EFSA defines the risks of Avian Influenza for poultry and makes recommendations to prevent its introduction and spread amongst flocks in Europe
The European Food Safety Authority’s (EFSA) Panel on Animal Health and Welfare (AHAW) has published today a scientific opinion and report on the risks of Avian Influenza (AI) entering and spreading amongst the poultry population in Europe. The Opinion provides recommendations to risk managers on different options to reduce the risk and contain the disease should poultry flocks become infected. The AHAW Panel has also addressed animal welfare aspects of AI. EFSA’s opinion and report will be forwarded to support discussions at the meeting of the European Union’s Chief Medical Officers and Chief Veterinary Officers on AI to be held in Brussels on 22nd September.
With respect to the possible emergence of AI in Europe’s poultry flocks, the Opinion identifies the following as the most important risk factors:
- the potential mutation of Low Pathogenicity Avian Influenza (LPAI) viruses into Highly Pathogenic Avian Influenza (HPAI);
- the contact of poultry with wild birds (primarily migratory waterfowl);
- the legal and illegal imports of live poultry and captive caged birds;
- entry of infected poultry products into the animal feed chain;
- contact with other poultry products (faeces, litter, feathers and down).
- In order to address these risk factors, the AHAW Panel has provided a series of recommendations which are outlined below.
The most significant risk is the possible mutation of Low Pathogenicity Avian Influenza (LPAI) into Highly Pathogenic Avian Influenza (HPAI)(such as H5N1 currently present in South-East Asia), and its subsequent spread through Europe’s poultry population. LPAI has mutated to HPAI on several occasions in Europe and worldwide. While EU legislation provides for notification and control of HPAI, this is currently not the case for LPAI. EFSA’s AHAW Panel recommends that the LPAI strains (H5 and H7 subtypes) which have been demonstrated to mutate to HPAI now be included in EU legislation so that appropriate measures can be taken to control them.
Contact of poultry with migratory wild birds (and their excrement) cannot totally be avoided and therefore there will always be a certain level of risk of introduction of AI viruses, as wild birds (primarily migratory waterfowl) can be infected with LPAI and very rarely with HPAI. Densely populated poultry areas and poultry kept outside (free range farms, backyard flocks etc.) under migratory flyways are most at risk. The Panel makes the following recommendations: strengthen biosecurity measures * in order to ensure separation between wild birds and domestic poultry; increase awareness amongst farmers on all the possible tools and measures that contribute to reducing risk; and enhance monitoring of free-range establishments and develop structured cooperation between ornithologists and AI epidemiologists (monitoring, mapping of the flight patterns of migrating birds and AI epidemiology).
While imports of live poultry and captive caged birds can represent a risk, legal requirements concerning AI in the EU should reduce the likelihood of HPAI introduction, particularly if LPAI is also clearly identified in this legislation as recommended by the AHAW Panel.
The possible risk of introduction and spread of the disease through the entrance of infected poultry products (such as poultry meat, eggs and processed products) in the animal feed chain should be limited. This is due to a series of factors, namely pre-export safeguards, import controls, processing methods, prohibition of the use of swill in animal feed, dilution effects and other environmental factors. Concerning LPAI, the risk that this could be present in food is considered negligible. The Panel recommends that import controls with respect to live birds and other poultry be further tightened in order to reduce illegal imports of these commodities.
Poultry faeces and litter are recognised as important means for spreading the LPAI and HPAI forms of the virus. The Panel recommends that the trading of poultry faeces and litter as agricultural manure should be limited to manure that is treated appropriately to eliminate the possible presence of AI virus. Poultry feathers and down which may also be contaminated with faeces should also be treated appropriately to eliminate the virus before being allowed to circulate in or enter the EU.
In addition to assessing the above risks and making specific recommendations on how to address them, the AHAW Panel also recommends general measures to assist in dealing with the disease. In the event of an outbreak, the Panel recommends increased biosecurity and bio-containment measures. The Panel also recommends vaccination of poultry flocks (as an alternative to pre-emptive culling) as a possible way of achieving eradication of the disease. However, this should only be carried out in combination with appropriate biosecurity measures and other measures which would enable the detection of a real infection in the flock so that it is not “masked” ** by the effects of the vaccine. Hobby flocks and pet birds are not considered to greatly increase the spread of the disease and the Panel suggests that increased surveillance, biosecurity measures, quarantine and vaccination for these birds might be considered, particularly instead of the alternative of mass culling.
Other key recommendations are:
- the development of early warning systems for early detection of LPAI;
- the identification of high risk exposure areas (i.e. close proximity of poultry populations in relation to roosting or wintering sites and migration pathways, particularly for waterfowl);
- the setting of safe distances between farms and rules for regional planning to reduce the risk of spread of infection of the disease, particularly in densely populated poultry areas;
- the drawing up of contingency plans for the mass culling of poultry, in the case of major outbreaks;
- the use of the most humane methods for culling, if needed in a crisis (the Panel recommends such methods and lists those which should not be used).
HPAI includes the H5N1 strain which is currently widespread in South East Asia. Public health experts believe that it may eventually fuse with human flu, jump the species barrier, spread to humans and have a devastating effect on the human population. Whereas HPAI normally causes disease in poultry with a high mortality rate, LPAI is much more common amongst birds but most of the time only manifests mild or even harmless effects on birds.
EFSA’s Biological Hazards Panel has addressed the risk to human health from food and has indicated that by following WHO guidelines on food hygiene concerning food handling and food preparation, any threat to human health should be effectively addressed.