Rapid risk assessment on incursion of HPAI (predominantly ... · improving biosecurity measures and...
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Rapid risk assessment on incursion of
HPAI (predominantly H5N8) into
housed or not housed poultry flocks
and captive birds
01 March 2021
Situation as at 01 March 2021
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Contents
Summary ......................................................................................................................... 4
Introduction ..................................................................................................................... 6
Hazard Identification ........................................................................................................11
Previous outbreaks of HPAI H5N8: ......................................................................................13
Current Situation..............................................................................................................13
Risk Question...................................................................................................................15
Risk Levels ...................................................................................................................15
Entry Assessment .........................................................................................................16
Exposure Assessment........................................................................................................18
Domestic poultry ..........................................................................................................20
Captive birds ................................................................................................................21
Ratites ........................................................................................................................22
Game birds ..................................................................................................................22
Consequence assessment ..................................................................................................23
Conclusions .....................................................................................................................23
Assumptions and Uncertainties ..........................................................................................25
References ......................................................................................................................25
Annex 1 ..........................................................................................................................26
Annex 2 ..........................................................................................................................36
Annex 3 ..........................................................................................................................37
Annex 4 ..........................................................................................................................40
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Summary
This is an update of a rapid risk assessment last updated on 26 January 2021. It was
first produced on 09 November 2020 in response to findings of highly pathogenic
avian influenza (HPAI) H5N8 in poultry (on 02 November 2020) and wild birds (09
November 2020). All updates made on 01 March 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
09November 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. When this risk assessment was last updated on 26 January 2021, HPAI H5N8
had been detected at 15 premises in England (poultry and captive birds); 1 poultry
premises in Scotland; 2 poultry premises in Northern Ireland, with one outbreak of
HPAI H5N1 confirmed in poultry in England. There had been 299 wild bird findings of
HPAI H5 in England, Wales, and Scotland in a range of wild bird species, including
migratory birds, resident birds and bridging species (9 in Northern Ireland). The
majority of these were HPAI H5N8. Numbers of wild waterfowl to overwinter in the
UK peaked in January 2021. Therefore, as a result of ongoing infection pressure the
risk of AI H5N8 incursion in wild birds was maintained at VERY HIGH in January
2021, and the risk of exposure of poultry across the whole GB was assessed to be
MEDIUM (where stringent biosecurity is applied) and HIGH (where biosecurity is
sub-optimal).
4. 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. As
of 01 March, there have been 310 wild bird findings of HPAI H5 in wild birds, with no
new positive samples identified since 01 February. Of these, most were reported in
England with only a few in Scotland, Wales, and Northern Ireland. Of the wild bird
samples that have tested positive to date, these have mainly been in indigenous bird
species; of 310, 177 cases were reported in mute swans.
5. Wild bird infection pressure is decreasing. The migratory wild waterfowl
population is significantly reduced, and the frequency of wild bird cases is reduced.
Bridging species still play a role in fomite spread, but this is also decreasing as
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environmental contamination decreases. Therefore, the risk of AI H5N8 incursion in
wild birds has been reduced to MEDIUM (from VERY HIGH).
6. As of 01 March, the total number of HPAI outbreaks in poultry and/or captive
birds in the UK to 01 March, is 22. HPAI H5N8 has been identified in poultry in
England (14), Northern Ireland (2), Scotland (1), game birds in Wales (1), and
captive birds in England (2). HPAI H5N1 has been identified in poultry and game
birds in England (1) and Scotland (1). The most recent of these, where HPAI H5N1
was reported on 11 February, was in Scotland in a game bird rearing and breeding
premises. Given a decreasing wild bird infection pressure, decreasing environmental
contamination, we consider the risk of exposure of poultry across the whole GB to be
MEDIUM. (Risk level is reduced from HIGH, where biosecurity is sub-optimal, to
MEDIUM, where stringent biosecurity is applied.) A medium risk level covers a wider
spread of risk than at high or low, so for locations where biosecurity is suboptimal the
risk level will be higher within the medium band than where biosecurity is good.
7. An Avian Influenza Prevention Zone (AIPZ) is in place, and personnel should
be taking additional biosecurity measures. 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. 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.
8. 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 also effective (preventing wild bird contact and
improving biosecurity measures and education). In order 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 producing spread) or by other items that are taken into or enter the
housing.
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Introduction
Across Northern Europe, 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. In August and
September, cases in wild birds and outbreaks in poultry were reported in Russia and
Kazakhstan; as well as in Israel in September. The first report in Europe was on 16
October in a Eurasian wigeon in the Netherlands.
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 wild waterfowl from Europe during the
2020/2021 winter season. This was reviewed on 26 November 2020 and on 26
January 2021.
Two migration pathways contributed to infected wild waterfowl flying out of central
Russia/Kazakhstan. The first is the Black Sea Mediterranean pathway which
contributed to reported cases in the Middle East (Israel) as birds fly to Africa in
October. European countries along this route would include those in Central and
South-eastern Europe. The second is the East Atlantic route which contributed to
cases in the North European countries, particularly Scandinavia, Germany,
Denmark, Poland, Ireland and GB. There are no clear boundaries between these
migration routes and birds using each will mix in the shared breeding grounds.
Multiple waterfowl species may be found at the same breeding ground sites and at
the same wintering sites. The numbers of HPAI H5Nx cases in wild birds and captive
birds reported in Europe in the week commencing 01 March 2021 are presented in
Table 1.
Table 1: Current outbreaks of HPAI H5Nx in domestic poultry and captive birds
and cases in wild birds (26 January to 19 February), according to official
reporting sources. (Annex 3 lists the wild bird species involved in these reports).
Country
H5 H5N1 H5N3 H5N4 H5N5 H5N8
Total
Poultry
Wild/
Captive
Birds
Wild/
Captive
Birds
Wild/
Captive
Birds
Wild/
Captive
Birds
Poultry
Wild/
Captive
Birds
Poultry
Wild/
Captive
Birds
Austria
2
4 6
Belgium
1
1
2
7
Country
H5 H5N1 H5N3 H5N4 H5N5 H5N8
Total
Poultry
Wild/
Captive
Birds
Wild/
Captive
Birds
Wild/
Captive
Birds
Wild/
Captive
Birds
Poultry
Wild/
Captive
Birds
Poultry
Wild/
Captive
Birds
Bulgaria 4
4
Czech
Republic
4
4
Denmark
1
1 36 38
Finland
2 2 4
France
1
11 1 13
Germany
3 1
4 10 48 66
Hungary
3
3
Ireland
4 4
Italy
1 1
Latvia
4 4
Luxembourg
4
4
Netherlands
1
1
Norway
3 3
Poland
1 12 3 16
Romania
3
3
Russia
1 1 2
Spain
1 1
Sweden
1
1 2
Switzerland
2
2
8
Country
H5 H5N1 H5N3 H5N4 H5N5 H5N8
Total
Poultry
Wild/
Captive
Birds
Wild/
Captive
Birds
Wild/
Captive
Birds
Wild/
Captive
Birds
Poultry
Wild/
Captive
Birds
Poultry
Wild/
Captive
Birds
Ukraine
3
3
Total 4 1 1 5 3 1 11 51 109 186
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An Avian Influenza Prevention Zone (AIPZ) has been declared in England, Scotland
and Wales (effective from 5pm on the 11 November 2020) with the requirement for
additional housing measures in force from 14 December 2020. This means all bird
keepers (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). Elsewhere, a
housing order has been put in place in the Netherlands, southern Norway and in the
north German state of Schleswig-Holstein. In Italy, a housing order for poultry was
established in high risk areas in October 2020; this was expanded nationwide at the
end of November. In Denmark, from November 2020, birds (excluding ducks and
geese) should be kept inside, although if area is less than 40m2 need only be
“protected from entry of wild birds”. The Hungarian CVO has enforced “closed
keeping of birds”. Ireland introduced housing measures for poultry and captive birds
on 21st December 2020 (PAFF, 2021). The orders may cover just certain sectors of
commercial poultry and certain high risk areas. In the epizootic of 2016/2017, many
EU MSs put in place a housing order.
The effectiveness of a housing order is difficult to assess. In 2016/2017 it is possible
there would have been a higher number of outbreaks without an order in place;
however, in France, Germany and Hungary, countries with the highest number of
outbreaks and with housing orders in place, there was secondary spread, indicating
poor biosecurity in some sectors, rather than primary contact with wild birds per se.
Last year, the EU warned that secondary spread between establishments keeping
anseriforme species was observed (PAFF, 2020).
EFSA carried out a comprehensive review of the outbreaks of HPAI H5N8 in
2016/17 to assess the risk of introduction into poultry from migratory and residential
wild birds (EFSA, 2017). The opinion concluded that once virus is introduced to a
wild bird population, a critical population size is required before virus amplification
and further wild bird-associated geographical spread of the virus can take place.
Therefore, there is an increased likelihood of incursion into poultry farms most
closely located to large gatherings of wild birds (including but not exclusively
waterfowl) of target species1 during the migration season. Once the migratory birds
leave (from March onwards usually) the risk of incursion usually reduces but in cases
in which non-migratory birds are still testing positive, there will be a continual, albeit
lower, risk.
The opinion also concluded that the relative risk reduction for entry is three fold by
preventing access to water bodies, that housing gives a further two fold reduction,
1 The list of target species is available in Annex II Part 2 of Commission Decision 2010/367/EU on the implementation by Member States of surveillance programmes for avian influenza in poultry and wild birds.
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and by applying routine biosecurity there is a further four fold reduction in risk while
high biosecurity is a 44 fold reduction in risk.
The opinion recommends that the following biosecurity measures for housed birds
which should be applied are: separating from wild birds; separate waterfowl from
gallinaceous poultry; provide potable drinking water; implement a hygiene lock for
each poultry house and provide biosecurity training to all personnel. For non-housed
birds, it was recommended to restrict access to birds for people and provide
biosecurity training to personnel as the most feasible and sustainable measures. At
all times, feed must be provided indoors only, wild bird access should be restricted;
and contacts with other poultry premises limited. Feed and water could be provided
under a roof or a horizontal fabric for non-housed birds. The opinion used expert
knowledge elicitation to gather evidence on the biosecurity measures and a lack of
biosecurity awareness in the staff on sites was commonly reported.
A further supporting document to EFSA opinions on the risk of introduction of HPAI
into poultry farms in general (EFSA, 2017a) was a systematic review of previous
outbreaks to identify risk factors and concluded that the main risk factor for
introduction is contact with wild birds or fomites contaminated with wild bird faeces.
Other important risk factors were poultry species (waterfowl and turkeys are higher
risk); production system, where outdoor systems are higher risk than indoor; and
presence of biosecurity flaws.
This rapid risk assessment is aimed at providing advice around the most appropriate
form of prevention zone order for the different sectors and establishing a body of
evidence to help make decisions around mandatory housing.
Under article 6(1) of the Avian Influenza and Influenza of Avian Origin in Mammals
(England) (No 2) Order 2006 (“the Order”), the Avian Influenza and Influenza of
Avian Origin in Mammals (Scotland) Order 2006 and the Avian Influenza and
Influenza of Avian Origin in Mammals (Wales) (No 2) Order 2006, the Secretary of
State must carry out a risk assessment in order the declare an Avian Influenza
Prevention Zone.
Measures to reduce the risk of transmission of avian influenza
6.—(1) If, after carrying out a risk assessment, the Secretary of State considers such action necessary to reduce the risk of transmission of avian influenza to poultry or other captive birds from wild birds or from any other source, he must—
(a) declare an avian influenza prevention zone in all or part of England/Scotland/Wales; or
(b) serve or require an inspector to serve a notice on the occupier of any premises where poultry, other captive birds or any categories of poultry or captive birds specified in the notice are kept.
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(2) A declaration or notice under paragraph (1) must impose such measures as the Secretary of
State considers necessary to reduce the risk of transmission of avian influenza.
(3) When deciding the measures to impose under paragraph (2), the Secretary of State must consider whether measures are necessary—
(i) to prevent direct or indirect contact which wild birds might otherwise have with poultry and other captive birds;
(ii) to reduce the risk of feed and water provided to poultry and other captive birds being contaminated with avian influenza virus; and
(iii) to reduce the risk of the spread of avian influenza between premises.
(4) The power of the Secretary of State to impose measures by declaration or notice under this article includes the power—
(a) to require poultry and other captive birds to be housed or otherwise kept separate from
wild birds;
(b) to require poultry or other captive birds or categories of such birds specified in the
declaration or notice to be housed or otherwise kept separate from other poultry and captive
birds;
(c) to require that poultry and other captive birds are provided with feed and water to which
wild birds have no access;
(d) to require keepers of poultry and other captive birds and others who come into contact
with such birds to cleanse and disinfect their footwear and take such other biosecurity
measures as a veterinary inspector or an inspector under the direction of a veterinary
inspector may require;
(e) to ban or limit the collection of poultry or other captive birds at any fair, market, show,
exhibition, race or other gathering;
(f) to ban or limit the use of birds of the orders Anseriformes (including ducks, geese and
swans) and Charadriiformes (including gulls, murres, terns, avocets, puffins, woodcock,
oystercatchers, sandpipers, plovers, surfbirds, snipes and skimmers) as decoys during bird
hunting.
Hazard Identification
The hazard identified is the avian influenza virus, predominantly HPAI H5N8, but
other virus subtypes have been detected including H5N1, H5N2, H5N3 and H5N5.
Viral material has been detected, and where viable samples submitted, virus has
been isolated from poultry report cases (outbreaks) and wild birds in the UK during
the current epizootic, at the World Animal Health Organisation (OIE) and Food and
Agriculture Organisation (FAO) International Reference Laboratory (IRL) for Avian
Influenza (AI) at the Animal and Plant Health Agency (APHA). The IRL have utilised
frontline molecular assays and whole genome sequencing techniques to define the
genetic composition of the causative agent.
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The virus from the GB outbreaks maps across the whole genome with the H5N8
viruses (reported by the laboratory as part of an international collaboration) found
elsewhere in Europe (multiple countries), Middle East and Central Asia (including
Russian Federation and Kazakhstan) during the last 6 months.
Importantly, despite the detection of numerous different H5Nx isolates, the
haemagglutinin (HA) gene is highly conserved (amongst isolates characterised from
the 2020/21 epidemic to date) and all H5 HAs detected cluster within the same
clade, designated as clade 2.3.4.4b. This is important as the composition of
haemagglutinin gene underpins fundamental virus properties such as infectivity and
transmissibility. Certainly, the topology of the phylogenetic tree for the HA gene
indicates that all UK report case isolates detected during Autumn/Winter 2020/2021
(including 17 H5N8 and 1 H5N1) cluster within clade 2.3.4.4b alongside all European
isolates for which sequence is available. These viruses also cluster with H5N8,
H5N5 and H5N1 HPAI viruses from the across the EU, and Russia, again within
clade 2.3.4.4b. Interestingly, the H5N1 viruses from the UK and EU cluster together
whilst the UK H5N5 and H5N8 viruses group together on the HA phylogenetic tree
as a main Autumn/Winter 2020 cluster. All Autumn/Winter 2020 detected viruses
cluster separately from the H5N8 viruses responsible for the outbreaks in Europe in
late 2019- early 2020. Specifically, the HA gene appears to descend from the HPAI
H5N8 viruses which caused the previous epidemic wave that caused outbreaks
across the Eurasian and African continent in 2017-2018, and is highly related to the
H5N8 viruses which have been circulating in Egypt since 2017 with the closest
genetic linkage being an isolate detected in Iraq in May 2020.
In contrast, the genetic signatures of the three H5N1 viruses are almost identical and
cluster together across all genes. These isolates are postulated to result from
multiple reassortment events with LPAI viruses circulating in wild birds in Eurasia,
from which they have acquired six (PB2, PB1, PA, NP, NA and NS) out of eight gene
segments. Whether this reassortment event has occurred in Europe or Asia is an
issue that cannot be assessed from the data available to date.
Wild bird cases in England, Wales, and Scotland have tested positive for HPAI
H5N1, H5N5, and H5N8. The detection of three H5 HPAI subtypes in the same
epidemic event is unparalleled in the UK or indeed at European level. All these
viruses are genetically closely related through their haemagglutinin gene, which is
the key viral gene influencing pathogenesis, host range, transmission, and host
immunity. Continued virus evolution by either genetic shift (reassortment) or genetic
drift (accumulation of mutations in a single genome segment) in wild birds is not
unexpected, although to date evidence for either process is minimal.
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Previous outbreaks of HPAI H5N8:
In 2014/2015 several outbreaks of H5N8 HPAI were detected in poultry in Europe
(Germany, Italy, Netherlands and GB) all in housed birds and were attributed to
indirect contact with infected wild waterfowl. In the Netherlands, there were four
separate incursions and two were linked premises. In Germany, there were just two
separate introductions and, in both Italy and GB (England), only single premises
were affected. No direct links were found between the different countries. Wild
waterfowl testing positive for H5N8 HPAI were only detected in Netherlands and
Germany, in Eurasian wigeon and teal, after the outbreaks had been notified. No
significant wild bird mortality was observed in 2014/2015.
In the HPAI H5N8 2016/2017 epizootic, virus spread rapidly in migratory and non-
migratory wild waterfowl in Europe causing mortalities in these birds. This was
strikingly different to previous years and indicated a change in the virus pathogenicity
for certain species of bird. By the end of the season most EU countries, as well as
Europe, the Middle East and parts of southern and west Africa had reported cases of
this virus.
Current Situation
There is currently a lack of evidence for whether some species of wild waterfowl are
asymptomatically infected with this virus strain and whether the virus can continue to
circulate silently or with minimal clinical disease in non-migratory, sedentary birds.
However, considering the number of birds found dead in non-breeding sites across
Europe (in the hundreds) compared to the total number of birds in these sites (likely
to be in the many thousands), it is feasible that the virus is circulating widely with low
mortality (see Map 1).
This pattern of geographical distribution follows that seen for the epizootic of H5N1
HPAI in 2005/2008 in Europe, and in H5N8 HPAI in 2016/2017 in Europe. In those
years, spread occurred along a similar route of migratory wild waterfowl causing wild
bird die-offs in North and Central Europe (see maps 2 and 3). Therefore, the
2020/2021 epizootic is following a similar pattern of transmission in wild birds and
spill-over into domestic poultry as was observed with HPAI H5N8 in 2016-2017, and
H5N1 HPAI in 2005 – 2008 and it can be expected that the current H5N8 HPAI
epizootic will continue to cause issues with the poultry sector for several months to
come, as the virus continues to circulate in both migratory and non-migratory
waterfowl in Europe.
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Map 1: Current outbreaks and wild bird cases of H5N8 HPAI (as of 19
February). OIE ongoing outbreak data is only available until 19 February.
Map 2: Outbreaks and wild bird cases of HPAI H5N8 in Europe in 2016-2017
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Map 3: Outbreaks and wild bird cases of H5N1 HPAI in Europe, North Africa
and the Middle East in 2005-2008
Risk Question
What is the risk of incursion of HPAI (predominantly H5N8, but other virus subtypes have
been detected including H5N1, H5N2, H5N3 and H5N5) into housed and non-housed birds
(domestic poultry and captive birds) from contact with wild birds (resident species and
migratory wild waterfowl) during the 2020/2021 winter season?
Risk Levels For the purpose of this risk assessment, the following EFSA-derived definitions will
be used:
Negligible So rare that it does not merit to be considered
Very low Very rare but cannot be excluded
Low Rare but does occur
Medium Occurs regularly
High Occurs very often
Very high Events occur almost certainly
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Entry Assessment
The wild waterfowl population in GB is relatively well understood. Several NGOs
conduct regular surveys for the wild waterfowl at known wintering and breeding sites
across GB. In particular, the British Trust for Ornithology (BTO), the Royal Society
for the Protection of Birds (RSPB) and the Wildfowl and Wetlands Trust (WWT) carry
out counts of wild birds. Their evidence shows the sites of the largest waterbird
aggregations in GB (see Figure 1). The Wash is one of the premier sites for
wintering waterbirds in GB with over 300,000 birds counted each year, while other
top ten sites include the Somerset levels, the Dee estuary, the Humber estuary and
the Ribble, Alt and Mersey estuaries, but there is a variation of at least 10% from one
year to the next, attributed to the winter weather conditions. There are 53 sites with
at least 20,000 birds wintering year after year across GB.
Figure 1. Wild bird assemblage abundance in GB, derived from 109 species
considered most relevant for the transmission of AI to poultry flocks. (From
Hill et al. (2019) Scientific Reports 9:19973)
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In terms of migration, wild waterfowl arrive in GB from Northern Europe from August
and numbers generally peak in December to January. Annexe 2 gives estimated
numbers of wild birds entering the UK during this period (Flutest project, 2014).
While some species, such as swans, will be site loyal from one year to the next,
others will be less so, and there will be mixing between species in the large
aggregation sites.
Outward migration has already started and, as this year appears typical of an
‘average’ spring season, it is most likely that a substantial proportion of the migratory
birds will have left the UK by the end of March if the warm weather continues here
and there is no extreme cold weather event in continental Europe. In this respect,
the UK may differ from northern European member states in that the winter
populations of some species here will vanish, or diminish considerably, as a
consequence of eastwards migration to breeding sites. In contrast, substantial
populations of these same birds will continue for some weeks in European countries
at traditional aggregation sites along the North Sea and Baltic coasts which form part
of the eastwards flyway, representing winter migrants leaving European sites slightly
later, as well as migrants from the UK and western areas joining them at stop-over
sites. At this point in the outbreak, reports of cases in wild birds and outbreaks in
poultry in Europe are likely to continue for longer than in UK, given a higher ongoing
infection pressure in northern and central Europe.
There is evidence that resident birds (species which breed here and can be relatively
sedentary) have also been infected, may continue to circulate viruses and
consequently act as an ultimate source of infection to livestock. However, changes
in their behaviour may also reduce this risk, as birds make regional or
neighbourhood scale movements from moderate aggregations on larger waters into
smaller groups at their breeding sites on small waterbodies. This change in
population structure and contact behaviour ought to reduce the circulation of virus
(as was experienced in 2016/17).
There is a system for wild bird surveillance in GB, whereby found dead birds from
target species are reported either by wardens at reserves and wetland sites, or by
the public for testing at the NRL. As of 01 March 2021, there were 310 wild bird
positive findings of H5 in England (276), Wales (6), Scotland (19) and Northern
Ireland (9). 284 submissions tested were subtyped as H5N8, ten submissions were
H5N1, six submissions were H5N5, one submission was H5N3 and nine
submissions were H5Nx (as unidentifiable H5 subtypes). 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. HPAI H5N8 virus has been
identified in a range of wild bird species (both migratory and resident birds), with
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mute swans, greylag geese and Canada geese representing the majority of
detections. These species are listed in Annex 4.
Bridging species include several resident populations, such as various gulls (e.g.
Herring gull) and corvids (e.g. Eurasian magpie), with some testing positive for HPAI
H5N8 both here and on the Continent (Annex 3 & 4). These species are
distinguished by their propensity to scavenge potentially infected carcases, habit of
aggregating into large groups in winter (gulls often night roost in very large
aggregations on waterbodies along with wildfowl; corvids in substantial mixed
species assemblages in trees) as well as their boldness and habit of exploiting farms
for forage. Corvids and especially gulls are also mobile and may cover significant
distances every day between their night roosts, widely separated foraging locations
and loafing sites. As well as representing a potential source of infection (when
diseased), they may also have a role in fomite transmission from areas where there
is environmental contamination. At this stage in the outbreak, bridging species still
play a role in fomite spread, but this is reducing as environmental contamination
decreases.
We therefore consider the likelihood of there being infected wild waterfowl present in
GB is MEDIUM as a country-wide assessment. However, there will be regional
variation, based on the proximity to aggregation sites for non-breeding wild waterfowl
(MEDIUM uncertainty).
Exposure Assessment
There are multiple pathways for the exposure of poultry to notifiable avian diseases
(Defra, 2018).
These include:
• Contact with infected poultry such as live birds, hatching eggs and day old
chicks of poultry
• Contact with live infected wild birds, particularly waterfowl
• Contact with poultry products and by-products of infected poultry,
• Contact with contaminated feed, water, bedding, equipment, vermin or
clothing / footwear of people in contact with infected birds or contaminated
environment.
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Biosecurity advice which poultry keepers should practise at all times of the year are
focussed on these pathways as there is a constant low risk of incursion from any
notifiable avian disease being introduced into poultry because LPAI viruses circulate
constantly in wild waterfowl. The EFSA report from 2017 used a combination of
systematic review of all poultry outbreaks and expert knowledge elicitation from
members of the poultry sectors. What was clearly stated in the expert knowledge
elicitation was the need to not only implement biosecurity measures which are
feasible and sustainable but also the importance of training poultry workers in what
these measures mean.
Contact with live infected wild birds, particularly waterfowl:
Housing birds will reduce direct contact with wild waterfowl (both residual migrants
and resident species). It will not prevent any of the other pathways through which
disease may enter a poultry premises. Other biosecurity measures will be more
important. The likelihood of contact with wild waterfowl will be dependent on the
number of such species nearby and how attractive the premises are to birds. The
presence within the poultry premises of a pond or open feed bins are two well-known
factors which make direct contact with wild waterfowl more likely for poultry with
access to the outside environment, as well as encouraging bridging species to
regularly visit premises.
Expert opinion is that the virus will retain infectivity in the environment at low
temperatures, at least to 21 days at 4oC and 8.4 days at 20°C. Initial data indicate
that the current H5N8 HPAI virus has extended survival properties when compared
to the 2016 H5N8 virus that had survival properties of 14 days at 4°C and 6 days at
20°C. Ultimately, this suggests that the 2020/21 isolate lasts 50% longer at 4°C and
40% longer at 20°C than the H5N8 characterised in 2016/17. As higher
temperatures, sunlight intensity and day length reduce virus survival, it is probably
too early to say that there has been much environmental decay. Without further
bouts of cold weather, environmental decay will be starting.
As the most likely contact of poultry kept outdoors with wild waterfowl will be in those
areas where there are high concentrations of these species, the likelihood of direct
contact with wild waterfowl or indirect contact with their faeces would be greater for
those poultry establishments in close proximity to, or with sites attractive to, wild
waterfowl. Therefore, where there are no large aggregations of wild waterfowl, the
risk is lower for this particular pathway, but there are still other pathways which could
lead to the introduction of any notifiable avian disease. It is worth reiterating that H7
LPAI viruses which circulate in wild waterfowl, when introduced into housed layer
hens, have been known to mutate into HPAI which is a more disruptive infection to
control, due to the increased size in control zones.
20
Although in the 2016/2017 season, the outbreaks in commercial poultry
establishments in GB were all housed birds, since not all poultry premises
throughout GB were tested, it is not possible to say whether outdoor flocks were
exposed and did not exhibit clinical signs.
Incursion through imported live animals or products:
For the other pathways, contact with other live birds (i.e. trade in poultry, hatching
eggs, day old chicks) will be dependent on the business itself and the commercial
activities. Contact with products or by-products from infected birds will be dependent
on the activities of people entering the premises and bringing such products with
them and it should be noted that swill feeding is not legal. These will not be
addressed in detail for this assessment. However, housing birds will not impact on
this risk.
Contact with contaminated feed, water, bedding, equipment, vermin or clothing /
footwear of people in contact with infected birds or contaminated environment:
Contamination of feed, bedding and water by wild birds can be prevented by
sourcing such products from safe sources and keeping such items in containers
which no wild birds can access. The site can be made less attractive to wild
waterfowl by preventing access to any ponds on site or excluding ponds and pools of
standing water from the range and making sure feeding areas are protected.
Contact with contaminated equipment, footwear and clothing can be prevented by
making sure all personnel in contact with the birds use disinfectants appropriately.
This will be particularly important where birds are housed, as contact with the birds is
more frequent, as feed, bedding and water must be brought into the houses and
birds must be checked for welfare issues or eggs collected from inside the houses.
Visitors to the farm should also be recorded for security and to help tracing
exercises. Other biosecurity practices should be employed to ensure wild birds are
separated from flocks such as feeding birds indoors or under cover, discouraging
wild birds from landing, removing wild bird contamination and draining watercourses,
removing feeders and water stations from the range, ensuring good building
maintenance and regular inspections for signs of wild bird/rodent access. Vermin
control is strongly recommended because rodents act as fomite spreaders.
Above all, the EFSA opinion recommended ensuring all personnel are trained in, and
practise, good biosecurity, regardless of whether birds are housed or not.
Domestic poultry
The GB poultry sector is complex and seasonally variable. There is a requirement for
all poultry keepers in England, Scotland and Wales with more than 50 birds to be
21
registered with the British Poultry Register. For fewer than 50 birds it is voluntary.
Therefore, any data available will not necessarily include the backyard or smallholder
community. In comparison to data available in 2013, the outdoor chicken sector has
decreased from 62% of total holdings to 30% in 2018.
The poultry sector can be designated in the following way with the various
populations according to the 2018 poultry register. The “outdoor” label is only an
estimate and the NCP Salmonella survey estimates the free range population to be
55% of the layer birds and 18% of turkeys.
Poultry Type Number of
Birds
As proportion
of total
population
Number of
holdings
As proportion of
total poultry
holdings
Total Chickens 270986618 85.45% 10125 51.98%
Outdoor
Chickens 33500062 10.56% 5879 30.18%
Layers 47186064 14.88% 5454 28.00%
Broilers 166134899 52.39% 1663 8.54%
Total Turkeys 8462070 2.67% 1069 5.49%
Outdoor
turkeys 1642191 0.52% 443 2.27%
Total ducks 4108083 1.30% 1364 7.00%
Outdoor ducks 981325 0.31% 878 4.51%
Total geese 146332 0.05% 187 0.96%
Outdoor geese 116826 0.04% 125 0.64%
Total CDGT 283703103 89.46% 12745 65.43%
Total Pheasant 23918729 7.54% 4733 24.30%
Total Partridge 9512172 3.00% 2001 10.27%
Total Poultry 317134004 19479
Captive birds
Captive birds, such as those held in collections, zoos or approved bodies are already
semi-housed and should be kept separate from wild waterfowl. For some, this will be
difficult to prevent access to their water environment (penguins, pelicans, flamingos
etc), but it is unlikely it will be possible to house indoors, so every effort should be
made to prevent wild waterfowl access. There were outbreaks in captive birds in
Europe (in zoos) in 2016/2017 and a derogation exists in EU legislation which means
birds may not have to be destroyed, unless they are in contact with the infected
collection.
22
Ratites
Ratites, such as ostriches, cannot be housed on a long term basis. Outbreaks of
closely related H5N8 HPAIV have been reported in commercial ostriches in South
Africa since 2017. Ratites are therefore susceptible to some strains of HPAIV at least
and there has been a case in Germany of an emu showing clinical signs in a zoo and
therefore these birds should also be considered susceptible.
Game birds
The majority of game birds have already been released for the shooting season and
therefore are considered wild birds and outside the scope of a prevention order
around housing. Some will still be kept in pens and could not be housed due to
welfare issues, therefore the pens themselves would need to be netted where
possible to ensure the birds cannot escape and forage locally. Game bird keepers
should use the guidance
https://www.gfa.org.uk/user_files/uploads/Bird_Flu_and_Gamebirds.pdf
Captive birds used as decoys would be at risk of increased contact with wild
waterfowl. If they remain at one place for the duration of the fowling season, then
they will not come into contact with domestic poultry; however, if the birds are moved
around to other sites or spend any time at a premises where domestic poultry are
kept, this is an increased risk for the poultry. It is illegal to release by hand captive
birds for the purpose of being shot immediately after their liberation, under Part 1,
Section 8 of the Wildlife and Countryside Act, 1981.
Given the large poultry population and the proportion which would be outdoor and in
the regions close to the large aggregations of wild waterfowl, we consider the risk of
exposure of poultry across the whole GB to be MEDIUM (MEDIUM uncertainty). A
medium risk level covers a wider spread of risk than at high or low, so for locations
where biosecurity is suboptimal the risk level will be higher within the medium band
than where biosecurity is good. Twenty-two infected premises have been identified
across England, Scotland, Northern Ireland and Wales. Furthermore, HPAI H5N8
(and other subtype combinations) has been confirmed in many wild birds in England,
Scotland, Wales and Northern Ireland. An AIPZ is in place, and personnel should be
taking additional biosecurity measures. The pathways which lead to disease
incursion are not prevented by housing per se, but housing birds is a risk reduction
measure.
23
Consequence assessment
Any outbreak of notifiable avian disease has a significant impact on GB poultry
industry, through the trade and economic impacts on the producer and the sector.
This is the same for any notifiable avian influenza virus. Average costs to
government may be between £2 and £4 million per outbreak, depending on the
number of birds involved and time taken to complete secondary C&D and return to
disease free status.
Housing birds which are not used to housing can cause welfare issues. Making sure
their environment is enriched (e.g. with toys), that they have plenty of room to move,
access to feed and water, clean bedding and the ability to display natural behaviours
are all welfare priorities. For ducks, their bedding must be changed regularly as they
will mess it quickly and they need access to water so they can clean their feathers. If
the birds become stressed, they may be more prone to infections or other
behaviours which impact on welfare. Certain species cannot be housed for welfare
reasons or because they are already considered wild: geese, ratites and gamebirds.
GB is required to deliver surveillance for H5 and H7 LPAI incursions in poultry
(including H5 and H7 HPAI in Anseriformes) under Council Directive 2005/94/EC
and Commission Decision 2010/367/EU. An option for Risk Based Surveillance is
available and has been applied in GB since 2012. The output of the model used for
the risk based targeting of surveillance in poultry identified 2231 10km grid squares
where wild waterfowl and registered poultry flocks are co-located as identified from
2016 “Sam” (APHA’s registration database) and British Trust for Ornithology data.
For these grid squares, a risk score >0 could be assigned and then ranked into 6
bands of equal numbers of grid squares (approximately 373 in each rank) – where
Rank 1 represents the lowest and rank 6 the highest risk. The remaining areas of GB
where no poultry premises were registered have been assigned a “zero risk” score
even though non-commercial poultry may be resident and wild waterfowl abundant.
The actual risk of AI incursion therefore will not be “zero” in these areas.
Conclusions
Housing should only be applied in conjunction with other biosecurity measures, but it
should be noted that it will not be effective if used as a single measure. The trigger
for such an order should be associated with a primary case in wild waterfowl or high
confidence that a poultry outbreak is related to contact with wild birds.
In the current outbreak to 01 March 2021, there have been fourteen outbreaks of
HPAI H5N8 in poultry confirmed on premises in England; one outbreak confirmed on
24
a premises in Scotland; one outbreak confirmed in game birds in Wales, and two
outbreaks confirmed in Northern Ireland. There have also been two reports of HPAI
H5N8 in captive birds in England, one report of H5N1 in backyard chickens, in
England; and one report of H5N1 in gamebirds in Scotland (which was the most
recent of these reported on 11 February).
In GB the sensitivity of our wild bird avian influenza surveillance has been increased
to ensure collection and analyses of any number of targeted species of wild birds
(essentially ducks, geese, swans, gulls and birds of prey) known to carry risk of
infection with AI viruses. Single dead birds of target species where possible will be
collected and tested.
The HPAI H5N8 virus is circulating and established in resident wild waterfowl, as
happened with HPAI H5N1 in 2005-2008, and sedentary wild waterfowl species have
been the majority of wild bird-positive cases. Given the time of year, the higher
survival rate of this particular H5N8 virus in the environment during winter means the
risk of environmental transmission remains, and hence, the continued risk of
secondary spread into indigenous UK wild bird species and naïve non-indigenous
species. Higher environmental temperatures, together with increasing sunlight
intensities are likely to be starting to reduce environmental levels of H5N8 and the
associated risks.
At the beginning of March, migrating waterfowl are leaving the UK with most having
left the UK by the end of March, should current weather conditions continue.
Resident birds will now play a more important role in any residual spread of virus.
Bridging species will play a less important role in onward spread of virus given the
decrease in environmental contamination.
The following conditions will be used to inform when the risk levels will be reduced.
Firstly, the time of year and if our migrant non-breeding waterfowl have left GB;
secondly the period of time that has lapsed since the last reported case, and, if there
is a significant reduction in infection pressure from the Continent; thirdly if the
temperature has started to increase with higher sunlight levels, then the
environmental contamination and transmission would be reduced.
As the housing order has been applied, an exit strategy is now required and this
should also be based both on a risk assessment and other epidemic considerations.
However, an expectation of no wild bird cases could be disproportionate i.e. one
case per week when surveillance sensitivity has been maximised will not correlate
with a very high wild bird risk. The housing order was introduced on the basis of
numerous wild bird cases and several poultry outbreaks and the same criteria in
25
reverse could be used as an exit strategy in addition to using the three scientific
conditions above to inform the risk assessment.
Assumptions and Uncertainties
• The wild bird counts for this year are not known and we are using an annual
assessment based on previous years.
• Other wild waterfowl species (although this assessment considers the most
abundant) may also be important for the transmission of this virus.
• Gulls as both a source of direct infection, or a vector of environmental contamination
remain a potential threat, though considerable uncertainty is produced by their
mobility as well as their behaviour (scavenging infected carcases, aggregating with
wildfowl, exploiting farms for forage)
• The evidence for the economic benefits and dis-benefits of housing birds is not part
of this assessment.
• The 2016/2017 epidemic allowed experts to analyse the likely risk factors leading to
an incursion of avian influenza and while housing birds was assessed as giving a
twofold reduction, other factors such as preventing access to wild birds (three fold)
and improving biosecurity (four fold) are also significant.
• While housing may prevent direct contact with wild waterfowl, it could increase
indirect contact with contaminated environment and the birds may be under stress,
leading to more disease transmission and greater likelihood of viral mutation. Regular
contact with wild birds and their LPAI viruses may produce an environmental
“vaccine” protection against HPAI viruses.
References Defra (2018)
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_da
ta/file/759784/ai-rationale-hras-nov2018.pdf
EFSA (2017) https://www.efsa.europa.eu/en/efsajournal/pub/4991
EFSA (2017a) https://efsa.onlinelibrary.wiley.com/doi/abs/10.2903/sp.efsa.2017.EN-1282
Gale, P. et al. (2014) entry of H5N1 highly pathogenic avian influenza virus into Europe
through migratory wild birds: A qualitative release assessment at the species level. Journal
of Applied Microbiology 116, 1405-1417.
PAFF (2020) https://ec.europa.eu/food/sites/food/files/animals/docs/reg-
com_ahw_20201020_pres_hpai_efsa.pdf
26
Annex 1
Data on migratory waterfowl in Scotland
Wintering sites in
Scotland
Origin HPAI priority
for Scotland
Bewick’s Swan Does not tend to winter
in Scotland. Previously
flew through Scotland
from Netherlands to
Ireland, but less so
now
Western Siberia Very low
Whooper Swan Caerlaverock, grazes
in fields so could
contact poultry
Iceland Very low*
Mute Swan Generally sedentary Very low
Greylag Goose Wintering flocks in
Scotland, but sites in
extreme north and
north-west of Scotland
are occupied by a
resident population.
Greylags feed
exclusively on
agricultural land and
could contact poultry
Non-resident UK
Greylags originate
from Iceland.
Wintering populations
in northern Germany,
Denmark,
Netherlands more
likely to fly to England
in cold weather
Very low
Barnacle Goose Winter in Caerlaverock
(Solway )and also west
coast and islands
South-west Solway
wintering populations
are from Spitzbergen,
while north-west are
from Greenland
Low
Pink-footed Goose Grazes in fields so
could contact poultry,
Loch of Strathbeg
(Aberdeenshire) is
wintering site for 20%
of world population.
Winters around east
coast, central belt and
Solway (Caerlaverock)
breeding grounds in
Spitsbergen, Iceland
and Greenland. UK
birds are from
Greenland, Iceland.
Very low
27
Wintering sites in
Scotland
Origin HPAI priority
for Scotland
Bean Goose Rare in UK in general,
site in south-west
Scotland
Northern Eurasia,
Siberia, also eastern
population wintering
in south-east Asia
Very low
Greenland white-
fronted goose
(flavirostris)
West coast of Scotland Greenland Very low
Eurasian white-
fronted goose
(albifrons)
Rare in Scotland Northern Russia and
eastern population
wintering in South-
east Asia
Very low
Lesser white-fronted
Goose
Very rare vagrant Very low
Light-bellied brent
goose (hrota)
East Scotland, Solway,
central belt
Spitzbergen Very low
Light-bellied brent
goose (hrota)
West coast (and
Ireland)
Greenland Very low
Dark-bellied brent
Goose (bernicla)
Common in southern
England, but not in
Scotland
Northern Russia and
eastern population
wintering in South-
east Asia
Very low
Red-breasted Goose Very rare vagrant Very low
Eider Large wintering
population in Scotland,
all round coast, albeit
with 8 sites with counts
exceeding 1,500 birds.
Although, highly
gregarious, not likely to
come in contact with
poultry as sea duck
rarely found away from
coast due to
dependence on
mussels. Very rare
Low
28
Wintering sites in
Scotland
Origin HPAI priority
for Scotland
inland, no need for
freshwater
Goosander Largely freshwater
catches salmon and
trout, unlikely to come
in contact with poultry
Goldeneye Diving duck, unlikely to
come in contact with
poultry
Birds from northern
Europe winter in
Scotland
Very low
Eurasian Wigeon Grazes on grass, so
opportunity to come in
contact with poultry.
Although an estuarine
bird, loss of eelgrass
has resulted in switch
to inland grass in
flooded marshy areas.
Largest wintering sites
in England not
Scotland
Some breed in
Scotland, many from
Eurasia
Medium
Common Teal Could come in contact
with poultry. England
has largest numbers
with Loch Leven
having smaller
numbers
Wintering population
drawn from complete
breeding range –
Iceland, northern
Europe, the Baltic
States, and a large
area of the Russian
Federation.
Medium
Northern Pintail
Mallard Main sites are in
England but widely
distributed. Could
come into contact with
poultry
Medium
Gadwall
Tufted Duck Diving duck, unlikely to
come in contact with
Large wintering
population in GB
Low
29
Wintering sites in
Scotland
Origin HPAI priority
for Scotland
poultry. British
breeding birds
generally sedentary
during winter. Main site
in Scotland is Loch
Leven.
generally from
eastern parts of
European range
Pochard Diving duck, unlikely to
come in contact with
poultry. Low site fidelity
suggest highly mobile.
Loch Leven is principal
moulting site from end
of June
Wintering birds
originate mainly from
Baltic (62% from
Latvia) and Russia
Low
Greater Scaup Main sites are Solway
Firth, Loch Ryan,
Morray and the
Islands. Diving ducks
feed on mussels,
mainly coastal in
winter, unlikely to
contact poultry
Icelandic birds winter
in north-western
Scotland, those on
east coast from
Fennoscandian and
Russian populations
Low
References
Owen, M. (1980) Wild geese of the World. Batsford
Ogilvie, M.A. (1978) Wild geese. T&AD Poyser
Cramp, S. (1977) Handbook of the Birds of Europe the Middle East and North Africa.
The birds of the Western Palearctic. Volume 1, Ostrich to ducks.
30
Data on migratory waterfowl in England/Wales
The focus is on those birds coming to England/Wales via the Baltic coast
Species Wintering sites in
England
Origin HPAI priority for
England/Wales
Bewick’s Swan Some 9,000 birds
winter in Britain
(mainly England
including south-east
England and central
England) and Ireland
Single population for
north-western Siberia
Medium –
because of small
numbers which
always fly
through the Baltic
Whooper Swan 16,000 birds in Britain
and Ireland, mainly
Scotland. Some sites
in eastern, northern
England such as
Welney WWT in
Norfolk.
Mainly from Iceland.
Very few of the
Russian and Fenno-
Scandinavian
breeding population
come as far as
England even in cold
weather, normally
winter in the Baltic
Very low –
because not from
Baltic
Mute Swan Generally sedentary
in Britain, Ireland and
importantly in the Low
Countries
Very low because
does not migrate
from Low
Countries, hence
Mute Swan cases
in NL are not a
concern
Graylag Goose Wintering flocks in
Scotland, but sites in
extreme north and
north-west of Scotland
are occupied by a
resident population.
Greylags feed
exclusively on
agricultural land and
could contact poultry
Non-resident UK
Greylags originate
from Iceland.
Wintering populations
in northern Germany,
Denmark,
Netherlands more
likely to fly to England
in cold weather
Very low
Barnacle Goose Mainly winter in
Scotland and northern
Ireland. Wild birds are
rare in England,
Wintering populations
are from Spitzbergen,
while north-west are
from Greenland. A
Very low
31
Species Wintering sites in
England
Origin HPAI priority for
England/Wales
although there are
feral flocks
small number of
Russian birds which
winter in the
Netherlands could
come over to south-
east England in
severe weather.
Pink-footed Goose Grazes in fields so
could contact poultry.
Mainly East Anglia
and Lancashire.
UK birds are from
Greenland, Iceland
while Spitzbergen
breeding population
winters in Denmark,
West Germany and
the Low countries,
with a few reaching
Britain in severe
winters.
Low risk due to
small numbers
coming from
Denmark,
Germany in
severe winters,
presumably
south-east or
east coast of
England.
Bean Goose Rare in UK in general,
small numbers
wintering at sites in
East Anglia but not
many
Northern Eurasia,
Siberia, Finland
100,000 pairs breed
in western Siberia
Very low because
of low numbers in
England.
Greenland white-
fronted goose
(flavirostris)
Rare winter visitors to
England, a few winter
in Wales
Greenland Negligible
Eurasian white-
fronted goose
(albifrons)
Baltic-North Sea
group winters in the
Netherlands, Belgium,
England and Wales. In
England winters in the
selected sites in the
south (Severn
Estuary, Kent, East
Anglia)
Breeds in northern
Russia, Novoya
Zemlya and Kanin
Peninsula
Medium, comes
through the Baltic
to England each
year but not a
common bird.
Lesser white-fronted
Goose
Very rare vagrant, one
or two birds in
England each year,
most winter in the
Balkans
North Scandinavia,
western Siberia
Negligible
32
Species Wintering sites in
England
Origin HPAI priority for
England/Wales
Light-bellied brent
goose (hrota)
Very small numbers in
England/Wales, more
in Ireland
Spitzbergen and
Greenland
Negligible
Dark-bellied brent
Goose (bernicla)
Common in coastal
sites and marshes in
southern England. Not
common inland or on
lakes.
Northern Russia and
eastern population
wintering in South-
east Asia
Medium risk of
H5N8 entry and
highly gregarious,
but unlikely to
contact poultry
because coastal.
Red-breasted
Goose
Very rare vagrant Very low
Shelduck Many resident in
England but some
migrate to moult in
tidal mud flats in north
Germany in July
Breeding population
returns back from
moult migration to
breeding range in
Britain
October/November
Medium risk of
entry of H5N8 but
generally
coastal/estuarine
bird.
Eider Winter around south
and east coast of
England although less
common than in
Scotland. Although,
highly gregarious, not
likely to come in
contact with poultry as
sea duck rarely found
away from coast due
to dependence on
mussels. Very rare
inland, no need for
freshwater
Relatively small
movements, rarely
over 200 km.
Very low
Goosander Largely freshwater
catches salmon and
trout, unlikely to come
in contact with poultry.
Winters in sites across
UK although
uncommon and many
Males summer moult
in north Scandinavia.
Breeders in Russia
and Fenno-
Scandinavia migrate
west to Baltic and
yeyond to
Very low
33
Species Wintering sites in
England
Origin HPAI priority for
England/Wales
from breeding sites in
Scotland.
Netherlands and
Britain.
Goldeneye Diving duck, unlikely
to come in contact
with poultry with
wintering sites across
England.
Birds from northern
Europe, Russia winter
in the Baltic,
Denmark,
Netherlands and
Britain.
Low
Eurasian Wigeon Grazes on grass, so
opportunity to come in
contact with poultry.
Although an estuarine
bird, loss of eelgrass
has resulted in switch
to inland grass in
flooded marshy areas.
Bird is gregarious with
large wintering sites
across much of central
England.
Some 200,000 pairs
breed in western
Russia and 80,000
pairs in Finland.
Migrate through the
Baltic to winter in west
and south-west
Europe including
Germany,
Netherlands, France,
Britain and Ireland.
High
Common Teal Graze on grass and
could come in contact
with poultry. England
has large numbers
with wintering sites
across England. Bird
is gregarious.
Breeding birds from
north Russia,
Scandinavia, Baltic
States, north Poland,
north Germany and
Denmark fly south-
west in the autumn to
wintering grounds in
the Netherlands and
Britain. Winter
distribution between
Netherlands, England,
Wales and Ireland
greatly dependent on
weather; cold spells
cause immediate
westward movement.
High
34
Species Wintering sites in
England
Origin HPAI priority for
England/Wales
Northern Pintail Scattered sites across
England.
Icelandic birds winter
in Britain (no risk) but
some from north-west
Russian, Finland and
Baltic States fly west
to winter in
Netherlands and
Britain, with
movement from the
Netherlands to Britain
in hard weather.
Low due to
smaller numbers
than other ducks
Mallard Many are resident in
UK. Many sites are in
England and widely
distributed. Could
come into contact with
poultry
Icelandic birds winter
in Britain (no risk) but
some from north-west
Russian, Finland,
Baltic States and
northern Germany fly
west to winter from
Denmark to north
France and in Britain.
Medium but
reduce to low
because bird is
not gregarious
Gadwall Many resident in
England and also
wintering sites mainly
in England.
Breeders in Germany,
Poland, and west
central Russia winter
in the Netherlands
and Britain.
Medium
Shoveler Many wintering sites
across England. Filter
feeder so restricted to
water unlikely to feed
in fields. Bird is
gregarious.
Breeders from Fenno-
Scandinavia and
Russia migrate west
and south-west to
Netherlands, Britain
and Ireland.
Medium because
although water-
feeder could
infect other
gregarious
waterfowl species
which feed in
fields.
Tufted Duck Diving duck, unlikely
to come in contact
with poultry although
highly gregarious.
British breeding birds
generally sedentary
during winter, and
Large wintering
population in GB
generally from
eastern parts of
European range,
Medium risk of
entry because
although diving
duck could infect
other gregarious
waterfowl species
35
Species Wintering sites in
England
Origin HPAI priority for
England/Wales
many wintering sites
across England.
Russia and
Scandinavia.
which feed in
fields.
Pochard Resident population
but also many
wintering sites across
England and Wales.
Diving duck, unlikely
to come in contact
with poultry but highly
gregarious and may
infected other species.
Low site fidelity
suggest highly mobile.
Wintering birds
originate mainly from
Baltic (62% from
Latvia) and Russia
Medium risk of
entry because
although diving
duck could infect
other gregarious
waterfowl species
which feed in
fields..
Greater Scaup Mainly marine with a
few coming to inlake
lakes. Diving ducks
feed on mussels,
mainly coastal in
winter, unlikely to
contact poultry
Birds on east coast of
England from
Fennoscandian and
Russian populations
Low because
although highly
gregarious less
likely to contact
freshwater ducks.
References
Owen, M. (1980) Wild geese of the World. Batsford
Ogilvie, M.A. (1978) Wild geese. T&AD Poyser
Cramp, S. (1977) Handbook of the Birds of Eurpe the Middle East and North Africa.
The birds of the Western Palearctic. Volume 1, Ostrich to ducks.
36
Annex 2
Numbers of migratory birds (per year) entering GB, the Netherlands and Italy
calculated as the difference between totals of monthly counts (maximum -
minimum), taken from Flutest project work underpinning Gale et al. (2014).
HRS Bird Species GB, Wetland
Bird Survey
data of Austin
et al. 2008
The Netherlands (Hustings et al. 2008)
Italy, peak national
count in January
between 1990 and
2005. Atkinson et al.
(2006)
Bewick’s Swan Cygnus
columbianus
3,775 13,000 0
Whooper Swan Cygnus
cygnus
7,428 2,000 0
Mute Swan Cygnus olor 11,542 5,000 3,248
Greater White-fronted
Goose (European race)
Anser albifrons albifrons
1,341 600,000 11,049
Greylag Goose Anser
anser
72,980 150,000 5,392
Red-breasted Goose
Branta ruficollis
4 7 4
Eurasian Wigeon Anas
penelope
324,097 600,000 123,936
Common Teal Anas
crecca
126,498 50,000 97,529
Mallard Anas
platyrhynchos
97,872 180,000 208,000
Northern Pintail Anas
acuta
25,344 20,000 12,781
Garganey Anas
querquedula
38 (May) + 47
(Aug)*
80 (Apr) + 110
(Aug)*
223
Northern Shoveler Anas
clypeata
11,200 10,000 22,811
Common Pochard
Aythya ferina
24,160 45,000 42,189
Tufted Duck Aythya
fuligula
46,429 150,000 7,725
Black-headed Gull
Larus ridibundus
150,555 150,000 217,468
*Spring and autumn migration
37
Annex 3
Species list for cases in wild birds (as of 7 am on 25/01/2021), according to
OIE.
Country Wild bird species affected
Belgium Canada Goose (Branta canadensis)
Common Wood Pigeon (Columba palumbus)
Egyptian Goose (Alopochen aegyptiaca)
Eurasian Curlew (Numenius arquata)
Eurasian Magpie (Pica pica)
European Herring Gull (Larus argentatus)
Great Crested Grebe (Podiceps cristatus)
Greater White-fronted Goose (Anser albifrons)
Greylag Goose (Anser anser)
Mute Swan (Cygnus olor)
Pink-footed Goose (Anser brachyrhynchus)
Czech Republic Mute Swan (Cygnus olor)
Denmark Barnacle Goose (Branta leucopsis)
Black-headed Gull (Chroicocephalus ridibundus)
Brant Goose (Branta bernicla)
Common Buzzard (Buteo buteo)
Common Eider (Somateria mollissima)
Common Pheasant (Phasianus colchicus)
Eurasian Curlew (Numenius arquata)
Eurasian Sparrowhawk (Accipiter nisus)
European Herring Gull (Larus argentatus)
Gadwall (Mareca strepera)
Greater White-fronted Goose (Anser albifrons)
Greylag Goose (Anser anser)
Mallard (Anas platyrhynchos)
Mute Swan (Cygnus olor)
Northern Gannet (Morus bassanus)
Northern Goshawk (Accipiter gentilis)
Peregrine Falcon (Falco peregrinus)
Pink-footed Goose (Anser brachyrhynchus)
Taiga Bean Goose (Anser fabalis)
White-tailed Eagle (Haliaeetus albicilla)
Whooper Swan (Cygnus cygnus)
Finland Common Pheasant (Phasianus colchicus)
France Black-headed Gull (Chroicocephalus ridibundus)
Brant Goose (Branta bernicla)
38
Country Wild bird species affected
Common Buzzard (Buteo buteo)
Common Shelduck (Tadorna tadorna)
European Herring Gull (Larus argentatus)
Greylag Goose (Anser anser)
Mute Swan (Cygnus olor)
Red Knot (Calidris canutus)
Germany Accipitridae (unidentified) (Accipitridae (incognita))
Anatidae (unidentified) (Anatidae (incognita))
Anserinae (unidentified) (Anserinae (incognita))
Ardeidae (unidentified) (Ardeidae (incognita))
Charadriidae (unidentified) (Charadriidae (incognita))
Common Buzzard (Buteo buteo)
Crane (unidentified) (Grus (incognita))
Gull (unidentified) (Larus (incognita))
Haematopodidae (unidentified) (Haematopodidae (incognita))
Laniidae (unidentified) (Laniidae (incognita))
Passeridae (unidentified) (Passeridae (incognita))
Rallidae (unidentified) (Rallidae (incognita))
Strigidae (unidentified) (Strigidae (incognita))
Swan (unidentified) (Cygnus (incognita))
Hungary Great Egret (Ardea alba)
Ireland Barnacle Goose (Branta leucopsis)
Charadriidae (unidentified) (Charadriidae (incognita))
Eurasian Curlew (Numenius arquata)
Mute Swan (Cygnus olor)
Peregrine Falcon (Falco peregrinus)
Whooper Swan (Cygnus cygnus)
Italy Common Buzzard (Buteo buteo)
Eurasian Teal (Anas crecca)
Eurasian Wigeon (Mareca penelope)
Greater White-fronted Goose (Anser albifrons)
Greylag Goose (Anser anser)
Lithuania Mute Swan (Cygnus olor)
Netherlands Barnacle Goose (Branta leucopsis)
Charadriidae (unidentified) (Charadriidae (incognita))
Common Buzzard (Buteo buteo)
Eurasian Teal (Anas crecca)
Eurasian Wigeon (Mareca penelope)
Greater White-fronted Goose (Anser albifrons)
Greylag Goose (Anser anser)
Indian Peafowl (Pavo cristatus)
Mallard (Anas platyrhynchos)
39
Country Wild bird species affected
Muscovy Duck (Cairina moschata)
Mute Swan (Cygnus olor)
Phasianidae (unidentified) (Phasianidae (incognita))
Short-eared Owl (Asio flammeus)
Taiga Bean Goose (Anser fabalis)
Norway Barnacle Goose (Branta leucopsis)
Eurasian Wigeon (Mareca penelope)
European Herring Gull (Larus argentatus)
Great Black-backed Gull (Larus marinus)
Mew Gull (Larus canus)
Mute Swan (Cygnus olor)
Pink-footed Goose (Anser brachyrhynchus)
Poland Greylag Goose (Anser anser)
Mute Swan (Cygnus olor)
Taiga Bean Goose (Anser fabalis)
Whooper Swan (Cygnus cygnus)
Romania Whooper Swan (Cygnus cygnus)
Russia Anatidae (unidentified) (Anatidae (incognita))
Common Pochard (Aythya ferina)
Mallard (Anas platyrhynchos)
Mute Swan (Cygnus olor)
Tufted Duck (Aythya fuligula)
Slovakia Muscovy Duck (Cairina moschata)
Mute Swan (Cygnus olor)
Mute Swan (Cygnus olor)
Spain Greylag Goose (Anser anser)
Peregrine Falcon (Falco peregrinus)
Sweden Barnacle Goose (Branta leucopsis)
Eurasian Eagle-Owl (Bubo bubo)
Peregrine Falcon (Falco peregrinus)
40
Annex 4
UK wild bird detections by species indicting whether populations are largely
sedentary or migratory
Country & species H5N1 H5N5 H5N8 H5N3 H5Nx Grand Total Status
England 10 1 258 7 276
Black Swan 11 11 Sedentary
Brent Goose 6 6 Migrant
Buzzard 3 1 4 Sedentary
Canada Goose 1 24 25 Sedentary
Great White Egret 1 1 Sedentary
Grey Heron 1 1 Sedentary
Greylag goose 8 2 10 Sedentary
Herring Gull 2 2 Sedentary
Kestrel 1 1 Sedentary
Lesser Black Backed Gull 1
1 Sedentary
Lesser Black headed Gull 1
1 Sedentary
Mixed Avian 1 1 -
Mute Swan 8 1 155 1 165 Sedentary
Peregrine Falcon 2 2 Sedentary
Pink footed goose 2 2 Migratory
Shelduck 1
1
Partial migrant
but mainly
sedentary at this
time of year
Sparrow Hawk 1 1 Sedentary
Unspecified 1 1 -
Unspecified Goose 1 1 -
Unspecified Swan 11 11 -
Whooper Swan 21 2 23 Migratory
Wigeon 1
1
Migratory
Common Buzzard 1 2 3 Sedentary
Red Kite 1 1 Sedentary
Wales 5 1 6
41
Country & species H5N1 H5N5 H5N8 H5N3 H5Nx Grand Total Status
Little Grebe 1 1 Sedentary
Mute Swan 5
5 Sedentary
Scotland 17 2 19
Greylag goose 1 1 Migratory
Mute Swan 7 7 Sedentary
Unspecified Swan 4 4
Whooper Swan 4 4 Migratory
Knot 1 1 Migratory
Red Knot 1 1 2 Migratory
Northern Ireland 9
Peregrine Falcon 1 1 Sedentary
Unspecified Swan 6 6 -
Whooper Swan 2 2 Migratory
Grand Total 10 6 284 1 9 310