Is there a risk from avian flu on waste sites?
As concern has grown over the possible threat posed by the spread westwards of avian flu over recent weeks, bird nuisance control specialist, NBC Bird Solutions, reports that it has been contacted by a number of waste management personnel and concerned members of the public about the potential risk to them from birds - especially birds frequenting waste management sites. In this special contribution, the company summarises the current situation and addresses key questions which could arise in the event of the disease reaching the British Isles
At present, there have not been any suspected or confirmed cases of H5N1 avian flu reported in the UK or any EU member state. DEFRA has a surveillance operation under way to monitor wild birds for any signs of the virus and, as Chief Vet Debby Reynolds stated on 8 November, “The risk to the UK can be described as an increased, but still low, likelihood of the imminent introduction of H5N1 to the UK.”
All EU Member States are understood to have effective systems for disease surveillance, notification and reporting
The risk appears to be greatest from wild migratory waterbirds. Currently, outbreaks of the H5N1 virus abroad has been detected in dead migratory waterbirds such as Ruddy shelduck, Bar-headed geese, great cormorants, some species of swans and, relevant to the waste management industry, great black-headed and brown-headed gulls
The information available suggests that there is negligible direct risk to the UK from the suspected outbreak of avian influenza in Romania. The finding of seropositive ducks is not an unusual event.
There also appears to be a negligible direct risk to the UK from the suspected outbreak of avian influenza in Turkey.
The European Commission has announced its intention to suspend imports of any risk commodities such as poultry, captive birds and feathers to the EU. Given that a virus of H5 serotype has been isolated, and that the high mortality seen suggests that it is pathogenic, then this is proportionate as a precautionary measure.
Overall, at this stage, risk assessment indicates that the likelihood of further geographical spread or detection of the H5N1 virus is high. This conclusion takes into account the existing uncertainty, and the latest epidemiological developments which suggest that the H5N1 virus has been detected over broad geographic areas within a few months. This, in turn, increases the risk to the UK as it increases the opportunities for the introduction of the virus via various potential pathways (eg migrating birds, trade in live birds, movement of people).
It remains uncertain how widespread the H5N1 virus may be in Asia and Europe or beyond and how the virus was introduced to any of the affected eastern European countries. Also uncertain is whether the increasing level of detection in the wider geographic region may in part be as a result of increased surveillance following the availability of modern diagnostic techniques and heightened sensitivities about the disease.
This highlights uncertainty whether the virus may have already been present in many areas of the world at a very low level, either in non-commercial poultry or wild bird populations and escaped detection in the past. It remains uncertain what possible pathways may exist for the H5N1 virus being disseminated over broad geographic areas. Systematic studies are therefore required at international and national level to understand these routes, the species susceptibility, pathogenesis and ecology of the virus.
Nevertheless, the fact is that the emerging epidemiological evidence, although circumstantial so far, points to the virus continuing to be detected in dead migratory waterfowl and non-commercial domestic poultry in wider geographic regions since May 2005. The virus was detected mainly in areas that potentially provide for some contact between domestic and wild birds.
The H5N1 virus was detected in dead migratory waterbirds (Ruddy shelduck, Bar-headed geese, Great black-headed and Brown-headed gulls, great cormorants) in China. In August 2005, H5N1 was confirmed in a few dead migratory waterbirds (Bar-headed geese and a Whooper swan) in the northern part of Mongolia close to the Russian border, and in eastern Romania (Whooper swan) DEFRA concludes in its “Highly Pathogenic Avian Influenza (H5N1) in Eastern Europe Working Document,” that there is an increased (but still low) likelihood of the introduction of H5N1 virus to the UK by migratory birds from the affected regions in Eastern Europe.
Nevertheless, this estimate is highly likely to change to high should H5N1 be detected in northern Russia because of the existing direct migratory routes between northern Russia and the UK.
Advice on precautions
As with any emerging disease, experts are cautious and advise that the situation will continue to be monitored and the risks assessed. For now there are some sensible precautions that waste management personnel can take to protect themselves. John Dickson, of NBC Bird Solutions, advises that it is essential to keep sites clear of birds and for all staff to be vigilant. Should staff find a sick or dead bird, the bird should not be disturbed and DEFRA should be contacted. If the bird must be moved then protective clothing should be worn and DEFRA contacted. Any personnel who have been in close vicinity to wild birds should consult a doctor if they develop flu like symptoms such as fever, cough, sore throat, muscle aches, conjunctivitis. Most important – remain calm – and visit the NBC or DEFRA websites for the latest news at www.defra.gov.uk or www.birdsolutions.co.uk
As an operator of a waste management site that can attract large numbers of gulls, what should I do?
Culling of birds would be ineffective as further wild birds would simply come in and you would have to deal with the carcasses.
Currently the advice is careful vigilance; our advice would be to not allow migratory birds to congregate in large numbers.
How can I minimise the risk to myself and staff?
Be vigilant for any signs of sick birds. Should this arise staff should wear a protective face mask, disposable gloves and overalls before handling any such bird. DEFRA should be contacted immediately concerning the bird.
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