Avian Influenza and Birdwatchers
Over the last few weeks, many birdwatchers will have become aware of considerable media interest in the subject of avian influenza or 'bird flu', following outbreaks in central Asia and the Black Sea region of the highly pathogenic type of the H5N1 virus strain which developed within poultry.
Representatives of BTO, WWT, RSPB and JNCC have been involved in discussions with the relevant government agencies, principally to advise on the latest knowledge of the origins of birds wintering in the UK, migration routes and timing, and bird distributions within the UK. Such information is derived in large part from the hard work of volunteers working on schemes such as the BTO Ringing Scheme and the BTO/WWT/RSPB/JNCC Wetland Bird Survey (WeBS). We have also remained in close contact with international colleagues.
The overall assessment is that the chance of this strain of the virus being carried to the UK by a migrating bird is currently low (and perhaps much less than the chance of transmission via illegally imported poultry). In addition, even if the highly pathogenic form of H5N1 avian influenza did make it to the UK, it is important to note that there are no known cases of transmission from wild birds to humans; in south-east Asia, the virus has spread (infrequently) to humans as a result of people coming into close contact with infected poultry within the context of the confined proximities of poultry farms. Thus the risk to human health from wild birds carrying avian influenza would currently appear to be extremely low.
Nevertheless, it is clearly sensible to keep the situation under review. A number of organisations are working together to deliver a national surveillance programme for wild birds on behalf of Defra (for further details see http://www.defra.gov.uk/animalh/diseases/notifiable/disease/ai/index.htm). This will include enhanced monitoring for sick or dead birds, coupled with a programme of taking faecal samples from a) apparently healthy live birds, and b) birds shot as part of legal wildfowling activities.
As part of this process, we would ask birdwatchers in the field to keep an eye out for any suspicious cases of large-scale mortality or sickness amongst wild birds. Wildfowl are potentially among the most vulnerable wild birds. Obviously, all birdwatchers encounter dead birds occasionally, almost all due to perfectly natural causes, so use your common sense. However, if you should come across an incident that seems out of the ordinary, this should be reported via the Defra Helpline on 08459 335577. Calls would then be referred to the nearest Veterinary Laboratories Agency (VLA) regional laboratory or, in Scotland , to the nearest Scottish Agricultural College (SAC) laboratory. Specialists at the labs would then make an assessment on what further action, if any, should be taken.
Although there have been no proven cases of humans catching the disease from wild birds, the virus is spread through nasal secretions and faeces so please do not touch sick birds or corpses in the event of a suspicious die-off. Note that separate guidelines have been provided to ringers and these will be made available to anyone else who regularly handles wild birds. In general, however, to guard against a wide variety of illness including avian influenza it is always prudent to exercise basic hygiene (e.g. washing hands with soap, especially before eating) when coming into close contact with wild animals.
At a time when there is a lot of misinformation on this issue circulating, it is essential to keep matters in perspective and to sift fact from fiction. We reiterate that, to the best of our current knowledge, we consider the chance of wild birds bringing highly pathogenic H5N1 to the UK to be low and the potential for onwards transmission from wild birds to people to be very low. Obviously, however, we are continuing to monitor the situation and if there are any further developments we will communicate these widely, in the first instance via organisational websites.