Exactly a year ago a Dutch researcher took a sailing laboratory at the Antarctic Peninsula, under South America. A month earlier it was announced that the very pathogenic variant of the bird flu virus that has been around the world since 2021, since the mainland of Antarctica had reached. The fast, small international mission tried to determine how far the virus had already spread, which animal species were hit and how great the mortality was. What is the case now, a year later?
“There is now another mission sailing,” says Thijs Kuiken, virologist and professor of comparative pathology at Erasmus MC in Rotterdam. He is in various international expert groups around the bird flu virus. “Our researcher Lineke Begeman is not with this time, but we are involved sideways.”
Last year the mission found that the bird flu virus has already been over hundreds of kilometers of coastline had spreadin view of the place where the first dead infected birds (Antarctic great hunters, a predatory gull species) were found on the mainland. At four different locations, the team found dead animals that were infected with bird flu. They also saw suspicious massive death in many other places, including penguins. But they could not determine the bird flu virus on the spot, perhaps because the animals had perished too much.
Mass penguin
Kuiken cannot yet say whether the dead animals with bird flu had really died through bird flu, and whether the massive penguin mortality was also caused by that. “Our team has taken samples back to Rotterdam, to investigate it virologically and pathologically. We still have to publish those results. ” With earlier outbreaks among marine birds and marine mammals, including in South America among sea elephants, that causal link is already demonstratedso he is also obvious here. A Spanish investigation team reported last month from the Weddellzee, at the basis of the Antarctic Peninsula, “Large numbers of virus particles“In various dead types of seagulls and penguins and with crab eaters.
Kuiken can already share the findings of the mission that is now sailing. “We wondered if the virus would remain present for a very Antarctic year, and whether it would again arise again in the next breeding season. That now appears to be the case. The virus is still there, and also hundreds of kilometers further south along the coast of the Antarctic Peninsula. ”
The researchers again found many dead big hunters who were infected with bird flu, and for the first time also dead crab eaters: a large seal species. “Of these, hundreds of death were found, and they wore the virus.”
In the meantime, other researchers came with findings from the rest of the southern hemisphere, Kuiken reports. On the island of South Georgia, where the virus was the first to end up from South America at the end of 2023, there is again massive death among royal penguins and giant storm birds. “There is also suspicion of bird flu mortality in new species, including macaronipinguins, soot head albatroses and sea leopards.”
East
Moreover, it is now clear that the virus has moved to the east five to more than six thousand kilometers. In the past year it also has the Subantarctic Islands groups, Marion, Crozet and Kerguelen reached, in the southern Indian Ocean. “For example, on the crozet Islands it is confirmed by sea elephants and royal penguins,” says Kuiken, “and there is suspicious death among giant albatrosses and hunters. Sea elephants are contaminated on noise, and there is suspicious death among the endemic Kerguelen-Aalvers and Cape Stormvogels. ”
This information answers an important question that the researchers could not answer last year: is the virus limited to the Antarctic Peninsula and goes out after the breeding season, or does it move along the edge of the continent? And how fast? “From the Antarctic Peninsula to Kerguelen is much further than from noise to Australia,” Kuiken notes. “Australia and New Zealand are still ‘clean’, with regard to this variant of the bird flu virus. So the question is how long that is. “
What can we do with this information? “Once a virus spreads among wild animals, then there is not much what you can do about it,” says Kuiken. “Certainly in areas with such huge numbers of seabirds and marine mammals such as Antarctica. But at least you have to document what happens. How it spreads, what impact it has on animals and on ecosystems. Policy makers must have that on their retina so that they can make the right decisions to prevent such outbreaks from coming more often. ”
This global outbreak goes back to a variant that once originated in poultry, Kuiken emphasizes. “And we still see that new variants are emerging – especially in intensive poultry farming.”