Defra risk assessment Nov 9th 2005

HPAI (H5N1) in Eastern Europe Page 1 of 27
Working document- Version 1 (8 November 2005)
HIGHLY PATHOGENIC AVIAN INFLUENZA (H5N1)
IN
EASTERN EUROPE
Working Document
Dr Mirzet Sabirovic
Simon Hall
Dr Nick Coulson
Dr Peter Grimley
Vanessa Wilson
Fred Landeg
INTERNATIONAL ANIMAL HEALTH DIVISION
International Animal Disease Monitoring Team
Qualitative Risk Assessments
www.defra.gov.uk/animalh/diseases/monitoring/index.htm
Ref: VITT1200/HPAI
Version No.:
1
Date:
8 November 2005
DISCLAIMER: IAHD reserves the right to update this publication and make changes to the outcomes at any time if
new information become available following this release. The update will be carried out without prior notice. This
publication or any related updates are published at the Defra’s website above. This publication and any
subsequent update, if available, may be used free of charge in any format or medium provided it is used accurately
and not used in a misleading context. The material must be acknowledged as crown copyright and the title of the
publication specified.
Suggested reference for this publication:
Defra, (2005). Highly Pathogenic Avian Influenza (H5N1) in Western Eastern Europe (Authors: Sabirovic, Hall, S.,
Coulson, N., Grimley, P., Wilson, V., Landeg F.), International Animal Health Division, 1A Page Street, London,
SW1P 4PQ, United Kingdom. Version 1, Released 8 November 2005, pp. 27
©Crown copyright
Copyright in the typographical arrangement and design rests with the Crown
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Working document- Version 1 (8 November 2005)
Table of Contents
1 SUMMARY................................................................................................................................................... 4
1.1 OVERALL CONCLUSION.......................................................................................................................... 4
1.2 PATHWAYS CONSIDERED ........................................................................................................................ 4
2 INTRODUCTION........................................................................................................................................ 7
3 HAZARD IDENTIFICATION.................................................................................................................... 8
3.1 OUTBREAKS OF HPAI (H5N1) – OFFICIAL DISEASE REPORTS................................................................ 8
3.1.1 Central Asia (China, Russia – southern Siberia, Kazakhstan, Mongolia) ....................................... 8
3.1.2 Eastern Europe............................................................................................................................... 8
3.1.2.1 Turkey.................................................................................................................................. 8
3.1.2.2 Romania ............................................................................................................................... 9
3.1.2.3 Russian Federation – western Russia ....................................................................................9
3.1.2.4 Croatia.................................................................................................................................. 9
3.1.3 European Union .............................................................................................................................. 9
3.1.3.1 Imported captive birds in secure quarantine (United Kingdom) ........................................... 9
3.2 OTHER RECENT REPORTS OF SUSPECTED AVIAN INFLUENZA..................................................................... 9
3.2.1 European Union .............................................................................................................................. 9
3.2.1.1 Greece .................................................................................................................................. 9
3.2.1.2 Sweden............................................................................................................................... 10
3.2.1.3 Germany............................................................................................................................. 10
3.2.2 Western Asia................................................................................................................................. 10
3.2.2.1 Iran..................................................................................................................................... 10
3.2.3 Asia............................................................................................................................................... 10
3.2.3.1 Nepal.................................................................................................................................. 10
3.2.3.2 China.................................................................................................................................. 10
3.2.4 Eastern Europe............................................................................................................................. 10
3.2.4.1 Bulgaria.............................................................................................................................. 10
3.2.4.2 Other Balkan countries........................................................................................................ 11
3.2.5 North America ............................................................................................................................... 11
3.3 HAZARDS TO BE CONSIDERED ............................................................................................................... 11
4 RISK ASSESSMENT................................................................................................................................. 11
4.1 RELEASE ASSESSMENT........................................................................................................................ 11
4.1.1 Terms and definitions .................................................................................................................... 11
4.1.2 Potential pathways for spread of H5N1......................................................................................... 12
4.1.2.1 Waterbird migration............................................................................................................ 12
4.1.2.1.1 Likelihood of further geographical spread.................................................................... 12
4.1.2.1.2 Likelihood of H5N1 spread to the UK..........................................................................15
4.1.2.1.2.1 Wildbirds migration between Eastern Europe and the UK .................................. 15
4.1.2.2 Third Countries – Legal trade and the likelihood of the introduction of H5N1 to the UK by
other pathways ........................................................................................................................................ 19
4.1.2.2.1 Live poultry and poultry products................................................................................. 19
4.1.2.2.2 Captive and wild birds and pet birds from third countries ............................................ 19
4.1.2.3 Third Countries – Illegal imports and the likelihood of the introduction of H5N1 to the UK
by possible pathways............................................................................................................................... 21
4.1.2.3.1 Captive, wild caught and pet birds................................................................................ 21
4.1.2.3.2 Other illegal imports ..................................................................................................... 22
4.1.2.4 Intra-Community trade - Likelihood of the introduction of H5N1 to the UK ..................... 22
4.1.2.4.1 Possible detection of H5N1 in an EU Member State .................................................... 22
4.1.2.4.2 Other pathways ............................................................................................................. 23
4.1.2.4.2.1 Bird markets and bird fairs/shows........................................................................ 23
4.1.2.4.2.2 Pigeon racing ....................................................................................................... 24
4.1.2.5 Mechanical transmission by the movement of people......................................................... 24
5 CONCLUSIONS......................................................................................................................................... 24
5.1 AN OVERALL LIKELIHOOD OF FURTHER GEOGRAPHICAL SPREAD............................................................ 25
5.2 LIKELIHOOD OF H5N1 SPREAD TO THE UK........................................................................................... 25
5.2.1 Wildbirds migration between Easter Europe and the UK.............................................................. 25
5.2.2 Third Countries – Legal trade ....................................................................................................... 25
5.2.2.1 Live poultry and poultry products ....................................................................................... 25
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5.2.2.2 Captive, wild caught and pet birds ...................................................................................... 25
5.2.2.3 Illegal imports ..................................................................................................................... 25
5.2.2.3.1 Captive, wild caught birds and pet birds....................................................................... 25
5.2.2.3.2 Other illegal imports ..................................................................................................... 26
5.2.3 Intra-Community trade .................................................................................................................. 26
5.2.3.1 Possible H5N1 detection in an EU Member State............................................................... 26
5.2.4 Other pathways............................................................................................................................. 26
5.2.4.1 Bird markets and bird fairs/shows....................................................................................... 26
5.2.4.2 Pigeon racing ...................................................................................................................... 26
5.2.4.3 Mechanical transmission by the movement of people......................................................... 26
6 REFERENCES........................................................................................................................................... 27
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1 Summary
An outbreak of HPAI (H5N1) in domestic poultry in Asia is on-going. Following its
detection in central China, southern Russia, Kazakhstan and Mongolia in mid 2005,
the H5N1 virus has been confirmed in western Turkey, eastern Romania, western
Russia and eastern Croatia in October 2005.
1.1 Overall conclusion
Overall, at this stage the risk assessment considers that the likelihood of further
geographical spread or detection of the H5N1 virus is high. This conclusion takes into
account the existing uncertainty, and the latest epidemiological developments which
suggest that the H5N1 virus has been detected over broad geographic areas within a
few months. This in turn increases the risk to the UK as it increases the opportunities
for the introduction of the virus via various potential pathways (e.g. migrating birds,
trade in live birds, movement of people).
It remains uncertain how widespread the H5N1 virus may be in Asia and Europe or
beyond. It remains uncertain how the virus was introduced to any of the affected
eastern European countries. It also remains uncertain whether the increasing level of
detection in the wider geographic region may in part be as a result of increased
surveillance following the availability of modern diagnostic techniques and
heightened sensitivities about the disease. This highlights uncertainty whether the
virus may have already been present in many areas of the world at a very low level
either in non-commercial poultry or wild bird populations and escaped detection in
the past. It remains uncertain what possible pathways may exist for the H5N1 virus
being disseminated over broad geographic areas. Systematic studies are therefore
required at international and national level to understand these routes, the species
susceptibility, pathogenesis and ecology of the virus.
Nevertheless, the fact is that the emerging epidemiological evidence, although
circumstantial so far, points to the virus continuing to be detected in dead migratory
waterfowl and non-commercial domestic poultry in wider geographic regions since
May 2005. The virus was detected mainly in areas that potentially provide for some
contact between domestic and wild birds.
1.2 Pathways considered
The recent spread over a broad geographical region suggests existence of a
potentially very mobile carrier of the virus. It is tempting to conclude that (A) migrating
wild birds have at least a part to play at this stage. This risk assessment also
recognises that there are several other possible pathways by which the H5N1 virus
can be introduced to the UK from the affected regions. These are: (B) legal trade, (C)
illegal imports; (D) intra-community trade; (E) other activities, and (F) mechanical
transmission by people.
A) With regard to migratory waterfowl, the following has been considered:
For the purpose of this assessment, it is assumed that migrating waterbirds may to
some extent be asymptomatic carriers of the virus, and therefore, have at least a part
to play in the virus dissemination given that the current H5N1 virus detection in
Eastern Europe appears to coincide with seasonal migration. It is also assumed that
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the recent outbreaks in eastern Europe indicate that the H5N1 virus is getting
geographically closer to the EU and the UK. Based on these assumptions, this risk
assessment considers that two conclusions are possible at this stage:
1) There is an increased (but still low) likelihood for the introduction of the H5N1
virus to the UK from the outbreaks in the known affected countries in eastern
Europe. This is based on the advice from the UK experts on migration that
there is no major migration of waterbirds from these countries to the UK.
However, there is a possibility that the frequency of H5N1 virus detection in
wild birds may increase in these countries. Should this be the case, the
experts consider that H5N1 virus may arrive to the UK at some point in the
future because of the potential for limited ‘mixing’ at some ‘contact’ points
between the existing waterbirds populations from this part of Europe with the
populations in the EU.
2) The likelihood of the H5N1 virus being introduced to the UK may escalate to
high should outbreaks be detected in the northern part of european Russia.
This conclusion is based on the fact that outbreaks of H5N1 virus in this area
would be within the direct migratory routes that exist between northern Russia
and the UK and involve greater numbers of migratory waterfowl.
This risk assessment acknowledges that these two conclusions are based on much
uncertainty given that currently only a few outbreaks have been reported and that
migration has just begun. Nevertheless, these two conclusions will be subject to
scrutiny when more structured epidemiological information becomes available within
the next few months once this migration season has occurred in Europe and the
European-wide surveillance in wild birds have been completed for this migratory
season.
B) With regard to legal trade in poultry and poultry products from the
countries where the H5N1 virus was confirmed, the following has been
considered:
1) There is a negligible likelihood of the H5N1 virus being introduced by legal
imports of live game birds and poultry and their products from the affected
countries. This conclusion is based on the EU bans on imports of poultry and
their products from the affected countries provided these bans are effectively
applied and monitored. That is, these imports will not be admitted through any
UK Border Inspection Posts (BIPs) and the same should apply at any EU
border. In accordance with international trade agreements, legal imports from
countries that have not reported an outbreak of H5N1 continue undisrupted
subject to official veterinary certification that specific EU requirements for
HPAI have been fulfilled.
2) There is an increased (but still low) likelihood of the H5N1 virus being
introduced by legal trade in captive, wild caught birds and possibly pet birds
from Third Countries. Therefore, on the basis of uncertainty about how
widespread the virus is in Asia, Europe and beyond this trade is now banned
from all Third Countries until options for limited trade are examined.
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C) With regard to illegal imports of poultry meat and poultry products from
the countries where the H5N1 virus was confirmed, the following has
been considered:
1) There is an undeterminable likelihood of the H5N1 virus being introduced by
illegal imports (live birds and personal imports). On this basis, there is a need
to improve understanding of the nature and extent of illegal trade in live birds
and enhance detection and prevention measures accordingly. This will also
require revision of the existing quarantine requirements to enable fully
controlled legal trade to resume following a ban, so as to mitigate the risk
from potentially increased illegal imports.
D) Intra-Community trade
1) In the light of the increasing likelihood of the virus being introduced to the EU
on a larger scale, this risk assessment concludes that the relevant EU rules
for intra-community trade should be reviewed.
E&F) With regard to other activities and potential for mechanical transmission
by the movement of people, the following has been considered:
1) In the light of the increasing likelihood of the virus being introduced to the EU
on a larger scale, this risk assessment concludes that issues of bird
markets/fairs/shows, pigeon racing and the potential mechanical transmission
of the virus by the movement of people should be considered in accordance
with the potentially increased knowledge on the epidemiology and disease
spread and relevant expert advice.
The International Animal Health Division will continue to monitor and review the
outcomes of this risk assessment and will provide an update, if required.
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2 Introduction
This qualitative risk assessment considers the likelihood of the introduction of highly
pathogenic avian influenza (HPAI) to the UK following the confirmed outbreaks of
highly pathogenic avian influenza (HPAI) virus of H5N1 type in Eastern Europe
(Western Turkey, Romania and the European part of Russia – western Russia
thereof) and Croatia.
It builds on several previous qualitative risk assessments that have been carried out
by Defra (http://www.defra.gov.uk/animalh/diseases/monitoring/index.htm) during this
evolving situation in Central Asia and Turkey and Romania. These risk assessments
concluded that there was an increased (but still low) likelihood of the introduction of
H5N1 virus by migratory
waterbirds from the affected
region to the UK during the
migratory season.
Nevertheless, these risk
assessments stressed that
their estimates of the likelihood
for the virus to be introduced to
the UK should be viewed in the
context of the lack of
epidemiological evidence and
uncertainties regarding wild
birds in the breeding grounds
of Russia. They also indicated
that the situation will continue
to be monitored and the risk
assessment updated if
required.
An outbreak of HPAI (H5N1) in
domestic poultry in Asia is ongoing.
Since its spread to
southern Russia, Kazakhstan
and Mongolia during the past
few months, the H5N1 virus
has now been confirmed in
Turkey, Romania, western
Russia and Croatia
The detection of H5N1 in Eastern Europe requires that our previous risk assessment
be reviewed in order to determine whether the most recent epidemiological
information may have any impact on the change in the likelihood of H5N1 virus
introduction to the UK.
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3 Hazard identification
3.1 Outbreaks of HPAI (H5N1) – Official Disease Reports
3.1.1 Central Asia (China, Russia – southern Siberia, Kazakhstan,
Mongolia)
Between May and October 2005, outbreaks of HPAI (H5N1) virus have been
reported in Central Asia and Eastern Europe (see map) (OIE, 2005), and one case in
a secure quarantine facility in UK which is not classified as an outbreak.
3.1.2 Eastern Europe
Following confirmed reports of H5N1 in Central Asia during the period between May
and August 2005, the virus was detected in eastern Europe. The affected countries
have taken appropriate control measures to contain the further spread. EU has
banned imports of poultry and poultry products from countries where H5N1 virus was
detected (OIE, 2005).
3.1.2.1 Turkey
Turkey has confirmed an outbreak of H5N1 in an open-air turkey farm at the
beginning of October 2005. The farm is located in the Region of Balikesir, in the
north-western part of Anatolia (see map). It is near to an area supporting large
numbers of waterbirds in the Kus Lake. No further outbreaks have since been
reported from Turkey (OIE, 2005).
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3.1.2.2 Romania
Following reports from Turkey, two outbreaks of the H5N1 virus were confirmed in
back-yard poultry and waterbirds (swans – species not specified) in the eastern part
of Romania in October 2005. This area is near to an area supporting large numbers
of waterbirds in the Danube Delta (OIE, 2005). No further outbreaks have since been
reported from Romania.
3.1.2.3 Russian Federation – western Russia
A number of H5N1 outbreaks in mixed free-range village poultry (geese, ducks,
turkeys and chicken) have been reported from six provinces in southern Siberia in
mid 2005 (OIE, 2005).
Following these reports, a number of H5N1 outbreaks in village poultry (ducks,
muskovy ducks, chicken, geese, turkeys) have been reported for the first time in
western Russia (Tula province) at the end of October (OIE, 2005). No outbreaks
have since been reported from the affected province. No outbreaks have since been
reported in other provinces in western Russia.
NOTE: Information from the World Reference Laboratory for Avian Influenza,
Weybridge, UK, suggest that the H5N1 virus detected in Turkey and Romania in
October 2005 is almost identical to the virus isolated in wild birds in Central Asia in
May 2005.
3.1.2.4 Croatia
On 25 October 2005, the Croatian authorities confirmed that the H5N1 virus has
been confirmed in dead swans (species not stated) that have recently been
discovered in eastern Croatia. Croatia has applied disease control measures in the
affected area and intensified surveillance of wild waterbirds (OIE, 2005).
3.1.3 European Union
3.1.3.1 Imported captive birds in secure quarantine (United Kingdom)
The HPAI H5N1 virus was detected in a secure quarantine facility in Essex in
October 2005 (Defra, 2005)
Note: The closest match is a strain identified in ducks in China earlier this year. It is
not similar to the strains from Romania and Turkey
3.2 Other recent reports of suspected avian influenza
3.2.1 European Union
3.2.1.1 Greece
The Greek authorities have informed the European Union of a suspected H5 virus
infection on a turkey farm on an island near to Turkish border. Further laboratory
tests, including virus isolation have, excluded the H5 virus.
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3.2.1.2 Sweden
The Swedish authorities informed the European Commission that a recent case of
the H5 virus in a duck in Sweden was confirmed to be a mild H5N3 type (low
pathogenic) of the avian influenza virus.
3.2.1.3 Germany
NOTE: An unofficial report indicate that that some 20 dead migratory birds have
been found at a lake in Germany which died from poison and that an avian influenza
virus has been found in two of these birds. No official information has been received
from Germany on this event so far.
3.2.2 Western Asia
3.2.2.1 Iran
Iran reported a high mortality in wild waterbirds (wild ducks) in the Poldasht, coast of
Arras, West Azerbaijan province in October 2005 (OIE, 2005). There is currently no
information on laboratory tests that may have been carried out.
3.2.3 Asia
3.2.3.1 Nepal
The Nepalese authorities reported to the OIE that an H5 virus has been excluded as
a cause of death of pigeons that were brought to a local market in the Gorkha district.
3.2.3.2 China
The Chinese authorities reported to the OIE that an outbreak of an H5 virus was
reported in domestic chicken and ducks in a village located in the Inner Mongolia
province of China.
NOTE: An unofficial report indicates an outbreak has been reported on a geese farm
in Anhui and that outbreaks (species unspecified) have also been noted in Xinjiang
and Qinghai. No official information from China is available on the OIE website so far.
3.2.4 Eastern Europe
3.2.4.1 Bulgaria
There were recent media reports on suspected AI in three birds (species not stated)
found dead in north-east Bulgaria. The Bulgarian authorities have informed the
European Commission that the preliminary (post-mortem) examination of these birds
does not suggest infection with AI. However, further laboratory tests are underway.
As a precautionary measure Bulgaria has stepped up surveillance on wild birds in the
area (European Commission, 2005).
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3.2.4.2 Other Balkan countries
Increased mortality in village poultry in southern part of the Former Yugoslav
Republic of Macedonia has been due to Newcastle disease. However, serological
testing against a panel of AI viruses indicated that one sample tested positive for
influenza A virus. Further samples have been submitted for laboratory testing (OIE,
2005).
NOTE: The situation in Balkan countries remains unclear. Unofficial reports indicate
that dead wild birds (information on species currently unavailable) found in Serbia
and Montenegro and Bosnia and Herzegovina have tested negative for the presence
of the virus.
3.2.5 North America
The Canadian Food Inspection Agency (CFIA) confirmed that three pigeons out of a
shipment of 102 pigeons recently exported from Canada to Australia have antibodies
to AI but not the virus. (CFIA, 2005).
3.3 Hazards to be considered
As it currently stands, it appears that the H5N1 virus is quickly spreading over large
geographic areas. It should also be born in mind that the H5N1 virus may have
already been present in many areas of the world at a very low level and escaped
detection due to the absence in the past of sophisticated diagnostic tools that are
available now.
As a working hypothesis, several risk pathways have been considered as potential
hazards for the H5N1 virus introduction to the UK.
4 Risk assessment
4.1 Release Assessment
4.1.1 Terms and definitions
This release assessment considers the likelihood of HPAI virus introduction to the UK
from the affected or potentially affected countries in Eastern Europe. For the purpose
of the release assessment (Section 4.1) the following definitions will apply:
Term Definition
HPAI “HPNAI viruses have an IVPI in 6-week-old chickens greater than 1.2 or, as an
alternative, cause at least 75% mortality in 4-to 8-week-old chickens infected
intravenously. H5 and H7 viruses which do not have an IVPI of greater than 1.2 or
cause less than 75% mortality in an intravenous lethality test should be sequenced
to determine whether multiple basic amino acids are present at the cleavage site of
the haemagglutinin molecule (HA0); if the amino acid motif is similar to that
observed for other HPNAI isolates, the isolate being tested should be considered as
HPNAI” (OIE, 2005a)
Waterbirds “Means those species of birds that are ecologically dependant on wetlands for at
least part of their annual cycle…” (UNEP, 2005)
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For the purpose of the release assessment (Section 4.1) the following terminology*
will apply (OIE, 2004):
Term Definition
Likelihood Probability; the state or fact of being likely
Likely Probable; such as well might happen or be true; to be reasonably expected
High Extending above the normal or average level
Highly In a higher degree
Low Less than average; coming below the normal level
Negligible Not worth considering; insignificant
Remote Slight, faint
* This risk assessment uses the OIE recommended terminology. This is important to maintain
consistency in expressing estimates. Defra is aware of some concerns that have been
expressed lately about the appropriateness of this terminology for practical purposes (ie.
clarity for the purpose of understanding by wider non-technical audience). Defra will consider
this issue in the near future.
NOTE: This qualitative risk assessment was undertaken to assist the process of
identifying appropriate safeguard measures to prevent the introduction of the H5N1
virus to the UK via legal trade among other pathways specified. Any such measures
must maintain appropriate level of protection (ALOP) without unduly restricting trade.
The UK ALOP is that legal importation of live animals or their products from EU
Member States or Third Countries must present a negligible likelihood that the
diseases of concern will be introduced.
4.1.2 Potential pathways for spread of H5N1
4.1.2.1 Waterbird migration
Recent experience demonstrated that the H5N1 virus is likely to cause the death of
migratory birds as a result of infection. However, limited experimental evidence
suggests that the virus may be able to infect domestic ducks without causing overt
clinical signs. This is yet to be proven in field conditions.
Nevertheless, as a working hypothesis, this risk assessment considers that migratory
waterbirds can be infected with the H5N1 virus to a certain extent without causing
overt clinical signs. This is on the basis of limited experimental evidence of a
possibility of such infection in domestic ducks.
4.1.2.1.1 Likelihood of further geographical spread
Conclusion: There is a high likelihood of further geographical spread or detection of
H5N1 virus on the basis of uncertainty about how widespread the virus is in Asia,
Europe and beyond.
Key facts:
a) It remains largely uncertain how widespread H5N1 may be in Asia, Europe
and beyond;
b) An outbreak of HPAI (H5N1) in domestic poultry in Asia is on-going. Since its
spread to southern Russia, Kazakhstan and Mongolia during the past few
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months, H5N1 has now been confirmed in Turkey, Romania, western Russia
and Croatia;
c) It is not certain how the virus was introduced to any of these countries, but the
detection over a broad geographical region leads us to suspect that migrating
wild birds have at least a part to play. Nevertheless, other possible pathways
will have to be considered (see below sections);
d) It also remains uncertain whether the increasing level of detection may in part
be the result of increased surveillance following the availability of modern
diagnostic techniques and heightened sensitivities about the disease.
Supporting evidence
It remains uncertain how widespread H5N1 may be in Asia and Europe or beyond. It
remains uncertain how the virus was introduced to any of the affected eastern
European countries.
It also remains uncertain whether the increasing level of detection in the wider
geographic region may in part be as a result of increased surveillance following the
availability of modern diagnostic techniques and heightened sensitivities about the
disease. This highlights uncertainty about whether the virus may have already been
present in many areas of the world at a very low level either in non-commercial
poultry or wild bird populations and escaped detection in the past. That is, the
outbreaks of the disease in domestic poultry have been reported in China, the
southern part of Russia (Siberia), north-east Kazakhstan, Turkey, Romania and
western Russia (OIE, 2005). On the other hand, in May 2005, the H5N1 virus was
detected in dead migratory waterbirds (Ruddy shelduck, Bar-headed geese, Great
black-headed and Brown-headed gulls, great cormorants) in China. In August 2005,
H5N1 was confirmed in a few dead migratory waterbirds (Bar-headed geese and a
Whooper swan) in the northern part of Mongolia close to the Russian border, eastern
Romania (Whooper swan) and Croatia (swans – species not stated).
Nevertheless, the fact is that the emerging epidemiological evidence, although
circumstantial so far, points to the virus continuing to be detected in dead migratory
waterfowl and non-commercial domestic poultry in thewider geographic regions since
May 2005. The virus was detected mainly in areas that potentially provide for some
contact between domestic and wild birds.
Wildbird migration is a natural phenomenon where the waterbirds “entire population
or a significant proportion of the population cyclically and predictably crosses one or
more national jurisdictional boundaries. Waterbirds use a wide variety of habitats
during their annual cycle, from the artic tundra, forested wetlands of the temperate
taiga, forest-steppe, steppe grasslands, deserts, inland and coastal wetlands, wet
and dry agriculture croplands, rivers, floodplain wetlands, marshes, lakes, tanks,
ponds, irrigation tanks, sewage and waste treatment farms” (UNEP, 2005).
Wetland habitat in Siberia supports large numbers of breeding waterbirds, many of
which migrate in the autumn to wintering areas in Europe, Africa, India and East and
South-East Asia using various routes (“flyways”) (BirdLife International (2005). “A
“flyway” is the total area used by (groups of) populations or species of birds,
throughout their annual cycle, including the breeding areas, migration stop-over and
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non-breeding (wintering) sites. Many of these sites tend to be highly productive and
are thus also of importance to non-migratory birds and other biodiversity”) (UNEP,
2005).
For migratory waders (shorebirds) the principal flyways of Eurasia (Hötker and
others, 1998; Stroud and others, 2004) are:
• The East Atlantic Flyway
• The Black Sea/Mediterranean flyway,
• The West Asia/West African flyway
• The Central Asia/India flyway,
• The East Asian-Australasian flyway.
(Map from: Stroud and others, 2004)(*)
[NOTE: (*)the map indicates existence of West Asia/West Africa flyway (in pink). It has been pointed out
to us that this should be “West Asia/East Africa” flyway. Defra will seek clarification from the author of
the map]
Anatidae (ducks, geese and swans) have different migration systems (Scott and
Rose 1996; Miyabayashi and Mundkur 1999). For ducks especially, flyways tend to
be poorly defined, and migration occurs on a broad front, typically between a number
of wetland staging areas. (See also Stroud and others, 2005, for a recent review of
migratory waterbird biogeographic populations).
There is no information on whether there has been systematic clinical or laboratory
surveillance for H5N1 in wild migratory waterbirds or domestic poultry in the affected
regions on a regular basis. It is, therefore, possible that recent awareness of HPAI
has also impacted on raising the level of surveillance, hence, these cases are now
more readily noticed and reported and investigated in more detail. It is hoped that
more information will become available from the affected or potentially affected
regions. On the other hand, increased surveillance of wild migratory waterbirds for
the presence of the virus, combined with ringing data should provide a better insight
on the virus ecology in migratory waterbirds, including information on their
movements, respectively.
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It would appear that the virus has become endemic in free range domestic ducks,
certainly in countries like Thailand, Vietnam and probably some parts, if not all, of
China. Therefore, there could have been some spill-over into wild waterbirds
probably as a result of the extensive nature of rearing domestic ducks and their
frequent movement, especially on paddy fields where they are used for pest control
(Alexander, 2005). These conditions can accelerate virus transmission (Matsiu,
2005) between birds and other susceptible species. Nevertheless, both past and
recent work has shown that experimentally infected ducks had detectable HPAI virus
in a variety of organs including the brain. This raises questions on how efficient such
birds would be at travelling over any substantial distance (Alexander, 2005).
In contrast, the possibility that infection could have been carried to the region and
remain undetected for two months, it is also possible that waterbirds in their breeding
grounds could have acquired H5N1 virus from undetected infection in local poultry.
4.1.2.1.2 Likelihood of H5N1 spread to the UK
Our previous risk assessment emphasised that caution is required when generalising
trends that may relate to carriage of the HPAI H5N1 virus or any other HPAI virus to
different regions or countries because wild migratory waterbirds use different routes
(flyways).
To assess the likelihood for the H5N1 virus introduction to the UK via migratory
waterbirds, this risk assessment considers the following:
4.1.2.1.2.1 Wildbirds migration between Eastern Europe and the UK
Conclusion: There is an increased (but still low) likelihood of the introduction of
H5N1 virus to the UK by migratory birds from the affected regions in Eastern Europe.
Nevertheless, this estimate is highly likely to change to high should H5N1 be
detected in northern Russia because of the existing direct migratory routes between
northern Russia and the UK.
Key facts:
A) Migratory waterbirds from southern Siberia
1) With regard to migratory birds moving from southern Siberia to the UK, expert
ornithologists consider that:
a) Ringing recoveries indicate limited movement of migratory waterbirds
between southern Siberia in Russia and the UK and from Turkey, Romania
and Croatia to the UK during the migratory season;
b) It is unlikely that extreme eastern recoveries of UK waterbirds will involve
birds that have travelled from southern Siberia in Russia to the UK or from
Turkey, Romania or Croatia to the UK in a single winter. However, more
information is required about population sizes in the area and reporting rates.
The furthest east recoveries probably represent waterbirds visiting different
wintering areas in different winters;
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c) The UK plays host to only a proportion of these species’ populations during
the winter: the majority of individual birds breeding in Russia east of the Urals
are highly unlikely to reach Britain because they winter further east in Europe,
for example in the Mediterranean, and for some species in the Baltic;
2) Because of the geographical closeness, recent outbreaks in Turkey, Romania
western Russia and Croatia indicate an increased possibility that the virus
may be introduced to some EU Member States that are on the major north-tosouth
migratory routes of the birds from southern Siberia;
3) Currently, the H5N1 virus has not been detected in any EU Member State.
Nevertheless, a possibility that it may be present, but still undetected in some
EU Member States cannot be excluded;
4) EU Member States are on high alert for the potential introduction of H5N1 to
the EU and have broadened surveillance to include migratory waterbirds;
5) Given the above, it would be reasonable to expect that the virus is likely to be
detected in waterbird populations in some Member States that are
geographically closer to the currently affected regions in Eastern Europe
before its detection in the UK waterbirds population.
B) Migratory waterbirds from northern Russia
1) With regard to migratory birds moving from northern Russia to the UK, expert
ornithologists consider that:
a) The majority of many migratory species that arrive in the UK are from arctic
areas of North America, Greenland, Iceland, Fenno-Scandia and further east
in northern Russia;
2) Should outbreaks of the H5N1 virus be detected in the northern part of
European Russia, these outbreaks would be within the direct migratory routes
that exist between northern Russia and the UK.
Supporting evidence
Our previous risk assessment emphasised that caution is required when generalising
trends that may relate to carriage of the HPAI H5N1 virus or any other HPAI virus to
different regions or countries by migratory birds because they use different migratory
routes (flyways).
NOTE: The map below in this section was prepared by Defra’s International Animal
Health Division staff and is based on information sourced from Wetlands
International (Scott & Rose,1996). It does not necessarily reflect the true situation.
The map should be regarded as indicative rather than as a definitive reflection of
migratory flyways between Siberia and Europe. The map was produced using ESRI
Data and maps CD - 2002.
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The following map outlines broad ranges of migratory waterbirds. Within these,
migratory routes of ducks, geese and swans follow mainly north-to-south and
northeast-to-southwest directions. Although it may appear confusing, we have
produced it to highlight the possible complexity of the situation, in the first instance.
There may be some limited mixing of the waterbird populations in northern Russia
from the four major flyways in Eurasia. However, it is uncertain at this stage whether
there is any significant geographic and temporal overlap of these waterbird
populations in northern Russia with the waterbird populations in southern Siberia.
Therefore, the level of risk, which will vary from one season of the year to another,
will depend on migratory pathways, either direct from infected areas or through
contact at intermediate ‘mixing’ points for migratory species. The evidence to quantify
this risk seems to be incomplete. Systematic studies are therefore required to
understand these routes, the species susceptibility, pathogenesis and ecology of the
virus.
A) Southern Siberia
The Volga Basin and North Caspian regions are considered cross-roads for
migratory waterbirds that use four major routes in Eurasia and East Europe. These
two regions host the vast majority of migratory birds which are nesting in Eastern
Fennoscandia, Northern-Central territories of the Russian plain, Ural and parts of
western Siberia on their way to overwintering grounds in east Africa. A small
proportion of these birds spend winters in south-western Asia. (Lvov and others
2001).
Ringing recoveries (Wernham and others, 2002) show there is some, albeit limited
movement of birds between the UK and southern Russia. Therefore, the inferences
about the scale and regularity of movement of birds between Southern Russia and
the UK can only be preliminary and need to be treated with caution. For example,
some of the extreme eastern recoveries of UK birds are highly unlikely to have
travelled that far in a single winter. Rather, they may have paired with different mates
in different breeding seasons and their wintering and breeding grounds may have
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moved east. Lastly, the UK plays host to only a proportion of these species’
populations during the winter: the majority of individuals breeding in Russia are highly
unlikely to reach Britain because they winter further east in Europe, for example in
the Mediterranean, and for some species in the Baltic (Cranswick, 2005)
Nevertheless, it needs to be emphasised that “although bird banding has enabled
scientists to gather very detailed information on birds, tracking the birds to
understand their movements is a difficult task” (Anonymous, 2005).
NOTE: We have been advised by experts that there is a great amount of ring
recovery data. This data is held by individual schemes within the EU member states
and centrally at the EU level on behalf of the different schemes for birds ringed in
Europe.
We consider that it would be useful if this data could be collated and analysed on a
continental and national scale to provide much more information on bird movements.
B) Northern Russia
Around 5 million waterbirds are present in Britain in winter. While some species are
resident in the UK (i.e. birds present in winter that have bred here) many species
arrive in the UK from arctic areas of North America, Greenland, Iceland, Fenno-
Scandia and further east in northern Russia. Many of the waterbird species or
populations wintering in the UK derive from northern (arctic or sub-arctic) areas and
are highly unlikely to act as carriers of the virus to the UK from the current outbreaks
in central Asia. Further, several species of wildfowl have a marine distribution during
winter, and, remaining at sea, will therefore not come in to contact with farms or
domestic livestock (Cranswick, 2005).
In their official notification to the OIE on 21 October 2005, the Russian authorities
confirmed that the H5N1 virus has been confirmed in ducks, muskovy ducks,
chicken, geese and turkeys on a number of backyard farms in Tula (Moscow region).
At the moment, this appear to be the only report of the H5N1 virus detection in
western Russia. However, should more outbreaks of the H5N1 virus be detected in
wider areas of western Russia, this will impact on the likelihood of the virus
introduction to the UK. That is, this changed situation could indicate that the virus
may be present in migratory populations that arrive to the UK from further east in
northern Russia. The expert ornithologists consider that this area would be within the
direct migratory routes that exist between the northern Russia and the UK and
involve greater numbers of migratory waterfowl.
The UK experienced two outbreaks of HPAI H5N1 virus in the past. The first
outbreak occurred in a flock of chicken in Scotland in 1959. The second outbreak
occurred in a flock of turkeys in England in 1991. These outbreaks were limited to the
affected flock only. The source of infection was not identified. There were no reports
of the disease in humans during these outbreaks. These outbreaks were detected
quickly due to sudden and high mortality associated with the introduction of the virus
and effectively dealt with at the time resulting in no further spread. The H5N1 viruses
isolated in these earlier outbreaks are different to the virus currently present in
Central Asia.
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4.1.2.2 Third Countries – Legal trade and the likelihood of the introduction
of H5N1 to the UK by other pathways
4.1.2.2.1 Live poultry and poultry products
Legal imports of all live birds and their products from countries where H5N1 has been
detected have been banned. They will not be admitted through any UK Border
Inspection Posts (BIPs) and the same should apply at any EU border. Therefore,
direct legal importation to the UK of live birds and products from a third country
known to be affected, or indirect importation to the UK of live birds and products from
a third country known to be affected through another Member State to the UK is
highly unlikely to occur.
NOTE: Defra also considers that there is a negligible likelihood of the H5N1 virus
introduction by legal imports of live poultry and their products from countries where
H5N1 has been detected. Imports of live poultry, day-old chicks and hatching eggs
into the EU and the UK from countries that have not reported an outbreak of HPAI
and are on the approved EU list is subject to official veterinary certification that
specific EU requirements AI have been fulfilled. (e.g. HPAI must be notifiable; export
farms must be specially approved on the basis of biosecurity and disease
surveillance, the birds must come from areas not subject to restrictions for HPAI).
Processed feathers and, for some countries, processed (cooked) poultry meat are
exceptions to the general ban. It is unlikely that the raw material would have been
contaminated and in any case would have been heat treated to destroy any virus
present.
4.1.2.2.2 Captive and wild birds and pet birds from third countries
Conclusion: There is a low likelihood risk of H5N1 virus arriving in the UK by captive
and wild birds and pet birds. This estimate raises the possibility of a ban on
importations of captive and pet birds to ensure that adequate measures are in place
to mitigate the potential from an evolving risk of this magnitude.
Key facts:
a) It remains largely uncertain how widespread H5N1 may be in Asia, Europe
and beyond;
b) The recent detection of a highly pathogenic avian influenza in a consignment
of captive birds has highlighted uncertainties related to species susceptibility.
c) There is potential for illegal movements of birds from the affected areas to
unaffected areas which may result in arrival of potentially infected birds to the
UK presented as legal consignments from unaffected areas. Therefore the
UK has called for a ban on importations of captive birds from all countries with
a possibility of derogation on a country by country basis;
d) In order to make this ban effective it is also necessary to suspend imports of
pet birds because the concession for fewer than 6 birds could be exploited as
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a loophole for unscrupulous traders. However, this could have a
disproportionate effect on EU citizens;
e) Therefore, the UK asked the European Commission to come forward with a
proposal for strict, harmonised rules for importation of genuine pets and a
Decision was passed on 25 Oct 2005.
Supporting evidence:
A) Captive and wild caught birds
Imports of captive birds are normally permitted from any country which is a member
of the World Organisation for Animal Health (Office International des Epizooties,
Paris, France - OIE). This could include Asian or African countries where H5N1 virus
has been introduced but has not yet been detected.
Although this trade is highly regulated, the detection of the H5N1 virus in a UK
quarantine indicates that this trade poses a plausible pathway for its introduction into
unaffected countries. As H5N1 continues to be detected over large geographic areas,
the risk that a small error or oversight in the quarantine facility could lead to the
introduction of the virus and its possible escape cannot be discounted. This
possibility is difficult to quantify.
Captive birds (other than parrots and poultry of any species) intended for ‘exhibition,
show or contest’ may be traded from a registered establishment in a member state
on the basis of an owner’s self-certificate. These include waterbirds. It is more likely
that undetected infection could be present in such birds than for farmed poultry
because there is no pre-export veterinary inspection or certification.
This trade would appear to present a low likelihood of the disease being introduced
into the UK while there is no evidence of H5N1 being present in other EU Member
States.
B) Pet birds
Imports of pet birds are not subject to harmonised EU rules. Great Britain requires 35
days domestic quarantine and two official veterinary inspections after arrival (but no
tests) for birds from all third countries.
Individual import licences are issued by local Divisional Veterinary Managers. No
central record is kept of these licences.
Other Member States set their own conditions for pet bird imports. It is possible that
another Member State may admit a pet bird from a high risk country (other than one
which has an explicit ban) with minimal conditions.
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4.1.2.3 Third Countries – Illegal imports and the likelihood of the
introduction of H5N1 to the UK by possible pathways
4.1.2.3.1 Captive, wild caught and pet birds
Conclusion: There is an increased likelihood that illegally imported live birds may
be infected with H5N1 given the recent geographical dispersal of the virus. This
likelihood might be further increased if a ban on currently legal trade were introduced.
Key facts:
a) The risk that illegal trade may be one of the potential routes for the virus
introduction to the UK of illegal trade has always been present. This risk is
difficult to quantify;
b) The UK recent experience with H5N1 virus detected in a legally imported
parrot highlighted a possibility of the virus introduction by this pathway;
c) There is potential for illegal activities that may result in arrival of potentially
infected birds to the UK as legal consignments. Therefore the UK has called
for a ban on the import of captive birds from all countries with a possibility of
derogation on a country by country basis;
Supporting evidence: There is lot of uncertainty related to illegal imports of captive
birds to the UK. Therefore, Defra has always maintained that this risk is
undeterminable.
The illegal import of live birds from the affected areas and their neighbouring areas
pose a risk, the scale of such risk depending upon the scale of the trade which in turn
seem difficult to quantify. Therefore, these imports will also have to be considered as
a potential mechanism for the virus to spread. Whether coincidentally or not, it is
noticeable that the recent outbreaks in western Siberia broadly occurred in the
regions through which the main Trans-Siberian railway lines pass. Some consider
(Chu and others, 2005) that illegal hunting and catching of wild waterbirds in the two
bird reserves in China (Quinghai lake and Zhalong reserve) are still happening. The
most recent unofficial reports indicate that H5N1 virus was detected in captive birds
that have been smuggled by ship from China to Taiwan.
Although the H5N1 virus has not been isolated from apparently healthy wild
waterbirds in Mongolia in August 2005 and Hong Kong in January 2005, it has been
isolated from two crested hawk-eagles from Thailand that were seized at Brussels
International Airport in 2004. The birds showed no apparent clinical signs of the
disease. However, necropsy indicated that both eagles suffered from enteritis and
one of them had bilateral pneumonia. This study highlights the notion that
“international travel and smuggling represent major threats for introducing and
disseminating H5N1 virus worldwide” (Van Borm and others, 2005).
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Therefore, there would be a need to consider improving intelligence gathering in
order to get a better handle on what the illegal trade in live birds looks like and
enhance detection and prevention measures accordingly. There would also be a
need to consider revising quarantine requirements/measures to enable fully
controlled legal trade to resume following a ban, so as to mitigate the risk from
increased illegal trade.
4.1.2.3.2 Other illegal imports
Conclusion: There is an indeterminable likelihood of the introduction of H5N1 virus
to the UK by illegal imports of meat/meat products
Key assumption:
a) Illegal movements of poultry meat/meat products pose a risk for the
introduction of the disease from any infected countries worldwide;
b) The risk of the introduction of H5N1 to the UK via illegal imports from the
affected countries exists and is difficult to estimate.
Supporting evidence
We cannot rule out the possibility that poultry and poultry products may be imported
illegally to the UK from any country and may contain HPAI virus.
Attempts to illegally import meat as personal imports have been recorded from many
countries. As with all disease agents, illegal imports from worldwide infected
countries give rise to a constant, background risk of infection. Refrigeration of illegally
imported meat is unlikely and makes detection by enforcement authorities more
likely. The risk associated with the illegal personal import of poultry meat appears to
be negligible because it is highly likely that the meat will be cooked. The virus has
been recovered from fresh duck meat (Tumpey and others, 2002). However, cooking
temperatures for consumption purposes (usual temperature above 700C) are
considered sufficient to destroy the virus.
Large-scale commercial illegal imports of poultry may be attempted from any country
using false or forged documentation. However, thorough documentary checks and
awareness at Border Inspection Posts (BIPs) that this may happen are likely to
mitigate this type of risk. The information on these intercepted consignments must
also be entered in the EU electronic notification system for trade in live animals and
their products (Trade Control and Expert System – TRACES).
4.1.2.4 Intra-Community trade - Likelihood of the introduction of H5N1 to
the UK
4.1.2.4.1 Possible detection of H5N1 in an EU Member State
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Conclusion: There is an increased likelihood of the H5N1 virus being introduced to
the EU on a larger scale. The EU rules should be reviewed to ensure that adequate
measures are in place to mitigate the potential for further spread.
Key facts:
a) EU rules for movement of traded birds within the single market have proved
adequate in the face of isolated outbreaks;
b) The recent detections of the virus in Turkey, Romania, western Russia and
Croatia have increased the risk of the virus introduction to many EU Member
States because of the geographical proximity.
Supporting evidence:
H5N1 is not currently known to exist in the UK or any other EU Member State. All EU
Member States are understood to have effective systems for disease surveillance,
notification and reporting. Given the geographic proximity, this risk is now increased,
but could change at any time if disease is detected within the EU. This raises
questions about intra-community trade in live birds.
Intra-community trade in live birds relies on monitoring and detection of disease at
source, rather than on controls at or post-import. Therefore, intra-Community trade in
live birds would seem to present an increased risk because of possible trade in live
birds from premises where disease has been introduced but remains undetected.
In the recent past, HPAI of a different virus H (H7N7) type has been detected in three
EU Member States (the Netherlands, Germany, Belgium) and was dealt with
effectively without further spread to other Member States. Similarly, mild strains of
avian influenza (low pathogenic avian influenza – LPAI) outbreaks in Italy have been
contained effectively using vaccination in the affected areas.
Much trade is in high health status breeding birds or commercial poultry which should
have been kept under conditions of high biosecurity. However, game birds (including
ducks) could be wild caught or reared in open pens. The recent Newcastle disease
outbreak in pheasants, legally imported to the UK from France, highlights the risk that
disease may enter a holding and that birds may be traded before the disease is
detected.
The official veterinary services are responsible for certifying that the holding of origin
of birds is free from notifiable disease. They then notify the local Animal Health
Divisional Office at the point of destination in the UK so that post-import checks may
be carried out. This is done using the TRACES computer system. In Great Britain,
the State Veterinary Service checks a proportion of consignments based on risk.
4.1.2.4.2 Other pathways
4.1.2.4.2.1 Bird markets and bird fairs/shows
This issue should be considered in the light of the disease spread; expert advice on
bird migration and illegal trade. This would enable these events to proceed only on
the basis of a veterinary risk assessment and subject to strict conditions.
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4.1.2.4.2.2 Pigeon racing
The 2005 racing season has now finished. Racing takes place from April to October.
Birds are released in western Europe to fly home to the UK. In the event of H5N1
being confirmed in an EU Member State restrictions would have to be considered
proportionate to the risk.
4.1.2.5 Mechanical transmission by the movement of people
As with any disease outbreak in any country, there is a low likelihood that the
movement of people could transmit the pathogen by mechanical transfer or through
themselves being infected.
In the case of H5N1 virus, categories of people which could present a risk for the
virus introduction to the UK are likely to be:
• UK farm workers on holiday to countries where the H5N1 virus has been
confirmed (high-risk countries),
• Migrant workers from high-risk countries working on UK livestock farms
• Military personnel,
• Tourists, particularly any staying in the countryside or visiting bird markets in
high-risk countries,
• Hunters, birdwatchers or anyone else who goes out of their way to contact
wildlife in high-risk countries and who then come into contact with birds in the
UK.
Defra, the Department of Health and the Health Protection Agency are working
together to ensure that the risk of human mechanical transmission from birds is
addressed adequately through biosecurity on farms and other places where poultry
are kept.
NOTE: Defra has been advised that the Royal Society for Protection of Birds have
undertaken to consult the relevant veterinary authority over measures necessary to
reduce the risk of mechanical transmission, should an outbreak be confirmed on one
of their reserves.
5 Conclusions
An outbreak of HPAI (H5N1) in domestic poultry in Asia is on-going. Since its spread
to southern Russia, Kazakhstan and Mongolia during May to August 2005, the H5N1
virus has been confirmed in Turkey, Romania, western Russia and Croatia in
October 2005. It is not certain how the virus was introduced to any of these eastern
European countries. However, it should also be borne in mind that the increasing
level of detection may simply be the result of increased surveillance following the
availability of modern diagnostic techniques and heightened sensitivities about the
disease.
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With regard to:
5.1 An overall likelihood of further geographical spread
Overall, at this stage the risk assessment considers that the likelihood of further
geographical spread of the H5N1 virus is high. This conclusion takes into account the
existing uncertainty, and the latest epidemiological developments which suggest that
the H5N1 virus has been detected over a broad geographic areas within a few
months.
This in turn increases the risk to the UK as it increases the opportunities for the
introduction of the virus via various potential pathways (e.g. migrating birds, trade in
live birds, movement of people).
5.2 Likelihood of H5N1 spread to the UK
5.2.1 Wildbirds migration between Easter Europe and the UK
There is an increased (but still low) likelihood of the introduction of H5N1 virus to the
UK by migratory birds from the affected regions in Eastern Europe.
Nevertheless, this estimate is highly likely to change to high should H5N1 be
detected in northern Russia because of the existing direct migratory routes between
northern Russia and the UK.
5.2.2 Third Countries – Legal trade
5.2.2.1 Live poultry and poultry products
Defra also considers that there is a negligible likelihood of the H5N1 virus
introduction by legal imports of all live birds and their products from countries where
H5N1 has been detected. These imports have been banned from the affected
countries and will not be admitted through any UK Border Inspection Posts (BIPs).
The same should apply at any EU border.
5.2.2.2 Captive, wild caught and pet birds
There is a low likelihood risk of H5N1 virus arriving in the UK by captive and wild
birds and pet birds. This estimate raises the possibility of a ban on importations of
captive and pet birds to ensure that adequate measures are in place to mitigate the
potential from an evolving risk of this magnitude.
5.2.2.3 Illegal imports
5.2.2.3.1 Captive, wild caught birds and pet birds
There is an increased likelihood that illegally imported live birds (captive, wild caught
or pet birds) may be infected with H5N1 given the recent geographical dispersal of
the virus. This likelihood might be further increased if a ban on currently legal trade
were introduced.
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5.2.2.3.2 Other illegal imports
There is an indeterminable likelihood of the introduction of H5N1 virus to the UK by
illegal imports of meat/meat products
5.2.3 Intra-Community trade
5.2.3.1 Possible H5N1 detection in an EU Member State
There is an increased likelihood of the H5N1 virus being introduced to the EU on a
larger scale. The EU rules should be reviewed to ensure that adequate measures are
in place to mitigate the potential for further spread.
5.2.4 Other pathways
5.2.4.1 Bird markets and bird fairs/shows
This issue should be considered in the light of the disease spread; expert advice on
bird migration and illegal trade. This would enable these events to proceed only on
the basis of a veterinary risk assessment and subject to strict conditions.
5.2.4.2 Pigeon racing
In the event of H5N1 being confirmed in an EU Member State restrictions would have
to be considered proportionate to the risk.
5.2.4.3 Mechanical transmission by the movement of people
As with any disease outbreak in any country, there is a low likelihood that the
movement of people could transmit the pathogen by mechanical transfer or through
themselves being infected.
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