19 October 2005
Avian influenza(AI)/Bird flu
I. Background to the disease
Q 1. What is avian influenza(AI)/Bird flu and which birds does it affect?
A. Avian influenza is a highly infectious disease affecting many species of birds, including commercial, wild and pet birds. It may also affect people and other animals in certain circumstances. It is caused by a Type A influenza virus.
AI viruses can be classified according to their ability to cause severe disease (pathogenicity) as either highly pathogenic or low pathogenic. Highly pathogenic avian influenza viruses-(HPAI) can cause severe disease in susceptible birds and low pathogenic avian influenza viruses-(LPAI) generally cause mild disease or no disease at all. Avian influenza is one of the most important poultry diseases, and serious outbreaks of disease have been reported in many countries. In the UK it was last confirmed in a flock of 8000 turkeys in Norfolk back in January 1992.
Q 2. Is AI connected to Newcastle disease?
A. No. This disease is different from Newcastle disease and is caused by a totally different virus.
Q 3. What are the signs of the disease?
A. The severity depends upon the strain of virus and the type of bird infected. Birds infected with HPAI may die suddenly or show a range of clinical signs including respiratory signs, swollen heads, dullness, a drop in egg production, and a loss of appetite. Some birds, especially waterfowl, can be infected with LPAI without showing any signs of disease.
Q 4. Once it is present, how is it spread?
A. AI is spread by movement of infected birds or contact with their secretions, particularly faeces, either directly or through contaminated objects, clothes or vehicles.
Q 5. Is AI notifiable in UK?
A. Yes. If anyone suspects AI it should be reported to the local Animal Health Office .
II. Health Concerns
N.B. Health concerns are primarily the responsibility of the Health Protection Agency, The Health & Safety Executive and the Department of Health. Answers in this section point to where further advice or information can be obtained. The World Health Organisation provides information and guidance on health issues.
Q 6. Why is there so much concern about the current outbreaks?
A. There is concern that the virus may change (reassort or mutate) to emerge as a new virus that is easily transmissible between people and capable of causing disease in people, birds and other animals. Influenza A viruses occur worldwide in man and a wide range of mammals.
The high pathogenic H5N1 AI strain involved in most of the Asian outbreaks during the last 18 months has shown the ability to jump the species barrier occasionally and cause severe disease, with high mortality, in humans. It has not shown the ability to move easily between humans.
Avian and human influenza viruses can exchange genetic material when a person or other animal susceptible to infection with both viruses is simultaneously infected with both viruses. This could create a completely new subtype of the influenza virus to which few, if any, humans would have immunity and which might be able to spread between humans.
More information on the risks of this happening and the implications are held on the
World Health Organisation (WHO) and Health Protection Agency (HPA) websites.
Q 7. I have heard bird flu will kill millions of people. Is this the same disease?
A. No. Avian influenza (bird flu) is primarily a disease of birds . It is caused by influenza viruses closely related to human influenza viruses. Transmission to humans in close contact with poultry or other birds occurs rarely and only with some strains of avian influenza.
There is potential for mutation of avian influenza viruses to new forms of virus that can causes severe disease in humans and spread easily from person to person. That possibility is a great concern for public health. More information is available on the HPA website .
Q 8. Are all of the currently reported outbreaks in birds equally dangerous for humans?
A. No. It varies between strains. See the Health Protection Agency website for further details.
Q 9. Does it affect humans and if so, how?
A. Humans are usually infected only through close contact with live infected birds.
The severity of disease in humans varies from mild disease to severe respiratory disease. This depends on the strain of virus and characteristics of the person infected. Human deaths have been reported following severe disease.
Since December 2003, AI in Vietnam and Thailand, and more recently Cambodia and Indonesia, has resulted in 112 cases in humans (and 57 deaths) – to 10th October 2005 - see the
WHO website for up to date information.
Q 10. Can people get it from other people?
A. There has been a limited number of well documented cases in which there is evidence to suggest person-to-person transmission but to date there is no evidence that the highly pathogenic avian influenza virus has adapted to spread easily in humans.
Examples of these family clusters are described on the Health Protection Agency website.
Q 11. Which groups of people would be at most risk if we had the disease in poultry in the UK?
A. People in close contact with infected poultry or infective material from poultry are most at risk. This would include poultry farm workers, veterinarians and others involved in disease control.
Q 12. Can we vaccinate people against bird flu?
A. No. There is currently no vaccine to protect people against AI infection or disease
, though one is being developed. There is however good evidence that avian flu viruses respond to antiviral drugs, and in the UK oseltamivir or other appropriate antiviral agent would be used for the treatment of avian flu in people exposed to the virus. Or to protect people, including poultry workers, who might become exposed to the virus during disease control activities. Such people will be supplied with appropriate antiviral drugs, under prescription, as soon as possible and at least within 48 hours of exposure.
The Joint Committee on Vaccination and Immunisation (JCVI) currently advise that routine vaccination of poultry workers and veterinarians with seasonal human flu vaccine is not recommended , but should be used in a confirmed outbreak of avian flu as a protection against the possibility of re-assortment with human flu virus for those people who might be exposed to the virus during disease control activities.
Q 13. What about the H5N1 vaccine?
A. On 20 July, the Government announced its intention to purchase a limited amount of H5N1 vaccine as part of its ongoing preparations for a possible influenza pandemic. This vaccine will be used for further research, and could be used to provide some protection to frontline healthcare workers. These vaccines are currently in development and it is not expected that these vaccines will become available for 12 to 18 months. There is no guarantee that H5N1 vaccine would protect against any new pandemic influenza strain.
The Government is considering how this vaccine, when available could be used during an AI outbreak in birds in this country.
Q 14. What measures should we take now or in future to protect those who work with poultry?
A. High standards of personal hygiene will help prevent ingestion and inhalation of infective material and reduce the risk of transmission to others. Thorough washing with soap and water is an effective method of decontamination and may usefully be enhanced by the use of anti-viral hand wash/wipes following effective washing.
Workers should take additional care when handling obviously sick or diseased poultry.
Q 15. What measures should we take if avian influenza in poultry is confirmed?
A. Employers must provide their employees who have had, or are likely to have contact with infected birds with information as to how to protect themselves and their families from infection. The Health and Safety Executive have advised that to protect against infection, a hierarchy of control measures is likely to be required that include:
• Limiting exposure to potentially infected poultry
• the wearing of appropriate personal protective equipment
• safe disposal of used personal protective clothing and equipment
• use of appropriate antiviral agent for the prescribed period by all who are considered to be at risk of infection and for whom antiviral therapy is not contraindicated
• vaccination with seasonal flu vaccine of all those considered to be at risk of infection and for whom vaccine is not contraindicated
• monitoring of health status of persons exposed to infected birds; and
• guidance to those at risk of infection on the personal hygiene measures to be taken to protect their health and to prevent the spread of infection
Q 16. If there is an outbreak, what personal protective equipment (PPE) is recommended for those who deal with it?
A. The choice of PPE will depend upon the local risk assessment which will take account of the nature of the disease, virus strain and the level of human exposure. Disposable PPE must be of good quality, properly maintained and issued individually. Where appropriate, a range of sizes should be available. The ‘one size fits all’ principle is not an option as, badly fitting PPE is, at best, inconvenient and, at worst, ineffective and may give a false sense of protection.
Current advice is that a FFP3(1) respirator with exhalation valve in conjunction with close fitting goggles or other equipment which gives similar levels of protection is necessary where protection against airborne transmission is required. Where a good seal cannot be achieved with other respirators e.g. because of facial hair, a full hood powered respirator should be considered. Lightweight disposable overalls with hoods should be worn to prevent contamination of personal clothing. Wellington boots, disposable surgical type rubber/vinyl gloves should be worn. Where available, toughened, tear resistant brands are preferred.
(1) Respirators are intended to help reduce the wearer’s exposure to airborne particles. Some, including the ones recommended here resemble surgical face masks. They are made to defined national standards, such as European standard EN149:2001 FFP3 respirator the similar (but not identical) United States NIOSH-approved N99 respirator. The standards define the performance required of the respirator, including filtration efficiency. When worn correctly, they seal firmly to the face, thus reducing the risk of leakage.
Further information on PPE is available on the Health & Safety Executive website.
Q 17. Is it safe to eat poultry or game?
A. The Food Standards Agency considers that the outbreak of avian flu does not pose a food safety risk for UK consumers. This is because the risk of catching the disease in humans is from being in close contact with live poultry that have the disease and not through eating poultry. There have been no reports of people handling poultry meat getting infected. WHO advice is that there is no health risk from well cooked poultry meat or from eggs.
Q 18. Can I get AI from handling wild birds?
A. Avian Influenza is not known to be present in the country. Wildfowlers and those in contact with wild birds should always take appropriate hygiene precautions when handling wild birds.
III. Current assessment and response
Q 19. Where is AI at the moment?
A. There have been outbreaks of AI in parts of SE Asia for over 18 months now and there have been reports of infection of birds in South East Russia and in Kazakhstan.
There is a great deal of uncertainty about the situation in Russia and Kazakhstan. We do not know what their background level of surveillance is and it is possible that this disease may have been endemic in the region for some time - they may have just looked for the first time and found it - we simply do not know. More recently there has been a reported outbreak in Turkey (please see question 31).
Q 20. What are the chances it could come here?
A. There is always a low risk that any avian influenza virus may be introduced to the UK via migratory birds or other routes. Once here, LPAI could mutate into a highly pathogenic form.
On 17 August 2005, Defra updated its provisional assessment of the risk from avian influenza in Central Asia. This is available on the Defra website.
It concludes that recent reports of H5N1 virus in Russia do not significantly alter our previous conclusion regarding the increased (but still low) likelihood of the introduction of H5N1 virus to the UK. We will continue to monitor developments and reassess the situation when additional information becomes available.
Q 21. Have we banned imports of birds and their products from areas with HPAI?
A. In line with EU-wide measures, we have banned imports of live birds and products which could potentially transmit the disease to other birds. This includes unprocessed feathers, as they might be contaminated with faecal material which can transmit the disease. Our risk assessment supports the view that no further preventative action in respect of legal imports is necessary at this time.
Q 22. How do we know that infected poultry meat is not coming into the country?
A. European Community rules aim to prevent the import of susceptible birds and products which might carry disease from countries known to be experiencing outbreaks of HPAI. Animals and products imported from third countries are subject to veterinary checks on arrival to determine that they comply with import rules. An unquantifiable risk exists in respect of illegally imported animals and products. HM Revenue and Customs is responsible for action to prevent and detect illegally imported animal products from outside the EU and animals of endangered species covered by the CITES (Convention on International Trade in Endangered Species) convention. They are kept informed of any changes in disease risk and target their resources accordingly.
Q 23. Should we be requiring all imports of poultry meat to be labeled with the country of origin?
A. We have no plans to update our rules on labeling meat in response to AI outbreaks in other countries – as we do not allow imports from such countries.
Q 24. I keep birds. What should I do now?
A. The risk remains low that we will experience and outbreak of HPAI in the near future. However, all keepers of birds will wish to be vigilant about the health of their birds. They should also consider the biosecurity guidance available on the Defra website, or through their local animal health offices. Local private veterinary advisers should also be able to advise on appropriate measures.
Q 25. Should free-range poultry be locked up?
A. In discussion with the industry, we are content that the risk of AI spread to domestic poultry remains low and that currently, there is no need for the industry to house free-range birds. However, all keepers of poultry should plan ahead and consider how they would manage their flock and any consequent welfare problems if they were required to isolate them from wild birds e.g. in the event of a nearby outbreak of AI. For example you might wish to consider whether to prepare material for a temporary extension to your housing. Further guidance can be found on our website.
Q 26. Shouldn’t Defra do more to inform poultry keepers of the risks and the actions they should be taking?
A. Industry representatives agree with the Government’s assessment that the risk remains low, but we are not complacent. There is an up to date risk assessment on AI, biosecurity guidance and core briefing on the issues on the Defra website. We are reviewing with key stakeholders what further steps might be necessary in which circumstances and will develop our communications strategy further in that light.
Q 27. What precautionary measures should we take against bird flu now?
A. There is a constant low risk of AI entering the country through migrating wildfowl. The Government assessment is that that risk remains low. This is constantly reviewed. Key industry stakeholders agree with the Government’s current assessment that no further precautionary action is required at the moment.
Any action would have to be based on our own risk assessment and be proportionate. Housing free range birds, for example, is not a simple matter as many farms buildings are not designed to house birds permanently. Welfare, marketing and economic factors would need to be taken into account and we would need to know in what circumstances we could withdraw any additional precautionary measures.
Q 28. What else should the industry be doing?
A. Poultry keepers are advised to maintain vigilance for the signs of any disease and report any concerns to their local Defra Divisional Veterinary Manager. Signs of disease may include increased mortality, falling egg production and signs of respiratory problems.
They should maintain a high standard of biosecurity. Advice is available on the Defra website.
Q 29. Was HPAI found in a seagull in Finland?
A. Finnish officials have confirmed that a low-pathogenic strain of avian flu virus was found in three seagulls discovered dead, but that the birds had died of starvation, not the disease itself.
Tests were carried out to determine the exact strain of the virus the birds carried. The National Veterinary and Food Research Institute ruled out the highly pathogenic version H5 or H7 strains and confirmed that it was a low pathogenic form of avian influenza commonly found in wild birds.
Q 30. What's happening in Romania?
The three EU laboratory experts sent to Romania by the European Commission have confirmed that avian influenza virus H5 has been detected in tests on two samples from a chicken and a duck taken in a suspected backyard farm in the Danube delta. This finding has been confirmed by using reagents the EU experts took with them from the Community reference laboratory. Further tests are necessary to ascertain if the virus in question is the highly pathogenic H5N1 strain circulating in parts of Asia.
On 13 October 2005 the Commission adopted a decision to ban imports of live birds, poultry meat and other poultry products from Romania following the new tests by EU experts. Imports of live birds and feathers from Turkey have been banned since Monday following the finding of Avian Influenza there.
Q 31. What's happening in Turkey?
Turkey has reported an outbreak of avian influenza to the European Commission. The outbreak occurred in an open-air turkey farm with 1800 turkeys, 1700 of which died after that the first clinical signs were detected on 1 October. All remaining birds on the farm and in the village have been killed and all carcasses destroyed. Disinfection has been applied. The farm is located in the Region of Balikesir, in the north-western part of Anatolia. Laboratory tests have given positive results for avian influenza virus serotype H5. Further tests are pending to determine the pathogenicity of the isolate and the "N" of the virus strain. The origin of the outbreak is unknown. There is so far no information on whether wild birds in the area are infected. The Turkish authorities are investigating whether this incident could have been caused by the highly pathogenic H5N1 strain circulating in parts of Asia.
Q 32. What are you doing to see if wild birds are carrying disease?
A. The EU Expert Group agreed that member states should increase sampling of migratory wildfowl along the flyways that could pose a risk for disease introduction. The Government has already met bird experts to develop proposals and has submitted a plan to the European Commission. Member states will be meeting in the next few days to discuss their proposals. The aim is to put in place arrangements quickly. The survey of poultry during the winter will also go ahead. A questions & answers page about Surveillance for avian influenza in wild birds has been published.
IV. Available controls
Q33. How would we control it if it came here?
A. The Government’s contingency plan was laid before Parliament on 21 July 2005.
As required under EU legislation, disease control would include killing infected birds and dangerous contacts, and the imposition of movement controls around the infected premises. A new AI Directive is currently being negotiated.
Q34. Can we vaccinate birds?
A. There is provision in the Diseases of Poultry (England) Order 2003 for the imposition of a compulsory vaccination zone. However, in view of the limitations, summarised below, vaccination is not expected to be part of the current GB avian influenza control strategy.
• The vaccines that are currently available to protect against AI disease are inactivated types and need to be delivered by injecting birds individually. It can take up to three weeks for birds to develop optimum protective immunity and some poultry require two doses. Delivering such a vaccine, as an emergency measure, to large numbers of birds can raise significant logistical difficulties.
• These vaccines protect against disease but will not protect birds from becoming infected and shedding virus. Although vaccination will reduce the amount of virus shed by birds and hence the viral load, this reduced amount may be still be significant and could cause infection in other birds
• Although there are strategies to differentiate vaccinated birds from infected birds, such as the use of DIVA strategies and unvaccinated sentinel birds, vaccination may lead to difficulties in identifying birds that are carrying the virus; this can be a problem for control
• No AI vaccines have marketing authorisation in Great Britain
However, there may be a role for vaccination in the protection of zoological collections of rare breeds or endangered species. Such use would be subject to a Commission Decision adopted by the Standing Committee on Food Chain and Animal Health in Brussels.
Q 35. Does Avian Influenza affect pigs?
A. It is possible for certain AI viruses to infect pigs. The virus has been found in pigs in the Far East. Pig to pig transmission is limited and is not believed to play a part in the spread of disease.
Q 36. How can we monitor the spread of the disease?
A. Awareness of bird disease has been heightened in the UK due to the recent outbreak of Newcastle disease; keepers of poultry will be increasing their vigilance.
Surveillance for the disease has several key strands:
• Monitoring the overseas distribution of disease and keeping in close contact at EU level to monitor the situation through the OIE etc
• Raising awareness when the risk of disease increases, among the industry and veterinary profession and reiterating the importance of biosecurity in preventing contact between domestic poultry and migratory or wild birds. Avian and poultry biosecurity advice is available.
• Constant scanning surveillance for HPAI. There is a legal requirement for anyone suspecting AI to notify their local animal health office, and such notifications are fully investigated
• An annual survey to determine the prevalence of LPAI infection in commercial poultry and wild birds (part of an EU-wide initiative). The survey provides valuable information across the EU for an early warning system of H5 and H7 sub-types that may be introduced to poultry from wild birds. The most recent surveys have not identified any infection in poultry in the UK. A summary of the results of the 2004 survey shows a relatively low prevalence of low pathogenic H5 and H7 influenza viruses in poultry in member states except in one where several outbreaks were reported.
• There is monitoring of wild bird die-offs for important poultry diseases, including AI, by Defra’s Veterinary Laboratories Agency
Q 37. Is the Government ready if we do have an outbreak?
A. The Government’s contingency plan is available on the Defra website.
It sets out all the steps to be taken if a suspected case of disease is notified and how the Government will control any confirmed outbreak.
Previous outbreaks of avian influenza in this country have been rapidly contained and eradicated. However, Parliament extended the Government’s range of powers to tackle AI available during the Netherlands outbreak in 2003.
Detailed instructions and the necessary equipment and drugs that will be available to Government staff on managing an outbreak are in place. This includes protection against being infected.
Q 40. Are Customs putting in any additional checks on passengers from Turkey and Romania?
A. Yes. Customs are responsible for anti-smuggling controls on products of animal origin from third countries (including Turkey and Romania). Their enforcement activity is based on risk. Given the recent outbreaks of Avian Flu Customs are increasing their levels of checks on passengers from these countries.
VI. Dutch Free Range Status
Q 41. Can the action taken by the Dutch authorities in August 2005 to deny free-range poultry outdoor access mean such eggs can continue to be marketed as ‘free-range’ eggs?
A. Yes. The Dutch authorities are using a temporary veterinary restriction under the EC Egg Marketing Regulations (Commission Regulation (EC) No 2295/2003 - as amended by 1515/2004 - introducing detailed rules for implementing Council Regulation (EEC) No 1907/90 on certain marketing standards for eggs). Annex III: ‘Minimum requirements to be met by poultry establishments for the various egg farming methods of the EC Egg Marketing Regulations’ of Commission Regulation 2295/2003, states:
‘Free-range eggs’ must be produced in establishments which satisfy at least the conditions specified in Article 4 of Council Directive 1999/74/EC(1) and in which:hens have continuous daytime access to open-air runs, except in the case of temporary restrictions imposed by veterinary authorities.
Q 42. Does the UK have grounds for banning the import of such eggs?
A. The UK does not have grounds for banning the import of such eggs, as the Regulations themselves do not contain any provision permitting such unilateral action, and nor does EC law more generally. Although Member States may (under Article 30 of the EC Treaty) prohibit imports of goods on certain grounds (eg public morality, policy, or security; or the protection of health and life of humans, animals or plants) these grounds are construed narrowly and would not apply here.
Q43. Can retailers and food processors continue to market their table eggs and products containing free-range eggs as such where the birds have been locked up?
A. This is of course a matter for the relevant retailer or food processor, who are advised to seek their own legal advice relating to the way they present relevant products onto the market. For example, although free-range eggs may continue to be marketed as such under the EC Egg Marketing Regulations, retailers may make promotional statements that go beyond those Regulations, where perhaps general trade descriptions considerations might apply.
Q 44. Is the position the same for poultrymeat?
A. No. Under the EC Poultrymeat marketing regulations, there is no provision for the maintenance of the ‘free-range’ status of meat in cases where a temporary veterinary restriction is in place. If birds have been kept indoors because of such a restriction, then meat coming from such birds should not be marketed as ‘free-range’ meat if this results in a contravention of the ordinary rules relating to access to outdoor runs. For example, in the case of ‘free-range’ poultry, free-range status is not automatically removed at the point a bird is denied access to range outdoors. It loses this status if the controls mean that the bird will have lived for more than half of its life inside.
There are stricter controls in the case of poultry marketed as ‘traditional free-range’ and ‘free-range - total freedom’. Such birds must have continuous daytime access to open-air runs from a specified age. If the birds do not have such access after that age then they cannot be marketed using these terms.
This situation has been drawn to the attention of the European Commission to consider amending the relevant EC Regulations to provide a provision for poultrymeat similar to that which already exists for eggs. The EC is considering the matter.
Q 45. What about organic eggs and poultry?
A. Much the same considerations arise for organic eggs and poultry. To qualify for the organic designation birds have to have access to range for one third of their life. In addition much organic egg and poultry production is also produced to the free range standard besides being organic.
Q 46. Why is poultry being included on the Livestock Register?
During requirements gathering it became apparent that many stakeholders considered a central consolidated set of poultry data an essential tool to ensure that Defra and it’s delivery partners could respond appropriately in the event of a disease outbreak. There is increasing public interest and concern around the threat of an Avian Influenza outbreak and new EU legislation is being introduced which requires a central consolidated set of poultry data, Livestock Register will help farmers to comply with these new legal obligations.