2016–2017, 2017–2018, 2018–2019, 2019–2020, 2020–2021 and 2021–2022 by month of suspicion in (a) wild birds (8,389) and (b) domestic birds (poultry and captive birds) (6,240), from 1 October 2016 to 2 December 2022
<figure><img src="image_5.png" /></figure>

*When the date of suspicion is not available then the date of confirmation is used to assign the week of suspicion.
United Kingdom data are from ADNS up to 31 December 2020. From 1 January 2021 onwards, the data source was the World Animal Health Information System (WOAH-WAHIS) for United Kingdom (excluding Northern Ireland), and ADNS/ADIS for the United Kingdom (Northern Ireland)⁴.

Source: ADIS and WOAH (data extraction carried out on 2 December 2022).

Note that the scale of the vertical axes is specific to each bird population.

**Figure 2:** Distribution of number of HPAI virus detections reported in Europe in the epidemiological years 2016–2017, 2017–2018, 2018–2019, 2019–2020, 2020–2021 and 2021–2022 by month of suspicion in (a) wild birds (8,389) and (b) domestic birds (poultry and captive birds) (6,240), from 1 October 2016 to 2 December 2022
<figure><img src="image_6.png" /></figure>

United Kingdom data are from ADNS up to 31 December 2020. From 1 January 2021 onwards, the data source was the World Animal Health Information System (WOAH-WAHIS) for United Kingdom (excluding Northern Ireland), and ADNS/ADIS for the United Kingdom (Northern Ireland)⁴.

Source: ADIS and WOAH (data extraction carried out on 2 December 2022).

**Figure 3:** Geographical distribution at NUTS3 level of HPAI detections in Europe in the epidemiological years (a) 2020-2021 (3,791), (b) 2021-2022 (6,614) and (c) 2022 - 2023 (922) in domestic birds (red circles) and wild birds (grey coloured area), from 1 October 2020 to 2 December 2022. An epidemiological year refers to the period starting on 1 October and ending on 30 September of the following year.
<figure><img src="image_6.png" /></figure>

United Kingdom data are from ADNS up to 31 December 2020. From 1 January 2021 onwards, the data source was the World Animal Health Information System (WOAH-WAHIS) for United Kingdom (excluding Northern Ireland), and ADNS/ADIS for the United Kingdom (Northern Ireland)⁴.

Source: ADIS and WOAH (data extraction carried out on 2 December 2022).

**Figure 3:** Geographical distribution at NUTS3 level of HPAI detections in Europe in the epidemiological years (a) 2020-2021 (3,791), (b) 2021-2022 (6,614) and (c) 2022 - 2023 (922) in domestic birds (red circles) and wild birds (grey coloured area), from 1 October 2020 to 2 December 2022. An epidemiological year refers to the period starting on 1 October and ending on 30 September of the following year.
<figure><img src="image_7.png" /></figure>

One poultry and one captive birds outbreaks reported by France occurred in La Reunion, therefore they are not displayed in the maps. United Kingdom data are from ADNS up to 31 December 2020. From 1 January 2021 onwards, the data source was the World Animal Health Information System (WOAH-WAHIS) for United Kingdom (excluding Northern Ireland), and ADNS/ADIS for the United Kingdom (Northern Ireland)⁴. Note that data in December 2022 are up to 2 December. Source: ADIS and WOAH (data extraction carried out on 2 December 2022).

<caption>**Figure 4:** Geographical distribution, based on available geocoordinates, of HPAI virus detections in Europe by month of suspicion from September to December in 2021 (upper row) and 2022 (bottom row)</caption>
<figure><img src="image_7.png" /></figure>

One poultry and one captive birds outbreaks reported by France occurred in La Reunion, therefore they are not displayed in the maps. United Kingdom data are from ADNS up to 31 December 2020. From 1 January 2021 onwards, the data source was the World Animal Health Information System (WOAH-WAHIS) for United Kingdom (excluding Northern Ireland), and ADNS/ADIS for the United Kingdom (Northern Ireland)⁴. Note that data in December 2022 are up to 2 December. Source: ADIS and WOAH (data extraction carried out on 2 December 2022).

<caption>**Figure 4:** Geographical distribution, based on available geocoordinates, of HPAI virus detections in Europe by month of suspicion from September to December in 2021 (upper row) and 2022 (bottom row)</caption>
<figure><img src="image_8.png" /></figure>

**Figure 5:** Distribution of total number of HPAI virus detections reported in Europe by week of suspicion (dates indicate the first day of the week) and (a) virus subtype (11,328), (b) affected poultry categories (4,166), (c) affected wild bird categories (6,799), from October 2020 to 2 December 2022

<footnote>*When the date of suspicion is not available then the date of confirmation is used to assign the week of suspicion.</footnote>

<footnote>**Other domestic species' category contains mixed, unknown bird species, or categories different from those displayed (e.g. guinea fowl, peacock, pheasant and quail).</footnote>

<footnote>***Other wild species' category contains unknown bird species, or categories different from those displayed. The complete list of species by each wild bird category is reported in Table B.1 in Annex B.</footnote>

<footnote>United Kingdom data are from ADNS up to 31 December 2020. From 1 January 2021 onwards, the data source was the World Animal Health Information System (WOAH-WAHIS) for United Kingdom (excluding Northern Ireland), and ADNS/ADIS for the United Kingdom (Northern Ireland)⁴.</footnote>

<footnote>Source: ADNS, ADIS and WOAH (data extraction carried out on 2 December 2022), EFSA.</footnote>

<footnote>Note that the information reported in panel (b) have been collected from the affected countries up to outbreaks occurred by 18 November 2022; the outbreaks that occurred later were too close to the publishing of this report to collect the data, therefore, for those poultry outbreaks the information presented was unknown at the time of publication and will be included in the next report.</footnote>

<footnote>Note that the scale of the vertical axes is specific to each category and that the unit reported in panel (c) on wild birds is the number of HPAI detection in different wild bird species and not the number of HPAI detections in wild birds (as more than one species can be involved in one single HPAI reported detection).</footnote>
<figure><img src="image_8.png" /></figure>

Source: ADNS, ADIS and WOAH (data extraction carried out on 2 December 2022), EFSA.

Note that the information reported in panel (b) have been collected from the affected countries up to outbreaks occurred by 18 November 2022; the outbreaks that occurred later were too close to the publishing of this report to collect the data, therefore, for those poultry outbreaks the information presented was unknown at the time of publication and will be included in the next report.

Note that the scale of the vertical axes is specific to each category and that the unit reported in panel (c) on wild birds is the number of HPAI detection in different wild bird species and not the number of HPAI detections in wild birds (as more than one species can be involved in one single HPAI reported detection).

**Figure 5:** Distribution of total number of HPAI virus detections reported in Europe by week of suspicion (dates indicate the first day of the week) and (a) virus subtype (11,328), (b) affected poultry categories (4,166), (c) affected wild bird categories (6,799), from October 2020 to 2 December 2022

<footnote>*When the date of suspicion is not available then the date of confirmation is used to assign the week of suspicion.</footnote>

<footnote>**Other domestic species' category contains mixed, unknown bird species, or categories different from those displayed (e.g. guinea fowl, peacock, pheasant and quail).</footnote>

<footnote>***Other wild species' category contains unknown bird species, or categories different from those displayed. The complete list of species by each wild bird category is reported in Table B.1 in Annex B.</footnote>

<footnote>United Kingdom data are from ADNS up to 31 December 2020. From 1 January 2021 onwards, the data source was the World Animal Health Information System (WOAH-WAHIS) for United Kingdom (excluding Northern Ireland), and ADNS/ADIS for the United Kingdom (Northern Ireland)⁴.</footnote>
<table><caption>**Table 1:** Number of highly pathogenic avian influenza outbreaks in Europe, by country, virus subtype and affected sub-population in the epidemiological year 2021-2022 (from 1 October 2021 to 30 September 2022)</caption><thead><tr><th rowspan="2">Country</th><th colspan="2">Captive Birds (227)</th><th colspan="2">Poultry (2,520)</th><th colspan="8">Wild Birds (3,867)</th><th rowspan="2">Total</th></tr><tr><th>A(H5Nx)</th><th>A(H5N1)</th><th>A(H5N1)</th><th>A(H5N2)</th><th>A(H5N8)</th><th>A(H5Nx)</th><th>A(H5Nx)</th><th>A(H5N1)</th><th>A(H5N2)</th><th>A(H5N5)</th><th>A(H5N8)</th></tr></thead><tbody><tr><td>Albania</td><td></td><td>1</td><td></td><td></td><td>6</td><td></td><td></td><td>1</td><td></td><td></td><td></td><td>8</td></tr><tr><td>Austria</td><td></td><td>4</td><td></td><td></td><td></td><td></td><td></td><td>27</td><td></td><td></td><td></td><td>31</td></tr><tr><td>Belgium</td><td></td><td>7</td><td>7</td><td></td><td></td><td></td><td>6</td><td>134</td><td></td><td></td><td></td><td>154</td></tr><tr><td>Bosnia and Herzegovina</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td><td></td><td></td><td></td><td>1</td></tr><tr><td>Bulgaria</td><td>1</td><td>2</td><td>16</td><td></td><td></td><td>9</td><td>2</td><td></td><td></td><td></td><td></td><td>30</td></tr><tr><td>Croatia</td><td></td><td></td><td>3</td><td></td><td></td><td></td><td></td><td>13</td><td></td><td></td><td></td><td>16</td></tr><tr><td>Czechia</td><td></td><td></td><td>19</td><td></td><td></td><td></td><td></td><td>9</td><td></td><td></td><td></td><td>28</td></tr><tr><td>Denmark</td><td></td><td>4</td><td>6</td><td></td><td>1</td><td></td><td>1</td><td>164</td><td></td><td></td><td>2</td><td>178</td></tr><tr><td>Estonia</td><td></td><td></td><td></td><td></td><td>1</td><td></td><td></td><td>9</td><td></td><td></td><td></td><td>10</td></tr><tr><td>Finland</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>29</td><td></td><td>1</td><td>1</td><td>31</td></tr><tr><td>France</td><td>3</td><td>64</td><td>1,248</td><td></td><td></td><td>147</td><td>5</td><td>252</td><td></td><td></td><td></td><td>1,719</td></tr><tr><td>Germany</td><td></td><td>10</td><td>98</td><td></td><td></td><td></td><td>13</td><td>1,504</td><td>2</td><td></td><td>1</td><td>1,628</td></tr><tr><td>Greece</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>16</td><td></td><td></td><td></td><td>16</td></tr><tr><td>Hungary</td><td></td><td>4</td><td>290</td><td></td><td></td><td></td><td>1</td><td>28</td><td></td><td></td><td></td><td>323</td></tr><tr><td>Iceland</td><td></td><td></td><td>1</td><td></td><td></td><td></td><td></td><td>32</td><td></td><td></td><td></td><td>33</td></tr><tr><td>Ireland</td><td></td><td></td><td>6</td><td></td><td></td><td></td><td>2</td><td>83</td><td></td><td></td><td></td><td>91</td></tr><tr><td>Italy</td><td></td><td>1</td><td>314</td><td></td><td></td><td>4</td><td></td><td>23</td><td></td><td></td><td></td><td>342</td></tr><tr><td>Kosovo<sup>(a)</sup></td><td></td><td></td><td></td><td></td><td>3</td><td></td><td></td><td></td><td></td><td></td><td></td><td>3</td></tr><tr><td>Latvia</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>2</td><td></td><td></td><td></td><td>2</td></tr><tr><td>Lithuania</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>11</td><td></td><td></td><td></td><td>11</td></tr><tr><td>Luxembourg</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>5</td><td></td><td></td><td></td><td>5</td></tr><tr><td>Moldova</td><td></td><td></td><td>4</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>4</td></tr><tr><td>Montenegro</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td><td></td><td></td><td></td><td>1</td></tr><tr><td>Netherlands</td><td></td><td>21</td><td>70</td><td></td><td></td><td></td><td>38</td><td>695</td><td></td><td>2</td><td></td><td>826</td></tr><tr><td>North Macedonia</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>3</td><td></td><td></td><td></td><td>3</td></tr><tr><td>Norway</td><td></td><td></td><td>2</td><td></td><td></td><td></td><td>17</td><td>42</td><td></td><td>20</td><td></td><td>81</td></tr><tr><td>Poland</td><td></td><td></td><td>98</td><td>1</td><td></td><td></td><td></td><td>36</td><td></td><td></td><td></td><td>135</td></tr><tr><td>Portugal</td><td></td><td>8</td><td>11</td><td></td><td></td><td></td><td></td><td>12</td><td></td><td></td><td></td><td>31</td></tr><tr><td>Romania</td><td></td><td></td><td>3</td><td></td><td></td><td></td><td>1</td><td>15</td><td></td><td></td><td></td><td>19</td></tr><tr><td>Serbia</td><td></td><td></td><td>3</td><td></td><td></td><td></td><td></td><td>4</td><td></td><td></td><td></td><td>7</td></tr><tr><td>Slovakia</td><td></td><td>2</td><td>4</td><td></td><td></td><td></td><td>1</td><td>6</td><td></td><td></td><td></td><td>13</td></tr><tr><td>Slovenia</td><td></td><td>37</td><td>1</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>38</td></tr><tr><td>Spain</td><td></td><td>3</td><td>36</td><td></td><td></td><td></td><td>4</td><td>114</td><td></td><td></td><td></td><td>157</td></tr></tbody></table>
<table><caption>**Table 1:** Number of highly pathogenic avian influenza outbreaks in Europe, by country, virus subtype and affected sub-population in the epidemiological year 2021-2022 (from 1 October 2021 to 30 September 2022)</caption><thead><tr><th rowspan="2">Country</th><th colspan="2">Captive Birds (227)</th><th colspan="2">Poultry (2,520)</th><th colspan="8">Wild Birds (3,867)</th><th rowspan="2">Total</th></tr><tr><th>A(H5Nx)</th><th>A(H5N1)</th><th>A(H5N1)</th><th>A(H5N2)</th><th>A(H5N8)</th><th>A(H5Nx)</th><th>A(H5Nx)</th><th>A(H5N1)</th><th>A(H5N2)</th><th>A(H5N5)</th><th>A(H5N8)</th></tr></thead><tbody><tr><td>Albania</td><td></td><td>1</td><td></td><td></td><td>6</td><td></td><td></td><td>1</td><td></td><td></td><td></td><td>8</td></tr><tr><td>Austria</td><td></td><td>4</td><td></td><td></td><td></td><td></td><td></td><td>27</td><td></td><td></td><td></td><td>31</td></tr><tr><td>Belgium</td><td></td><td>7</td><td>7</td><td></td><td></td><td></td><td>6</td><td>134</td><td></td><td></td><td></td><td>154</td></tr><tr><td>Bosnia and Herzegovina</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td><td></td><td></td><td></td><td>1</td></tr><tr><td>Bulgaria</td><td>1</td><td>2</td><td>16</td><td></td><td></td><td>9</td><td>2</td><td></td><td></td><td></td><td></td><td>30</td></tr><tr><td>Croatia</td><td></td><td></td><td>3</td><td></td><td></td><td></td><td></td><td>13</td><td></td><td></td><td></td><td>16</td></tr><tr><td>Czechia</td><td></td><td></td><td>19</td><td></td><td></td><td></td><td></td><td>9</td><td></td><td></td><td></td><td>28</td></tr><tr><td>Denmark</td><td></td><td>4</td><td>6</td><td></td><td>1</td><td></td><td>1</td><td>164</td><td></td><td></td><td>2</td><td>178</td></tr><tr><td>Estonia</td><td></td><td></td><td></td><td></td><td>1</td><td></td><td></td><td>9</td><td></td><td></td><td></td><td>10</td></tr><tr><td>Finland</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>29</td><td></td><td>1</td><td>1</td><td>31</td></tr><tr><td>France</td><td>3</td><td>64</td><td>1,248</td><td></td><td></td><td>147</td><td>5</td><td>252</td><td></td><td></td><td></td><td>1,719</td></tr><tr><td>Germany</td><td></td><td>10</td><td>98</td><td></td><td></td><td></td><td>13</td><td>1,504</td><td>2</td><td></td><td>1</td><td>1,628</td></tr><tr><td>Greece</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>16</td><td></td><td></td><td></td><td>16</td></tr><tr><td>Hungary</td><td></td><td>4</td><td>290</td><td></td><td></td><td></td><td>1</td><td>28</td><td></td><td></td><td></td><td>323</td></tr><tr><td>Iceland</td><td></td><td></td><td>1</td><td></td><td></td><td></td><td></td><td>32</td><td></td><td></td><td></td><td>33</td></tr><tr><td>Ireland</td><td></td><td></td><td>6</td><td></td><td></td><td></td><td>2</td><td>83</td><td></td><td></td><td></td><td>91</td></tr><tr><td>Italy</td><td></td><td>1</td><td>314</td><td></td><td></td><td>4</td><td></td><td>23</td><td></td><td></td><td></td><td>342</td></tr><tr><td>Kosovo<sup>(a)</sup></td><td></td><td></td><td></td><td></td><td>3</td><td></td><td></td><td></td><td></td><td></td><td></td><td>3</td></tr><tr><td>Latvia</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>2</td><td></td><td></td><td></td><td>2</td></tr><tr><td>Lithuania</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>11</td><td></td><td></td><td></td><td>11</td></tr><tr><td>Luxembourg</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>5</td><td></td><td></td><td></td><td>5</td></tr><tr><td>Moldova</td><td></td><td></td><td>4</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>4</td></tr><tr><td>Montenegro</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>1</td><td></td><td></td><td></td><td>1</td></tr><tr><td>Netherlands</td><td></td><td>21</td><td>70</td><td></td><td></td><td></td><td>38</td><td>695</td><td></td><td>2</td><td></td><td>826</td></tr><tr><td>North Macedonia</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>3</td><td></td><td></td><td></td><td>3</td></tr><tr><td>Norway</td><td></td><td></td><td>2</td><td></td><td></td><td></td><td>17</td><td>42</td><td></td><td>20</td><td></td><td>81</td></tr><tr><td>Poland</td><td></td><td></td><td>98</td><td>1</td><td></td><td></td><td></td><td>36</td><td></td><td></td><td></td><td>135</td></tr><tr><td>Portugal</td><td></td><td>8</td><td>11</td><td></td><td></td><td></td><td></td><td>12</td><td></td><td></td><td></td><td>31</td></tr><tr><td>Romania</td><td></td><td></td><td>3</td><td></td><td></td><td></td><td>1</td><td>15</td><td></td><td></td><td></td><td>19</td></tr><tr><td>Serbia</td><td></td><td></td><td>3</td><td></td><td></td><td></td><td></td><td>4</td><td></td><td></td><td></td><td>7</td></tr><tr><td>Slovakia</td><td></td><td>2</td><td>4</td><td></td><td></td><td></td><td>1</td><td>6</td><td></td><td></td><td></td><td>13</td></tr><tr><td>Slovenia</td><td></td><td>37</td><td>1</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>38</td></tr><tr><td>Spain</td><td></td><td>3</td><td>36</td><td></td><td></td><td></td><td>4</td><td>114</td><td></td><td></td><td></td><td>157</td></tr></tbody></table>
<table><tr><td>Sweden</td><td></td><td>4</td><td>3</td><td></td><td></td><td></td><td>79</td><td></td><td>1</td><td>87</td></tr><tr><td>Switzerland</td><td></td><td>2</td><td></td><td></td><td></td><td></td><td>1</td><td></td><td></td><td>3</td></tr><tr><td>Ukraine</td><td>2</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>2</td></tr><tr><td>United Kingdom<sup>(b)</sup></td><td></td><td>47</td><td>105</td><td></td><td></td><td></td><td>394</td><td></td><td>1</td><td>547</td></tr><tr><td>Total</td><td>6</td><td>221</td><td>2,348</td><td>1</td><td>11</td><td>160</td><td>91</td><td>3,745</td><td>2</td><td>21</td><td>8</td><td>6,614</td></tr></table>

(a): This designation is without prejudice to positions on status and is in line with United Nations Security Council Resolution 1244 and the International Court of Justice Opinion on the Kosovo Declaration of Independence.

(b): United Kingdom data are from ADNS up to 31 December 2020. From 1 January 2021 onwards, the data source was the World Animal Health Information System (WOAH-WAHIS) for United Kingdom (excluding Northern Ireland), and ADNS/ADIS for United Kingdom (Northern Ireland)⁴.

`-`: means that no HPAI outbreaks or detections were notified to ADIS or WOAH.

Source: EFSA, ADNS and WOAH (data extraction carried out on 2 December 2022).
## 4.2. HPAI and LPAI detections in Europe, 10 September to 2 December 2022 (ToR 1 and ToR 2)

### 4.2.1. HPAI detections in poultry, other captive birds and wild birds

From 10 September to 2 December 2022, 1,162 HPAI A(H5) virus detections were notified in poultry (398), captive (151) and wild birds (613) to the ADIS or WOAH-WAHIS, as presented in Table 2. The timelines, virus subtypes, locations and the affected bird categories of the HPAI virus detections are presented in Figures 6, 7 and 8. The reported HPAI virus detections and outbreaks were distributed all over the reporting period and occurred in 16 European countries (Figure 6).

For wild birds, the highest number of HPAI virus reported detections were in the United Kingdom (160 detections), the Netherlands (97), Germany (86), France (62), Belgium (59), Spain (46), Italy (35) and Denmark (20) (Figure 7A and Table 2). Most of the HPAI virus detections were reported in waterbirds (371), followed by colony-breeding seabirds (109). This contrasts with the previous reporting period, when detections in seabirds predominated. This switch probably is associated on the one hand with the post-breeding dispersal of seabirds from their colony sites, and on the other hand with the increased numbers of waterbirds in Europe due to autumn migration. The geographical distribution of HPAI virus detections in wild birds was more limited than in the previous reporting period and was concentrated along the North Sea and Atlantic coasts of continental Europe from Denmark to Spain, as well as the UK and northern Italy. In domestic birds, HPAI virus outbreaks occurred primarily in north-west Europe (Germany, the Netherlands, Belgium, the United Kingdom and France), and were mainly distributed along the Atlantic coastal areas, following the distribution of the HPAI events in wild birds, except for outbreaks in Italy and Hungary. For poultry, Germany, the Netherlands, Belgium, UK and France accounted together for 86% of the reported HPAI outbreaks. In total, 83 poultry outbreaks were notified to the ADIS as secondary mainly in Hungary (64 out of 69 poultry outbreaks), but also in France (10 out of 98) Germany (8 out of 42) and Belgium (1 out of 8).

Overall, 9.8 million birds died or were culled in the HPAI poultry establishments with the UK accounting for 42% of the birds died or culled in the affected establishments during this reporting period, followed by the Netherlands (18%) and France (14%).

Characterisation of HPAI-affected poultry establishments<fnref n="5" /> is reported in Section 4.2.1.1; the description of the HPAI detections in wild birds is reported in Section 4.2.1.2.

HPAI A(H5N1) continues to be far the predominant virus type reported, with few exceptions for A(H5N5) virus detected in Norway and Finland in wild birds (3) and non-typed HPAI A(H5Nx) in Belgium (1), Bulgaria (1), France (1) and Germany (1) (Table 2).

Since 2 December and as of 16 December 2022, 249 HPAI outbreaks were confirmed in poultry (126), captive (66) and wild birds (57) outside the reporting period for this report in France (99), Germany (74), the Netherlands (19), Hungary (18), Poland (9), Belgium (8), Czechia (5), Denmark (4), Italy (3), Sweden (3), Romania (2), the United Kingdom<fnref n="6" /> (2), Luxemburg, Ireland and Switzerland (1 each). Those HPAI outbreaks were too close to the publication date to be described in this report and will be fully reported in the next report.

<footnote n="5">⁵ According to Regulation (EU) 2016/429 'establishment' means any premises, structure, or, in the case of open-air farming, any environment or place, where animals or germinal products are kept, on a temporary or permanent basis, except for: (a) households where pet animals are kept; (b) veterinary practices or clinics. Regulation (EU) 2016/429 of the European Parliament and of the Council of 9 March 2016 on transmissible animal diseases and amending and repealing certain acts in the area of animal health ('Animal Health Law'). OJ L 84, 31.3.2016, pp. 1-208.</footnote>

<footnote n="6">⁶ Only data from United Kingdom (Northern Ireland) from ADIS are included</footnote>
## 4.2. HPAI and LPAI detections in Europe, 10 September to 2 December 2022 (ToR 1 and ToR 2)

### 4.2.1. HPAI detections in poultry, other captive birds and wild birds

From 10 September to 2 December 2022, 1,162 HPAI A(H5) virus detections were notified in poultry (398), captive (151) and wild birds (613) to the ADIS or WOAH-WAHIS, as presented in Table 2. The timelines, virus subtypes, locations and the affected bird categories of the HPAI virus detections are presented in Figures 6, 7 and 8. The reported HPAI virus detections and outbreaks were distributed all over the reporting period and occurred in 16 European countries (Figure 6).

For wild birds, the highest number of HPAI virus reported detections were in the United Kingdom (160 detections), the Netherlands (97), Germany (86), France (62), Belgium (59), Spain (46), Italy (35) and Denmark (20) (Figure 7A and Table 2). Most of the HPAI virus detections were reported in waterbirds (371), followed by colony-breeding seabirds (109). This contrasts with the previous reporting period, when detections in seabirds predominated. This switch probably is associated on the one hand with the post-breeding dispersal of seabirds from their colony sites, and on the other hand with the increased numbers of waterbirds in Europe due to autumn migration. The geographical distribution of HPAI virus detections in wild birds was more limited than in the previous reporting period and was concentrated along the North Sea and Atlantic coasts of continental Europe from Denmark to Spain, as well as the UK and northern Italy. In domestic birds, HPAI virus outbreaks occurred primarily in north-west Europe (Germany, the Netherlands, Belgium, the United Kingdom and France), and were mainly distributed along the Atlantic coastal areas, following the distribution of the HPAI events in wild birds, except for outbreaks in Italy and Hungary. For poultry, Germany, the Netherlands, Belgium, UK and France accounted together for 86% of the reported HPAI outbreaks. In total, 83 poultry outbreaks were notified to the ADIS as secondary mainly in Hungary (64 out of 69 poultry outbreaks), but also in France (10 out of 98) Germany (8 out of 42) and Belgium (1 out of 8).

Overall, 9.8 million birds died or were culled in the HPAI poultry establishments with the UK accounting for 42% of the birds died or culled in the affected establishments during this reporting period, followed by the Netherlands (18%) and France (14%).

Characterisation of HPAI-affected poultry establishments<fnref n="5" /> is reported in Section 4.2.1.1; the description of the HPAI detections in wild birds is reported in Section 4.2.1.2.

HPAI A(H5N1) continues to be far the predominant virus type reported, with few exceptions for A(H5N5) virus detected in Norway and Finland in wild birds (3) and non-typed HPAI A(H5Nx) in Belgium (1), Bulgaria (1), France (1) and Germany (1) (Table 2).

Since 2 December and as of 16 December 2022, 249 HPAI outbreaks were confirmed in poultry (126), captive (66) and wild birds (57) outside the reporting period for this report in France (99), Germany (74), the Netherlands (19), Hungary (18), Poland (9), Belgium (8), Czechia (5), Denmark (4), Italy (3), Sweden (3), Romania (2), the United Kingdom<fnref n="6" /> (2), Luxemburg, Ireland and Switzerland (1 each). Those HPAI outbreaks were too close to the publication date to be described in this report and will be fully reported in the next report.

<footnote n="5">⁵ According to Regulation (EU) 2016/429 'establishment' means any premises, structure, or, in the case of open-air farming, any environment or place, where animals or germinal products are kept, on a temporary or permanent basis, except for: (a) households where pet animals are kept; (b) veterinary practices or clinics. Regulation (EU) 2016/429 of the European Parliament and of the Council of 9 March 2016 on transmissible animal diseases and amending and repealing certain acts in the area of animal health ('Animal Health Law'). OJ L 84, 31.3.2016, pp. 1-208.</footnote>

<footnote n="6">⁶ Only data from United Kingdom (Northern Ireland) from ADIS are included</footnote>
<figure><img src="image_9.png" /></figure>

United Kingdom data are from ADNS up to 31 December 2020. From 1 January 2021 onwards, the data source was the World Animal Health Information System (WOAH-WAHIS) for United Kingdom (excluding Northern Ireland), and ADNS/ADIS for the United Kingdom (Northern Ireland)⁴.

Source: EFSA, ADIS and WOAH (data extraction carried out on 2 December 2022).

Note that the scales of the vertical axes are specific to each category of birds.

<caption>**Figure 6:** Distribution of the highly pathogenic avian influenza virus detections in (A) wild birds (613) and (B) outbreaks in domestic birds (poultry and captive birds) (549), in Europe, by day of suspicion and country from 10 September to 2 December 2022</caption>

<footnote>* 'Other' groups all other affected countries that are not indicated in the legend</footnote>

<footnote>** When the date of suspicion is not available then the date of confirmation is used to assign the week of suspicion.</footnote>
<figure><img src="image_9.png" /></figure>

United Kingdom data are from ADNS up to 31 December 2020. From 1 January 2021 onwards, the data source was the World Animal Health Information System (WOAH-WAHIS) for United Kingdom (excluding Northern Ireland), and ADNS/ADIS for the United Kingdom (Northern Ireland)⁴.

Source: EFSA, ADIS and WOAH (data extraction carried out on 2 December 2022).

Note that the scales of the vertical axes are specific to each category of birds.

**Figure 6:** Distribution of the highly pathogenic avian influenza virus detections in (A) wild birds (613) and (B) outbreaks in domestic birds (poultry and captive birds) (549), in Europe, by day of suspicion and country from 10 September to 2 December 2022

<footnote>* 'Other' groups all other affected countries that are not indicated in the legend</footnote>

<footnote>** When the date of suspicion is not available then the date of confirmation is used to assign the week of suspicion.</footnote>
<table><caption>**Table 2:** Number of highly pathogenic avian influenza outbreaks in Europe, by country, virus subtype and affected sub-population, from 10 September to 2 December 2022. Cumulative numbers since the start of the 2022–2023 epidemiological year are reported in parentheses (1 October 2022 to 2 December 2022).</caption><thead><tr><th rowspan="2">Reporting Country</th><th colspan="2">Captive birds</th><th colspan="2">Poultry</th><th colspan="3">Wild birds</th><th rowspan="2">Total</th></tr><tr><th>A(H5N1)</th><th>A(H5Nx)</th><th>A(H5Nx)</th><th>A(H5N1)</th><th>A(H5Nx)</th><th>A(H5N1)</th><th>A(H5N5)</th></tr></thead><tbody><tr><td>Austria</td><td>1 (1)</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>1 (1)</td></tr><tr><td>Belgium</td><td>11 (8)</td><td>-</td><td>8 (5)</td><td>1 (1)</td><td>58 (37)</td><td>-</td><td>-</td><td>78 (51)</td></tr><tr><td>Bulgaria</td><td>-</td><td>1 (1)</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>1 (1)</td></tr><tr><td>Croatia</td><td>-</td><td>-</td><td>1 (1)</td><td>-</td><td>2 (2)</td><td>-</td><td>-</td><td>3 (3)</td></tr><tr><td>Cyprus</td><td>1 (1)</td><td>-</td><td>1 (1)</td><td>-</td><td>1 (1)</td><td>-</td><td>-</td><td>3 (3)</td></tr><tr><td>Czechia</td><td>-</td><td>-</td><td>1 (1)</td><td>-</td><td>-</td><td>-</td><td>-</td><td>1 (1)</td></tr><tr><td>Denmark</td><td>2 (2)</td><td>-</td><td>1 (1)</td><td>-</td><td>20 (14)</td><td>-</td><td>-</td><td>23 (17)</td></tr><tr><td>Finland</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>1</td><td>-</td><td>1 (0)</td></tr><tr><td>France<sup>(a)</sup></td><td>52 (33)</td><td>1</td><td>97 (89)</td><td>-</td><td>62 (43)</td><td>-</td><td>-</td><td>212 (163)</td></tr><tr><td>Germany</td><td>32 (31)</td><td>-</td><td>42 (34)</td><td>1 (1)</td><td>85 (74)</td><td>-</td><td>-</td><td>160 (140)</td></tr><tr><td>Hungary</td><td>-</td><td>-</td><td>69 (69)</td><td>-</td><td>-</td><td>-</td><td>-</td><td>69 (69)</td></tr><tr><td>Iceland</td><td>-</td><td>-</td><td>-</td><td>-</td><td>7 (4)</td><td>-</td><td>-</td><td>7 (4)</td></tr><tr><td>Ireland</td><td>2 (2)</td><td>-</td><td>2 (2)</td><td>-</td><td>4 (4)</td><td>-</td><td>-</td><td>8 (8)</td></tr><tr><td>Italy</td><td>1 (1)</td><td>-</td><td>28 (27)</td><td>-</td><td>35 (34)</td><td>-</td><td>-</td><td>64 (62)</td></tr><tr><td>Moldova</td><td>-</td><td>-</td><td>1 (1)</td><td>-</td><td>-</td><td>-</td><td>-</td><td>1 (1)</td></tr><tr><td>Netherlands</td><td>18 (11)</td><td>-</td><td>25 (19)</td><td>-</td><td>97 (67)</td><td>-</td><td>-</td><td>140 (97)</td></tr><tr><td>North Macedonia</td><td>1 (1)</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>1 (1)</td></tr><tr><td>Norway</td><td>-</td><td>-</td><td>2 (2)</td><td>-</td><td>7 (6)</td><td>2 (1)</td><td>-</td><td>11 (9)</td></tr><tr><td>Poland</td><td>-</td><td>-</td><td>1</td><td>-</td><td>2 (2)</td><td>-</td><td>-</td><td>3 (2)</td></tr><tr><td>Portugal</td><td>-</td><td>-</td><td>1</td><td>-</td><td>3 (1)</td><td>-</td><td>-</td><td>4 (1)</td></tr><tr><td>Romania</td><td>-</td><td>-</td><td>-</td><td>-</td><td>7 (7)</td><td>-</td><td>-</td><td>7 (7)</td></tr><tr><td>Serbia</td><td>-</td><td>-</td><td>-</td><td>-</td><td>3 (3)</td><td>-</td><td>-</td><td>3 (3)</td></tr><tr><td>Slovenia</td><td>-</td><td>-</td><td>-</td><td>-</td><td>3 (3)</td><td>-</td><td>-</td><td>3 (3)</td></tr><tr><td>Spain</td><td>-</td><td>-</td><td>1</td><td>-</td><td>46 (18)</td><td>-</td><td>-</td><td>47 (18)</td></tr><tr><td>Sweden</td><td>-</td><td>-</td><td>-</td><td>-</td><td>4 (3)</td><td>-</td><td>-</td><td>4 (3)</td></tr><tr><td>Switzerland</td><td>1 (1)</td><td>-</td><td>-</td><td>-</td><td>2 (2)</td><td>-</td><td>-</td><td>3 (3)</td></tr><tr><td>United Kingdom<sup>(b)</sup></td><td>29 (23)</td><td>-</td><td>115 (99)</td><td>-</td><td>160 (127)</td><td>-</td><td>-</td><td>304 (249)</td></tr><tr><td>Total</td><td>151 (115)</td><td>2 (1)</td><td>396 (351)</td><td>2 (2)</td><td>608 (452)</td><td>3 (1)</td><td>-</td><td>1,162 (922)</td></tr></tbody></table>

(a): one poultry and one captive birds outbreaks occurred in La Reunion

(b): United Kingdom data are from ADNS up to 31 December 2020. From 1 January 2021 onwards, the data source was the World Animal Health Information System (WOAH-WAHIS) for United Kingdom (excluding Northern Ireland), and ADNS/ADIS for United Kingdom (Northern Ireland)⁴.

'-': means that no HPAI outbreaks or detections were notified to ADIS or WOAH.

Source: EFSA, ADNS and WOAH (data extraction carried out on 2 December 2022).
<table><caption>**Table 2:** Number of highly pathogenic avian influenza outbreaks in Europe, by country, virus subtype and affected sub-population, from 10 September to 2 December 2022. Cumulative numbers since the start of the 2022–2023 epidemiological year are reported in parentheses (1 October 2022 to 2 December 2022).</caption><thead><tr><th rowspan="2">Reporting Country</th><th colspan="2">Captive birds</th><th colspan="2">Poultry</th><th colspan="3">Wild birds</th><th rowspan="2">Total</th></tr><tr><th>A(H5N1)</th><th>A(H5Nx)</th><th>A(H5N1)</th><th>A(H5Nx)</th><th>A(H5N1)</th><th>A(H5N5)</th></tr></thead><tbody><tr><td>Austria</td><td>1 (1)</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>1 (1)</td></tr><tr><td>Belgium</td><td>11 (8)</td><td>-</td><td>8 (5)</td><td>1 (1)</td><td>58 (37)</td><td>-</td><td>-</td><td>78 (51)</td></tr><tr><td>Bulgaria</td><td>-</td><td>1 (1)</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>1 (1)</td></tr><tr><td>Croatia</td><td>-</td><td>-</td><td>1 (1)</td><td>-</td><td>2 (2)</td><td>-</td><td>-</td><td>3 (3)</td></tr><tr><td>Cyprus</td><td>1 (1)</td><td>-</td><td>1 (1)</td><td>-</td><td>1 (1)</td><td>-</td><td>-</td><td>3 (3)</td></tr><tr><td>Czechia</td><td>-</td><td>-</td><td>1 (1)</td><td>-</td><td>-</td><td>-</td><td>-</td><td>1 (1)</td></tr><tr><td>Denmark</td><td>2 (2)</td><td>-</td><td>1 (1)</td><td>-</td><td>20 (14)</td><td>-</td><td>-</td><td>23 (17)</td></tr><tr><td>Finland</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>1</td><td>-</td><td>1 (0)</td></tr><tr><td>France<sup>(a)</sup></td><td>52 (33)</td><td>1</td><td>97 (89)</td><td>-</td><td>62 (43)</td><td>-</td><td>-</td><td>212 (163)</td></tr><tr><td>Germany</td><td>32 (31)</td><td>-</td><td>42 (34)</td><td>1 (1)</td><td>85 (74)</td><td>-</td><td>-</td><td>160 (140)</td></tr><tr><td>Hungary</td><td>-</td><td>-</td><td>69 (69)</td><td>-</td><td>-</td><td>-</td><td>-</td><td>69 (69)</td></tr><tr><td>Iceland</td><td>-</td><td>-</td><td>-</td><td>-</td><td>7 (4)</td><td>-</td><td>-</td><td>7 (4)</td></tr><tr><td>Ireland</td><td>2 (2)</td><td>-</td><td>2 (2)</td><td>-</td><td>4 (4)</td><td>-</td><td>-</td><td>8 (8)</td></tr><tr><td>Italy</td><td>1 (1)</td><td>-</td><td>28 (27)</td><td>-</td><td>35 (34)</td><td>-</td><td>-</td><td>64 (62)</td></tr><tr><td>Moldova</td><td>-</td><td>-</td><td>1 (1)</td><td>-</td><td>-</td><td>-</td><td>-</td><td>1 (1)</td></tr><tr><td>Netherlands</td><td>18 (11)</td><td>-</td><td>25 (19)</td><td>-</td><td>97 (67)</td><td>-</td><td>-</td><td>140 (97)</td></tr><tr><td>North Macedonia</td><td>1 (1)</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>1 (1)</td></tr><tr><td>Norway</td><td>-</td><td>-</td><td>2 (2)</td><td>-</td><td>7 (6)</td><td>2 (1)</td><td>-</td><td>11 (9)</td></tr><tr><td>Poland</td><td>-</td><td>-</td><td>1</td><td>-</td><td>2 (2)</td><td>-</td><td>-</td><td>3 (2)</td></tr><tr><td>Portugal</td><td>-</td><td>-</td><td>1</td><td>-</td><td>3 (1)</td><td>-</td><td>-</td><td>4 (1)</td></tr><tr><td>Romania</td><td>-</td><td>-</td><td>-</td><td>-</td><td>7 (7)</td><td>-</td><td>-</td><td>7 (7)</td></tr><tr><td>Serbia</td><td>-</td><td>-</td><td>-</td><td>-</td><td>3 (3)</td><td>-</td><td>-</td><td>3 (3)</td></tr><tr><td>Slovenia</td><td>-</td><td>-</td><td>-</td><td>-</td><td>3 (3)</td><td>-</td><td>-</td><td>3 (3)</td></tr><tr><td>Spain</td><td>-</td><td>-</td><td>1</td><td>-</td><td>46 (18)</td><td>-</td><td>-</td><td>47 (18)</td></tr><tr><td>Sweden</td><td>-</td><td>-</td><td>-</td><td>-</td><td>4 (3)</td><td>-</td><td>-</td><td>4 (3)</td></tr><tr><td>Switzerland</td><td>1 (1)</td><td>-</td><td>-</td><td>-</td><td>2 (2)</td><td>-</td><td>-</td><td>3 (3)</td></tr><tr><td>United Kingdom<sup>(b)</sup></td><td>29 (23)</td><td>-</td><td>115 (99)</td><td>-</td><td>160 (127)</td><td>-</td><td>-</td><td>304 (249)</td></tr><tr><td>Total</td><td>151 (115)</td><td>2 (1)</td><td>396 (351)</td><td>2 (2)</td><td>608 (452)</td><td>3 (1)</td><td>-</td><td>1,162 (922)</td></tr></tbody></table>

(a): one poultry and one captive birds outbreaks occurred in La Reunion

(b): United Kingdom data are from ADNS up to 31 December 2020. From 1 January 2021 onwards, the data source was the World Animal Health Information System (WOAH-WAHIS) for United Kingdom (excluding Northern Ireland), and ADNS/ADIS for United Kingdom (Northern Ireland)⁴.

'-': means that no HPAI outbreaks or detections were notified to ADIS or WOAH.

Source: EFSA, ADNS and WOAH (data extraction carried out on 2 December 2022).
<figure><img src="image_10.png" /></figure>

One poultry and one captive birds outbreak reported from France were detected in La Reunion, therefore they are not displayed in the above map.

United Kingdom data are from ADNS up to 31 December 2020. From 1 January 2021 onwards, the data source was the World Animal Health Information System (WOAH-WAHIS) for United Kingdom (excluding Northern Ireland), and ADNS/ADIS for United Kingdom (Northern Ireland)⁴.

Source: EFSA, ADIS and WOAH (data extraction carried out on 2 December 2022).

<caption>**Figure 7:** Geographical distribution, based on available geocoordinates, of highly pathogenic avian influenza virus detections in wild birds (613) (upper panel) and outbreaks in poultry and captive birds (549) (lower panel) reported by virus subtype in Europe from 10 September to 2 December 2022</caption>
<figure><img src="image_10.png" /></figure>

One poultry and one captive birds outbreak reported from France were detected in La Reunion, therefore they are not displayed in the above map.

United Kingdom data are from ADNS up to 31 December 2020. From 1 January 2021 onwards, the data source was the World Animal Health Information System (WOAH-WAHIS) for United Kingdom (excluding Northern Ireland), and ADNS/ADIS for United Kingdom (Northern Ireland)⁴.

Source: EFSA, ADIS and WOAH (data extraction carried out on 2 December 2022).

<caption>**Figure 7:** Geographical distribution, based on available geocoordinates, of highly pathogenic avian influenza virus detections in wild birds (613) (upper panel) and outbreaks in poultry and captive birds (549) (lower panel) reported by virus subtype in Europe from 10 September to 2 December 2022</caption>
### 4.2.1.1. HPAI in domestic birds

#### Characterisation of the HPAI-affected poultry establishments

In this section a detailed analysis of the HPAI-affected poultry establishments is presented. Due to the time needed to carry out the data collection, the outbreaks that occurred later than 18 November were too close to the publishing of this report to collect the data, and in many cases, the epidemiological investigations of those outbreaks were still ongoing. Therefore, for those poultry outbreaks some of the information presented in this section was unknown at the time of publication and will be included in the next report.

The information on poultry outbreaks that occurred before the reporting period for this report but too close to the publication of the previous EFSA report (EFSA et al., 2022b), i.e. from 2 to 9 September 2022, are reported in Annex A (they have been collected during this reporting period but are not described in the text of this section).

During this reporting period, from 10 September to 2 December 2022, in total, 398 poultry outbreaks were notified in 18 countries through ADIS or WOAH: 115 in the United Kingdom, 98 in France, 69 in Hungary, 42 in Germany, 28 in Italy, 25 in the Netherlands, 8 in Belgium, two in Ireland and Norway respectively and one each in Bulgaria, Croatia, Cyprus, Czechia, Denmark, Moldova, Poland, Spain and Portugal (Table 2). Overall, 9.8 million birds died or were culled in the affected establishments. The United Kingdom accounted for 29% of the reported outbreaks and 42% of the birds that died or were culled in the HPAI establishments, France accounted for 25% of the reported outbreaks 14% of the birds dead or culled, followed by Germany, 11% and 5% respectively, Italy 7% and 10% respectively, the Netherlands 6% and 18% respectively, Belgium 2% and 5% respectively, Hungary 17% and 4% respectively, (Figure 8).

Compared with the previous reporting period (from 11 June to 9 September 2022), during which 63 outbreaks were notified by eight affected countries, a markable increase of around six times as many outbreaks (398 outbreaks) were notified during this period (Table 3). An increasing trend was also observed between the same reporting periods in 2021-2022, when a lot more outbreaks were reported from 10 September to 2 December 2021 compared to the period from 11 June to 9 September 2021. Also, nearly six times as many cases were reported in the period 11 June to 9 September 2022 compared to the year before (Table 3).

<table><caption>**Table 3:** Number of highly pathogenic avian influenza outbreaks in poultry in Europe, by reporting period and epidemic season</caption><thead><tr><th>Epidemic season</th><th colspan="2">2021-2022</th><th colspan="2">2022-2023</th></tr><tr><th>Reporting period</th><th>11 June to 9<br>September 2021</th><th>10 September to 2<br>December 2021</th><th>11 June to 9<br>September 2022</th><th>10 September to 2<br>December 2022</th></tr></thead><tbody><tr><th>Number of HPAI<br>poultry outbreaks</th><td>10</td><td>294</td><td>63</td><td>398</td></tr></tbody></table>
### 4.2.1.1. HPAI in domestic birds

#### Characterisation of the HPAI-affected poultry establishments

In this section a detailed analysis of the HPAI-affected poultry establishments is presented. Due to the time needed to carry out the data collection, the outbreaks that occurred later than 18 November were too close to the publishing of this report to collect the data, and in many cases, the epidemiological investigations of those outbreaks were still ongoing. Therefore, for those poultry outbreaks some of the information presented in this section was unknown at the time of publication and will be included in the next report.

The information on poultry outbreaks that occurred before the reporting period for this report but too close to the publication of the previous EFSA report (EFSA et al., 2022b), i.e. from 2 to 9 September 2022, are reported in Annex A (they have been collected during this reporting period but are not described in the text of this section).

During this reporting period, from 10 September to 2 December 2022, in total, 398 poultry outbreaks were notified in 18 countries through ADIS or WOAH: 115 in the United Kingdom, 98 in France, 69 in Hungary, 42 in Germany, 28 in Italy, 25 in the Netherlands, 8 in Belgium, two in Ireland and Norway respectively and one each in Bulgaria, Croatia, Cyprus, Czechia, Denmark, Moldova, Poland, Spain and Portugal (Table 2). Overall, 9.8 million birds died or were culled in the affected establishments. The United Kingdom accounted for 29% of the reported outbreaks and 42% of the birds that died or were culled in the HPAI establishments, France accounted for 25% of the reported outbreaks 14% of the birds dead or culled, followed by Germany, 11% and 5% respectively, Italy 7% and 10% respectively, the Netherlands 6% and 18% respectively, Belgium 2% and 5% respectively, Hungary 17% and 4% respectively, (Figure 8).

Compared with the previous reporting period (from 11 June to 9 September 2022), during which 63 outbreaks were notified by eight affected countries, a markable increase of around six times as many outbreaks (398 outbreaks) were notified during this period (Table 3). An increasing trend was also observed between the same reporting periods in 2021-2022, when a lot more outbreaks were reported from 10 September to 2 December 2021 compared to the period from 11 June to 9 September 2021. Also, nearly six times as many cases were reported in the period 11 June to 9 September 2022 compared to the year before (Table 3).

<table><caption>**Table 3:** Number of highly pathogenic avian influenza outbreaks in poultry in Europe, by reporting period and epidemic season</caption><thead><tr><th>Epidemic season</th><th colspan="2">2021-2022</th><th colspan="2">2022-2023</th></tr><tr><th>Reporting period</th><th>11 June to 9<br>September 2021</th><th>10 September to 2<br>December 2021</th><th>11 June to 9<br>September 2022</th><th>10 September to 2<br>December 2022</th></tr></thead><tbody><tr><th>Number of HPAI<br>poultry outbreaks</th><td>10</td><td>294</td><td>63</td><td>398</td></tr></tbody></table>
<figure><img src="image_11.png" /><figcaption>**Figure 8:** Number of (A) HPAI-affected establishments and (B) number of poultry in the HPAI-affected establishments in Europe between 10 September and 2 December 2022 (398)</figcaption></figure>

Out of 398 outbreaks, 150 were reported in commercial farms, 26 in non-commercial farms and this information was not available at the time of writing this report for 222 establishments. 83 of the outbreaks were secondary outbreaks, 24 in commercial establishments (14 in Hungary, seven in France, two in Germany and one in Belgium) and 4 in non-commercial establishments (in Germany).

Increased mortality, or other types of clinical signs were observed in most of the affected establishments keeping chicken and domestic goose (Figure 9).
<figure><img src="image_11.png" /><figcaption>**Figure 8:** Number of (A) HPAI-affected establishments and (B) number of poultry in the HPAI-affected establishments in Europe between 10 September and 2 December 2022 (398)</figcaption></figure>

Out of 398 outbreaks, 150 were reported in commercial farms, 26 in non-commercial farms and this information was not available at the time of writing this report for 222 establishments. 83 of the outbreaks were secondary outbreaks, 24 in commercial establishments (14 in Hungary, seven in France, two in Germany and one in Belgium) and 4 in non-commercial establishments (in Germany).

Increased mortality, or other types of clinical signs were observed in most of the affected establishments keeping chicken and domestic goose (Figure 9).
<figure><img src="image_12.png" /></figure>

'Other' species category contains mixed, unknown bird species, or categories different from those displayed. 'Other' production type contains unknown or different production type from those displayed.

<caption>**Figure 9:** Number of HPAI poultry outbreaks with and without reporting of signs of HPAI infection (either mortality, clinical signs, drop in feed/water intake or drop in egg production) per poultry species and production type, between 10 September and 2 December 2022 (398)</caption>

### HPAI A(H5N1)-affected poultry establishments in Belgium

Between 22 September and 10 November 2022 seven primary and one secondary HPAI A(H5N1) virus outbreaks were reported in Vlaanderen. The affected establishments were commercial farms keeping chickens for breeding (4/7) and egg production (4/7). In none of the establishments the animals had outdoor access. In the primary outbreaks the source of infection was thought to be indirect contact with wild birds and in the secondary outbreak the most likely source was indirect contact with infected poultry because of two outbreaks in the immediate vicinity.

All farms reported increased mortality and three of the four farms keeping laying hens reported clinical signs, while none of the farms keeping chickens for breeding reported no other clinical signs. None of the farms reported a drop in feed and water intake or, where applicable, in egg production.

No data on the number of people exposed to the virus were available at the time of publication of this report. The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in Bulgaria

On 21 October 2022 Bulgaria reported one primary HPAI A(H5Nx) virus outbreak in the Haskovo region. The outbreak was on a commercial farm with laying hens without outdoor access. The source of introduction was unknown. No data on observed clinical signs or mortality were available, neither on the number of people exposed to the virus at the time of publication of this report.

The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in Croatia

On 16 November 2022 one primary HPAI A(H5N1) virus outbreak was notified in the region of Zagreb. The establishment was a non-commercial farm keeping chickens, domestic duck and domestic goose for egg production as well as turkey and peacock. The animals had outdoor access and the most likely source of introduction was direct contact with wild birds since there is a water area in the middle of the affected holding and two dead swans which were found in the area some days before were positive for HPAI A(H5N1). Increased mortality was present in the chickens (except silkie breed) and peacocks. No other clinical signs were present on the farm.
<figure><img src="image_12.png" /></figure>

'Other' species category contains mixed, unknown bird species, or categories different from those displayed. 'Other' production type contains unknown or different production type from those displayed.

<caption>**Figure 9:** Number of HPAI poultry outbreaks with and without reporting of signs of HPAI infection (either mortality, clinical signs, drop in feed/water intake or drop in egg production) per poultry species and production type, between 10 September and 2 December 2022 (398)</caption>

### HPAI A(H5N1)-affected poultry establishments in Belgium

Between 22 September and 10 November 2022 seven primary and one secondary HPAI A(H5N1) virus outbreaks were reported in Vlaanderen. The affected establishments were commercial farms keeping chickens for breeding (4/7) and egg production (4/7). In none of the establishments the animals had outdoor access. In the primary outbreaks the source of infection was thought to be indirect contact with wild birds and in the secondary outbreak the most likely source was indirect contact with infected poultry because of two outbreaks in the immediate vicinity.

All farms reported increased mortality and three of the four farms keeping laying hens reported clinical signs, while none of the farms keeping chickens for breeding reported no other clinical signs. None of the farms reported a drop in feed and water intake or, where applicable, in egg production.

No data on the number of people exposed to the virus were available at the time of publication of this report. The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in Bulgaria

On 21 October 2022 Bulgaria reported one primary HPAI A(H5Nx) virus outbreak in the Haskovo region. The outbreak was on a commercial farm with laying hens without outdoor access. The source of introduction was unknown. No data on observed clinical signs or mortality were available, neither on the number of people exposed to the virus at the time of publication of this report.

The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in Croatia

On 16 November 2022 one primary HPAI A(H5N1) virus outbreak was notified in the region of Zagreb. The establishment was a non-commercial farm keeping chickens, domestic duck and domestic goose for egg production as well as turkey and peacock. The animals had outdoor access and the most likely source of introduction was direct contact with wild birds since there is a water area in the middle of the affected holding and two dead swans which were found in the area some days before were positive for HPAI A(H5N1). Increased mortality was present in the chickens (except silkie breed) and peacocks. No other clinical signs were present on the farm.
No data on the number of people exposed to the virus were available at the time of publication of this report. The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in Denmark

On 9 November 2022 one primary HPAI A(H5N1) virus outbreak was reported in Slagelse. The outbreak was in a commercial farm keeping turkey for fattening without outdoor access. The source of introduction was unknown. Increased mortality, presence of clinical signs and drop in feed and water intake were observed. No data on the number of exposed people was available at the time of publication of this report.

The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in France

Between 12 September and 17 November 2022 50 primary and five secondary HPAI A(H5N1) virus outbreaks and one primary HPAI A(H5NX) outbreak was reported. The outbreaks were detected in the following regions: Pays de la Loire (28), Bretagne (10), Nouvelle-Aquitaine (7), Centre-Val de Loire (5), Hauts-de-France (3), Auvergne-Rhône-Alpes (2), Grand Est (1), Île-de-France (1), Normandie (1) and Saint-Paul, La Réunion (1). All outbreaks were in commercial establishments. The type of farmed species were: chicken for egg production (8), chicken for fattening (3), chicken for breeding (1), turkey for fattening (18), turkey for breeding (1), turkey with production type not specified (1), mulard duck for foie gras (7), Muscovy duck for fattening (6) domestic duck for breeding (3), domestic duck for fattening (5), domestic duck for other production type (3) and pheasants for game (1). Two farms kept more than one poultry species: Muscovy ducks for breeding and pheasants and chicken for fattening and domestic guineafowl respectively.

No data on outdoor access, most likely source of introduction, mortality, clinical signs, drop in feed/water intake, egg production or number of exposed people were available at the time of publication of this report.

The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in Germany

Between 13 September and 15 November 2022 32 primary and six secondary HPAI A(H5N1) virus outbreaks were reported in five regions: Niedersachsen (17), Nordrhein-Westfalen (11), Schleswig-Holstein (8), Bayern (1) and Hessen (1). 24 were commercial farms and 14 were non-commercial. Some establishments were keeping only one species: chicken (10), turkey (7), domestic duck (2) and domestic goose (2); whereas 17 farms kept more than one species, including chicken, domestic goose, domestic duck, domestic pigeon, turkey, pheasant, domestic guineafowl and one species listed as other.

Sixteen establishments had no outdoor access, two had and for the remaining it was unknown. The most likely source of introduction of the virus was indirect contact with wild birds (22), unknown (14), direct contact with poultry because of purchase of animals (5) and direct contact with wild birds (1).

One establishment of domestic ducks detected by outbreak related surveillance showed no mortality or clinical signs in an early stage of infection. Furthermore, a turkey farm without mortality or clinical signs was detected using bucket sampling in a HPAI affected district.

The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in Hungary

Between 4 and 17 November 2022 4 primary and 14 secondary outbreaks of HPAI A(H5N1) virus were notified in two regions: Bács-Kiskun (15) and Csongrád-Csanád (3). All establishments were commercial farms keeping domestic goose for foie gras (7), mulard duck for foie gras (6), domestic duck for fattening (2), domestic goose for breeding (1), pheasant for breeding (1) and turkey for fattening (1).

Eight out of the 18 farms had outdoor access. The most likely source of introduction in the primary outbreaks was indirect contact with wild birds and in the secondary outbreaks indirect contact with poultry.
No data on the number of people exposed to the virus were available at the time of publication of this report. The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in Denmark

On 9 November 2022 one primary HPAI A(H5N1) virus outbreak was reported in Slagelse. The outbreak was in a commercial farm keeping turkey for fattening without outdoor access. The source of introduction was unknown. Increased mortality, presence of clinical signs and drop in feed and water intake were observed. No data on the number of exposed people was available at the time of publication of this report.

The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in France

Between 12 September and 17 November 2022 50 primary and five secondary HPAI A(H5N1) virus outbreaks and one primary HPAI A(H5NX) outbreak was reported. The outbreaks were detected in the following regions: Pays de la Loire (28), Bretagne (10), Nouvelle-Aquitaine (7), Centre-Val de Loire (5), Hauts-de-France (3), Auvergne-Rhône-Alpes (2), Grand Est (1), Île-de-France (1), Normandie (1) and Saint-Paul, La Réunion (1). All outbreaks were in commercial establishments. The type of farmed species were: chicken for egg production (8), chicken for fattening (3), chicken for breeding (1), turkey for fattening (18), turkey for breeding (1), turkey with production type not specified (1), mulard duck for foie gras (7), Muscovy duck for fattening (6) domestic duck for breeding (3), domestic duck for fattening (5), domestic duck for other production type (3) and pheasants for game (1). Two farms kept more than one poultry species: Muscovy ducks for breeding and pheasants and chicken for fattening and domestic guineafowl respectively.

No data on outdoor access, most likely source of introduction, mortality, clinical signs, drop in feed/water intake, egg production or number of exposed people were available at the time of publication of this report.

The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in Germany

Between 13 September and 15 November 2022 32 primary and six secondary HPAI A(H5N1) virus outbreaks were reported in five regions: Niedersachsen (17), Nordrhein-Westfalen (11), Schleswig-Holstein (8), Bayern (1) and Hessen (1). 24 were commercial farms and 14 were non-commercial. Some establishments were keeping only one species: chicken (10), turkey (7), domestic duck (2) and domestic goose (2); whereas 17 farms kept more than one species, including chicken, domestic goose, domestic duck, domestic pigeon, turkey, pheasant, domestic guineafowl and one species listed as other.

Sixteen establishments had no outdoor access, two had and for the remaining it was unknown. The most likely source of introduction of the virus was indirect contact with wild birds (22), unknown (14), direct contact with poultry because of purchase of animals (5) and direct contact with wild birds (1).

One establishment of domestic ducks detected by outbreak related surveillance showed no mortality or clinical signs in an early stage of infection. Furthermore, a turkey farm without mortality or clinical signs was detected using bucket sampling in a HPAI affected district.

The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in Hungary

Between 4 and 17 November 2022 4 primary and 14 secondary outbreaks of HPAI A(H5N1) virus were notified in two regions: Bács-Kiskun (15) and Csongrád-Csanád (3). All establishments were commercial farms keeping domestic goose for foie gras (7), mulard duck for foie gras (6), domestic duck for fattening (2), domestic goose for breeding (1), pheasant for breeding (1) and turkey for fattening (1).

Eight out of the 18 farms had outdoor access. The most likely source of introduction in the primary outbreaks was indirect contact with wild birds and in the secondary outbreaks indirect contact with poultry.
All eight establishments keeping domestic goose reported increased mortality, six reported presence of other clinical signs and two a drop in feed and water intake. Among the establishments keeping mulard duck four (4/6) reported increased mortality, three (3/6) presence of clinical signs and two (2/6) a drop in feed and water intake. The farm keeping pheasant reported increased mortality and presence of clinical signs and the farm keeping turkey reported increased mortality, presence of clinical signs and drop in feed/water intake. None of the two farms keeping domestic ducks reported any signs of disease.

No data on the number of people exposed to the virus were available at the time of publication of this report. The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in Ireland

On 14 November and 22 November 2022 two primary HPAI A(H5N1) virus outbreaks were notified in the region of Monaghan. Both establishments were commercial farms keeping turkey for fattening. In one of the establishments the animals had outdoor access. In both outbreaks the most likely source of introduction was indirect contact with wild birds. Both farms reported increased mortality, presence of other clinical signs and a drop in feed and water intake. The total number of exposed people were 37.

The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in Italy

Between 23 September and 18 November 2022, 25 primary HPAI A(H5N1) virus outbreaks were notified in Veneto (16), Lombardia (5), Emilia-Romagna (3) and Friuli-Venezia Giulia (1). 15 farms were commercial and ten non-commercial. Nine of the farms kept only chicken for either breeding (2/9), egg production (5/9) or fattening (2/9). Six farms kept only turkey for fattening. Two farms kept only domestic duck for mixed production and domestic goose respectively. The other eight establishments kept more than one poultry species, including chicken (4/8), domestic duck (3/8), domestic goose (3/8), turkey (1/8), domestic guineafowl (1/8) and other species (3/8).

On 15 of the 25 farms the animals had no outdoor access and on ten farms they had outdoor access. The most likely source of infection was indirect contact with wild birds (23/25), direct contact with poultry (1/25) and in one (1/25) establishment it was unknown.

Increased mortality was reported in ten (10/17) of the farms keeping chicken. For two (2/17) farms increased mortality was reported in chicken for egg production but not in those kept for fattening. Four (4/17) reported no increased mortality and for one (1/17) farm it was unknown. All seven farms keeping turkey reported increased mortality. Two farms (2/5) keeping duck reported increased mortality. Two (2/3) farms reported increased mortality in domestic goose and one (1/3) farm reported increased mortality in one of the two species of domestic goose kept on the farm. No increased mortality was reported in the only farm keeping domestic guineafowl. For the species listed as other, no information or unknown was reported for four (4/7), no increase in mortality in two (2/7) and increased mortality for one (1/7).

Presence of other clinical signs were reported in four (4/17) farms keeping chicken and two (2/17) farms reported clinical signs in those kept for egg production but not in those kept for fattening. Three (3/7) turkey farms reported presence of clinical signs. No (0/5) farms keeping domestic duck reported presence of clinical signs. Of the farms keeping domestic goose, one (1/3) reported clinical signs. For the species listed as other, two (2/7) reported presence of clinical signs.

Drop in feed and water intake was reported in two (2/17) farms keeping chicken and in one (1/7) farm keeping turkey. One (1/17) farm keeping chicken reported a drop in egg production.

No data on the number of people exposed to the virus were available at the time of publication of this report. The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5)-affected poultry establishments in Norway

On 22 October and 12 November 2022 two primary HPAI A(H5N1) virus outbreaks were reported in Rogaland. The affected establishments were commercial farms keeping chicken for breeding and egg production respectively. On neither farm the animals had outdoor access. For the farm keeping chicken for breeding the most likely source of infection was indirect contact with wild birds since the farm is located nearby a wetland area with a dense wild bird population. For the other farm the source of
All eight establishments keeping domestic goose reported increased mortality, six reported presence of other clinical signs and two a drop in feed and water intake. Among the establishments keeping mulard duck four (4/6) reported increased mortality, three (3/6) presence of clinical signs and two (2/6) a drop in feed and water intake. The farm keeping pheasant reported increased mortality and presence of clinical signs and the farm keeping turkey reported increased mortality, presence of clinical signs and drop in feed/water intake. None of the two farms keeping domestic ducks reported any signs of disease.

No data on the number of people exposed to the virus were available at the time of publication of this report. The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in Ireland

On 14 November and 22 November 2022 two primary HPAI A(H5N1) virus outbreaks were notified in the region of Monaghan. Both establishments were commercial farms keeping turkey for fattening. In one of the establishments the animals had outdoor access. In both outbreaks the most likely source of introduction was indirect contact with wild birds. Both farms reported increased mortality, presence of other clinical signs and a drop in feed and water intake. The total number of exposed people were 37.

The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in Italy

Between 23 September and 18 November 2022, 25 primary HPAI A(H5N1) virus outbreaks were notified in Veneto (16), Lombardia (5), Emilia-Romagna (3) and Friuli-Venezia Giulia (1). 15 farms were commercial and ten non-commercial. Nine of the farms kept only chicken for either breeding (2/9), egg production (5/9) or fattening (2/9). Six farms kept only turkey for fattening. Two farms kept only domestic duck for mixed production and domestic goose respectively. The other eight establishments kept more than one poultry species, including chicken (4/8), domestic duck (3/8), domestic goose (3/8), turkey (1/8), domestic guineafowl (1/8) and other species (3/8).

On 15 of the 25 farms the animals had no outdoor access and on ten farms they had outdoor access. The most likely source of infection was indirect contact with wild birds (23/25), direct contact with poultry (1/25) and in one (1/25) establishment it was unknown.

Increased mortality was reported in ten (10/17) of the farms keeping chicken. For two (2/17) farms increased mortality was reported in chicken for egg production but not in those kept for fattening. Four (4/17) reported no increased mortality and for one (1/17) farm it was unknown. All seven farms keeping turkey reported increased mortality. Two farms (2/5) keeping duck reported increased mortality. Two (2/3) farms reported increased mortality in domestic goose and one (1/3) farm reported increased mortality in one of the two species of domestic goose kept on the farm. No increased mortality was reported in the only farm keeping domestic guineafowl. For the species listed as other, no information or unknown was reported for four (4/7), no increase in mortality in two (2/7) and increased mortality for one (1/7).

Presence of other clinical signs were reported in four (4/17) farms keeping chicken and two (2/17) farms reported clinical signs in those kept for egg production but not in those kept for fattening. Three (3/7) turkey farms reported presence of clinical signs. No (0/5) farms keeping domestic duck reported presence of clinical signs. Of the farms keeping domestic goose, one (1/3) reported clinical signs. For the species listed as other, two (2/7) reported presence of clinical signs.

Drop in feed and water intake was reported in two (2/17) farms keeping chicken and in one (1/7) farm keeping turkey. One (1/17) farm keeping chicken reported a drop in egg production.

No data on the number of people exposed to the virus were available at the time of publication of this report. The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5)-affected poultry establishments in Norway

On 22 October and 12 November 2022 two primary HPAI A(H5N1) virus outbreaks were reported in Rogaland. The affected establishments were commercial farms keeping chicken for breeding and egg production respectively. On neither farm the animals had outdoor access. For the farm keeping chicken for breeding the most likely source of infection was indirect contact with wild birds since the farm is located nearby a wetland area with a dense wild bird population. For the other farm the source of
introduction was unknown. The breeding farm reported increased mortality, presence of clinical signs and a decrease in feed and water intake and in egg production while the egg production establishment reported increased mortality and presence of clinical signs. The number of exposed people was 21 for the farm keeping chicken for breeding, for the other farm the number of exposed people was not available at the time of publication of this report.

The characteristics of the affected establishment and species reared are presented in Annex A.

### HPAI A(H5)-affected poultry establishments in Moldova

On 14 November 2022 one primary HPAI A(H5N1) virus outbreak was notified in the Telenesti region. The affected establishment was a non-commercial holding keeping chicken and the animals had outdoor access. The most likely source of infection was direct contact with wild birds. Data related to presence of signs of infection were not available at the time of publishing this report. The number of exposed people was three. The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in the Netherlands

Between 15 September 2022 and 9 November 2022, 22 primary HPAI A (H5N1) outbreaks were notified in the Netherlands in the following regions: Friesland (3), Gelderland (3), Limburg (3), Overijssel (2), Noord- Brabant (2), Zuid-Holland (2) and Drenthe (1). All affected establishments were commercial farms keeping chicken for fattening (7), chickens for breeding (6), laying hens (6), turkey for fattening (2) and domestic duck for fattening. Information about outdoor access was not available at the time of publication. The most likely sources of infection were unknown or the investigation inconclusive for all affected establishments. Presence of clinical signs and drop in feed and water intake was present in all establishments and in all farms keeping laying hens a drop in egg production was reported. In all but two farms increased mortality was reported.

No data on the number of people exposed to the virus were available at the time of publication of this report. The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1) -affected poultry establishments in Poland

On 21 September 2022 one primary HPAI A(H5N1) virus outbreak was notified in Łódzkie. The affected establishment was a commercial farm that kept domestic goose for fattening and chicken for egg production. The animals had outdoor access on the farm and the most likely source of infection was reported to be indirect contact with wild birds.

Increased mortality, presence of clinical signs and drop in feed and water intake was reported in the domestic geese. In the chickens drop in egg production was reported.

The number of exposed people were five.

The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in Portugal

On 30 September 2022 one primary HPAI A(H5N1) virus outbreak was notified in the region of Lisbon. The affected establishment was a commercial farm holding turkeys for fattening and the animals had no outdoor access. The source of infection was unknown. The number of exposed people was 18. There was an increased mortality, presence of clinical signs and a decrease in feed intake.

The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in Spain

On 17 September one primary HPAI A(H5N1) virus outbreak was reported in the Castilla La Mancha region. The affected establishment was a commercial farm holding laying hens and the animals had no outdoor access. The most likely source of introduction was indirect contact with wild birds due to a river being located nearby. The total number of exposed people was 34. Increased mortality was reported in the farm.

The characteristics of the affected establishments and species reared are presented in Annex A.
introduction was unknown. The breeding farm reported increased mortality, presence of clinical signs and a decrease in feed and water intake and in egg production while the egg production establishment reported increased mortality and presence of clinical signs. The number of exposed people was 21 for the farm keeping chicken for breeding, for the other farm the number of exposed people was not available at the time of publication of this report.

The characteristics of the affected establishment and species reared are presented in Annex A.

### HPAI A(H5)-affected poultry establishments in Moldova

On 14 November 2022 one primary HPAI A(H5N1) virus outbreak was notified in the Telenesti region. The affected establishment was a non-commercial holding keeping chicken and the animals had outdoor access. The most likely source of infection was direct contact with wild birds. Data related to presence of signs of infection were not available at the time of publishing this report. The number of exposed people was three. The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in the Netherlands

Between 15 September 2022 and 9 November 2022, 22 primary HPAI A (H5N1) outbreaks were notified in the Netherlands in the following regions: Friesland (3), Gelderland (3), Limburg (3), Overijssel (2), Noord- Brabant (2), Zuid-Holland (2) and Drenthe (1). All affected establishments were commercial farms keeping chicken for fattening (7), chickens for breeding (6), laying hens (6), turkey for fattening (2) and domestic duck for fattening. Information about outdoor access was not available at the time of publication. The most likely sources of infection were unknown or the investigation inconclusive for all affected establishments. Presence of clinical signs and drop in feed and water intake was present in all establishments and in all farms keeping laying hens a drop in egg production was reported. In all but two farms increased mortality was reported.

No data on the number of people exposed to the virus were available at the time of publication of this report. The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1) -affected poultry establishments in Poland

On 21 September 2022 one primary HPAI A(H5N1) virus outbreak was notified in Łódzkie. The affected establishment was a commercial farm that kept domestic goose for fattening and chicken for egg production. The animals had outdoor access on the farm and the most likely source of infection was reported to be indirect contact with wild birds.

Increased mortality, presence of clinical signs and drop in feed and water intake was reported in the domestic geese. In the chickens drop in egg production was reported.

The number of exposed people were five.

The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in Portugal

On 30 September 2022 one primary HPAI A(H5N1) virus outbreak was notified in the region of Lisbon. The affected establishment was a commercial farm holding turkeys for fattening and the animals had no outdoor access. The source of infection was unknown. The number of exposed people was 18. There was an increased mortality, presence of clinical signs and a decrease in feed intake.

The characteristics of the affected establishments and species reared are presented in Annex A.

### HPAI A(H5N1)-affected poultry establishments in Spain

On 17 September one primary HPAI A(H5N1) virus outbreak was reported in the Castilla La Mancha region. The affected establishment was a commercial farm holding laying hens and the animals had no outdoor access. The most likely source of introduction was indirect contact with wild birds due to a river being located nearby. The total number of exposed people was 34. Increased mortality was reported in the farm.

The characteristics of the affected establishments and species reared are presented in Annex A.
*Information extracted from the scientific literature*

There were four studies relevant for the phenotype of HPAI viruses in poultry in Europe published since the previous EFSA report. Liang et al. (Liang et al., 2022) investigated the pathogenesis and transmission of a HPAI clade 2.3.4.4b A(H5N6) virus infection from 2018 in Denmark in seven-to-nine-week-old ring-necked pheasants (*Phasianus colchicus*) inoculated via the intranasal and intraocular routes, and onward transmission to cohoused six-to-eight-week-old White Leghorn chickens. Clinical signs in infected pheasants ranged from mild to severe neurological signs 24-48 h prior to death or euthanasia. Histopathological changes consisted of necrosis and inflammation in multiple organs colocalised with influenza virus antigen expression. Efficient virus transmission was detected between pheasants over multiple rounds of naïve pheasant introductions and onwards to chickens. Mortality of up to 100% was observed for both infected pheasants and chickens. Intra-species transmission from chicken to chicken was less efficient. The study indicates that game bird premises are at risk of HPAI virus incursion, that these viruses can be maintained within this sector, and that they may subsequently spread to commercial and backyard chickens.

Hayama et al. (2022) estimated the time window from the introduction of HPAI virus into poultry farms using field data from the HPAI A(H5N8) virus outbreak, clade 2.3.4.4b, in the 2020–2021 winter season in Japan. The time window from the introduction of the virus to notification in each farm was estimated at 14.0 days in median (min: 8.6 days, max: 24.1 days) in the deterministic model. In the stochastic model, the upper value of 95% credible interval of the time window ranged from 12 to 34 days, with a median of 21 days. The results suggest that although one to three weeks had elapsed on most farms until notification after the virus introduction, the time window could exceed three weeks. These results provide reliable information for setting up a tracing period for a potential source farm and enhancing the efforts for early detection.

Isoda et al. (2022) investigated the pathogenicity of a major strain of clade 2.3.4.4b HPAI A(H5N1) viruses isolated from wild birds in Japan in winter 2021–2022, which were genetically highly similar to the viruses circulating in Europe. Different virus titres of a representative strain, Crow/Hok, isolated from a crow (presumably *Corvus macrorhynchos*) were intranasally inoculated into 6-week-old chickens. All chickens inoculated with $10^6$ or $10^5$ EID$_{50}$ died before 4 days post challenge, whereas birds inoculated with $\leq 10^4$ EID$_{50}$ survived for 14 days after the challenge without any apparent clinical manifestations. The median chicken lethal dose of Crow/Hok in 6-week-old chickens was calculated as $10^{4.5}$ EID$_{50}$, which is similar to that of other HPAI viruses invading Japan in the last decade.

Elsayed et al. (2022) reported that ostriches (*Struthio camelus*) on ostrich farms in Egypt diagnosed with HPAI A(H5N8) virus clade 2.3.4.4b in 2021 showed clinical signs including loss of appetite, drop in production, oculo-nasal discharges, depression, and diarrhea, with different degrees of high mortality. Pathological changes included bleeding from natural orifices and hemorrhage in intestine and trachea. The authors recommend that ostriches should be included in the surveillance of poultry species for HPAI.

#### 4.2.1.2. HPAI in wild birds

Between 10 September and 2 December 2022, 613 HPAI virus detections in sick, dead or hunted wild birds were reported to the ADIS and WOAH by EU/EEA and United Kingdom (Figure 10), which is 73% of the detections in the previous reporting period (from 10 June to 9 September 2022): 844 HPAI virus detections. The HPAI virus detections in wild birds were concentrated in countries bordering the North Sea and the Bay of Biscay: United Kingdom (160), the Netherlands (97), Germany (86), France (62), Belgium (59), and Spain (46) (Table 2). Together, these countries accounted for 82% (502/613) of the detections. In these countries, the detections were predominantly but not exclusively along the sea coasts (Figure 10). The overall geographical range of HPAI virus detections in wild birds extended from the northern tip of Norway to the southern tip of the Iberian Peninsula, and west to Iceland (Figure 10). Locations included the Orkney Islands and Faroe Islands in the north-east Atlantic Ocean. The number of HPAI virus detections in colony-breeding seabirds, predominantly including the orders of Sulariformes (64) and Charadriiformes (59) decreased during the course of this reporting period (Figure 11a) and were lower in this reporting period (109) than in the previous reporting period (581) (Table C.1 in Annex C). This is likely due to the post-breeding dispersal of colony-breeding seabirds after their breeding periods in the summer. In contrast, the number of HPAI virus detections in the order of Anseriformes (408) (Figure 11a) was high throughout the reporting period and the number of detections in waterfowl was higher in this reporting period (371) than in the previous reporting period (129) (Table C.1 in Annex
*Information extracted from the scientific literature*

There were four studies relevant for the phenotype of HPAI viruses in poultry in Europe published since the previous EFSA report. Liang et al. (Liang et al., 2022) investigated the pathogenesis and transmission of a HPAI clade 2.3.4.4b A(H5N6) virus infection from 2018 in Denmark in seven-to-nine-week-old ring-necked pheasants (*Phasianus colchicus*) inoculated via the intranasal and intraocular routes, and onward transmission to cohoused six-to-eight-week-old White Leghorn chickens. Clinical signs in infected pheasants ranged from mild to severe neurological signs 24-48 h prior to death or euthanasia. Histopathological changes consisted of necrosis and inflammation in multiple organs colocalised with influenza virus antigen expression. Efficient virus transmission was detected between pheasants over multiple rounds of naïve pheasant introductions and onwards to chickens. Mortality of up to 100% was observed for both infected pheasants and chickens. Intra-species transmission from chicken to chicken was less efficient. The study indicates that game bird premises are at risk of HPAI virus incursion, that these viruses can be maintained within this sector, and that they may subsequently spread to commercial and backyard chickens.

Hayama et al. (2022) estimated the time window from the introduction of HPAI virus into poultry farms using field data from the HPAI A(H5N8) virus outbreak, clade 2.3.4.4b, in the 2020–2021 winter season in Japan. The time window from the introduction of the virus to notification in each farm was estimated at 14.0 days in median (min: 8.6 days, max: 24.1 days) in the deterministic model. In the stochastic model, the upper value of 95% credible interval of the time window ranged from 12 to 34 days, with a median of 21 days. The results suggest that although one to three weeks had elapsed on most farms until notification after the virus introduction, the time window could exceed three weeks. These results provide reliable information for setting up a tracing period for a potential source farm and enhancing the efforts for early detection.

Isoda et al. (2022) investigated the pathogenicity of a major strain of clade 2.3.4.4b HPAI A(H5N1) viruses isolated from wild birds in Japan in winter 2021–2022, which were genetically highly similar to the viruses circulating in Europe. Different virus titres of a representative strain, Crow/Hok, isolated from a crow (presumably *Corvus macrorhynchos*) were intranasally inoculated into 6-week-old chickens. All chickens inoculated with $10^6$ or $10^5$ EID$_{50}$ died before 4 days post challenge, whereas birds inoculated with $\leq 10^4$ EID$_{50}$ survived for 14 days after the challenge without any apparent clinical manifestations. The median chicken lethal dose of Crow/Hok in 6-week-old chickens was calculated as $10^{4.5}$ EID$_{50}$, which is similar to that of other HPAI viruses invading Japan in the last decade.

Elsayed et al. (2022) reported that ostriches (*Struthio camelus*) on ostrich farms in Egypt diagnosed with HPAI A(H5N8) virus clade 2.3.4.4b in 2021 showed clinical signs including loss of appetite, drop in production, oculo-nasal discharges, depression, and diarrhea, with different degrees of high mortality. Pathological changes included bleeding from natural orifices and hemorrhage in intestine and trachea. The authors recommend that ostriches should be included in the surveillance of poultry species for HPAI.

#### 4.2.1.2. HPAI in wild birds

Between 10 September and 2 December 2022, 613 HPAI virus detections in sick, dead or hunted wild birds were reported to the ADIS and WOAH by EU/EEA and United Kingdom (Figure 10), which is 73% of the detections in the previous reporting period (from 10 June to 9 September 2022): 844 HPAI virus detections. The HPAI virus detections in wild birds were concentrated in countries bordering the North Sea and the Bay of Biscay: United Kingdom (160), the Netherlands (97), Germany (86), France (62), Belgium (59), and Spain (46) (Table 2). Together, these countries accounted for 82% (502/613) of the detections. In these countries, the detections were predominantly but not exclusively along the sea coasts (Figure 10). The overall geographical range of HPAI virus detections in wild birds extended from the northern tip of Norway to the southern tip of the Iberian Peninsula, and west to Iceland (Figure 10). Locations included the Orkney Islands and Faroe Islands in the north-east Atlantic Ocean. The number of HPAI virus detections in colony-breeding seabirds, predominantly including the orders of Sulariformes (64) and Charadriiformes (59) decreased during the course of this reporting period (Figure 11a) and were lower in this reporting period (109) than in the previous reporting period (581) (Table C.1 in Annex C). This is likely due to the post-breeding dispersal of colony-breeding seabirds after their breeding periods in the summer. In contrast, the number of HPAI virus detections in the order of Anseriformes (408) (Figure 11a) was high throughout the reporting period and the number of detections in waterfowl was higher in this reporting period (371) than in the previous reporting period (129) (Table C.1 in Annex
C). This is likely due to the increased number of Anseriformes present in Europe as a result of the autumn migration. Together, Suliformes, Anseriformes and Charadriiformes comprised 79% (531/671) of the HPAI-positive wild bird detected species in the reporting period.

At least 64 wild bird species were involved: at least 18 waterfowl species, 10 colony-breeding seabird species, 12 raptor species, and 24 other wild bird species (Figure 11 and Table C.3 in Annex C). The number of HPAI virus detections was quite similar as in the same period last year (10 September to 2 December 2021), when there were 669 detections (Table C.2 in Annex C). During this reporting period, the main waterfowl species in which HPAI virus was detected were mute swans (117 detections), greylag geese (83), Canada geese (60), and mallards (42); the main colonial seabird species were northern gannets (61), European herring gulls (14), great black-backed gulls and black-headed gulls (11 each); and the main raptor species were European buzzards (29) and peregrine falcons (11).

<figure><img src="image_13.png" /></figure>

Author: EFSA
Data sources: ADIS, WOAH
Date updated: 02/12/2022

Source: EFSA, ADIS and WOAH (data extraction carried out on 2 December 2022). Note that in one single detection more than one wild bird species might be involved and each wild bird categories detected as HPAI infected is presented in the map.

**Figure 10:** Geographical distribution, based on available geocoordinates, of highly pathogenic avian influenza detections in wild birds' categories in Europe, by species category, from 10 September to 2 December 2022
C). This is likely due to the increased number of Anseriformes present in Europe as a result of the autumn migration. Together, Suliformes, Anseriformes and Charadriiformes comprised 79% (531/671) of the HPAI-positive wild bird detected species in the reporting period.

At least 64 wild bird species were involved: at least 18 waterfowl species, 10 colony-breeding seabird species, 12 raptor species, and 24 other wild bird species (Figure 11 and Table C.3 in Annex C). The number of HPAI virus detections was quite similar as in the same period last year (10 September to 2 December 2021), when there were 669 detections (Table C.2 in Annex C). During this reporting period, the main waterfowl species in which HPAI virus was detected were mute swans (117 detections), greylag geese (83), Canada geese (60), and mallards (42); the main colonial seabird species were northern gannets (61), European herring gulls (14), great black-backed gulls and black-headed gulls (11 each); and the main raptor species were European buzzards (29) and peregrine falcons (11).

<figure><img src="image_13.png" /></figure>

Author: EFSA
Data sources: ADIS, WOAH
Date updated: 02/12/2022

Source: EFSA, ADIS and WOAH (data extraction carried out on 2 December 2022). Note that in one single detection more than one wild bird species might be involved and each wild bird categories detected as HPAI infected is presented in the map.

**Figure 10:** Geographical distribution, based on available geocoordinates, of highly pathogenic avian influenza detections in wild birds' categories in Europe, by species category, from 10 September to 2 December 2022
<figure><img src="image_14.png" /><figcaption>**Figure 11:** Number of reported detections of highly pathogenic avian influenza virus A(H5) in wild birds by (A) bird order and week of suspicion and (B) wild bird species in the EU/EEA and United Kingdom, from 10 September to 2 December 2022</figcaption></figure>
<figure><img src="image_14.png" /><figcaption>**Figure 11:** Number of reported detections of highly pathogenic avian influenza virus A(H5) in wild birds by (A) bird order and week of suspicion and (B) wild bird species in the EU/EEA and United Kingdom, from 10 September to 2 December 2022</figcaption></figure>
*Information extracted from the scientific literature*

There were three studies relevant for the phenotype of HPAI viruses in wild birds in Europe that have been published since the latest EFSA report. Rijks et al. (Rijks et al., 2022) documented the mass mortality in Sandwich terns (*Thalasseus sandvicensis*) during the 2022 breeding season in the Netherlands from HPAI (H5N1) virus clade 2.3.4.4b. In 9 of 10 breeding colonies with mass mortality, 8,001 adult Sandwich terns were found dead out of a total of 18,151 breeding pairs, and only a few chicks fledged. Outside of colonies, another 1,600 adult Sandwich terns were reported dead. Clinical signs in diseased birds included debilitation, lethargy, inability to fly, and opisthotonos. Histopathological changes consisted of necrosis and inflammation in pancreas, duodenum, or lung and nasal tissue, colocalized with influenza virus antigen expression. Like other seabirds, Sandwich terns have low annual reproductive output but relatively long life-expectancy. Therefore, the effect of high adult mortality on population size could be seen for a long time. This mass mortality event exemplifies how severely the continued circulation of HPAI H5N1 viruses in spring 2022 affected populations of colony-breeding birds without flock immunity in Europe.

Fujimoto et al. (2022) diagnosed HPAI H5N8 clade 2.3.4.4b in an adult white-tailed eagle (*Haliaeetus albicilla*) found in Japan in 2021. It showed clinical signs including depression, head shake, and edema in both legs, followed by death. Histopathological examination showed myocardial necrosis throughout the heart and neuronal necrosis throughout the brain, colocalized with influenza viral antigen expression, but no prominent lesions or virus antigen expression in other organs. Comprehensive comparisons of both viral distribution and histopathological observations between experimentally and naturally infected white-tailed eagles imply that viral replication in the brain is responsible for the disease severity and mortality in this species.

Caliendo et al. (2022) inoculated two species of wild ducks—tufted duck (*Aythya fuligula*) and mallard (*Anas platyrhynchos*)—first with 2014 H5N8 HPAI virus and after 9 months with 2016 H5N8 HPAI virus, to test the hypothesis that previous infection with a HPAI virus provides long-term immunity against subsequent infection with another HPAI virus. Both viruses belong to the 2.3.4.4b clade. They found that the previously infected ducks were protected against clinical signs of disease and shed significantly less virus. This finding will help in understanding and potentially predicting the impact that an HPAI virus outbreak may have on wild bird populations, depending on whether they are previously exposed or naive to HPAI virus infections.

4.2.2. Genetic characterisation of avian influenza viruses

*Description of the nomenclature of the HPAI A(H5) viruses used in the document*

The HA gene of clade 2.3.4.4 A(H5) viruses has rapidly evolved since the most recent official update of the nomenclature of the A/goose/Guangdong/1/1996-lineage H5Nx virus (Smith et al., 2015). This clade emerged in China in 2008 and since then it has acquired various neuraminidase subtypes, including N1, N2, N3, N4, N5, N6 and N8, by reassortments with other avian influenza viruses from different regions, and has evolved into several subgroups. While a revised nomenclature of clade 2.3.4.4 viruses is pending, in previous reports we used the genetic clustering described in 2018 by Lee and co-authors, who recognised four groups (a–d) within clade 2.3.4.4 (Lee et al., 2018). Recently, an update to the unified nomenclature for clade 2.3.4.4 A(H5) viruses has been proposed by the WHO (WHO, 2020a) and eight genetic groups (a–h) have been recognised. To align the nomenclature system between international organisations this classification has been adopted for this report. Based on this proposed clustering, A(H5) viruses of clades 2.3.4.4a and d–h have mainly been circulating in poultry in Asia, while clades 2.3.4.4b and 2.3.4.4c have spread globally through wild bird migrations during 2014–2015 (2.3.4.4c) and from 2016 to the present day (2.3.4.4b).

*Global overview of HPAI viruses of the A(H5) subtype of clade 2.3.4.4b*

A(H5N1) viruses of clade 2.3.4.4b have spread to many countries in Europe, Africa, Asia, and America since their emergence in the Netherlands in October 2020, undergoing multiple reassortment events. In January 2021, an A(H5N1) related to the 2020–2021 European viruses was reported in West Africa and subsequently in South African countries. Since then, it has been persistently circulating in this geographic area, and in West Africa it has reassorted with the A(H9N2) subtype of the zoonotic G1 lineage. From late 2021, different clade 2.3.4.4b A(H5N1) genotypes, one of them previously identified in Europe, have been detected in South and East Asia, including China. In December 2021, the A(H5N1)
*Information extracted from the scientific literature*

There were three studies relevant for the phenotype of HPAI viruses in wild birds in Europe that have been published since the latest EFSA report. Rijks et al. (Rijks et al., 2022) documented the mass mortality in Sandwich terns (*Thalasseus sandvicensis*) during the 2022 breeding season in the Netherlands from HPAI (H5N1) virus clade 2.3.4.4b. In 9 of 10 breeding colonies with mass mortality, 8,001 adult Sandwich terns were found dead out of a total of 18,151 breeding pairs, and only a few chicks fledged. Outside of colonies, another 1,600 adult Sandwich terns were reported dead. Clinical signs in diseased birds included debilitation, lethargy, inability to fly, and opisthotonos. Histopathological changes consisted of necrosis and inflammation in pancreas, duodenum, or lung and nasal tissue, colocalized with influenza virus antigen expression. Like other seabirds, Sandwich terns have low annual reproductive output but relatively long life-expectancy. Therefore, the effect of high adult mortality on population size could be seen for a long time. This mass mortality event exemplifies how severely the continued circulation of HPAI H5N1 viruses in spring 2022 affected populations of colony-breeding birds without flock immunity in Europe.

Fujimoto et al. (2022) diagnosed HPAI H5N8 clade 2.3.4.4b in an adult white-tailed eagle (*Haliaeetus albicilla*) found in Japan in 2021. It showed clinical signs including depression, head shake, and edema in both legs, followed by death. Histopathological examination showed myocardial necrosis throughout the heart and neuronal necrosis throughout the brain, colocalized with influenza viral antigen expression, but no prominent lesions or virus antigen expression in other organs. Comprehensive comparisons of both viral distribution and histopathological observations between experimentally and naturally infected white-tailed eagles imply that viral replication in the brain is responsible for the disease severity and mortality in this species.

Caliendo et al. (2022) inoculated two species of wild ducks—tufted duck (*Aythya fuligula*) and mallard (*Anas platyrhynchos*)—first with 2014 H5N8 HPAI virus and after 9 months with 2016 H5N8 HPAI virus, to test the hypothesis that previous infection with a HPAI virus provides long-term immunity against subsequent infection with another HPAI virus. Both viruses belong to the 2.3.4.4b clade. They found that the previously infected ducks were protected against clinical signs of disease and shed significantly less virus. This finding will help in understanding and potentially predicting the impact that an HPAI virus outbreak may have on wild bird populations, depending on whether they are previously exposed or naive to HPAI virus infections.

4.2.2. Genetic characterisation of avian influenza viruses

*Description of the nomenclature of the HPAI A(H5) viruses used in the document*

The HA gene of clade 2.3.4.4 A(H5) viruses has rapidly evolved since the most recent official update of the nomenclature of the A/goose/Guangdong/1/1996-lineage H5Nx virus (Smith et al., 2015). This clade emerged in China in 2008 and since then it has acquired various neuraminidase subtypes, including N1, N2, N3, N4, N5, N6 and N8, by reassortments with other avian influenza viruses from different regions, and has evolved into several subgroups. While a revised nomenclature of clade 2.3.4.4 viruses is pending, in previous reports we used the genetic clustering described in 2018 by Lee and co-authors, who recognised four groups (a–d) within clade 2.3.4.4 (Lee et al., 2018). Recently, an update to the unified nomenclature for clade 2.3.4.4 A(H5) viruses has been proposed by the WHO (WHO, 2020a) and eight genetic groups (a–h) have been recognised. To align the nomenclature system between international organisations this classification has been adopted for this report. Based on this proposed clustering, A(H5) viruses of clades 2.3.4.4a and d–h have mainly been circulating in poultry in Asia, while clades 2.3.4.4b and 2.3.4.4c have spread globally through wild bird migrations during 2014–2015 (2.3.4.4c) and from 2016 to the present day (2.3.4.4b).

*Global overview of HPAI viruses of the A(H5) subtype of clade 2.3.4.4b*

A(H5N1) viruses of clade 2.3.4.4b have spread to many countries in Europe, Africa, Asia, and America since their emergence in the Netherlands in October 2020, undergoing multiple reassortment events. In January 2021, an A(H5N1) related to the 2020–2021 European viruses was reported in West Africa and subsequently in South African countries. Since then, it has been persistently circulating in this geographic area, and in West Africa it has reassorted with the A(H9N2) subtype of the zoonotic G1 lineage. From late 2021, different clade 2.3.4.4b A(H5N1) genotypes, one of them previously identified in Europe, have been detected in South and East Asia, including China. In December 2021, the A(H5N1)
clade 2.3.4.4b strongly related to the A(H5N1) identified in Northern Europe during the 2020-2021 epidemic season was introduced in North America. At the beginning of 2022, a new introduction in North America from the Pacific flyway of an A(H5N1) related to the viruses circulating in Japan was identified (Alkie et al., 2022). Since then the virus has spread all over North America undergoing reassortment events with LPAI viruses of the American lineages (Alkie et al., 2022). In October 2022, A(H5N1) viruses spread for the first time to Mexico and soon after to South America, including Peru, Colombia, Ecuador and Venezuela, with mass mortality events reported in wild birds (BBC, online) and detections in poultry farms. The characterized viruses belong to clade 2.3.4.4b first detected in January 2022 in the Atlantic coast of North America (ProMed, online-a) and have been described as reassortant viruses between the Eurasian and American lineages (WOAH, 2022).

### Genetic characterisation of HPAI viruses of the A(H5) subtype detected in Europe

All the genetically characterised HPAI viruses collected since October 2020 in Europe fall within clade 2.3.4.4b. In the current reporting period (September-December 2022) sequences have been generated from viruses collected in nine EU Member States, Norway and in the United Kingdom (available in GISAID on 6 December, provided by the National Reference Laboratories (NRL) or generated by the EURL). Overall, a total of eleven distinct genotypes have been identified among the characterized viruses collected over the period considered, eight of which were detected for the first time. However, the majority of the viruses belongs to a single genotype, which has been circulating in Europe since autumn 2021, indicating a persistent circulation of these viruses in Europe from the 2021-2022 epidemiological year. All the new genotypes identified seem to have evolved through local reassortment events with viruses circulating in the European wild bird population, and each genotype has been identified in one or few viruses in a single country.

The partial genome sequences of a HPAI avian influenza A(H5N1) virus collected in September 2022 from virus detected in an asymptomatic poultry worker in Spain, likely originating from an environmental contamination and not an active replication of the virus in the human host, was genetically characterised. The virus clusters with the viruses collected from infected laying hens in the farm where the person was working and involved in the culling activity. No mutation previously described as associated to increased zoonotic potential has been observed in the viral genome detected in this worker.

In October 2022, an A(H5N1) outbreak in a mink farm was reported in Spain. The virus responsible of this outbreak belongs to a genotype generated through reassortment events for the PA, NP and NS gene segments with the gull-adapted H13 subtype. This genotype has been circulating since May 2022 in wild birds (mainly European herring gulls) in Northern Europe and has caused a poultry outbreak and a case in a fox (*Vulpes vulpes*) during the summer in Belgium. Of note, the characterized viruses from mink carry an amino acid mutation in the PB2 protein that has been previously demonstrated to enhance the polymerase activity of influenza A viruses in mammalian host cells and mice (Bussey et al., 2010). Workers of the mink farm have been tested and no detection of avian influenza virus in humans related to this outbreak in mink has been identified.

To date, few mutations recognised as being associated with mammalian adaptation have been identified in the analysed viruses from avian species collected since October 2020, as previously reported (EFSA et al., 2021) and most of them have only been sporadically detected. In the A(H5N1) viruses from this reporting period, a mutation in the HA protein associated with increased binding to human-type receptors was identified in all the analysed viruses (S137A, H3 numbering) (Yang et al., 2007). Mutations associated with increased resistance to antiviral drugs were observed in the neuraminidase or ion channel proteins of few of the circulating A(H5N1) viruses.

### 4.3. Human cases reported and transmission to other mammal species due to clade 2.3.4.4b A(H5Nx) avian influenza viruses detected in birds in Europe

Since 10 September as of 18 November 2022, data from six countries (Ireland, Norway, Moldova, Poland, Portugal and Spain) have been reported on the total number of people exposed to infected birds (e.g. during culling activities). In total, 118 exposed people⁷ were reported.
clade 2.3.4.4b strongly related to the A(H5N1) identified in Northern Europe during the 2020-2021 epidemic season was introduced in North America. At the beginning of 2022, a new introduction in North America from the Pacific flyway of an A(H5N1) related to the viruses circulating in Japan was identified (Alkie et al., 2022). Since then the virus has spread all over North America undergoing reassortment events with LPAI viruses of the American lineages (Alkie et al., 2022). In October 2022, A(H5N1) viruses spread for the first time to Mexico and soon after to South America, including Peru, Colombia, Ecuador and Venezuela, with mass mortality events reported in wild birds (BBC, online) and detections in poultry farms. The characterized viruses belong to clade 2.3.4.4b first detected in January 2022 in the Atlantic coast of North America (ProMed, online-a) and have been described as reassortant viruses between the Eurasian and American lineages (WOAH, 2022).

### Genetic characterisation of HPAI viruses of the A(H5) subtype detected in Europe

All the genetically characterised HPAI viruses collected since October 2020 in Europe fall within clade 2.3.4.4b. In the current reporting period (September-December 2022) sequences have been generated from viruses collected in nine EU Member States, Norway and in the United Kingdom (available in GISAID on 6 December, provided by the National Reference Laboratories (NRL) or generated by the EURL). Overall, a total of eleven distinct genotypes have been identified among the characterized viruses collected over the period considered, eight of which were detected for the first time. However, the majority of the viruses belongs to a single genotype, which has been circulating in Europe since autumn 2021, indicating a persistent circulation of these viruses in Europe from the 2021-2022 epidemiological year. All the new genotypes identified seem to have evolved through local reassortment events with viruses circulating in the European wild bird population, and each genotype has been identified in one or few viruses in a single country.

The partial genome sequences of a HPAI avian influenza A(H5N1) virus collected in September 2022 from virus detected in an asymptomatic poultry worker in Spain, likely originating from an environmental contamination and not an active replication of the virus in the human host, was genetically characterised. The virus clusters with the viruses collected from infected laying hens in the farm where the person was working and involved in the culling activity. No mutation previously described as associated to increased zoonotic potential has been observed in the viral genome detected in this worker.

In October 2022, an A(H5N1) outbreak in a mink farm was reported in Spain. The virus responsible of this outbreak belongs to a genotype generated through reassortment events for the PA, NP and NS gene segments with the gull-adapted H13 subtype. This genotype has been circulating since May 2022 in wild birds (mainly European herring gulls) in Northern Europe and has caused a poultry outbreak and a case in a fox (*Vulpes vulpes*) during the summer in Belgium. Of note, the characterized viruses from mink carry an amino acid mutation in the PB2 protein that has been previously demonstrated to enhance the polymerase activity of influenza A viruses in mammalian host cells and mice (Bussey et al., 2010). Workers of the mink farm have been tested and no detection of avian influenza virus in humans related to this outbreak in mink has been identified.

To date, few mutations recognised as being associated with mammalian adaptation have been identified in the analysed viruses from avian species collected since October 2020, as previously reported (EFSA et al., 2021) and most of them have only been sporadically detected. In the A(H5N1) viruses from this reporting period, a mutation in the HA protein associated with increased binding to human-type receptors was identified in all the analysed viruses (S137A, H3 numbering) (Yang et al., 2007). Mutations associated with increased resistance to antiviral drugs were observed in the neuraminidase or ion channel proteins of few of the circulating A(H5N1) viruses.

### 4.3. Human cases reported and transmission to other mammal species due to clade 2.3.4.4b A(H5Nx) avian influenza viruses detected in birds in Europe

Since 10 September as of 18 November 2022, data from six countries (Ireland, Norway, Moldova, Poland, Portugal and Spain) have been reported on the total number of people exposed to infected birds (e.g. during culling activities). In total, 118 exposed people⁷ were reported.
During the period covered by this report, avian influenza A(H5N1) virus, as currently detected in wild birds and poultry in Europe, has been detected in two poultry workers in Spain, which were the first human cases related to avian influenza A(H5) viruses reported in the EU/EEA (Table 4). Spanish Authorities reported that two poultry workers involved in culling and cleaning activities exposed to contaminated environment tested positive for A(H5N1) virus on 27 September and 13 October 2022, respectively, following an outbreak on a poultry farm in Guadalajara, in Castilla-La Mancha region, Spain, (ECDC, 2022a, b; Sanidad, 2022; WHO, online-a). Other farm workers involved in the outbreak at the same farm tested negative. Close contacts were followed up and all tested negative, providing evidence that there was no human-to-human transmission. According to the Spanish authorities, the low viral load detected, the absence of clinical symptoms and the absence of serological evidence indicates that both detections were probably due to an environmental contamination and not an active replication of the virus in the human host.

Earlier human infections with A(H5N1) or A(H5N8) viruses of clade 2.3.4.4b were reported since 2021, in the US, the United Kingdom, Russia and Nigeria, all related to outbreaks in poultry or wild birds (Table 4) (Pyankova et al., 2021; WHO, 2021c; CDC, online-c). There are no sequence data available yet from the recently reported human case of A(H5N1) virus infection in China. Sequence data from A(H5N1) viruses detected in China in birds and shared through GISAID have shown that the HA genes of the viruses belong to clade 2.3.4.4b and cluster with viruses collected in Europe, Africa and other Asian countries since 2020, however, the other gene segments indicate a high genetic variability among the circulating viruses in China and differ in at least one gene segment from European viruses. Further analyses are needed to when the genome sequence of the human case will become available.

So far, information from these human A(H5) cases suggest limited evidence of systemic infection and rather amplification of low-level virus RNA following exposure to contaminated environment and infected birds during culling activities (Table 4). Spanish authorities consider these findings the result of an environmental contamination and not an active replication of the virus in the human hosts. This is also reflected in the low virus load in the tested specimens resulting in high Ct values in the initial PCR tests at the detection limit of the assay, the inability to generate full length genomes, the lack of virus cultivation and inconclusive or negative serological findings.

<table><caption>**Table 4:** Details about human infections with avian influenza A(H5Nx) virus clade 2.3.4.4b related to viruses circulating in Europe, 2021–2022</caption><thead><tr><th>Date reported</th><th>Country (cases, subtype)</th><th>Exposure</th><th>Symptom</th><th>Confirmation</th></tr></thead><tbody><tr><td>27 Sept, 13 Oct 2022</td><td>Spain (2; H5N1) same farm</td><td>Culling, cleaning and disinfection</td><td>Asymptomatic</td><td>PCR, partial sequencing, no virus culture, high Ct Values (&gt;35), no serological evidence (preliminary data)</td></tr><tr><td>Apr 2022</td><td>USA (1; H5N1)</td><td>Culling</td><td>Fatigue</td><td>PCR, no sequencing or culture possible</td></tr><tr><td>Jan 2022</td><td>UK (1; H5N1)</td><td>Raised birds, "lived with"</td><td>Asymptomatic</td><td>PCR, reproduced on two successive swabs following days; no serological response identified (UKHSA personal communication)</td></tr><tr><td>Apr 2021</td><td>Nigeria (3(7); H5) related to H5N1 poultry outbreak</td><td>Culling</td><td>Asymptomatic</td><td>7 type A positive, 3 H5 positive PCR, no full sequencing or culture</td></tr><tr><td>Feb 2021</td><td>Russia (7; H5N8)</td><td>Culling</td><td>Asymptomatic</td><td>7 PCR, 1 isolated, 4 pos focus reduction neutralisation assay (FRNA) serum titres, 1 4-fold in sample 14d after (1:20), decreased titre 44d after; 5 samples positive for IgG biolayer interferometry</td></tr></tbody></table>

Sources: (Pyankova et al., 2021; WHO, 2021a, e; ECDC, 2022b, a; Sanidad, 2022; CDC, online-e; GovUK, online-b, c; WHO, online-f, a, c)
During the period covered by this report, avian influenza A(H5N1) virus, as currently detected in wild birds and poultry in Europe, has been detected in two poultry workers in Spain, which were the first human cases related to avian influenza A(H5) viruses reported in the EU/EEA (Table 4). Spanish Authorities reported that two poultry workers involved in culling and cleaning activities exposed to contaminated environment tested positive for A(H5N1) virus on 27 September and 13 October 2022, respectively, following an outbreak on a poultry farm in Guadalajara, in Castilla-La Mancha region, Spain, (ECDC, 2022a, b; Sanidad, 2022; WHO, online-a). Other farm workers involved in the outbreak at the same farm tested negative. Close contacts were followed up and all tested negative, providing evidence that there was no human-to-human transmission. According to the Spanish authorities, the low viral load detected, the absence of clinical symptoms and the absence of serological evidence indicates that both detections were probably due to an environmental contamination and not an active replication of the virus in the human host.

Earlier human infections with A(H5N1) or A(H5N8) viruses of clade 2.3.4.4b were reported since 2021, in the US, the United Kingdom, Russia and Nigeria, all related to outbreaks in poultry or wild birds (Table 4) (Pyankova et al., 2021; WHO, 2021c; CDC, online-c). There are no sequence data available yet from the recently reported human case of A(H5N1) virus infection in China. Sequence data from A(H5N1) viruses detected in China in birds and shared through GISAID have shown that the HA genes of the viruses belong to clade 2.3.4.4b and cluster with viruses collected in Europe, Africa and other Asian countries since 2020, however, the other gene segments indicate a high genetic variability among the circulating viruses in China and differ in at least one gene segment from European viruses. Further analyses are needed to when the genome sequence of the human case will become available.

So far, information from these human A(H5) cases suggest limited evidence of systemic infection and rather amplification of low-level virus RNA following exposure to contaminated environment and infected birds during culling activities (Table 4). Spanish authorities consider these findings the result of an environmental contamination and not an active replication of the virus in the human hosts. This is also reflected in the low virus load in the tested specimens resulting in high Ct values in the initial PCR tests at the detection limit of the assay, the inability to generate full length genomes, the lack of virus cultivation and inconclusive or negative serological findings.

<table><caption>**Table 4:** Details about human infections with avian influenza A(H5Nx) virus clade 2.3.4.4b related to viruses circulating in Europe, 2021–2022</caption><thead><tr><td>Date reported</td><td>Country (cases, subtype)</td><td>Exposure</td><td>Symptom</td><td>Confirmation</td></tr></thead><tbody><tr><td>27 Sept, 13 Oct 2022</td><td>Spain (2; H5N1) same farm</td><td>Culling, cleaning and disinfection</td><td>Asymptomatic</td><td>PCR, partial sequencing, no virus culture, high Ct Values (&gt;35), no serological evidence (preliminary data)</td></tr><tr><td>Apr 2022</td><td>USA (1; H5N1)</td><td>Culling</td><td>Fatigue</td><td>PCR, no sequencing or culture possible</td></tr><tr><td>Jan 2022</td><td>UK (1; H5N1)</td><td>Raised birds, "lived with"</td><td>Asymptomatic</td><td>PCR, reproduced on two successive swabs following days; no serological response identified (UKHSA personal communication)</td></tr><tr><td>Apr 2021</td><td>Nigeria (3(7); H5) related to H5N1 poultry outbreak</td><td>Culling</td><td>Asymptomatic</td><td>7 type A positive, 3 H5 positive PCR, no full sequencing or culture</td></tr><tr><td>Feb 2021</td><td>Russia (7; H5N8)</td><td>Culling</td><td>Asymptomatic</td><td>7 PCR, 1 isolated, 4 pos focus reduction neutralisation assay (FRNA) serum titres, 1 4-fold in sample 14d after (1:20), decreased titre 44d after; 5 samples positive for IgG biolayer interferometry</td></tr></tbody></table>

Sources: (Pyankova et al., 2021; WHO, 2021a, e; ECDC, 2022b, a; Sanidad, 2022; CDC, online-e; GovUK, online-b, c; WHO, online-f, a, c)
ECDC published a Threat Assessment Brief in February 2021 that assessed the risk as very low for the general population and low for occupationally exposed people (ECDC, 2021b) and revised the risk to low for the general population and low to medium for occupationally exposed people in December 2021 due to the increase in transmission events to mammal species including sporadic human cases with no or mild symptoms. The assessment remains valid. The high diversity and ongoing reassortment events add a high uncertainty to the assessment, and transmission events to humans cannot be excluded.

Other transmission events to different mammal species have been increasingly reported as mentioned in this report and in previous reports (Table 5). So far foxes had been majorly found to be infected with avian influenza viruses of clade 2.3.4.4b and displayed neurological signs leading to death or were already found dead. An outbreak of A(H5N1) in a mink farm with increased mortality among the animals also indicates mink-to-mink transmission with spread across the farm through animal contact but also likely through aerosol after possible introduction of the virus through infected wild birds to the open-housed farm (Galicia, online). All workers on this farm were tested negative for influenza. During the summer period 2022, also likely seal-to-seal transmission accompanied with seal mortality due to avian influenza A(H5N1) viruses were observed in the USA (Puryear et al., 2022). Although seals have been found infected with A(H5N1) viruses in Europe as well, such transmission event between the same mammal species has not been reported so far.

A study on currently circulating A(H5N1) viruses in North America showed that these viruses are able to replicate efficiently in human respiratory tract cell types and that in ferret infection and transmission studies, animals got infected but showed only very mild symptoms mostly limited to upper respiratory tract and viruses did not transmit to other ferrets kept in a direct-contact setting (Pulit-Penaloza et al., 2022). Supporting also the previously issued risk assessment using the Influenza Risk Assessment Tool (IRAT) of the United States Centers for Disease Control and Prevention (US CDC) that placed the risk of clade 2.3.4.4b viruses in the low-to-moderate category and issued a Health and Alert Notification message about 'Recommendations for Human Health Investigations and Response' (CDC, online-d, f, c, a). The risk of the A(H5N1) clade 2.3.4.4b viruses currently circulating in the United States bird and poultry populations, and which are closely related to European viruses, were assessed by the United States CDC to be of low risk for human health in the general population and higher for people occupationally or recreationally exposed to birds (CDC, online-b). The WHO assessed the risk related to the recent (H5N1) human cases as low for the general public and low to moderate for occupationally exposed people (WHO, online-a). A joint EFSA, ECDC, EURL publication from 2021 already described the threat to humans with the objective to raise awareness among clinicians in the EU around zoonotic avian influenza virus infection and consider testing (Adlhoch et al., 2021).

The UKHSA assesses that 'at present there are no indicators of increasing risk to human health' with a low confidence (GovUK, online-c). The WHO assessed the risk associated with A(H5N6) virus as low (CDC, online-b). The WHO issued a risk assessment on the increase in human cases due to A(H5N6) virus infections in 2021 and recommended remaining vigilant about zoonotic infections and to share unsubtypable influenza A viruses from human infections with the WHO Collaborating Centres (CDC, online-d).
ECDC published a Threat Assessment Brief in February 2021 that assessed the risk as very low for the general population and low for occupationally exposed people (ECDC, 2021b) and revised the risk to low for the general population and low to medium for occupationally exposed people in December 2021 due to the increase in transmission events to mammal species including sporadic human cases with no or mild symptoms. The assessment remains valid. The high diversity and ongoing reassortment events add a high uncertainty to the assessment, and transmission events to humans cannot be excluded.

Other transmission events to different mammal species have been increasingly reported as mentioned in this report and in previous reports (Table 5). So far foxes had been majorly found to be infected with avian influenza viruses of clade 2.3.4.4b and displayed neurological signs leading to death or were already found dead. An outbreak of A(H5N1) in a mink farm with increased mortality among the animals also indicates mink-to-mink transmission with spread across the farm through animal contact but also likely through aerosol after possible introduction of the virus through infected wild birds to the open-housed farm (Galicia, online). All workers on this farm were tested negative for influenza. During the summer period 2022, also likely seal-to-seal transmission accompanied with seal mortality due to avian influenza A(H5N1) viruses were observed in the USA (Puryear et al., 2022). Although seals have been found infected with A(H5N1) viruses in Europe as well, such transmission event between the same mammal species has not been reported so far.

A study on currently circulating A(H5N1) viruses in North America showed that these viruses are able to replicate efficiently in human respiratory tract cell types and that in ferret infection and transmission studies, animals got infected but showed only very mild symptoms mostly limited to upper respiratory tract and viruses did not transmit to other ferrets kept in a direct-contact setting (Pulit-Penaloza et al., 2022). Supporting also the previously issued risk assessment using the Influenza Risk Assessment Tool (IRAT) of the United States Centers for Disease Control and Prevention (US CDC) that placed the risk of clade 2.3.4.4b viruses in the low-to-moderate category and issued a Health and Alert Notification message about 'Recommendations for Human Health Investigations and Response' (CDC, online-d, f, c, a). The risk of the A(H5N1) clade 2.3.4.4b viruses currently circulating in the United States bird and poultry populations, and which are closely related to European viruses, were assessed by the United States CDC to be of low risk for human health in the general population and higher for people occupationally or recreationally exposed to birds (CDC, online-b). The WHO assessed the risk related to the recent (H5N1) human cases as low for the general public and low to moderate for occupationally exposed people (WHO, online-a). A joint EFSA, ECDC, EURL publication from 2021 already described the threat to humans with the objective to raise awareness among clinicians in the EU around zoonotic avian influenza virus infection and consider testing (Adlhoch et al., 2021).

The UKHSA assesses that 'at present there are no indicators of increasing risk to human health' with a low confidence (GovUK, online-c). The WHO assessed the risk associated with A(H5N6) virus as low (CDC, online-b). The WHO issued a risk assessment on the increase in human cases due to A(H5N6) virus infections in 2021 and recommended remaining vigilant about zoonotic infections and to share unsubtypable influenza A viruses from human infections with the WHO Collaborating Centres (CDC, online-d).