Surveillance for avian influenza ( AI) viruses in wild birds is a European legislative requirement and is carried out in all European Member States. The UK strategy for AI surveillance in wild birds takes a two pronged approach and involves:
- The wild bird survey for AI viruses.
- The investigation of mass mortality events in wild birds.
The wild bird survey for AI viruses
The aims of the survey are:
- To detect highly pathogenic AI ( HPAI) H5N1 viruses in wild birds through surveying dead birds; and
- To protect domestic poultry and safeguard public health since AI maybe transmitted to humans.
Wild bird ecologists and wardens patrol designated reserves across the UK on a regular, year-round basis to look for dead wild birds. There are an extremely large number of wild birds in the UK so it is therefore only practical to sample a small percentage of these.
Dead wild birds are screened because they are a convenient source for sampling. Certain species of wild birds that experts believe to have a greater potential role in the spread of AI viruses (e.g. gulls, ducks, geese, swans and waders) are central to the survey.
The likelihood of a wild bird that is found dead being infected with HPAI H5N1 is very small.
Testing is carried out at the Animal & Plant Health Agency (APHA) at Weybridge.
The investigation of mortality events in wild birds
As part of routine wildlife disease surveillance post-mortem examinations of birds are undertaken in incidents where any ‘at risk’ bird species (wildfowl or gulls), birds of prey or five or more birds of any other species, are found dead in the same location and at the same time. Members of the public are asked to report these incidents to Defra’s national helpline telephone 03459 335577, Mon-Fri 8am to 6pm).
Deaths occur for a number of reasons e.g. poisoning, adverse weather conditions, starvation or infectious diseases. It is recommended that members of the public avoid handling dead birds.