Highly pathogenic avian influenza (HPAI) in the UK, and Europe - GOV.UK
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Department for Environment, Food and Rural Affairs Animal & Plant Health Agency Advice Services Team - International Disease Monitoring Updated Outbreak Assessment #24 Highly pathogenic avian influenza (HPAI) in the UK, and Europe 28 July 2021 Ref: VITT/1200 HPAI in the UK and Europe Disease Report Following the unprecedented epizootic of highly pathogenic avian influenza (HPAI) H5 during autumn/winter 2020/2021, there have been no new cases of HPAI H5 in wild birds in the United Kingdom (UK) since early April 2021, and no new outbreaks of HPAI in poultry, or in captive birds, since March. However, in Europe, including France, Germany and Denmark, outbreaks of HPAI H5N8 have continued sporadically in poultry. HPAI H5 cases in wild birds in Europe have greatly decreased since the peak in March, although the virus is still present in wild water birds along the Baltic coasts. Further afield H5 HPAIVs have been reported recently in wild water birds and poultry in southern Russia north of Kazakhstan, and this is an indication that migratory birds could reintroduce the virus into Northern and Eastern Europe this autumn. Situation Assessment The epizootic of HPAI H5 in Europe in autumn/winter 2020/2021 was unprecedented both in the number of neuraminidase (N) subtypes and the number of wild birds affected. While many poultry outbreaks and wild bird cases were reported in European countries, the UK reported 24 outbreaks in poultry and captive birds. Of these most were HPAI H5N8 in England, with Scotland, Wales and Northern Ireland reporting two, one and two HPAI H5 outbreaks respectively as described fully in our previous report (https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_ data/file/987350/Updated_Outbreak_Assessment_23_HPAI_in_UK_and_Europe.pdf). In total, 320 HPAI H5 cases were reported in wild birds in the UK over the autumn/winter 2020/2021 epizootic, with most UK wild bird cases in England, and only a few in Scotland, Wales or Northern Ireland. There have been no new outbreaks of HPAI H5 in poultry or in captive birds (to 30 July 2021) in Great Britain (GB) since 31 March 2021, and no new outbreaks in poultry in Northern Ireland since 12 January 2021. There have been no new positive HPAIV H5 cases in wild birds in the UK since the three dead rooks (Corvus frugilegus) testing positive for HPAIV H5N1 in a rookery in Fife in early April 2021. 1
Department for Environment, Food and Rural Affairs Animal & Plant Health Agency Advice Services Team - International Disease Monitoring HPAI in Europe since 1 June 2021 The map below shows the distribution of HPAI outbreaks in poultry, captive birds and wild birds across Europe since February. Cases of HPAI in wild birds in Europe peaked in March at around 200 per week and have greatly decreased over the summer to
Department for Environment, Food and Rural Affairs Animal & Plant Health Agency Advice Services Team - International Disease Monitoring and ducks) in north-west Germany near to the border with the Netherlands. On 04 July an outbreak of HPAI H5N8 started on a poultry farm (38,000 birds producing eggs for broiler production) in Denmark. France also reported an outbreak of HPAI H5N8 commencing on 03 July in a private backyard premises where five galliformes and 20 palmipeds (duck and geese) were kept without interaction with the professional breeding compartment. The three H5N8 poultry outbreaks reported by the Czech Republic began in mid-April and were reported later to OIE. Table 1: Total number of outbreaks in poultry across Europe 1 June – 28 July 2021 (from OIE) Strain Country H5 H5N1 H5N3 H5N4 H5N5 H5N8 Grand Total Albania 6 6 Bulgaria 1 1 Czech Republic 3 3 Denmark 1 1 Germany 1 1 Netherlands 1 1 Romania 2 2 Russia 1 1 Grand Total 1 15 16 Table 2: Total number of outbreaks in wild birds in Europe 1 June – 28 July 2021 (from OIE) Strain Country H5 H5N1 H5N3 H5N4 H5N5 H5N8 Grand Total Belgium 2 Denmark 1 1 Estonia 6 4 10 Finland 14 2 16 France 1* 1 Germany 12 1 1 2 11 27 Latvia 1 1 Lithuania 2 2 Netherlands 3 1 1 6 11 Norway 7 7 Russia 2 5 Serbia 1 1 Sweden 1 1 15 19 Grand Total 6 39 2 2 3 50 102 *Interpreted here in the text as backyard poultry and not wild birds as suggested in OIE 3
Department for Environment, Food and Rural Affairs Animal & Plant Health Agency Advice Services Team - International Disease Monitoring In wild birds, a total of 102 cases of HPAI H5 have been reported across Europe since 01 June 2021 (Table 2). Of these, over a quarter were in Germany (mainly in the north), with countries on the Baltic Sea (Sweden, Finland, Lithuania and Estonia) accounting for almost half of the cases. Norway, the Netherlands and Belgium together accounted for 20% of the cases. Very few wild bird cases have been reported in south-east Europe with Serbia finding a mute swan with H5N8 in early June. Germany not only has the highest number of wild bird cases reported since 01 June but also the largest range of N subtypes (Table 2) including 12 H5N1 cases in addition to 11 H5N8. However, in terms of a risk to the UK, all of these wild bird cases in Germany started in early May or before. Indeed, only seven of the wild bird cases in Europe have been reported since 01 July. These are the Northern eider ducks (Somateria mollissima) and unidentified geese in Norway and Sweden and the Herring gulls (Larus argentatus) and white-tailed eagle (Haliaeetus albicilla) in Finland and are indicative of sporadic low levels of localised infection. Implications for the UK The main concentration of wild bird HPAI H5 cases continues to be in northern Europe, with relatively few in southern or central Europe. While the number of HPAI H5 cases in wild birds in north-western Europe has decreased markedly since March (when cases rates were around 200 per week), the virus is still sporadically detected in wild birds particularly in southern Scandinavia and countries surrounding the Baltic Sea. It is not known whether the virus is being maintained in these birds or whether they are exposed to residual infectivity in the environment. With such heavy infection pressure over the winter and into the spring a small number of cases would be expected in a residual tail through the summer. However, in the previous two years HPAI was not reported in wild birds in the Baltic region in the summer months. Thus in 2019, although two wild birds of prey were reported with HPAI H5N6 by OIE in January 2019 in Denmark there were no further HPAI cases in wild birds (or poultry) reported for the rest of 2019 in northern Europe or the Baltic region. Similarly in 2020, although there were a few HPAI H5 cases in January, February and March in northern Europe, there were no cases in the Baltic in May through to September, with H5N8 emerging in Germany and the Netherlands in October 2020 and marking the start of the epizootic in northern Europe. Any potential for continued maintenance of the virus in the European resident wild bird population is uncertain, because of uncertainty in population dynamics and the sizes of the immune populations and the immunologically naïve populations of juvenile/first winter water birds which will migrate west through the Baltic coasts to wintering grounds in the Netherlands and the UK this autumn. 4
Department for Environment, Food and Rural Affairs Animal & Plant Health Agency Advice Services Team - International Disease Monitoring Furthermore, there have been continued detections of HPAI H5 in Southern Russia with cases of H5N1 in wild Dalmatian pelicans near the border with Kazakhstan starting in late June 2021 and again in early July 2021 and further east, cases of HPAI H5 in wild ducks and gulls on the border with Mongolia starting in late May (see map below). In comparison to last year, cases of HPAI H5N8 were detected in southern Russia, north of Kazakhstan in early August 2020 with more cases in late August and September 2020 tracking west in southern Russia along the border of Kazakhstan and near to the Caspian Sea. The presence of HPAI H5 in wild birds in this region of Asia during the months of July, August, September potentially presents a source of new introductions of virus into eastern and central Europe in the autumn. Many of the migratory water birds migrating to western Europe and the UK will be immunologically naïve juvenile/first winter birds which present a source of susceptible birds to reintroduce infection in the autumn. Map 2: HPAI outbreaks (from OIE) in poultry, captive and wild birds across Europe and Asia: 1 February 2021 to 28 July 2021. Symbols with a central dot represent those reported in June and July. 5
Department for Environment, Food and Rural Affairs Animal & Plant Health Agency Advice Services Team - International Disease Monitoring The dynamic of the epizootic in wild birds changed as winter progressed into spring earlier this year and will change again as summer moves into autumn and the migratory wild water birds move west from northern Russia and central Europe to overwinter in the UK. At this current stage of the epizootic cycle (i.e. mid-summer), the residual risk of incursion of HPAI H5 in wild birds in the UK will be at a minimum. The high temperatures this summer will have rapidly inactivated much of any residual environmental infectivity. However, the risk to the UK will undoubtedly increase as migratory water birds begin to arrive from late September. Conclusion The risk of HPAI H5 incursion in wild birds remains at LOW. Given all factors with ongoing detections in wild bird populations especially in central Asia and the possibility of HPAI H5 entering eastern or central Europe from southern Russia, the risk level may increase through the autumn. We will continue to closely monitor the situation. The risk of poultry and captive bird exposure to HPAI H5 across the whole GB is still LOW (with HIGH uncertainty) where biosecurity is sub-optimal, and LOW (with MEDIUM uncertainty) where stringent biosecurity measures are applied. It is particularly important that stringent adherence to biosecurity measures are maintained as summer progresses into autumn, so as to prevent disease being introduced to poultry and captive birds, through contaminated fomites and environmental exposure. If you keep poultry (including game birds or as pets), you should follow our biosecurity best practice advice, which can be found here: https://www.gov.uk/guidance/avian-influenza- bird-flu#biosecurity-advice . Remain vigilant for any signs of disease in your flock and report any signs of avian influenza to Defra Rural Services Helpline on 03000 200 301. Further information is available here: https://www.gov.uk/guidance/avian-influenza-bird-flu including updated biosecurity advice for poultry keepers for England; https://gov.wales/avian-influenza for Wales and; http://gov.scot/avianinfluenza for Scotland. The OIE/FAO International Reference Laboratory/UK National Reference Laboratory at Weybridge has the necessary ongoing proven diagnostic capability for these strains of virus, whether low or high pathogenicity AI, and continually monitors changes in the virus on a wide scale whilst utilising global networks to gain early insights to epidemiological trends and potential emergence of new genotypes which might change the risk profile. We will continue to report on any updates on the situation in Europe and, in particular, any changes in disease distribution or wild bird movements which may increase the risk to the UK. 6
Department for Environment, Food and Rural Affairs Animal & Plant Health Agency Advice Services Team - International Disease Monitoring We ask that the public use Defra’s national telephone helpline (Tel: 03459 33 55 77 – please select option 7) to report findings of five or more of any other species found dead in the same location and at the same time. Authors Dr Paul Gale Dr Lauren Perrin Anthony Pacey Prof Ian Brown Joe Bowen References All outbreaks and cases were taken from the World Organisation for Animal Health (OIE). Please note that changes in format and level of detail are due to the change of data source for this report, from EU’s Animal Disease Notification System (ADNS) to World Organisation for Animal Health (OIE). https://www.daera-ni.gov.uk/articles/avian-influenza-ai https://www.gov.uk/guidance/avian-influenza-bird-flu#trade-import-and-export-issues IZSVe (2021) https://www.izsvenezie.com/reference-laboratories/avian-influenza- newcastle-disease/europe-update/ FLI (2021) https://www.fli.de/de/aktuelles/tierseuchengeschehen/aviaere-influenza-ai- gefluegelpest/karten-zur-klassischen-gefluegelpest/ © Crown copyright 2021 7
Department for Environment, Food and Rural Affairs Animal & Plant Health Agency Advice Services Team - International Disease Monitoring You may re-use this information (excluding logos) free of charge in any format or medium, under the terms of the Open Government Licence v.2. To view this licence visit www.nationalarchives.gov.uk/doc/open-government-licence/version/2/ or email PSI@nationalarchives.gov.uk This publication is available at https://www.gov.uk/government/collections/animal- diseases-international-monitoring Any enquiries regarding this publication should be sent to us at iadm@apha.gov.uk 8
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