Avian influenza viruses pose an increasing threat, with the potential to adapt to humans and trigger future pandemics says the European Centre for Disease Prevention and Control (ECDC) and the European Food Safety Authority (EFSA).
The agencies have jointly 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.
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.
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 made in the joint report are:
- 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.
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