Rapid risk assessment on incursion of HPAI H5N8 into housed or not housed poultry flocks and captive birds 29 January 2021 Situation as at 26 January 2021 © Crown copyright 2021 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.3. To view this licence visit www.nationalarchives.gov.uk/doc/open-government-licence/version/3/ or email [email protected] This publication is available at www.gov.uk/government/publications Any enquiries regarding this publication should be sent to: [email protected] www.gov.uk/defra 2 Contents Summary ............................................................................................................................................. 4 Introduction ........................................................................................................................................ 6 Hazard Identification ......................................................................................................................... 10 Previous outbreaks of HPAI H5N8: ................................................................................................... 12 Current Situation ............................................................................................................................... 12 Risk Question .................................................................................................................................... 16 Risk Levels ..................................................................................................................................... 16 Entry Assessment .......................................................................................................................... 16 Exposure Assessment........................................................................................................................ 22 Domestic poultry ........................................................................................................................... 24 Captive birds ................................................................................................................................. 25 Ratites ........................................................................................................................................... 25 Game birds .................................................................................................................................... 26 Consequence assessment ................................................................................................................. 26 Conclusions ....................................................................................................................................... 28 Assumptions and Uncertainties ........................................................................................................ 30 References ........................................................................................................................................ 30 Annex 1 ............................................................................................................................................. 32 Annex 2 ............................................................................................................................................. 42 Annex 3 ............................................................................................................................................. 43 Annex 4 ............................................................................................................................................. 46 3 Summary This is an update of a rapid risk assessment undertaken on 26 November 2020 in response to findings of HPAI H5N8 in poultry (on 02 November 2020) and wild birds (09 November 2020). Since then, there have been further findings of HPAI H5N8 in poultry, captive birds and wild birds in the UK, HPAI H5N1 in one backyard flock as well as HPAI H5N1, H5N2 and H5N5 in wild birds. All updates made on 26 January 2021 are shown in red for ease of reference. 1. In October 2020 the risk of AI H5N8 incursion through migratory wild waterfowl was increased to MEDIUM on the basis of outbreaks in north-west Europe. 2. The report of HPAI H5N8 in a broiler-breeder rearing unit flock in Cheshire (AIV 2020/02) on Monday 2 November was the first confirmed event of HPAI H5N8 in GB since 2017. Two wild geese tested positive for HPAI H5N8 in south-west England on 3 November 2020. The risk of AI H5N8 incursion through movements of migratory wild waterfowl was increased to HIGH on 6 November 2020 and then to VERY HIGH in early December. 3. To 26 January, HPAI H5N8 has been detected at 12 poultry premises in England with three outbreaks in captive birds; 1 poultry premises in Scotland; 2 poultry premises in Northern Ireland, with one outbreak of HPAI H5N1 confirmed in poultry in England. To 26 January 2021 the last infected premises detected in GB was in Devon, SW England, on 29 December 2020, while that in Northern Ireland in County Antrim was detected on 11 January 2021. Wales reported an outbreak of HPAI H5N8 on 27 January 2021 at a game rearing establishment. 4. There have been numerous reports of HPAI H5N8 in a range of wild bird species, including migratory birds, resident birds and bridging species (including gulls and a few corvids, namely Eurasian magpies) in Europe and UK. The arrival of wild waterfowl to overwinter in the UK has by and large ended, and numbers are expected to have peaked in December and January, depending on the species and also the weather conditions in Continental Europe. Large populations of migratory water fowl are still present in the UK. These birds will remain here till March/April and will start departing in numbers from early/mid-March. 5. As of 26 January 2021 there were 299 wild bird positive findings of H5 in England, Wales, and Scotland across 41 counties, and 25 different species. Of there, 274 tested were subtyped as H5N8, 10 H5N1, 6 H5N5 and 9 H5Nx. The total number of positive wild birds detected in addition to the detection of multiple H5 HPAI subtypes in the same epidemic event is unparalleled in the UK. 4 6. As a result of the ongoing infection pressure, the risk of AI H5N8 incursion in wild birds is maintained at VERY HIGH. 7. There has been a pattern of spread consistent with previous disease epidemics in which wild bird transmission was a primary factor. There is substantive evidence that spread of H5 HPAI to GB by migrating wild waterfowl has happened on numerous occasions since 2006. 8. Given the large poultry population and the proportion which are outdoor and in regions close to large aggregations of wild waterfowl, we consider the risk of exposure of poultry across the whole GB sill to be MEDIUM (where stringent biosecurity is applied) and still to be HIGH (where biosecurity is sub-optimal). An Avian Influenza Prevention Zone (AIPZ) is in place, and personnel should be taking additional biosecurity measures. 9. Housing free range poultry could reduce the likelihood of infection incursion, by reducing both the direct/indirect contact of free range poultry with wild waterfowl and contact with the contamination in the environment. An EFSA analysis of the 2016/2017 HPAI H5N8 epidemic concluded that housing birds gave a two-fold reduction in risk of virus incursion into poultry houses. However, other measures were equally or more effective (preventing wild bird contact and improving biosecurity measures and education). 10. However, to be effective, housing must be accompanied by thorough biosecurity measures to prevent the disease from being introduced to the poultry through contaminated fomites (e.g. human behaviours affecting spread) or by other items that are taken into or enter the housing. Under some circumstances, it will not be possible to house poultry, captive birds and breeding game birds, whether for practical or welfare reasons relating to their husbandry needs, and so housing will not be universally achieved. 11. An AIPZ was declared in England, Wales and Scotland with additional housing measures that came into force from 14 December 2020. This means all bird keepers in GB (whether they have pet birds, commercial flocks or just a few birds in a backyard flock) are required by law to take a range of biosecurity precautions, including housing their birds (except in very specific circumstances). Any legal requirements to house and take biosecurity measures should be kept under review and adapted as needed to reflect emerging evidence, including levels of compliance with housing and biosecurity measures and the disease picture across Europe. 5 Introduction Across Northern Europe and Russia, and the Middle East since September 2020, HPAI H5N8 infection has been detected in multiple species of wild bird, sometimes prior to the detection of the same virus in various types of domestic poultry. The OIE Reference Laboratory at Weybridge has confirmed this strain is different to the HPAI H5N8 virus circulating in East Europe earlier this year and different to the virus circulating in 2016/2017. Outbreaks and cases (wild birds) reported in the lead up to the first reports of HPAI H5N8 in the UK on 09 November 2020 are shown in Table 1. In early November a rapid risk assessment was undertaken to address the risk of incursion of H5N8 HPAI into housed and non-housed birds (domestic poultry and captive birds) from contact with migratory