Avian influenza overview October 2016–August 2017
2017; Wiley; Volume: 15; Issue: 10 Linguagem: Inglês
10.2903/j.efsa.2017.5018
ISSN1831-4732
AutoresIan H. Brown, Paolo Mulatti, Krzysztof Śmietanka, Christoph Staubach, Preben Willeberg, Cornelia Adlhoch, Candiani Denise, Chiara Fabris, Gabriele Zancanaro, Joana Morgado, Frank Verdonck,
Tópico(s)Animal Disease Management and Epidemiology
ResumoEFSA JournalVolume 15, Issue 10 e05018 Scientific ReportOpen Access Avian influenza overview October 2016–August 2017 European Food Safety Authority, European Food Safety AuthoritySearch for more papers by this authorEuropean Centre for Disease Prevention and Control, European Centre for Disease Prevention and ControlSearch for more papers by this authorEuropean Union Reference Laboratory for Avian influenza, European Union Reference Laboratory for Avian influenzaSearch for more papers by this authorIan Brown, Ian BrownSearch for more papers by this authorPaolo Mulatti, Paolo MulattiSearch for more papers by this authorKrzysztof Smietanka, Krzysztof SmietankaSearch for more papers by this authorChristoph Staubach, Christoph StaubachSearch for more papers by this authorPreben Willeberg, Preben WillebergSearch for more papers by this authorCornelia Adlhoch, Cornelia AdlhochSearch for more papers by this authorDenise Candiani, Denise CandianiSearch for more papers by this authorChiara Fabris, Chiara FabrisSearch for more papers by this authorGabriele Zancanaro, Gabriele ZancanaroSearch for more papers by this authorJoana Morgado, Joana MorgadoSearch for more papers by this authorFrank Verdonck, Frank VerdonckSearch for more papers by this author European Food Safety Authority, European Food Safety AuthoritySearch for more papers by this authorEuropean Centre for Disease Prevention and Control, European Centre for Disease Prevention and ControlSearch for more papers by this authorEuropean Union Reference Laboratory for Avian influenza, European Union Reference Laboratory for Avian influenzaSearch for more papers by this authorIan Brown, Ian BrownSearch for more papers by this authorPaolo Mulatti, Paolo MulattiSearch for more papers by this authorKrzysztof Smietanka, Krzysztof SmietankaSearch for more papers by this authorChristoph Staubach, Christoph StaubachSearch for more papers by this authorPreben Willeberg, Preben WillebergSearch for more papers by this authorCornelia Adlhoch, Cornelia AdlhochSearch for more papers by this authorDenise Candiani, Denise CandianiSearch for more papers by this authorChiara Fabris, Chiara FabrisSearch for more papers by this authorGabriele Zancanaro, Gabriele ZancanaroSearch for more papers by this authorJoana Morgado, Joana MorgadoSearch for more papers by this authorFrank Verdonck, Frank VerdonckSearch for more papers by this author First published: 16 October 2017 https://doi.org/10.2903/j.efsa.2017.5018Citations: 36 Correspondence: ALPHA@efsa.europa.eu Requestor: European Commission Question number: EFSA-Q-2017-00229 Competing interests: In line with EFSA's policy on declarations of interest, the following working group (WG) experts: Ian Brown, Paolo Mulatti, Krzysztof Smietanka and Christoph Staubach, have declared that they have current involvement in risk assessment activities at national level related to avian influenza, which constitutes a conflict of interest (with the mandate of the EFSA WG in hand. The CoIs have been waived and the waivers were adopted in accordance with Article 16(5) of the Decision of the Executive Director on Declarations of Interest of 31 July 2017 EFSA/LRA/DEC/02/2014, available at http://www.efsa.europa.eu/sites/default/files/corporate_publications/files/independencerules2014.pdf. Pursuant to Article 16(7) of the above mentioned Decision, the concerned experts were allowed to take part in the discussions and in the drafting phase of the EFSA Scientific report on Avian influenza monitoring (Art. 31) - overview October 2016 - August 2017, and have not been allowed to be, or act as, a chairman, a vice-chairman or rapporteur of the WG. Acknowledgements: In addition to the listed authors, EFSA, ECDC and the EURL wish to thank the following: the hearing expert Thijs Kuiken for his support provided to this scientific output; Kaja Kaasik Aaslav, Epidemic Intelligence team at ECDC and Pasi Penttinen, Head of the Disease Programme Influenza and other Respiratory Viruses for the support provided to this scientific output; Members States representatives that provided the data on AI outbreaks and/or animal population for this scientific output: Austria (Andrea Hoeflechner-Poeltl, Eveline Wodak), Belgium (Philippe Houdart, Katie Vermeersch), Bulgaria (Aleksandra Miteva, Anna Zdravkova), Croatia (Zlatko Krovina, Tihana Miškić) Cyprus (Giorgos Krasias), the Czech Republic (Marie Vágnerová), Denmark (Thorkild Bastholm, Torben Grubbe), Estonia (Kärt Jaarma, Helen Prommik), Finland (Tiia Tuupanen), France (Loïc Evain, Isabelle Guerry, Alexandra Troyano-Groux), Germany (Franz Conraths, Andrea Coßmann), Greece (Sokratis Perdikaris), Hungary (Zsófia Szepesiné Kókány, Zsolt Terjék, Gabor Wyszoczky), Ireland (Stephanie Ronan, Eoin Ryan), Italy (Anna Sorgente), Latvia (Rudīte Vārna), Lithuania (Paulius Busauskas), Luxembourg (Roger Gindt), Malta (Joseph Caruana), the Netherlands (Nina Berendsen, Dennis Bol, Geert Eleveld, Marcel Spierenburg), Poland (Edyta Swieton), Portugal (Yolanda Vaz), Romania (Ioana Neghirla, Alexandru Supeanu, Claudiu Stroe), Slovakia (Vilem Kopriva, Barbora Pavlikova), Slovenia (Aleksandra Hari), Spain (Ana Fernandez Martín, Inés Moreno), Sweden (Annica Wallén Norell), the United Kingdom (Adam Brouwer, Helen Roberts); Members States representatives that wrote the case reports on the AI secondary outbreaks and on the AI applied prevention and control measures, as reported in the Annex: Austria (Andrea Hoeflechner-Poeltl, Eveline Wodak), Belgium (Philippe Houdart, Bénédicte Lambrecht, Marjorie Piret, Mieke Steensels), Bulgaria (Aleksandra Miteva, Anna Zdravkova), the Czech Republic (Milada Dubská, Petr Šatrán, Marie Vágnerová), Denmark (Pernille Dahl Nielsen, Stig Mellergaard), France (Mohamed Boukottaya, Anne Bronner, Alexandre Fediaevsky, Claire Guinat, Adeline Huneau-Salaün, Mathilde Paul), Greece (Sokratis Perdikaris), Hungary (Zsófia Szepesiné Kókány, Gerda Pállai, Anna Luca Vecsei, Gabor Wyszoczky), Ireland (Eoin Ryan), Italy (Tiziano Dorotea, Lebana Bonfanti, Stefano Marangon, Paolo Mulatti), the Netherlands (Marcel Spierenburg), Romania (Nicolae Drăgan, Ioana Neghirlă, Alexandru Supeanu, Claudiu Stroe), the United Kingdom (Adam Brouwer, Ian Brown, Helen Roberts); Dominique Bicout and Arjan Stegeman for reviewing the document. Approved: 29 September 2017 Amended: 12 December 2017 Figures from 1 to 16 © EURL; Figures 17, 19, 20, 22, 23 © Friedrich-Loeffler-Institut (FLI); Figures 18, 21, 26, 27, 28 © ECDC; Figures from C1 to C6 © EFSA This publication is linked to the following EFSA Journal article: http://onlinelibrary.wiley.com/doi/10.2903/j.efsa.2017.4991/full This publication is linked to the following EFSA Supporting Publications article: http://onlinelibrary.wiley.com/doi/10.2903/sp.efsa.2017.EN-1282/full, http://onlinelibrary.wiley.com/doi/10.2903/sp.efsa.2017.EN-1283/full, http://onlinelibrary.wiley.com/doi/10.2903/sp.efsa.2017.EN-1284/full, http://onlinelibrary.wiley.com/doi/10.2903/sp.efsa.2017.EN-1285/full, http://onlinelibrary.wiley.com/doi/10.2903/sp.efsa.2017.EN-1286/full, http://onlinelibrary.wiley.com/doi/10.2903/sp.efsa.2017.EN-1287/full AboutSectionsPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract The A(H5N8) highly pathogenic avian influenza (HPAI) epidemic occurred in 29 European countries in 2016/2017 and has been the largest ever recorded in the EU in terms of number of poultry outbreaks, geographical extent and number of dead wild birds. Multiple primary incursions temporally related with all major poultry sectors affected but secondary spread was most commonly associated with domestic waterfowl species. A massive effort of all the affected EU Member States (MSs) allowed a descriptive epidemiological overview of the cases in poultry, captive birds and wild birds, providing also information on measures applied at the individual MS level. Data on poultry population structure are required to facilitate data and risk factor analysis, hence to strengthen science-based advice to risk managers. It is suggested to promote common understanding and application of definitions related to control activities and their reporting across MSs. Despite a large number of human exposures to infected poultry occurred during the ongoing outbreaks, no transmission to humans has been identified. Monitoring the avian influenza (AI) situation in other continents indicated a potential risk of long-distance spread of HPAI virus (HPAIV) A(H5N6) from Asia to wintering grounds towards Western Europe, similarly to what happened with HPAIV A(H5N8) and HPAIV A(H5N1) in previous years. Furthermore, the HPAI situation in Africa with A(H5N8) and A(H5N1) is rapidly evolving. Strengthening collaborations at National, EU and Global levels would allow close monitoring of the AI situation, ultimately helping to increase preparedness. No human case was reported in the EU due to AIVs subtypes A(H5N1), A(H5N6), A(H7N9) and A(H9N2). Direct transmission of these viruses to humans has only been reported in areas, mainly in Asia and Egypt, with a substantial involvement of wild bird and/or poultry populations. It is suggested to improve the collection and reporting of exposure events of people to AI. 1 Introduction 1.1 Background and Terms of Reference as provided by the requestor Avian influenza (AI) is an infectious viral disease in birds, including domestic poultry. Infections with avian influenza viruses in poultry cause two main forms of that disease that are distinguished by their virulence. The low pathogenic (LPAI) form generally only causes mild symptoms, while the highly pathogenic (HPAI) form results in very high mortality rates in most poultry species. That disease may have a severe impact on the profitability of poultry farming. Avian influenza is mainly found in birds, but under certain circumstances infections can also occur in humans even though the risk is generally very low. More than a decade ago, it was discovered that virus acquired the capability to be carried by wild birds over long distances. This occurred for the HP AI of the subtype A(H5N1) from Southeast and Far East Asia to other parts of Asia, Europe and Africa as well as to North America. In the current epidemic, the extent of the wild bird involvement in the epidemiology of the disease is exceptional. Since late October 2016 up to early February 2017, highly pathogenic avian influenza (HPAI) of the subtype A(H5N8) has been detected in wild migratory birds or captive birds on the territory of 21 Member States (MSs), namely Austria, Belgium, Bulgaria, Croatia, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, the Netherlands, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden and the United Kingdom. In 17 MSs, the virus has spilled over to poultry holdings leading also to lateral spread between holdings in a few MSs, in particular in those with a high density of duck and geese holdings where the poultry cannot sufficiently be protected against contacts with wild birds. A second HP AI subtype A(H5N5) has been detected in wild birds and recently also in poultry holdings in Germany. The number of infected migratory wild birds found dead and the geographical extent of these findings are posing an immense threat for virus introduction into poultry or captive birds holdings as demonstrated by the high number of outbreaks (~ 700 as of 8/2/2017). In the event of an outbreak of avian influenza, there is a risk that the disease agent might spread to other holdings where poultry or other captive birds are kept. As a result, it may spread from one MS to other MSs or to third countries through trade in live birds or their products. There is knowledge, legislation,1 technical and financial tools in the European Union (EU) to effectively deal with outbreaks of avian influenza in poultry and captive birds. However, the very wide virus spread by wild birds and the increased risk of direct or indirect virus introduction into poultry or captive bird holdings has led to the largest HP AI epidemic in the EU so far. This situation calls for a reflection and evaluation how preparedness, risk assessment, early detection and control measures could be improved. The European Food Safety Authority (EFSA) is already carrying out work for an exhaustive scientific opinion on avian influenza with the support of the EU Reference Laboratory (EURL) for avian influenza. That opinion should be finalised by September 2017. This work could benefit from using data from the current epidemic. The Commission and MSs are therefore in need of an epidemiological analysis based on the data collected from the disease affected Member States. The use of the EFSA Data Collection Framework is encouraged given it promotes the harmonisation of data collection. Any data that is available from neighbouring third countries should be used as well, if relevant. Therefore, in the context of Article 31 of Regulation (EC) No 178/20022, EFSA should provide the technical and scientific assistance to the Commission based on the following Terms of Reference (TOR): Analyse the epidemiological data on HPAI and LPAI, where co-circulating or linked within the same epidemic, from HPAI disease affected MSs. Analyse the temporal and spatial pattern of HPAI and LPAI as appropriate in poultry, captive birds and wild birds, as well the risk factors involved in the occurrence, spread and persistence of the HPAI virus in and at the interface of these avian populations. Based on the findings from the points above, describe the effect of prevention and control measures. Provide for regular quarterly reports updating on the avian influenza situation within the Union and worldwide, in particular with a view to describe the evolution of virus spread from certain regions towards the EU. In case of significant changes in the epidemiology of avian influenza, these reports could be needed more frequently. These reports should in particular closely follow the developments of zoonotic avian influenza viruses (such as HPAI A(H5N6) and LPAI A(H7N9)) in collaboration with the European Centre for Disease Prevention and Control (ECDC). 1.2 Interpretation of the Terms of Reference In reply to TORs 1 and 2, this scientific report gives an overview of the HPAI and LPAI outbreaks in poultry and captive birds as well as HPAI events in wild birds detected in Europe between 15 October 2016 and 31 August 2017, mainly based on data submitted by MSs and neighbouring countries via the Animal Disease Notification System (ADNS). A phylogenetic characterisation of the circulating viruses is included as well as a brief genetic characterisation to explain how related/distant viruses are. The affected MSs have also submitted additional epidemiological data to EFSA (see Section 2.1.1), which has been used to analyse the characteristics of holdings affected between October 2016 and April 2017. This data collection required a large effort for the Competent Authorities given the short time available and the high numbers of outbreaks. Bulgaria and France also provided information from their epidemiological investigations on the risk factors involved in the spread of HPAI virus (HPAIV) between holdings (Annexes A and B). The affected MSs made a huge of effort to collect and report data on the outbreaks, which made it possible to provide an overview of the main observations from the 2016/2017 epidemics. On the other hand, it was not possible to collect data for a risk factor analysis on occurrence and persistence of HPAIV within the EU. Risk factor analysis requires also data on the susceptible population (e.g. location of holdings, population structure, etc.), which should be collected in peace time. Limitations in the performed data collection, reporting and analysis are mentioned and recommendations are given on how these activities could be improved. The report provides several examples of definitions that need a common interpretation (e.g. commercial vs non-commercial). This report will be used as a basis to discuss with MSs how improvements could be achieved in a feasible manner and providing useful outcomes to the MSs and the European Commission. A description of the applied prevention and control measures (TOR 3) is reported based on case reports provided by MSs' representatives and attached as Annexes (from Annex C to O) to this report. The main topics covered are increasing awareness, release and repeal of housing order, strengthening biosecurity, preventive culling, implementation of regional stand still, hunting and derogations on restriction zone implementation after a risk assessment. The monitoring of the avian influenza situation in other continents (TOR 4) focuses on HPAI A(H5N6), HPAI/LPAI A(H7N9), HPAI A(H5N1), HPAI A(H5N8) and LPAI A(H9N2). Background and epidemiology, detections, phenotypic and genetic characterisations are described based on information from confirmed human and poultry cases as well as wild bird events reported in 2016–2017. Possible actions for preparedness in the EU are discussed. 2 Data 2.1 Data on animals 2.1.1 Epidemiological data The data on the AI outbreaks submitted by MSs between 1 October 2016 and 31 August 2017 to the European ADNS were taken into account for this report. In addition, MSs were asked to provide more detailed epidemiological data (see data dictionary in Table B.1, Appendix B) directly to EFSA on the AI outbreaks that occurred from October 2016 to 30 April 2017. The data model has been discussed with representatives appointed by the MSs during a teleconference. This was carried out via two rounds of exchanging Excel files via email to the representatives appointed by the 19 MSs.3 The slide presentations, which EU MSs affected by AI presented to the Standing Committee on Plants, Animals, Food and Feed (PAFF Committee), were consulted to extract information on the mortality rates and clinical signs of different species of domestic birds from HPAIV A(H5N8) and A(H5N1) infections, both in single species and multiple species holdings. The PDFs of these slide presentations are available on the European Commission website (European Commission, online). The three MSs (Bulgaria, France and Hungary) that had the highest number of AI secondary outbreaks were also asked to provide more information on these. To collect the information on the dynamics of the AI secondary outbreaks that occurred in the EU between October 2016 and end of April 2017 in a harmonised way, a specific template has been developed, to include: chronological overview of HPAI secondary spread, also indicating when prevention and control measures were implemented to manage the situation; production sector(s) that have been affected; how the secondary outbreaks were detected; role of surveillance and clinical signs in detecting secondary outbreaks; risk factor analysis, including assessment of which were the key risk factors for spreading the avian influenza virus (AIV) within a flock/between holdings; relevant references/evidence (if available). The provided information to EFSA can be consulted in Annexes A and B. 2.1.2 AI prevention and control measures All MSs that expressed their interest in supporting the analysis of the 2016–2017 AI outbreaks were asked to submit case reports on the AI prevention and control measures that have been put in countries that experienced at least one case of HPAI either in wild birds or in poultry. A specific template has been developed, to include: timing of the applied measures, also indicating the event that triggered the measures, and the target audience; actions implemented to inform stakeholders and general public on the epidemiological situation of AI in the MS, to increase the awareness on the AI-related risks; procedures, timing, and territorial extent of any housing order applied in the MS; biosecurity measures (beside the housing order) implemented to guarantee the bioexclusion and/or biocontainment of AI; procedures, criteria and extent of preventive culling measures, when applied, to identify its efficacy; territorial extent and timing of regional standstill, including ban on movements of poultry and eggs, but also game birds release and movements of other captive birds; criteria considered when allowing derogations on the above mentioned restrictions; regulation on hunting, to allow inferences on contact between wild birds and humans. The information provided to EFSA can be consulted in Annexes from C to O. 2.2 Data on humans The collection of numbers of human cases due to infection with AIVs has been performed by experts at the ECDC. Multiple sources are scanned regularly to collect information about laboratory-confirmed human cases, e.g. Disease Outbreak Alert pages at the World Health Organization (WHO),4 webpages of WHO's Regional offices, Chinese Center for Disease Control, health authorities in Hong Kong, CDC in Taiwan5 and others (Chinese CDC, online; Centre for Health Protection (CHP, online); TaiwanCDC, online; WHO, online-f). Data were extracted and collected in line lists. Double entries and validity of data are continuously checked by ECDC duty experts. Line lists have been developed to collect case-based information on virus type, date of onset of disease, country of reporting, country of exposure, sex, age, exposure, clinical information (hospitalisation, severity.) and outcome. All cases included in the line list and mentioned in the document are laboratory-confirmed cases. Literature searches were performed continuously until 8 September 2017 in the PubMed database with the key words: 'humans' and 'A(H5N1)'; 'A(H5N6)'; 'A(H5N8)'; 'A(H7N9)'; A(H9N2)'; and narrowed to the most recent available publications as well as using specific search parameters such as 'seroprevalence'; 'risk factors'; 'transmission'. The literature search was not systematic or comprehensive. The EU MSs were also asked to provide data on the number of people exposed to AIV during culling and destruction activities in the period October 2016–30 April 2017 (see last row Table B.1, Appendix B). This collection was carried out by EFSA via the same files through which the additional (animal) epidemiological data were requested (see Section 2.1). In addition, ECDC performed a survey about the protection measures recommended by the public health authorities during the outbreaks. Most of the participating 22 EU/EEA countries replied to have identified exposed people via the local veterinary services, food safety or agriculture authorities together with the local public health services. However, it was assessed challenging to retrieve comprehensive data on all events where people were directly exposed to infected birds and from all countries. 3 Results 3.1 Overview of HPAI and LPAI outbreaks in Europe between October 2016 and August 2017 (TOR 1 and TOR 2) 3.1.1 Phenotypic characterisation of AI viruses circulating in the EU 3.1.1.1 HPAI in domestic birds Information extracted from PAFF Committee presentations In chickens in single species holdings affected by HPAIV A(H5N8), mortality rates per holding ranged from 3% to 100%,6 but were often greater than 30% (Table A.1, Appendix A). Clinical signs were variable, and consisted of nervous signs including head shaking, ataxia, tremors, diarrhoea and poor general condition. On some holdings, chickens died suddenly without prior clinical signs. At autopsy, haemorrhagic pneumonia and catarrhal or haemorrhagic enteritis were reported. In holdings with multiple species affected by HPAIV A(H5N8), chickens were common (18 of 19 holdings) and usually they had the highest mortality rates (14 of 18 holdings; 6–100%) (Table A.2, Appendix A). In domestic turkeys in single species holdings affected by HPAIV A(H5N8), mortality rates per holding ranged from 0.3% to 100%, but mortality was reported for all affected holdings (Table A.1). In Germany, low mortality was reported at the beginning, followed by high mortality within 24 h. Clinical signs reported were decreased water consumption, nervous signs including depression and mild respiratory signs. In holdings with multiple species affected by HPAIV A(H5N8), turkeys were uncommon (2 out of 19 holdings) and showed mortality in one of these (Table A.2). In other Galliformes in single species holdings affected by HPAIV A(H5N8), mortality was recorded in pheasants (one holding) and peacocks (one zoo) (Table A.1). In other Galliformes in holdings with multiple species affected by HPAIV A(H5N8), guinea fowl (5 out of 19 holdings), quail (2 out of 19 holdings), pheasants (1 out of 19 holdings) and peacocks (1 out of 19 holdings) were present, but mortality only was observed in guinea fowl (2 out of 5 holdings) (Table A.2). No clinical signs were reported for these species, but at autopsy, haemorrhagic pneumonia was observed in affected guinea fowl. In domestic ducks in single species holdings affected by HPAIV A(H5N8), mortality occurred7 (Table A.1). Clinical signs reported were decreased water and food consumption, prostration, respiratory signs and neurological signs including torticollis. The latter were considered typical. At autopsy, severe pancreatitis, severe myocarditis, brain congestion and splenomegaly were observed. However, HPAIV A(H5N8) in a holding of mallard ducks only was detected based on epidemiological investigation; these birds showed neither morbidity nor mortality. In holdings with multiple species affected by HPAIV A(H5N8), domestic ducks were commonly present (12 out of 19 holdings), but mortality was uncommon (4 out of 12 holdings) and lower (from 20% to 30%) than commonly observed in chickens (Table A.2). In contrast with ducks infected with HPAIV A(H5N8), no clinical signs or mortality were observed in domestic ducks infected with HPAIV A(H5N1) in the one event reported by France in the past year. In the one single species holding of domestic geese affected by HPAIV A(H5N8), clinical signs were bloody diarrhoea and neurological signs (Table A.1). In holdings with multiple species affected by HPAIV A(H5N8), domestic geese were commonly present (9 out of 19 holdings), and showed mortality on some of these (4 out of 9 holdings) (Table A.2). Besides Galliformes and Anseriformes, a few other species were held in holdings with multiple species affected by HPAIV A(H5N8): pigeons (8 out of 19 holdings), parrots (2 out of 19 holdings), ostriches (1 out of 19 holdings) and zebra finches (1 out of 19 holdings) (Table A.2). None of these birds showed clinical signs or mortality from HPAIV A(H5N8) infection. Information extracted from the scientific literature There are several publications on the 2016/2017 outbreak of HPAIV A(H5N8) (e.g. El-Shesheny et al., 2017; Kwon et al., 2017; Lee et al., 2017; Marchenko et al., 2017; Nagarajan et al., 2017; Pohlmann et al., 2017; Selim et al., 2017), but only one (Pohlmann et al., 2017) reports on virulence of the virus infection at the species level. This study, on the outbreak in Germany, reports that macroscopic changes commonly observed in poultry included severe diffuse hepatic necrosis, multifocal petechiae and variably hyperaemic and oedematous lungs. Light microscopy confirmed influenza A virus antigen and variably distinct necrotising lesions in liver, heart, lungs, brain, pancreas, spleen and thymus. Some chickens also displayed severe diffuse catarrhal enterocolitis; influenza A virus antigen was present in the intestinal epithelium. Pohlmann et al. (2017) also determined that the intravenous pathogenicity index for a HPAIV A(H5N8) isolate from 2016 (A/tufted duck/Germany-SH/AR8444/2016) in chickens was comparable with that for a HPAIV A(H5N8) isolate circulating in 2014 (A/turkey/Germany-MV/AR2472/2014): 2.93 and 2.81, respectively (Pohlmann et al., 2017). The intravenous pathogenicity index of virus isolated from a turkey (early case in Hungary) was 3.0 (unpublished data of the EURL). 3.1.1.2 LPAI in domestic birds In the PAFF Committee report of November 2016, Germany reported the detection of LPAI virus (LPAIV) H5 in domestic geese (breeding and fattening). No clinical signs or mortality were reported. 3.1.1.3 HPAI in wild birds Pathogenicity in the affected species Information extracted from the World Organisation for Animal Health (OIE) reports The main HPAIV subtype that was identified in carcasses of wild birds submitted for AIV testing was A(H5N8), followed by A(H5N5) (Table A.3, Appendix A). The subtypes A(H5N1), H5N2 and H5N9 (distinct group of viruses from A(H5N8)/A(H5N5)) were also detected in domestic birds in France in this period, but not in wild birds (Table A.3). The reports to OIE provide the numbers of dead birds per virus-positive species, but not the average population size of the affected wild bird species from which wild bird carcasses were obtained, let alone the number of animals at risk in these populations. Therefore, it is not possible to make an objective estimate of the mortality rate to assess the pathogenicity of infection with these subtypes of HPAIV in wild bird populations. Some information may be gained using data on the number of carcasses of the different wild bird species that tested positive for HPAIV during surveillance activities. However, these figures need to be interpreted with caution, because they need to take into account multiple factors, inc
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