12/5/2022:
The world is changing and so is the way viruses develop. A good example of this is high-pathogen avian influenza (HPAI). For a long time, this could be kept under control, but in recent decades there have been many outbreaks. Why is this and what can we do about it?
The global HPAI situation has changed dramatically over the last two decades. Until the early 2000s, it was generally accepted that HPAI viruses emerged following the introduction of a low-pathogen avian influenza (LPAI) virus of the H5 or H7 subtype, from wild birds to gallinaceous poultry. Some of these LPAI strains mutated and became HPAI strains. Early detection and culling of such a HPAI infected flock or area resulted in eradication of that HPAI virus as it was only present in that particular farm or area.
Migratory birds changed the situation
This situation changed dramatically with the appearance of the Gs/GD-lineage H5 HPAIV and its offshoots in free-living birds, especially in species of ducks, geese and other waterfowl. Migratory birds now spread HPAI H5 strains in Asia, Africa, Europe and North America. In some areas, HPAI H5 seems to have become endemic in wild birds year-round. This means that mass culling of infected birds in a flock or an area does not necessarily eradicate the HPAI strain anymore as it can reoccur in an area at any time following contact with infected wild birds. This creates a formidable threat of major HPAI H5 outbreaks in large parts of the world for the decades to come; the sustainability of the poultry industry is at stake. Another major point of concern is the exposure of humans to strains such as HPAI H5 or LPAI H9N2, as these viruses have zoonotic potential.
Exploring possibilities
This new situation has re-opened the discussion about the potential value of the use of modern AIV vaccines in association with DIVA (differentiating infected from vaccinated animals) diagnostics and monitoring and surveillance so that essential trade in breeding stock and poultry products can proceed without disruption.
Royal GD is heavily involved in the fight against HPAI thanks to involvement in vaccine testing, monitoring and surveillance, scientific research, advising and communication to national and international authorities and representatives of the poultry industry. Royal GD efforts also include communication to the general public and antigen production for diagnostic purposes, including organization of the international proficiency testing schemes for AI diagnostics, to help the poultry industry combat HPAI.
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