What is avian influenza?
Avian influenza ('bird flu') is a viral disease that primarily affects poultry and wild fowl. Domestic chickens and turkeys are very susceptible to the disease, which is fatal in most infected birds. However, aquatic fowl (ducks etc.) may have greater resistance to the disease. These aquatic fowl may therefore act as a reservoir for the disease, perpetuating transmission of the virus to other birds.
While it is primarily a bird disease, these viruses have a tendency to mutate and may occasionally spread to other animals and to humans.
Why is it in the news?
A particularly virulent strain of avian influenza, H5N1 has been responsible for outbreaks in poultry throughout Asia since 2003, and has been implicated in outbreaks in various EU states including recent outbreaks in the UK and Hungary .
See: Update on Avian Influenza in Animals (Type H5): Most Recent Official Reports on the website of the World Organisation for Animal Health (OIE)
Does the virus affect humans?
In most cases, avian influenza viruses do not affect humans. However, in rare cases a number of humans have contracted the virus. Almost all cases in humans to date have been linked to close contact to diseased household flocks, often during slaughtering, de-feathering, butchering, and preparation of poultry for consumption.
Has anyone died from avian influenza?
According to WHO, since 2003 to date, 271 people that we know of have contracted the H5N1 strain of the virus and of those 165 have died (03.02.2007). However, this is a small number compared with the huge number of birds affected and the numerous associated opportunities for exposure.
For further information on the number of confirmed human cases of Avian Influenza A/(H5N1) Reported to WHO, see the WHO website
What are the implications for human health?
The ongoing incidence of H5N1 in poultry populations poses two main risks for human health.
The first is a direct risk of infection when the virus passes from poultry to humans, resulting in very severe disease. H5N1 strain has caused a number of cases of severe disease and death in humans. Unlike normal seasonal influenza viruses, where infection causes only mild respiratory symptoms in most people, the disease caused by H5N1 follows an unusually aggressive clinical course, with rapid deterioration and high fatality. Primary viral pneumonia and multi-organ failure are common. In the present outbreak, more than half of those infected with the virus have died. Most cases have occurred in previously healthy children and young adults.
A second risk, of even greater concern, is that the virus, if given enough opportunities, will change into a form that is highly infectious for humans and spreads easily from person to person. Such a change would be very serious and could mark the start of a global outbreak (a pandemic).
The European Commission and Member States are working continually on pandemic influenza planning and response measures in case of such an eventuality.
Is it safe to eat poultry?
Yes. To date, no epidemiological data suggest that the disease can be transmitted to humans through properly cooked food (even if contaminated with the virus prior to cooking) or that products shipped from affected areas have been the source of human infections. Human cases are linked to close contact with infected poultry, and exposure to the virus during the slaughter and preparation of infected birds.
Poultry and poultry products can be prepared and eaten as usual, provided that they are handled hygienically while raw, and cooked thoroughly prior to consumption.
Normal cooking temperatures of over 70°C will inactivate the virus, and therefore consumption of properly cooked poultry meat carries no risk of infection with the H5N1 virus. Poultry should be cooked thoroughly, so that it reaches at least 70°C in all parts, ensuring that it is piping hot all the way through, with no pink meat left and until the juices run clear.
Normal hygienic practices regarding handling of raw poultry meat should be observed. Hands, utensils and surfaces should be thoroughly cleaned following contact with raw poultry products; and there should be adequate separation of raw food from cooked or ready-to-eat foods.
Are eggs safe to eat?
Yes. Properly cooked eggs do not carry a risk of infection with the H5N1 virus. Consumers, caterers and food manufacturers should use and consume eggs as normal, following good hygiene practices. Use soap and hot water to wash hands after handling raw eggs and to clean surfaces and utensils that have come into contact with raw eggs. The World Health Organisation advises that in avian infected areas eggs should be cooked until both the yolks and whites are solid.
As for poultry meat, there is no evidence that the H5N1 virus is transmitted to humans by consuming properly cooked poultry or eggs. For people, the risk arises from having close contact with birds that have the disease, not from the consumption of poultry or eggs.
Is poultry meat from affected countries safe?
There are strict controls in place banning the importation of poultry and poultry products from countries or regions where avian flu has occurred. For example, no poultry can be imported from the currently affected Suffolk area of the UK . Poultry imported into Ireland is therefore free of the H5N1 virus and may be used and consumed as normal ensuring that it is handled hygienically while raw, and cooked thoroughly prior to consumption.
No cases have been linked to the consumption of properly cooked poultry meat or eggs, even in households where disease was known to be present in flocks.
The European Food Safety Authority (EFSA) and the World Health Organization has advised that there is no evidence to date to suggest that avian flu can be transmitted to humans through consumption of food, notably poultry and eggs.
EFSA further confirm that there should be no change to the longstanding advice that poultry products should be properly cooked in order to protect consumers from possible risks of food poisoning. Whilst it is unlikely that H5N1 could be passed on to humans by raw meat or eggs, cooking food properly would inactivate the virus and eliminate potential risk.
If poultry and poultry products from affected countries are safe, why have they been banned?
Import restrictions of raw poultry products from affected areas are commonly adopted to prevent the potential spread of the virus to domestic poultry flocks.
The prohibition on live poultry and their products from affected countries is a control measure designed to protect our animal health status. As an island, Ireland enjoys freedom from many animal diseases which are present in other countries, including avian influenza. It is in the interests of the health and welfare of our animals, and the marketability of our food products to maintain freedom from this disease.
Are eggs from chickens that are reared outside (e.g. free-range or organic eggs) safe to eat?
Ireland is currently free from avian influenza, therefore birds reared outside in Ireland are free of the H5N1 virus. Eggs laid by these birds may be used and consumed as normal, following usual good hygiene practices.
The Department of Agriculture, Fisheries and Food (DAFF) continue to monitor this situation. If circumstances change, and poultry reared outside in Ireland face the risk of contracting the H5N1 virus from wild birds, DAFF will require the compulsory housing of poultry.
What are the recommended good hygienic practices that I should follow?
Normal good hygienic practices are recommended to reduce exposure to the virus and to reduce spread through food:
- Wash hands after handling raw poultry or eggs using soap and hot water
- Clean utensils and surfaces that have been in contact with raw poultry or eggs using soap and hot water
- Separate raw poultry or eggs from foods that will not be cooked fully before eating to avoid cross-contamination:
- Use separate cutting boards, knives and utensils for ready-to-eat food and raw poultry and eggs (unless they are thoroughly cleaned between uses, with soap and hot water)
- Store raw poultry in sealed containers on the bottom shelf of the fridge to prevent juices dripping onto ready-to-eat food
What controls are in place nationally?
- Notifiability: Avian influenza is a 'Class A' notifiable disease. This means that there is a legal obligation to notify any suspicion of the disease to the authorities. In Ireland , a poultry farmer or veterinarian who encounters any clinical indication of avian influenza must notify that suspicion to the Department of Agriculture, Fisheries and Food (DAFF). An immediate quarantine is imposed on the holding to prevent movement of poultry, poultry products, waste products, or people from that holding. DAFF officials will gather samples and carry out confirmatory tests.
- Ante Mortem Inspection: Poultry entering the food chain as meat is subjected to 'ante mortem' inspection. An official veterinarian inspects the heath records of the flock and the clinical status of the birds before they are accepted for slaughter. Any suspicion of avian influenza will result in immediate quarantine of the slaughterhouse and holding, pending results of confirmatory tests.
- Post Mortem Inspection: Poultry entering the food chain is also subject to 'post mortem' inspection. The carcase and organs are inspected for any signs of abnormality. Any suspicion of avian influenza will result in immediate quarantine of the slaughterhouse and holding, pending results of confirmatory tests.
- Clinical Syndrome: It is important to note that Ireland is free of avian influenza and therefore Irish poultry have no immunity to any stain of the avian influenza virus. The current circulating strain is highly virulent, therefore birds infected with the virus will rapidly develop very profound clinical disease. Thus, ongoing passive surveillance by farmers and vets, together with ante mortem and post mortem inspection, cumulatively represent a significant level of control.
What controls are implemented when avian influenza is suspected in wild or farmed birds?
Suspect cases are treated as presumed positive until there is a negative result. The types of controls put in place when avian influenza is suspected or subsequently confirmed are prescribed by European legislation. A 'protection zone' is established in a three kilometre radius around the suspect/confirmed case for 21 days after confirmation, and a 'surveillance zone' is established in a ten kilometre radius around the suspect/confirmed case for 30 days after confirmation of the disease. Farms within these zones will be subject to active surveillance, stringent bio security and prohibition of movement of poultry or their products.
How can avian influenza be controlled in the poultry population?
Movement of live birds and their products is stopped from infected areas. All domestic poultry in the infected areas are slaughtered and their carcasses destroyed.
Who is responsible for controlling avian influenza in Ireland?
The Department of Agriculture, Fisheries and Food is responsible for controlling avian influenza in birds and mammals other than humans. Find more information on the Department of Agriculture, Fisheries and Food website
The Health Protection Surveillance Centre has published a number of guidance documents for the health system for use in the event of an avian influenza outbreak in animals in Ireland . Guidance on the investigation and management of suspected human cases of avian influenza is also available.
Last reviewed: 24/3/2011