Work to understand how avian influenza behaves in wild bird and mammal populations will be accelerated with the launch of a new £2.3 million research consortium it has been announced today (27 August).
Scientists from the UK's world leading Animal Plant Health Agency (APHA), alongside the British Trust for Ornithology, RSPB, University of Edinburgh and NatureScot, will collect and analyse samples from a range of bird and mammal populations to better understand how the virus behaves and fill current gaps in understanding about its transmission within wild birds, as well as the wider risks to mammals.
The most recent outbreaks of the current H5N1 strain of high pathogenicity avian influenza (HPAI), commonly known as bird flu, were the largest ever in the UK and devastated wild bird populations including seabirds such as gannets and black-headed gulls. This strain has also infected numerous species of wild mammals around the world, including otters and foxes in Great Britain.
To improve the existing data on wild birds, teams from across the consortia are sampling different bird species under license to assess the presence of active infection or antibodies from previous exposure to avian influenza viruses. This will help understand the extent to which native bird populations have developed an immune response to the virus and how the circulation of different avian influenza virus subtypes might impact upon the emergence of new notifiable avian influenza viruses.
During the recent HPAI outbreak in GB, the genetic make-up of the H5N1 virus changed on multiple occasions following the exchange of genetic material between notifiable and non-notifiable viruses. This led to the emergence of the H5N1 virus in a broader range of species, which was a critical factor in the devastation of populations of great skua, gannets and various gull species. Evaluating the spectrum of notifiable and non-notifiable viruses that are circulating in different wild bird species will fill a huge knowledge gap in our understanding of the origin and risk of virus emergence.
The research team will also consider the impact of avian influenza on wild mammals. In GB, mammals have been affected where they have likely scavenged on birds that have died from the disease. The project will assess the susceptibility of different species and the potential mechanisms by which the virus spreads between bird species and mammals and what role mammals might play in disease spread during an outbreak - such as via the feet and fur. The team will test mammals including rats, foxes and otters in high-risk environments - where there have been mass mortality events recorded in birds in the past two years - to understand whether exposure from infected wild birds and the carcasses of animals that have succumbed to infection has led to an antibody response.
Professor Ashley Banyard, Influenza and Avian Virology workgroup leader at the Animal and Plant Health Agency, said:
Having access to a wider range of samples will mean we can study avian influenza viruses in much greater detail to learn more about how they behave and interact and how this might affect future disease outbreaks.
This vital research project brings together some of the leading ornithological organisations to help gather the samples, and ultimately, following diagnostic testing, increase our understanding of avian influenza viruses across bird populations within Great Britain.
This will help APHA inform the development of future strategies to protect our wildlife and minimise the impacts of this awful disease on both animals and humans.
Defra Deputy Chief Scientific Adviser Justine Betja said:
This collaboration brings together a wealth of expertise to enhance our understanding of one of our most serious animal health challenges.
The results from this co-ordinated scientific effort will be a vital contribution to our preparations for future disease outbreaks to help us protect the health of animals, humans and the environment.
Between 2021-2023 the emergence of the current H5N1 strain of avian influenza saw the UK experience its largest ever outbreak of bird flu. The outbreak led to the death of 97 million birds globally (3.8 million in the UK), with significant consequences for agriculture and the environment. Thousands of wild birds tested positive for the virus across the country, with more than 90% of recorded bird flu detections in UK poultry happening during this period.
HPAI was previously only seen as a seasonal risk with incursions into Great Britain being linked directly to wild bird migration. However, the shift in infection dynamics seen with H5N1 has meant that the virus has 'over-summered' in different avian species and has also extended beyond avian populations.
By evaluating a broad range of species APHA will be able to define the likely impact of infection with different avian influenza viruses on different populations, not just where infection has caused clinical disease, but also where these viruses circulate in the absence of clinical disease.
This new, multidisciplinary project, funded by the Department for Environment, Food and Rural Affairs, will enhance our understanding of the factors behind the spread and evolution of avian influenza viruses, including the apparent decline in cases since January 2024 and the potential drivers behind this.
The work, which will run until next year, will inform future risk assessments and strategies for disease control in both animal and human populations. It takes a One Health approach, recognising the interconnectedness of human, animal, and environmental health in addressing the risks posed by emerging infectious diseases.
