Scientific Report
Scientific Report
Scientific Report
Avian influenza
Avian influenza is a highly contagious viral disease that occurs primarily in poultry and wild water birds. It is either highly 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 2021/2022 epidemiological year, the HPAI epidemic A widespread occurrence of an infectious disease in a community at a particular time 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 the following epidemiological year, and particularly in 2023, HPAI A(H5N1) viruses spread across the globe and expanded their host range, causing mortality events in multiple 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. As of now, more than 50 different mammal species have been found infected with HPAI viruses. Animal-to-human transmission has occasionally occurred, while no transmission between humans has been reported.
Avian influenza can be transmitted from animals to humans mainly in two ways:
- From direct contact with infected animals
- From contaminated environments
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) such as 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.
To date, there is no convincing evidence that avian influenza can be transmitted to humans through the consumption of contaminated food. 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 the European Centre for Disease Prevention and Control (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
October
According to the latest report by ECDC, EFSA and the EURL, there has been a resurgence of HPAI virus among seabirds along European coastlines. Overall, the situation in both poultry and wild birds has eased over summer and the number of cases is much lower compared to the last two years. The risk to the general population Community of humans, animals or plants from the same species remains low.
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 the EURL.
June
EFSA kicks off activities in 7 key locations across Europe to strengthen partnerships and build capacities for active surveillance Measures initiated to detect and control animal diseases as early as possible using defined protocols and activities of HPAI viruses in wild birds.
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 in Europe remains low. These are the main findings of the latest quarterly monitoring report by EFSA, ECDC and the EURL.
January
The SIGMA approach is adopted for the collection of Avian Influenza data, extending the data collection to all types of sampling and testing activities targeting the Avian Influenza virus. Poultry population data are collected for the first time. New reporting guidelines are published: one on animal (poultry) population and one on Avian Influenza.
2023
October
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 the 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 the 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 the 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 the 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 testsin 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 Europe. In this 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, the risk of LPAI strains mutating into HPAI strains, and the pandemic potential of circulating viruses. We provided advice on biosecurity and control measures, such as vaccination of poultry.
In addition, EFSA supports Member States in their data collection and surveillance activities.
Monitoring and surveillance
EFSA, in collaboration with ECDC, the EURL and competent authorities in affected Member States and third countries publishes quarterly monitoring reports on the situation of avian influenza in Europe and worldwide. These reports include analyses of:
- Risk of introduction and spread of HPAI in Europe
- Distribution in space and time of HPAI and LPAI outbreaks (in birds, mammals, humans) in Europe and other continents
- Genetic characteristics of HPAI virus strains involved
- Prevention and control measures 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 countries. 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 and third countries in the form of annual reports.
The latest information on the number and evolution of outbreaks can be found in EFSA’s interactive dashboard. Here, detailed information on all HPAI virus detections reported in poultry, captive and wild birds in Europe since October 2016 can be visually explored in space and time.
Data collection
Since 1 January 2019, Member States and third countries have submitted the results of their annual surveillance activities in domestic and wild birds to EFSA. In 2024, data collection has been improved to meet EFSA’s new standards, developed in the framework of the SIGMA project. The goal was to harmonise the Animal Health data collection in a One Health perspective and to simplify the process, minimising the workload of the data providers and increasing data quality.
With the implementation of the SIGMA approach, the reporting countries can submit data on any type of analytical result targeting the detection of avian influenza viruses, i.e.:
- Samples tested in the context of the Union Surveillance Programmes (mandatory)
- Samples tested in any other context, legal framework (national legislation) or goal (e.g. freedom from disease, outbreak investigation/containment) (voluntary)
In addition, it is important to note that the SIGMA approach entails the possibility for reporting countries to submit data on the domestic target population Section of the healthy population defined by a specified age range and gender. Because of their particular physiological status, pregnant and lactating women are specific target populations to better estimate the population at risk and provide risk managers with a more comprehensive 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.
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 page.
In 2024, EFSA published an External Scientific Report with an updated target list of 241 wild bird species for 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 of HPAI viruses in Europe. The list serves as a reference for national/regional reference laboratories and other stakeholders involved in surveillance activities. The report, which takes into account both ornithological and epidemiological data, provides recommendations on which species to be targeted for different scenarios of passive surveillance.
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 launched in 2022 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 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, by the end of 2024, 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. Users are moreover able to download the weekly estimates for their own risk assessment purposes.
In addition, EFSA previously piloted active surveillance systems at the borders of the Union with the aim of establishing an EU-wide surveillance system in wild birds, which would be able to rapidly detect and identify newly emerging or introduced HPAI viruses. Following up on this work, in 2024, EFSA has established a network of 7 surveillance nodes across Europe to build capacities and long-term partnerships for active surveillance of HPAI viruses in wild birds. Activities are centered in the following 7 geographical areas:
- Gulf of Finland (Estonia, Finland)
- Southern Baltic Sea (Latvia, Lithuania, Poland, Sweden)
- Eastern Black Sea (Georgia)
- Lake Constance region (Austria, Germany, Switzerland)
- Veneto region (Italy)
- Camargue region (France)
- Gulf of Cadiz (Spain)
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.
In a two-part opinion (part 1 and part 2 which was carried out in collaboration with the European Medicines Agency (EMA) and the EURL, EFSA assessed the availability of vaccines against HPAI for poultry and potential vaccination strategies as well as surveillance and risk mitigation measures.
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
EFSA has been collaborating with longstanding partners in the EU, through a transdisciplinary network that enhances the development of early warning systems for avian influenza. EFSA is also now building capacities for active surveillance of HPAI in wild birds across Europe. Check EFSA’s partners below in the interactive map:
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