Avian influenza – a devastating pandemic for birds and a threat for global health?
The highly pathogenic avian influenza virus (HPAI) has been causing outbreaks in wild birds and farmed poultry for decades [I]. In Central Europe, HPAI was usually only detected during the winter months. In 2022, this has changed, and the bird flu also caused infections during summer, leading to the largest epidemic in Europe so far that is ongoing and is affecting animals in 37 countries. Thousands of farmed and wild birds were infected. Seabird colonies in particular have been hit and massively decimated. In poultry farms 50 million birds died or had to be culled [II].
Even though HPAI is highly specific to birds, several spill-over events were documented in mammals. In rare cases the virus was also transmitted to humans, highlighting the zoonotic potential of the disease.
In October 2022, an HPAI-outbreak at a mink farm in the Galicia region in northwest Spain received major public interest because within a few weeks, the virus spread over the whole premises. The finding indicates a transmission of the virus from mink to mink which would be the first observed transmission between mammals [III].
Bringing together three experts on HPAI from Spain, the UK and Germany, we would like to discuss the current HPAI pandemic. Why has it become a pandemic? How detrimental is the impact on wild bird populations? Are there any measurements available to curb further spread? What is the potential of vaccination and where should it be applied? How big is the risk that HPAI could spill over to humans and become the next pandemic?
Those questions – as well as yours – were addressed during the 50 minute briefing.
- Ursula Höfle, Ph.D.
Contract professor at the SaBio (Health and Biotechnology) Research Group, National Game and Wildlife Research Institute (CSIC-UCLM-JCCM), University of Castilla-La Mancha, Spain - Prof. Ian H. Brown
Director of Scientific Services at the Animal and Plant Health Agency (APHA), Weybridge, Surrey, UK - Prof. Martin Beer
Head of the Institute for Diagnostic Virology (IVD), Friedrich-Loeffler-Institut, Bundesforschungsinstitut für Tiergesundheit, Greifswald-Insel Riems, Germany
Closing statements
At the end of the Press Briefing, the SMC asked the experts which aspect of avian flu they are most concerned about and which aspect they would address or stress in their reporting if they were a journalist. We provide the answers below as statements.
Ursula Höfle, Ph.D.
Contract professor at the SaBio (Health and Biotechnology) Research Group, National Game and Wildlife Research Institute (CSIC-UCLM-JCCM), University of Castilla-La Mancha, Spain
„I think the wild bird component of this is really the key – it's a wild birds and poultry panzootic. But it's the change in the epidemiology of this virus, the adaptation to wild birds and the impact it has on a lot of different wild bird populations and biodiversity that for me is something really serious.“
„And then the second part is that with increased numbers of individuals and increased circulation the opportunity for the virus increases to adapt to a lot of different situations increases and species. The risk is the many opportunities the virus gets through this really widespread and wide circulation. Now not only the viruses adapted more to wild birds and it has gathered force in violence and in spread between wild birds but it's also able to persist longer. We have outbreaks in summer even in regions, such as the Iberian Peninsula, where we've actually had very, very sporadic outbreaks, because of UV light and very high temperatures. And now we're seeing outbreaks in August in Spain, which is something really, really unprecedented. And this shows that this virus is changing in many ways that we don't have a handle on. And this is what I would like to stress.“
Prof. Ian H. Brown
Director of Scientific Services at the Animal and Plant Health Agency (APHA), Weybridge, Surrey, UK
„I would like to stress the expansion of the virus’ and it’s ability to infect other host populations. On several occasions now we see the extent of wild birds that take the virus into places, nations and ecosystems that he's not been in before. That increases its exposure to other populations. So that’s a whole new dynamic, transforming and evolving quite fast on a global scale. And as its gets into those places, have we got good surveillance systems that are globally set up to track and monitor those concerning events fast? It is again about global responsiveness here and working together globally to make sure that we can track this virus very fast and understand what it's doing next. So, I think that's my biggest concern, have we got that global structure to ensure that we're communicating? Have we learned all the lessons from COVID?“
Prof. Martin Beer
Head of the Institute for Diagnostic Virology (IVD), Friedrich-Loeffler-Institute, Bundesforschungsinstitut für Tiergesundheit, Greifswald-Insel Riems, Germany
„The major point is still that it is a global panzootic in birds and it's reaching more areas now. And this is a point which is also worrying me the most at the moment. It is reaching areas where this type of virus has never been seen. And we are talking about the whole continent South America with a lot of different bird species which never had contact to this kind of virus. We even don't know what kind of other influenza viruses have been there, how the whole population, the biosystem in South America will react. And there is also a lot of poultry farming in some of these countries. So, I think this is a new mixture we have to follow up very closely. Then, we really need to be aware that spill-over events can happen to non-bird species. And finally, the genetic variability, so that this virus is changing a lot even if it goes under the same public name: one H5N1 is not the same in all regions. This means it's a highly dynamic situation which we have to follow closely. Sequencing and surveillance monitoring is the measures we really need all over the globe. And this is a hurdle in some countries and we have to work on this to get this done even better in more countries. To be informed early enough if something crucial changes.“
Recording & transcript
You can also see the video on our YouTube-channel in speaker view or gallery view.
You'll find the transcript here.
References
[I] Shi W et al. (2021): Emerging H5N8 avian influenza viruses. Science. DOI: 10.1126/science.abg6302.
[II] EFSA et al. (2023): Scientific report: Avian influenza overview September–December 2022. EFSA Journal. DOI: 10.2903/j.efsa.2023.7786.
[III] Montserrat A et al. (2022): Highly pathogenic avian influenza A(H5N1) virus infection in farmed minks, Spain, October 2022. Euro Surveillance. DOI: 10.2807/1560-7917.ES.2023.28.3.2300001.
References for further reasearch
World Health Organization (21.12.2022): Assessment of risk associated with recent influenza A(H5N1) clade 2.3.4.4b viruses.
Delta Flu: Dynamics of avian influenza in a changing world.
Institutions in Germany:
Friedrich-Loeffler-Institut: Aviäre Influenza (AI) / Geflügelpest.
Institutions in Spain:
Ministerio de Agricultura, Pesca y Alimentación: Gripe Aviar.
Ministerio de Sanidad (03.02.2023): Prevención, detección precoz y control de gripe aviar en personas expuestas a focos en aves y visones.
Ministerio de Sanidad (02.02.2023): Evaluación rápida de riesgo – gripe aviar A(H5N1) en España.
Institutions in the UK:
Department for Environment, Food & Rural Affairs and Animal and Plant Health Agency: Bird flu (avian influenza): latest situation in England.
For Scotland go to the Scottish Government website.
For Wales go to the Welsh Government website.
For Northern Ireland go to the DAERA-NI website.