Quelle: Science Media Center Germany

Nicht mehr nur im Sommer

In Mitteleuropa wurde HPAI meist nur in den Wintermonaten nachgewiesen. Im Jahr 2022 hat sich dies geändert und die Vogelgrippe wütete auch im Sommer. Das führte zur bislang größten Epidemie in Europa, die bis heute andauert und Tiere in 37 Ländern betrifft. Tausende von Zucht- und Wildvögeln wurden infiziert. In Geflügelfarmen starben 50 Millionen Vögel oder mussten gekeult werden.²

Obwohl HPAI sehr spezifisch für Vögel ist, wurden mehrere Spillover-Ereignisse bei Säugetieren dokumentiert. In seltenen Fällen wurde das Virus auch auf den Menschen übertragen, was auf das zoonotische Potenzial der Seuche hinweist.

Im Oktober 2022 erregte ein HPAI-Ausbruch in einer Nerzfarm in der Region Galicien im Nordwesten Spaniens großes öffentliches Interesse, da sich das Virus innerhalb weniger Wochen auf dem gesamten Gelände ausbreitete. Der Befund deutet auf eine Übertragung des Virus von Nerz zu Nerz hin, was die erste beobachtete Übertragung zwischen Säugetieren wäre.³

Wir möchten mit drei HPAI-Experten aus Spanien, dem Vereinigten Königreich und Deutschland über die aktuelle HPAI-Pandemie sprechen: Warum hat sie sich zu einer Pandemie entwickelt? Wie schädlich sind die Auswirkungen auf die Wildvogelpopulationen? Gibt es Maßnahmen, um die weitere Ausbreitung einzudämmen? Welches Potenzial hat eine Impfung und wo sollte sie eingesetzt werden? Wie groß ist das Risiko, dass HPAI auf den Menschen übergreift und zur nächsten Pandemie wird?

Expertenstatements in englischer Sprache

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.“