#16,513
While migratory bird crossings from Asia to Alaska are well documented, eight years ago, in PLoS One: North Atlantic Flyways Provide Opportunities For Spread Of Avian Influenza Viruses, we looked at a study that found a similar potential for European AI viruses to cross the Atlantic to North America.
USGS scientists and Icelandic partners found avian flu viruses from North America and Europe in migratory birds in Iceland, demonstrating that the North Atlantic is as significant as the North Pacific in being a melting pot for birds and avian flu. A great number of wild birds from Europe and North America congregate and mix in Iceland's wetlands during migration, where infected birds could transmit avian flu viruses to healthy birds from either location.
In late 2014, we saw the long-feared incursion of HPAI H5Nx from Asia into North America (see EID Journal: Novel Eurasian HPAI A H5 Viruses in Wild Birds – Washington, USA) which sparked the largest avian epizootic in American history.
While the backdoor entry of HPAI viruses from Asia remains a serious concern - particularly with China's recent surge from HPAI H5N6 - the ongoing avian epizootic in Europe from the Eurasian HPAI H5N1 clade 2.3.4.4b virus is worrisome as well (see DEFRA: Highly pathogenic avian influenza (HPAI) in the UK, and Europe (Update #8)).
While not viewed as being as big of a public health concern as the asian lineages of H5N1 and H5N6, the Eurasian H5Nx virus has some zoonotic potential, and poses a grave danger to wild birds, and the poultry industry.
Three weeks ago, in Canada: N.L. Reports HPAI H5N1 in Captive Birds, we looked at the first reports of avian flu on the remote Avalon Peninsula on the island portion of Newfoundland and Labrador which were tentatively identified as being similar to the European H5N1 virus.
A few days later, we saw additional reports from the region (see Update: More Reports of HPAI H5N1 in Eastern Canada) of wild bird deaths. Yesterday, in USDA Confirms Highly Pathogenic H5 Avian Influenza in a Wild Bird in South Carolina, we saw the virus had been detected nearly 2,000 miles further south, in the Southern United States.
While it is too soon to know how much of an impact Eurasian H5 viruses will have here in North America this winter, this is a pretty good sign that migratory birds are introducing this virus into North American birds.
Which brings us to a preprint, published last Thursday on the BioRxiv Website, that echoes these concerns. I've only posted the abstract. Follow the link to read it in its entirety. I'll have a brief postscript after the break.
Valentina Caliendo, Nicola S Lewis, Anne Pohlmann, Jonas Waldenstrom, Marielle van Toor, Thomas Lameris, Henk van der Jeugd, Andrew S Lang, Greg Robertson, Martin Beer, Ron Fouchier, Ashley C Banyard, Ian H Brown, Yohannes Berhana, Sonja Laurendeau, Thijs Kuiken, Rowena Hansen, Carmencita Yason, Tamiru Alkie, Olivier Lung, Stephen Baillie, Kasper Thorup
doi: https://doi.org/10.1101/2022.01.13.476155
This article is a preprint and has not been certified by peer review [what does this mean?].
Preview PDF
Abstract
Highly pathogenic avian influenza (HPAI) viruses of the A/Goose/Guangdong/1/1996 lineage (GsGd), which threaten the health of poultry, wildlife and humans, are spreading across Asia, Europe and Africa, but are currently absent from Oceania and the Americas.
In December 2021, H5N1 HPAI viruses were detected in poultry and a free-living gull in St. John, Newfoundland and Labrador, Canada. Phylogenetic analysis showed that these viruses were most closely related to HPAI GsGd viruses circulating in northwestern Europe in spring 2021.
Analysis of wild bird migration suggested that these viruses may have been carried across the Atlantic via Iceland, Greenland/Arctic or pelagic routes. The here documented incursion of HPAI GsGd viruses into North America raises concern for further virus spread across the Americas by wild bird migration.
All of which means that while it is currently Europe and Asia who are currently battling avian epizootics, we in North America are far from immune. The USDA has some advice on how to Defend The Flock at the website below.
For more on how avian flu strains from Asia, Europe, or even Latin America might arrive again in North America, you may wish to revisit:
