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Avian influenza
Avian influenza is a highly contagious viral disease that occurs primarily in poultry and wild water birds. It is either high or low pathogenic (HPAI/LPAI) depending on the molecular characteristics of the virus involved and its ability to cause disease and mortality in chickens.
Poultry infected with LPAI viruses may show mild signs of the disease or none at all. Infections caused by HPAI are more severe and may even cause death. Both HPAI and LPAI can spread easily and quickly through poultry flocks. Therefore, the implementation of stringent biosecurity measures in farms is essential. Moreover, LPAI viruses can mutate into highly pathogenic strains, which highlights the importance of prompt outbreak management.
In the epidemic A widespread occurrence of an infectious disease in a community at a particular time. year 2021/2022 the HPAI epidemic was the largest observed so far in the EU in terms of number of poultry outbreaks, geographical spread and number of dead wild birds. In recent years, the range of wild bird and mammal species A subdivision of the genus, a species is a group of closely related and similar-looking organisms; for example, in the case of Homo sapiens (humans), the second part of the name (sapiens) represents the species. affected by HPAI viruses has also expanded, with the detection of HPAI viruses showing genetic markers of adaptation to replication in mammals. Animal-to-human transmission has occasionally occurred, while no transmissions between humans have been reported.
Avian influenza can be transmitted from animals to humans mainly in two ways:
- Directly from birds or from contaminated environments
- Through an intermediate host, such as a pig
Humans exposed to potentially infected birds, such as workers during culling operations, or those in close contact with potentially infected mammals (e.g., foxes or other wildlife) like workers at rehabilitation centres, must be adequately protected and actively monitored after exposure Concentration or amount of a particular substance that is taken in by an individual, population or ecosystem in a specific frequency over a certain amount of time..
There is no evidence that avian influenza can be transmitted to humans through the consumption of contaminated poultry products. Safe handling of raw meat and other raw food ingredients, thorough cooking and good kitchen hygiene can prevent or reduce the risks posed by contaminated food.
Latest
In April 2024, EFSA and ECDC issued a report discussing the drivers for a potential pandemic An epidemic that becomes very widespread and affects a region, continent or the whole world. of avian influenza currently in circulation worldwide. The report focuses on events such as reassortment, mutation A permanent, typically negative, change in the genetic material in a cell which, in most cases, can be passed onto any offspring. and adaptation of avian influenza viruses to mammals, including humans.
The experts also identified a number of risk mitigation measures to be implemented under a One Health approach at national and EU level to reduce the risk of the virus evolving.
Milestones
2024
July
The number of HPAI outbreaks in poultry and wild birds has decreased in Europe, but there is a need to step up surveillance in view of the next influenza season when migratory birds arrive in autumn. The risk to the general public in Europe remains low, according to the latest quarterly monitoring report on avian influenza by EFSA, ECDC, and EURL.
April
EFSA published a scientific opinion assessing the surveillance and risk mitigation measures in vaccinated areas and farms. Our scientists assessed these measures and evaluated whether the available surveillance strategies could demonstrate freedom from the disease thereby enabling the safe movement of poultry and related products.
March
HPAI cases are still widespread in Europe but the overall number of detections has decreased compared to the last two years. The risk for the general population Community of humans, animals or plants from the same species. in Europe remains low. These are the main findings of the latest quarterly monitoring report by EFSA, ECDC and EURL.
2023
October
EFSA assessed available vaccines and their efficacy How well something works in relation to predefined standards or expectations. against highly pathogenic avian influenza (HPAI) virus in poultry, and provided advice about possible vaccination strategies. In 2024 EFSA will publish a separate scientific opinion Opinions include risk assessments on general scientific issues, evaluations of an application for the authorisation of a product, substance or claim, or an evaluation of a risk assessment. assessing the surveillance and risk mitigation measures in vaccinated areas and farms.
September
While the situation in poultry has eased over the summer, HPAI virus continued to affect seabirds in Europe, mostly along coastlines. As the autumn migratory season starts, the protection of poultry and other farmed animals from wild birds should be prioritised. Biosecurity should be enhanced in fur animal farms, according to the latest report on avian influenza by EFSA, ECDC and EURL.
July
HPAI virus continues to circulate extensively among seabirds in Europe causing high mortality, while the overall situation in poultry has eased. Epidemiological investigations of an outbreak in cats in Poland are ongoing. The risk to the general public remains low.
May
The number of HPAI outbreaks in poultry has decreased in Europe but gulls continue to be heavily affected by the virus. The risk to the general public in Europe remains low, according to a report on avian influenza by EFSA, ECDC, and EURL.
March
The situation regarding avian influenza continues to evolve in Europe and globally, with reports of new outbreaks in birds and occasional infections in mammals. Sporadic human infections have been reported in countries outside the EU, while the risk to the public in the EU remains low, according to a report on avian influenza by EFSA, ECDC, and EURL.
2022
December
HPAI cases recorded in Europe among domestic and wild birds have risen since the summer according to the latest quarterly monitoring report by EFSA, ECDC and EURL.
EFSA publishes two reports: one on the development of a prototype early warning system for HPAI introductions in wild birds, based on risk mapping; and another on a proposal for an active surveillance system in wild birds to rapidly detect and identify HPAI viruses that are threatening the EU.
October
An unprecedented number of HPAI virus detections are reported in wild and domestic birds in Europe from June to September 2022, according to EFSA’s quarterly monitoring report. In previous years, no cases or only few cases were detected during the summer period.
June
With 5,300 HPAI virus detections in poultry, captive and wild birds, the 2021/2022 epidemic year was the largest ever recorded in Europe, according to EFSA’s quarterly monitoring report. The persistence Persistence refers to the ability of harmful organisms like bacteria to survive and thrive despite regular cleaning and disinfection efforts, potentially lingering in hidden places for months or even years. of the HPAI A(H5) virus in wild birds indicates that it may have become endemic Consistently present in a population or region, whether dormant or active as measured by clinical tests.in wild bird populations in Europe.
2021
January
EFSA experts assess the effectiveness of certain control measures for HPAI: clinical and laboratory sampling procedures, monitoring period, minimum radius of protection and surveillance zones, and minimum length of time for which the measures should be applied in these zones.
2019
October
Specific guidelines for submitting data on surveillance for avian influenza, including details on the individual data elements comprised in the EFSA (SSD2) data model, are provided to the EU Member States.
2018
November
EFSA publishes a report outlining the data collection framework to collate, validate and analyse data on surveillance for avian influenza that are submitted by Member States on a yearly basis.
2017
December
EFSA provides in its quarterly monitoring report a list of wild bird species that should be sampled and tested for HPAI if found dead or showing clinical signs.
October
EFSA experts assess the risk of avian influenza entering the EU and review surveillance approaches, comprising monitoring by Member States and actions that should be taken to minimise its spread. They conclude that migratory wild birds that cross the north-eastern and eastern borders of the EU represent the most likely pathway for avian influenza to enter the territory.
June
LPAI is assessed according to the criteria of the Animal Health Law (AHL) and is considered eligible to be listed for Union intervention by EFSA experts.
2016
December
EFSA experts conclude that the strict enforcement of biosecurity measures is the most effective way of preventing the introduction of HPAI A (H5N8) into poultry farms.
EFSA's role
EU legislation, particularly the Animal Health Law – Regulation (EU) 2016/429 sets out rules on the surveillance, control and eradication of avian influenza. In that framework, EFSA issues scientific advice to assist risk managers (the European Commission, the European Parliament and Member States) in making appropriate decisions and actions. Experts assess issues such as the risk of introduction and transmission of avian influenza, and the risk of LPAI strains mutating into HPAI strains. They provided advice on biosecurity and control measures.
In addition, EFSA supports Member States in their data collection and surveillance activities.
Monitoring and surveillance
EFSA, in collaboration with the European Centre for Disease Prevention and Control (ECDC), the EU reference laboratory (EURL) on avian influenza, and authorities in affected Member States publishes quarterly monitoring reports on the situation of avian influenza in Europe and at global level. Those reports include analyses of:
- Risk of introduction and spread of HPAI in Europe
- HPAI and LPAI outbreaks in Europe and other continents
- Prevention and control measures that are being applied
- Characteristics of affected poultry farms
EFSA’s quarterly monitoring reports are based on countries’ official outbreak notifications and additional data provided by affected Member States. In addition, EFSA has been requested to collate, validate, analyse and summarise the data resulting from the ongoing avian influenza surveillance programmes in Member States in the form of annual reports.
The latest information on the number and evolution of cases can be found in EFSA’s interactive dashboard. On it, detailed information on all HPAI detections reported in poultry, wild and captive birds in Europe since October 2016 can be visually explored in space and time.
Data collection
Since 1 January 2019, Member States have submitted the results of their annual surveillance activities in domestic and wild birds to EFSA. These results comprise data on:
- Active surveillance Measures initiated to detect and control animal diseases as early as possible using defined protocols and activities. in domestic birds (mandatory)
- Passive surveillance The reporting and investigation of increased mortality, other signs of serious disease or significantly reduced production rates with an undetermined cause in a targeted animal population in dead and moribund wild birds (mandatory)
- Active surveillance in wild birds (voluntary)
According to current legislation, Member States are required to submit their data on a yearly basis. Iceland, Norway and Switzerland report voluntarily. The detailed timelines for data reporting and validation are provided on a dedicated EFSA web page. In 2024, data collection will be adapted to meet EFSA’s new standards as envisaged under the SIGMA project.
Early warning
In line with EFSA’s strategic objective to increase preparedness, several outsourcing activities have targeted the development and implementation of early warning systems to allow Member States sufficient time for their outbreak response and management.
The Migration Mapping Tool, a tool to monitor and visually examine wild bird abundance, distribution and movement data has been developed for a range of 50 wild bird species:
EFSA’s Bird Flu Radar, an early warning system for HPAI in Europe, was launched in March 2023 and is accessible through the Migration Mapping Tool. Spatiotemporal risk assessment A specialised field of applied science that involves reviewing scientific data and studies in order to evaluate risks associated with certain hazards. It involves four steps: hazard identification, hazard characterisation, exposure assessment and risk characterisation. models were developed to generate weekly estimates of the probability The likelihood that a particular event will occur or that a measured value will fall within a particular range. of HPAI introduction in wild birds, which are displayed on automated risk maps. The tool is under constant development and, in future, will also be expanded to poultry. EFSA’s Bird Flu Radar is accompanied by an alert messaging system through which users can receive automated alerts for a geographic area of interest whenever a certain risk threshold A dose or exposure below which adverse effects are not detected. is exceeded.
In addition, EFSA has piloted active surveillance systems at the borders of the Union with the aim of establishing an EU-wide surveillance system in wild birds, which will be able to rapidly detect and identify newly emerging HPAI viruses. Following up on this work, EFSA is working on the establishment of a network of surveillance nodes across Europe to build capacities and long-term partnerships for active surveillance in wild birds. A webinar to provide preliminary information on the call was organised.
Control measures
The following control measures for HPAI have already been reviewed in a dedicated Scientific Opinion: clinical and laboratory sampling procedures, monitoring period, minimum radius of protection and surveillance zones, and minimum length of time for which the measures should be applied in these zones.
EFSA is currently assessing the availability of vaccines against HPAI for poultry and considering potential vaccination strategies. The outcome of this work, to which the European Medicines Agency (EMA) and the EURL are also contributing, will be available in the second half of 2023.
Disease profiles
EFSA has produced an interactive disease profile for HPAI, updated in seven living systematic reviews. When sufficient studies are found and reviewed, a meta-analysis A statistical method which enables the results of similar studies to be pooled in order to determine any significant trends. of the extracted data is carried out automatically, and the results are visualised in the form of disease profiles. Please check our video for a short demonstration of the disease profiles.
Collaboration
The EU reference laboratory (EURL) for avian influenza, hosted at the Istituto Zooprofilattico Sperimentale delle Venezie (Italy), ensures high-quality uniform testing in the EU for this disease.
The European Centre for Disease Prevention and Control (ECDC) assesses the risk of avian influenza infections in humans.
The European Medicines Agency (EMA) collaborates with EFSA on the assessment of appropriate vaccines for avian influenza.
The European Agency for Safety and Health at Work (OSHA) supports EFSA in assessing occupational health aspects.
The Institut Català d’Ornitologia (ICO, Spain), the British Trust for Ornithology (BTO, UK), the European Union for Bird Ringing (EURING, UK), Sovon (Dutch Centre for Field Ornithology, Netherlands), Linnaeus University (Sweden), the Erasmus Medical Center (Netherlands), the Animal and Plant Health Agency (APHA, UK), Ilia State University (Georgia), the Institute of Experimental and Clinical Veterinary Medicine (Ukraine) and the Royal Veterinary College (RVC, UK) have been EFSA’s longstanding partners in developing early warning systems for avian influenza in the EU.