Read more about bird flu (avian influenza)
Bird flu has hit the headlines in recent weeks as highly pathogenic strain H5N8 spreads across Europe. The virus has been detected in 13 European countries to-date with outbreaks in wild birds, poultry, hunting bird decoys, and a small number of zoological collections. The strain currently circulating has never been detected in humans.
So far this winter there have been no cases in the UK. Defra, along with Welsh and Scottish Governments, have declared a temporary requirement for all poultry keepers within Great Britain to keep their birds indoors, or take appropriate steps to keep them separate from wild birds. This is purely a precautionary measure to help prevent potential infection of poultry, and the actual role of wild birds in transmission of virus remains unclear.
Birds can be infected with the avian influenza virus through contact with infected saliva, nasal secretions or faeces, and wild birds can carry and transmit the virus to poultry. However there is no evidence of any wild bird species being able to carry this particular strain on a long-distance migration without it causing die-off in the birds themselves, making it unlikely that wild birds are the primary source of avian influenza spread.
There are several ways by which avian influenza may be transmitted, and globally the most important of these has been the unrestricted movement of poultry and poultry products. Therefore the risk of H5N8 circulation via poultry movements remains significantly high, and poultry keepers should help to prevent the spread of the virus by maintaining good biosecurity on their premises.
Defra are monitoring the situation, and members of the public are being asked to report any cases of dead wild waterfowl - such as swans, geese and ducks - or gulls, or five or more dead birds of other species to Defra (Tel: 03459 33 55 77). The RSPB have increased the level of surveillance on our reserves and are continuing to work closely with our partners to advise Defra on the actions required.
H5N8, the strain of avian influenza currently spreading across Europe, was confirmed on a turkey farm in Lincolnshire last Friday. Defra immediately put in place a 3km protection zone and 10km surveillance zone around the outbreak site, restricting all movements of poultry, captive birds or mammals in order to limit the risk of the virus from spreading, and all turkeys on the farm have since been humanely culled. These measures have been successfully used during previous UK outbreaks, including the most recent case on a poultry farm in Dunfermline in January 2016, when the virus was contained to a single farm and eradicated very quickly.
Defra are continuing to investigate the origin of the outbreak and at the present time the role of wild birds remains unknown. However biosecurity best practice on poultry farms remains the most effective way of preventing spread, and the GB-wide prevention zone requiring poultry keepers to house their birds wherever practicable, remains.
Defra have enhanced their surveillance of wild birds, and members of the public are being asked to report any cases of dead swans, geese, ducks or gulls, or five or more dead birds of other species, to the Defra hotline (Tel: 03459 33 55 77). Reports considered high risk will be collected by Defra for testing. To-date no wild birds have tested positive for avian influenza in the UK this winter. We will update this blog with new information as and when it becomes available.
Defra has today published its epidemiology report into the case of H7N7 avian influenza in chickens on premises near Banbury, in Oxfordshire. The source of infection has not been identified, with two hypotheses under investigation. These are infection from other domestic poultry premises and from wildlife in contact with the infected premises.
The report states that wild bird activity around the infected premises was low, and rates the risk of wild ducks or other waterfowl being the source of infection as low. This reflects the time of year and the absence of any major water features nearby. Samples taken from mallards introduced to a small pond on the farm for shooting have tested negative. There has been no virus detected in other wild birds or domestic poultry in the vicinity. Further investigations of both potential sources of infection are ongoing. The RSPB continues to work closely with the British Trust for Ornithology, the Wildfowl and Wetlands Trust and others to advise Defra on the actions required to investigate and manage the outbreak. We have curtailed RSPB fieldwork within the control zones to eliminate the very small chance that such activity could spread the disease.