The Avian Influenza Prevention Zone continues

The 2020/21 autumn and winter season has seen the largest ever number of outbreaks of avian influenza across the UK. There have been 26 poultry and captive bird positive cases in total UK-wide. Prior to this, the largest number was 13 cases in 2016/17. In addition, it is the first time a case of highly pathogenic avian influenza (HPAI) has occurred in poultry in Northern Ireland (NI).

However, with the risk levels now falling, the mandatory avian influenza housing measures imposed in Great Britain (GB) on 14 December 2020 were lifted at 23:59 on 31 March 2021. NI also revoked their housing order introduced on 23 December 2020 at midnight on 13 April 2021. Importantly the Avian Influenza Prevention Zone, with its mandatory biosecurity measures, remains in place across the UK as there is still a heightened risk of avian influenza.  If scrupulous biosecurity measures are practised the risk of avian influenza to poultry and captive birds is ‘low’ (rare but does occur), but if biosecurity measures are suboptimal, the risk is ‘medium’ (occurs regularly). The risk of avian influenza in wild birds is also currently assessed as ‘low’.

The fact that the risk to poultry and captive birds is only ‘low’ if biosecurity standards are high is a very important point to remind bird keepers of. Keepers should not interpret a low risk to mean a negligible risk.

The reduction in the risk level is based on several factors:

• Most migratory wild water birds have departed the UK;
• Infection in wild birds is now limited to resident sedentary species, such as mute swans and raptors;
• Contact between poultry and captive birds and resident wild birds decreases at this time of year as wild birds disperse to their breeding sites within the UK;
• Transmission through environmental contamination is further reduced at this time of year because of warmer temperatures and longer periods of higher intensity sunlight causing increased inactivation of the virus in the environment.

However, the poultry risk always lags behind the wild bird risk because decay of the virus in the environment is slower than clearance from infected birds. Initial indications are that this season’s H5N8 strain can survive in the environment up to 50% longer than the 2016/17 strain and especially with the cold spring weather we’ve had, the virus could remain in the environment for several weeks. This means it is vital that all poultry and captive bird keepers, whether they keep just a few pet chickens, keep chickens, ducks and geese on a small holding, or they farm commercially, implement the very highest standards of biosecurity. Some of the key measures are:

• Keeping their birds in a penned off area.
• Placing their birds’ food and water undercover where wild birds can’t access it.
• Deterring wild birds by using bird scarers, foils or streamers.
• Removing wild bird contamination such as feathers or faeces from their birds’ outdoor areas.
• Keeping ducks and geese separate from other poultry species.
• Fencing off ponds, streams, boggy areas or standing water and draining them where possible
• Netting or covering ponds.
• Cleansing and disinfecting hard surfaces regularly with a government approved disinfectant.
• Using disinfectant foot dips when entering and exiting enclosures or houses.
• Limiting the number of people who come onto the site.

Full details of the Avian Influenza Prevention Zone requirements are in the declarations for England, Scotland, Wales and NI.

It is reasonable to expect that the risk to poultry will reduce further in April and May as seasonal increases in temperature and day length further decrease environmental contamination. However, as was seen in the epizootic of 2016/17, there may be a long tail of a small number of outbreaks over the coming months, even as the risk of exposure to poultry is reducing.

Birds of prey

There have been two cases of avian influenza in captive birds of prey, the latest being two peregrine falcons in Skelmersdale, Lancashire. There have also been cases confirmed in several species of wild birds of prey. Vets should advise clients who keep birds of prey against feeding their birds any wild birds, and in particular, any wild shot or hunted wildfowl due to the avian influenza risk. This includes birds that may have been shot or hunted earlier in the autumn/winter and frozen since the virus can survive in frozen carcases for at least 12 months.

The latest situation:

To date in 2020/21, avian influenza has been confirmed in poultry or other captive birds at 26 premises in the UK. The first cases of avian influenza in the UK in 2020/21 were confirmed in England on 2 November 2020 (low pathogenic avian influenza (LPAI) H5N2 in Kent and HPAI H5N8 in Cheshire). Of the cases to date in 2020/2021 in the UK:

• 21 are in England including: one case of LPAI H5N2, one case of HPAI H5N1, one case of LPAI H5N3 and 18 cases of HPAI H5N8;
• 2 are in Scotland including one case of HPAI H5N8 (Orkney Islands) and one case of HPAI H5N1 (Leven);
• 1 is in Wales: a case of HPAI H5N8 on the Isle of Anglesey; and
• 2 are in Northern Ireland: both cases of HPAI H5N8.

Wild bird cases

The total number of positive wild birds detected is unparalleled in the UK. 317 have tested positive for HPAI H5N1, H5N5, H5N8 and H5Nx as at mid-April 2021. HPAI H5N8 virus has been identified in a range of wild bird species (both migratory and resident birds), with mute swans, greylag geese and Canada geese representing the majority of detections.

Bird gatherings

From 21 April 2021, certain bird gatherings can take place in the UK provided that the requirements of the relevant General Licence are complied with. This includes markets, shows, sales, exhibitions of pigeons, budgerigars, canaries, parrots, cockatiels and birds of prey. Some low risk pigeon racing is also permitted. The organiser of these gatherings must also notify the Animal and Plant Health Agency (APHA) at least 7 days before the event or in Northern Ireland, the Department of Agriculture, Environment and Rural Affairs (DAERA) must be notified 3 days in advance.  Gatherings of ducks, geese, chickens, turkeys or game birds whether kept commercially as poultry, as pets or for other purposes remain banned. For a full list of what is permitted see our guidance for bird gatherings.

Achieving avian influenza free status – the importance of poultry registration

The earliest date the UK can regain country-wide avian influenza disease free status following an outbreak is 3 months after a stamping out policy has been completed.  This includes culling the birds and secondary cleansing and disinfection (C&D) of all infected premises.  The Animal and Plant Health Agency (APHA) also need to undertake surveillance to demonstrate there is no undisclosed disease in the UK. In addition to our current risk-based surveillance, now we have left the EU there is an additional requirement, in GB, to undertake surveillance for disease in the 10 km restricted zone for 90 days after effective C&D to allow trade to resume from these areas. To enable this, all poultry keepers within the Protection Zone and Surveillance Zone need to be identified so that random sampling of poultry can be undertaken.

This requirement makes it even more important for poultry keepers to register their poultry with APHA. It is mandatory for keepers of 50 or more birds, but if keepers of less than 50 birds register it will make it much easier to undertake the necessary sampling to achieve avian influenza disease free status. Poultry keepers benefit from registering as they will be kept up to date by APHA on any notifiable avian disease in their area. If vets can encourage clients to register, this will help towards identifying as many poultry keepers as possible. 

Poultry registration forms for keepers in Great Britain can be found on the Government website. 

Poultry registration forms for keepers in Northern Ireland are available on the Daera NI website.

Guidance on how to prepare for the safe release of birds is available online. 

You can keep up to date with the latest situation and obtain the latest biosecurity requirements and guidance at:

• England
• Scotland
• Wales
• Northern Ireland 

Risk assessments for avian influenza in Europe, the UK and Russia can be found on the UK Government website.