Avian flu detected in Adélie penguins in Antarctica
Initial results from an international expedition along the West Antarctic Peninsula reveal that Adélie penguins are unaffected carriers of avian flu.
Adélie penguins carrying the HPAI H5N1 virus, i.e. highly pathogenic avian influenza, have been detected in Antarctica, but they are symptom-free carriers. A partial blow to Antarctic wildlife. BioRxiv (pronounced bioarchive), will publish a peer-reviewed article next week, but information is already circulating between universities and the media.
Since the virus first appeared in skuas, Chile and international scientific bodies have been coordinating their efforts to monitor the unprecedented spread of the epidemic around the Antarctic continent. This austral summer, two scientific expeditions sailed along the Antarctic peninsula. The first aboard the ice-breaking expedition cruise vessel named after the famous French explorer commander, the second aboard Janequeo of the Chilean Armada.
In total, thirteen sites were monitored, three by the cruise vessel and the Institut océanographique, Fondation Albert Ier, Prince de Monaco, ten by the Chileans from the Millennium Institute Biodiversity of Antarctic and Subantarctic Ecosystems (BASE). Out of 115 samples taken, eight Adélie penguins and one Antarctic shag tested positive in PCR tests carried out by the Catholic University of Chile. No emperor are positive.

The cormorant and some Adélie penguins originate from Red Rock Ridge, a place at the coast of Graham Land in the west-central part of the peninsula. The remaining Adélie carriers live in the northern part of the peninsula, on Danger Island.
Before disembarking in the Zodiacs, each team made sure that “there were no signs of mass mortality”, recalls Céline Le Bohec, French penguin researcher from CNRS and Centre Scientifique de Monaco on the first expedition. Dressed in sterile overalls, masks and gloves, the researchers focused their attention on symptom-free individuals, which were in a condition to successfully complete their reproductive cycle.

They equipped several penguins with GPS and are still tracking them. “I can tell they’re doing well,” she continues. “The virus is present, but it doesn’t seem to be affecting them. On the one hand, this is reassuring, as it doesn’t threaten their survival, but on the other hand it’s worrying because they could be used as Trojan horses.” Adélies are found all around the continent. The virus could spread rapidly and infect other, more sensitive animals.
Complete sequencing of the virus RNA is currently underway for each case. It will enable scientists to establish a map of variants, and understand the evolution of HPAI H5N1 during its expansion between South America and Antarctica.
Camille Lin, PolarJournal
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