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Reprinted with permission from the BSAVA If Highly Pathogenic Avian Influenza H5N1 Asian Lineage reaches the UK, it is possible that positive cases may initially be presented to a veterinary practice. All veterinary surgeons and reception staff should at this time be conversant with the typical presenting signs.
Clinical Signs
Typically the disease in poultry presents suddenly with affected birds showing oedema (swelling) of the head, cyanosis (purple/blue discolouration) of the comb and wattles, dullness, lack of appetite, respiratory distress, diarrhoea and drop in egg production. Birds may often die without any signs of disease being apparent. Death can occur so quickly that these signs may not be seen. Influenza therefore should be considered in the differential diagnosis of any significant unexplained mortality. There can be considerable variation in the clinical picture and severity of the disease depending on factors such as species of birds infected, management system, age of birds and general health status. Signs are often less apparent in species of duck.
Pictures are available on the DEFRA website at: http://www.defra.gov.uk/animalh/diseases/notifiable/pictures/avianinfluenza.htm
1. Anyone suspecting an avian notifiable disease (this includes highly pathogenic avian influenza) in domestic poultry or other captive birds should immediately contact their local State Veterinary Service Animal Health Office.
http://www.defra.gov.uk/corporate/contacts/ahdo.htm
2. For general advice about avian influenza, information is available on the Defra web site or by contacting the Defra Helpline ( 08459 33 55 77, choose the Avian Influenza option; the helpline is open from 9am - 5pm, Monday – Friday)
3. If members of the public wish to report one or more dead wild gulls, waders, swans, geese or ducks that are found dead in high priority survey areas (see map) for the avian influenza survey they should contact the Defra helpline.
4. Unusually high mortality events in wild birds (ten or more dead wild birds of any species found at the same time and in the same location) that occur anywhere in the UK can also be reported to the Defra helpline.
5. If the member of the public does not wish to report the dead wild bird to the Defra helpline for avian influenza surveillance they should avoid touching it and leave it where it is.
However if they do need to move a dead bird:
Avoid touching the bird with bare hands
6. If possible, wear disposable protective gloves when picking up and handling (if disposable gloves are not available see 11)
7. Place the dead bird in a suitable plastic bag, preferably leak proof. Care should be taken not to contaminate the outside of the bag
8. Tie the bag and place it inside a second plastic bag
9. Remove gloves by turning them inside out and then place them in the second plastic bag. Tie the bag and dispose of in the normal household refuse bin.
10. Hands should then be washed thoroughly with soap and water
11. If disposable gloves are not available, a plastic bag can be used as a make-shift glove. When the dead bird has been picked up, the bag can be turned back on itself and tied. It should then be placed in a second plastic bag, tied and disposed of in the normal household waste
12. Alternatively, the dead bird can be buried, but not in a plastic bag
13. Any clothing that has been in contact with the dead bird should be washed using ordinary washing detergent at the temperature normally used for washing the clothing.
14. Any contaminated indoor surfaces should be thoroughly cleaned with normal household cleaner. Action to be Taken at the Practice in the event of suspect cases being presented.
Those of us in practice will appreciate that all too often members of the public, as well as Welfare Charity Employees or Volunteers, simply arrive at a practice, without any prior telephone communication.
The logistical and financial implications of allowing a sick bird into a practice, which subsequently turns out to be suffering from AI, is massive and all staff should be fully aware of an approved protocol for dealing with sick (especially wild waterfowl) cases.
The RCVS stresses the obligation of the profession to treat all sick or injured animal, even if AI is suspected. Further details are available at:
http://www.rcvs.org.uk/Templates/Internal.asp?NodeID=94744
1. No sick or dead birds should be admitted into the premises, until a veterinary surgeon has examined them and concluded that they are not suffering from AI.
2. Initial examination should be made from a safe distance (>2 metres) and if a more detailed examination is required, appropriate protective clothing should be applied (gloves, overalls and mask).
3. If the birds are not thought to be affected by AI, they should be treated or euthanased in line with standard clinical and welfare guidelines.
4. If it is considered that the birds might be suffering from AI, an attempt should be made to contact Defra.
5. If Defra cannot be contacted, the birds should be euthanased. If the birds are privately owned, the owner should be required to sign a disclaimer (see Appendix A), to absolve the vet of any responsibility, in the event that compensation is not payable by Defra, subsequent to the destruction of these birds.
6. Carcasses should then be double bagged and tagged, in leak proof body bags, and retained in cool (refrigerated if possible but not frozen) secure storage until Defra can be contacted on the next working day.
Health and Safety Considerations
Risk of transmission from an infected carcass to a staff member is not high, however it is an acknowledged risk and standard avoidance measures should be practiced. All practices should have Health &Safety and COSSH assessments prepared for this risk and all staff members should be conversant with correct procedures (See Appendix B).
In the event of an outbreak of AI in the UK, any practice staff that might be at risk of exposure, must be advised to contact the Health Protection Agency, or their local Doctor, so that any suitable vaccinations which might be available can be given. Key Facts Relating to AI
• Avian Influenza (AI) is a disease of birds, not humans. But humans can, rarely, be affected
• There are both high pathogenic (HPAI) and low pathogenic (LPAI) forms and many strains
• The clinical picture following infection with LPAI may vary, depending on factors such as the strain of virus, species and types of birds infected, age, management system and general health status of the birds. Signs are usually milder than those seen following HPAI infection. It is normal to find a variety of LPAI viruses circulating in the wild bird population.
• It is thought that over-wintering migratory water birds is one of several risk factors in bringing HPAI H5N1 Asian Lineage to the UK. These migratory birds tend to arrive in the UK in the autumn and leave in the spring.
• Some subtypes of LPAI have the potential to mutate into HPAI. To date this has only occurred for some subtypes of H5 and H7 AI viruses. The likelihood of such mutation is generally greater when introduced into poultry populations
• Some strains of HPAI can spread readily between birds and cause severe illness, with a high death rate (up to 100%) in poultry populations. This can occur very quickly (often within 48 hours).
• In rare cases, some HPAI strains can lead to severe illness and deaths in humans where there has been close contact with infected birds. The World Health Organization (WHO), now states that there is mounting evidence that the H5N1 Asian Lineage strain has a unique capacity to jump the species barrier and cause severe disease, with high mortality, in people. To date (24/09/06), 247 humans are confirmed to have been infected globally, with 144 of those person having died of the infection.
• There are a limited number of reported cases of human-to-human spread of AI. There is no such thing as a human pandemic of bird `flu
• Migratory waterfowl – particularly wild ducks – are the main known natural reservoir of avian influenza viruses. These birds are the most resistant to clinical disease and can show no obvious clinical signs or mortality when infected
• It is possible for human and bird flu viruses to combine (reassort) to produce a new human flu virus if a person or other mammal is infected by both at the same time. That could produce a virus to which people have no current immunity and which could spread between humans
• It is therefore very important to ensure that any outbreak of AI is controlled quickly and that workers and veterinarians in close contact with infected birds are well protected. The Government has contingency plans in place to ensure that this is so
• The Government and key stakeholders are working closely together to ensure that the UK response to current circumstances is appropriate and comprehensive
• It is vital that a high level of surveillance, vigilance and preparedness is maintained by all bird (including poultry) owners, as well as veterinary surgeons in practice, to whom sick or dead birds may be presented and the public in general. The greatest risk period is October through to April, i.e. the autumn and spring water fowl migratory seasons.
• Further guidance is available on the Defra website http://www.defra.gov.uk/animalh/diseases/notifiable/disease/avianinfluenza.htm
• Advice on worker protection is a matter for the Health Protection Agency
• There is no confirmed outbreak of HPAI in the UK at the moment (November 2006). However, keepers of poultry will wish to be vigilant, to take care if handling birds which appear to be unwell and to observe high levels of biosecurity.
• In the event of an outbreak, Defra will be able to protect its workers with the necessary drugs and equipment. Detailed instructions to staff are in place
Biosecurity for free-range, exhibition and small scale poultry
http://defraweb/animalh/diseases/notifiable/disease/ai/keptbirds/index.htm#biosecurity
• separate wild birds from domestic poultry as much as possible
• Keep water fresh and free of droppings
• Keep waterfowl and chickens separate
• Control vermin
• Quarantine new stock for 2-3 weeks
• Quarantine birds for 7 days after taking to an exhibition
• Change clothes and wash boots before and after visiting other breeders
• Change clothes and wash boots before and after attending a sale
• Keep fresh disinfectant at the entrance to poultry areas for dipping footwear
• Disinfect crates before and after use, especially if lent to others. However, it is preferable not to be sharing equipment
• Disinfect vehicles, which have been on poultry premises but avoid taking vehicles onto other premises
• Comply with any import/export regulations/guidelines
• Wash hands before and after contact with birds
• Discourage people from attending bird or poultry shows in Europe.
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