#18,590
Today the ECDC has released two major documents pertaining to the growing threat posed by avian influenza. Due to their lengths (109 & 34 pages), I've only had time to briefly skim the contents, but I've posted the ECDC news release, and links (with summaries) from both reports.
Avian influenza: EU agencies track virus mutations and analyse response strategies
News story
29 Jan 2025Avian influenza viruses pose an increasing threat, with the potential to adapt to humans and trigger future pandemics. Employing a One Health approach, the European Centre for Disease Prevention and Control (ECDC) and the European Food Safety Authority (EFSA) have issued scientific advice that assesses avian influenza virus mutations and the potential of these viruses to spread to humans, along with recommendations for the animal and public health sectors.
The work of the two Agencies draws on extensive data, including genetic analyses, human case studies, and antibody presence to outline current risks and mitigation strategies.
Pamela Rendi-Wagner, ECDC Director, said “Global developments demand that we stay alert and make sure Europe is prepared to respond to the threat of avian influenza. ECDC is supporting EU/EEA Member States in preparing, preventing and containing potential future outbreaks in animals and humans. Having strong preparedness plans in place is paramount to protect public health in Europe.”
“In 2024, avian influenza viruses expanded their reach, infecting previously unaffected species. Our work identifies key mutations linked to a potential spread to humans, requiring rapid detection and response. Collaboration and data sharing along the chain of actors involved remain essential in tackling emerging situations,” said Bernhard Url, EFSA Acting Executive Director.
Experts generated a comprehensive list of mutations, from which they identified 34 genetic mutations that might increase the potential of avian influenza viruses to spread to humans. Using molecular analysis and genomic surveillance, animal and public health laboratories can refer to the list of mutations, which should be continuously updated, to monitor the emergence of strains that could potentially transmit to humans.
The scientific opinion also identifies how the adaptation of avian influenza viruses to mammals can be driven by factors such as genetic mutations, the mixing of genetic material between viruses, and the interaction with host immune response, alongside extrinsic factors that can increase the chance of transmission to humans, like human activities and environmental changes that increase contact between wildlife, poultry, livestock, and humans. High-density farming, low biosecurity practices, deforestation, urbanisation, and global trade amplify the risk of spillovers from animals to humans.
Key recommendations:
Genetic analysis: Use genetic sequencing to detect mutations or virus adaptations to mammals early. Invest in systems to quickly identify emerging viruses and mutations that enable animal-to-human spread.
Animal surveillance: Monitor sick or dead mammals linked to infected wild birds, poultry or mammals. Track unexplained illness during high-risk periods and areas with avian influenza.
Public health surveillance: Test exposed individuals and routinely send samples to further identify the flu sub-type. During outbreaks in animals, hospitals should enhance surveillance and vigilance, especially during flu season peaks when the risk of mixing of genetic material between viruses rises.
Prevention measures: Implement robust farm biosecurity measures, train staff, vaccinate poultry, and prepare outbreak response plans. Ensure humans at risk follow influenza vaccination and antiviral treatment guidelines.
Public health preparedness measures: Raise awareness among high-risk groups, the general public and train healthcare workers to recognise and manage avian influenza. Ensure coordinated response plans for human cases. Develop guidelines and standard operating procedures for testing of exposed individuals and contacts of patients, including preventive protocols. Ensure coordinated response plans for human cases as part of national prevention, preparedness and response plans.
Alongside the scientific opinion, the Agencies also developed a guidance on how to investigate and control outbreaks of avian influenza affecting both humans and animals, using a coordinated One Health approach. Experts developed flowcharts outlining response actions for five outbreak scenarios at the human-animal-environment interface, emphasising the importance of an interdisciplinary response among all stakeholders. This work will support Member States in creating tailored national guidelines.
The first, and largest report presents a risk assessment framework for dealing with zoonotic avian influenza, and includes a list of mutations related to mammalian adaptation.
Preparedness, prevention and control related to zoonotic avian influenza
Assessment
29 Jan 2025
A risk assessment framework was developed to evaluate the zoonotic potential of avian influenza (AI), focusing on virus mutations linked to phenotypic traits related to mammalian adaptation identified in the literature.
Virus sequences were screened for the presence of these mutations and their geographical, temporal and subtype-specific trends. Spillover events to mammals (including humans) and human seroprevalence studies were also reviewed. Thirty-four mutations associated with five phenotypic traits (increased receptor specificity, haemagglutinin stability, neuraminidase specificity, enhanced polymerase activity and evasion of innate immunity) were shortlisted.
AI viruses (AIVs) carrying multiple adaptive mutations and traits belonged to both low and highly pathogenic subtypes, mainly to A(H9N2), A(H7N9), A(H5N6) and A(H3N8), were sporadic and primarily detected in Asia. In the EU/EEA, H5Nx viruses of clade 2.3.4.4b, which have increased opportunities for evolution due to widespread circulation in birds and occasional cases/outbreaks in mammals, have acquired the highest number of zoonotic traits. Adaptive traits, such as enhanced polymerase activity and immune evasion, were frequently acquired, while receptor-specific mutations remained rare.
Globally, human cases remain rare, with the majority overall due to A(H5N1), A(H5N6), A(H7N9) and A(H9N2) that are among the subtypes that tend to have a higher number of adaptive traits. The main drivers of mammalian adaptation include virus and host characteristics, and external factors increasing AIV exposure of mammals and humans to wild and domestic birds (e.g. human activities and ecological factors). Comprehensive surveillance of AIVs targeting adaptive mutations with whole genome sequencing in animals and humans is essential for early detection of zoonotic AIVs and efficient implementation of control measures. All preparedness, preventive and control measures must be implemented under a One Health framework and tailored to the setting and the epidemiological situation; in particular, enhanced monitoring, biosecurity, genomic surveillance and global collaboration are critical for mitigating the zoonotic risks of AIV.
Download
Preparedness, prevention and control related to zoonotic avian influenza - EN - [PDF-12.76 MB]
Coordinated One Health investigation and management of outbreaks in humans and animals caused by zoonotic avian influenza virusesPublic health guidance
29 Jan 2025
The report should assist in developing guidance documents to facilitate coordinated One Health investigations and the management of outbreaks in humans and animals caused by zoonotic avian influenza viruses.
Executive summary
When investigating and controlling outbreaks caused by zoonotic avian influenza viruses (AIV), a One Health approach is key. However, knowledge-sharing on AIV-specific One Health strategies, tools and action plans remains limited across the EU/EEA. It is crucial to establish responsibilities, capacity requirements, and collaboration mechanisms during 'peace time' to enable timely and effective outbreak investigations and management.
This report focuses on five scenarios for outbreak investigation and management of zoonotic AIV at the human animal-environment interface, emphasising key actions for the stakeholders involved. The document primarily highlights the collaborative framework necessary for interdisciplinary coordinated responses, referring to more detailed guidance and technical reports published elsewhere when applicable. Three scenarios are triggered by suspected outbreaks in animals, including kept animals of listed species, non-listed species, companion animals and wild birds/mammals. The other two scenarios are initiated by a probable human case or detection of the virus in wastewater or environmental samples (e.g. surface water or other sources).
All scenarios require cross-sectoral coordination and a One Health approach. While the specific sequence of actions and communication needs may differ across scenarios, the overarching response mechanisms for outbreak investigations and management remain consistent. By presenting each scenario alongside the integrated actions of stakeholders, the report identifies critical development needs, such as tools (e.g. communication and data sharing platforms); key points for information exchange across sectors, triggers for joint risk assessments, and gaps in existing knowledge.
The document should assist in developing guidance documents to facilitate coordinated One Health investigations and the management of outbreaks in humans and animals caused by zoonotic avian influenza viruses.
Download
Coordinated One Health investigation and management of outbreaks in humans and animals caused by zoonotic avian influenza viruses - EN - [PDF-4.99 MB]
