Scottish wild bird highly pathogenic avian influenza response plan

HPAI in wild birds - research and monitoring

77. The integration of surveillance activities with research is essential to improve our understanding of avian influenza in wild bird populations. This includes presence of the virus in the environment; the need for serological testing; monitoring the impact to wild bird populations and prevention of spread within wild bird populations. This section highlights areas of research that are underway, and knowledge gaps that still remain.

Monitoring levels of infection of HPAI in wild birds

78. A critical component of the response to HPAI in wild birds is understanding how the disease is moving through a population and whether birds have developed a level of immunity to (the current strain of) HPAI (e.g., if the majority of the birds have encountered HPAI and have survived).

79. In June 2022 an eight-strong consortium 'FluMap' bringing together experts from the UK's leading research bodies led by APHA, was launched to develop new strategies to tackle avian influenza outbreaks. The FluMap consortium aims to deliver research into how avian influenza viruses are emerging in wild populations and to help understanding with regards to the risk posed to both domestic and wild birds including why some bird species are more resistant to avian influenza strains.

80. Ongoing monitoring and reporting of dead or sick wild birds in combination with testing for HPAI, allows the distribution, spread and any seasonality of infection and mortality to be identified. Alongside the GB avian influenza dead wild bird surveillance scheme, NatureScot, in discussion with APHA and SG, has identified priority areas for surveillance, thereby providing further intelligence and data on circulation in wild birds to aid conservation management.

81. NatureScot has set up a targeted reporting process using Epicollect (figure 2). This reporting is targeted at key sites and its primary aim is to provide real time intelligence on how the outbreak may be developing. In addition, the British Trust for Ornithology (BTO) have modified the Birdtrack software and mobile app to allow reporting of dead birds by the public. This continued monitoring, as with those schemes stated above, provides further data to monitor the spread of the outbreak and aid conservation.

82. NatureScot in conjunction with APHA have undertaken blood sampling from both the Svalbard and Greenland barnacle geese populations, with plans to sample gannets and great skua. This data may help to aid our understanding of disease resistance and transmission, and therefore the potential future risk to wild bird populations.

83. It is unlikely that there is currently the capacity to carry out extensive serological testing of wild birds during an outbreak over and above that undertaken through the GB dead wild bird surveillance scheme.

84. Certain avian influenza viruses including Influenza A (H5N1) are Specified Animal Pathogens (as set out in Scotland by The Specified Animal Pathogens (Scotland) Order 2009 (as amended)) and can therefore only be handled in a facility with an appropriate Specified Animal Pathogen Order (SAPO) containment level 4 licence.

85. All diagnostic testing for Influenza Type A viruses from animals in scope of official controls or other official activities (as defined by the Official Control Regulations (OCR) (EU Reg 2017/625; amended and retained in UK legislation under SI 2020/1481) must be undertaken at either a national reference laboratory or an official laboratory designated for a relevant purpose.

86. The UK NRL for avian influenza is:

Animal and Plant Health Agency (APHA)
Weybridge Laboratory
Woodham Lane
Addlestone
KT15 3NB
England

The APHA Weybridge laboratory is also an Avian Influenza International Reference Laboratory (IRL). It is designated as a World Organisation for Animal Health (WOAH) avian influenza reference laboratory and a Food and Agriculture Organisation (FAO) Reference Centre for Animal Influenza.

87. Summary:

• The provision of real time testing in specific colonies would help monitor any developing outbreak.
• Understanding how HPAI is circulating in live wild birds could increase understanding of its longer-term impacts. Specifically, in order to contribute to better targeted conservation management, it would be useful to understand the ability of specific species to develop resistance. Serological testing of apparently healthy birds will allow estimates of recovery rates from infection and focus management at colonies to aid in species recovery.
• As with serological testing of infected populations, testing capacity may be an issue.
• The potential to increase testing capacity in Scotland will be investigated and determination of whether the levels of testing that would be required to investigate how the virus moves through infected populations are achievable and affordable.

Surveillance of other wild bird species

88. The avian influenza dead wild bird surveillance scheme is designed to be flexible in terms of the species of birds that are routinely tested based on current evidence across the EU and other countries. Current focus is targeted towards wild migratory wildfowl (such as geese, ducks, swans), gulls and raptors. The reporting criteria is continually reviewed and is readily adaptable to accommodate any changes to the list of susceptible species^[10].

89. Birds not represented on the list are currently assessed as having a very low likelihood of HPAI being detected Error! Bookmark not defined.. It is recognised that this reporting criteria relies on the reporting of dead wild birds by members of the public, but the scheme was designed to meet the policy requirements (i.e., the species that play an active role in the epidemiology of HPAI). The threshold for inclusions within the list is low, meaning the species on the list are relevant to the contribution to the epidemiology.

90. Summary:

• Ongoing monitoring of the spread of the virus is critical for our wild bird populations.
• The triage of cases is continually reviewed against guidance and susceptible species lists that are agreed at an international level.

Presence of virus in the environment

91. Environmental sampling to detect the presence of organisms from their DNA is now an established technique in biology (eDNA). Using environmental sampling to detect HPAI could assist in estimating the likelihood of reinfection from the environment following an outbreak in wild birds. At present Scottish Government's policy for outbreaks of HPAI in poultry is outlined in the Notifiable Avian Diseases Control Strategy for Great Britain. Scottish Government has a policy to cull poultry and other captive birds, in line with its legal and international obligation, to cull birds on infected premises and cleanse and disinfect premises before re-stocking. This is clearly not logistically possible, or desirable, in wild birds where, in most cases, there is no alternative but to let the disease run its course.

92. The eDNA testing may, however, help understanding of where the disease remains a threat following an outbreak or where new outbreaks might occur because a reservoir of virus is present outside the birds themselves. It is unclear at present if the capacity to undertake environmental testing for HPAI exists in Scotland.

93. Summary:

• Further evidence to understand the prevalence and presence of the virus in the environment is needed to understand if there are infection routes other than from bird carcasses and faeces as this may have additional implications for non-avian species.
• Consideration of eDNA as a method of testing should be carried out.

Monitoring population level impacts of HPAI on wild birds

94. Long-term population monitoring is important in understanding the (long term) impacts of avian influenza on Scotland's wild bird populations.

95. Monitoring of seabird populations in Scotland (as well as the wider UK) is coordinated by the BTO under the Seabird Monitoring Programme (SMP). The SMP provides the opportunity to understand the extent and impacts of apparent HPAI mortality, in the context of baseline figures from the National Seabird Census.

96. The populations of species that qualify a site for protected status, (e.g., SPA qualifying species or assemblages), are routinely monitored.

97. For a number of goose species, monitoring data are already collected on a regular basis at local, national and international scales. The two barnacle goose populations are monitored regularly, with the Svalbard population monitored annually and the Greenland population, which winters across Scotland and Ireland, monitored on a three yearly cycle. A Greenland barnacle goose population census was conducted in February 2023. The population data feed into flyway level discussions, facilitated through the European Goose Management Platform, on species management decisions. Local data, particularly around goose management scheme locations, feed into local decisions on management and will continue to do so.

98. The Scottish Raptor Monitoring Scheme currently focuses primarily on the annual monitoring of diurnal birds of prey and owls native to, and which regularly occur within, Scotland. It also monitors ravens and provides annual information on breeding and numbers and productivity.

99. For some species or populations, the ability to detect even large population changes may be relatively poor ^[11]. Consideration will therefore be given to the ability of enhanced monitoring to detect population level impacts of HPAI. Some other species that may be impacted in the future (e.g., Common Buzzard), are less well assessed, and our understanding of the impact of the disease on these species is more limited. Consideration should be given to whether additional monitoring of particular species is needed, and this should be kept under periodic review.

100. Further to this existing monitoring and, in light of the unprecedented scale of the avian influenza outbreak since October 2021 and the potential impacts on wild bird species of conservation concern, NatureScot created a targeted mortality reporting system for gathering detailed information on wild bird mortality from site managers at key wild bird sites in Scotland (Figure 2), utilising Epicollect. The data gathered by Epicollect (and Bird Track) will help support the work of APHA on monitoring any spread of HPAI and can contribute to understanding the impacts of the disease on wild bird populations.

101. Summary:

• Monitoring under SMP and existing goose populations will continue to aid understanding of the long-term impacts of HPAI on wild bird colonies.
• As surveillance continues, consideration will be given to monitoring species that are not covered through existing programmes as necessary.
• The monitoring will have some level of flexibility to take into account any changes in circumstances during an outbreak.

Prevention of HPAI transmission to and within wild bird populations

102. The NatureScot Scientific Advisory Committee subgroup on Avian Flu have published a report which concluded that while there is relatively little understanding of the roles of different transmission routes and the importance of environmental persistence, this deficiency is of limited management consequence as there are almost no management options contingent on this knowledge^[12]. In addition, compared to high levels of exposure generated through, within and between wild-species contact, exposure resulting from human vectoring of virus should be very small indeed. The key focus here should be on avoiding introducing virus into sites where it has been previously absent. A summary of this report can be found in Annex A.

103. NatureScot have developed guidance for land managers on methods to prevent the spread and transmission of HPAIV to locations where there are no current reports of HPAIV. Biosecurity plans are a useful tool to educate any visitors to colonies.

104. Summary

• There is currently no proposal to close access to colonies generally.
• Guidance for land managers is in place to assist in limiting transmission of the virus to other colonies.

Wider measures to mitigate the impacts of HPAI on wild birds

105. To assist in the recovery of HPAI impacted populations of wild birds, it may be appropriate to identify and put in place actions that have the potential to increase survival or productivity. Such measures may include the removal of pressures that cause direct mortality, or improvements to nesting or foraging habitats.

106. A range of initiatives under way such as the Scottish Seabird Conservation Strategy and the UK Marine Wildlife Bycatch Mitigation Initiative will help identify the most appropriate action that could be taken to aid population recovery thereby helping mitigate the impacts of pressures, including HPAI on wild birds.

The population and HPAI monitoring discussed previously will help identify species or populations most in need of mitigation measures. In addition to this, NatureScot has commissioned research into the breeding success of Scottish raptors in order to identify those species most in need of support. A collaboration is underway with Edinburgh University and APHA to assess how levels of immunity are building up in seabird and goose populations that have been especially badly hit by the disease. This will help predict whether particular populations are likely to start to recover or whether they remain vulnerable to further losses in the months and years to come.

107. As well as focussing on the most impacted species, it may be appropriate to develop research programmes that allow work to identify and target measures that can bring wider benefits to a broader range of wild bird species. This will be assessed as the outbreak continues, and plans developed as the long-term pattern of the outbreak becomes clearer and impacts better understood. As an example, liaison with range states supporting migratory goose populations through the AEWA European Goose Management Platform is ongoing and population modelling will help predict ongoing impacts and guide modulation of flyway plans.

Summary of Activities that may impact wild bird HPAI transmission and or survivability.

108. All activities that may impact wild birds in terms of HPAI transmission and / or survivability are kept under regular review and are based on the latest advice.

109. The NatureScot Working Group reviewed a wide range of possibly disturbances, the possible ways of grouping species that might be impacted by the same disturbances in similar ways, the mechanisms by which they may increase the spread of HPAI, and approaches to mitigation and the process required to make decisions given the costs and benefits of curtailment/modification of human activities. There is however little available evidence to assess the impact from the very diverse forms of disturbance that may influence the epidemiology of H5Nx in wild birds or to inform policy on measures that could alleviate pressures on infection and recovery,

110. A matrix of activities that could have an impact on birds, where HPAI is having an impact, is identified below and associated with potential responses. The matrix (Table 3) includes research (bird ringing activities), access to sites, shooting and other land management activities.Currently there is no intention to ban the activities summarised in Table 3. Any further consideration will be undertaken in a site by site basis.