Spanish scientists discover “a massive outbreak” of deadly bird flu in Antarctica

The lethal bird flu virus that has already killed hundreds of millions of birds around the world is spreading through Antarctica, the last virgin continent, as warned this Monday by an international expedition in which Spanish scientists Antonio Alcamí and Begoña Aguado. Researchers, aboard a sailboat, have traveled through the Weddell Sea and the Antarctic Peninsula for a month, finding corpses of Antarctic skuas—migratory seabirds similar to seagulls—with flu in four of the 10 areas analyzed. Alcamí, recently arrived in the Argentine city of Ushuaia, explained by phone that on Beak Island they witnessed “a massive outbreak” in a colony of skuas. “We saw 80 alive and 50 dead. "That's crazy," warns the virologist from the Severo Ochoa Molecular Biology Center (CSIC) in Madrid.

Humanity is facing the worst bird flu crisis ever recorded. A new subtype of the virus, called H5N1 2.3.4.4b, emerged in 2021 and has since caused the culling of hundreds of millions of farmed birds and the deaths of millions of wild birds. The disease had spread across the five continents and conservation experts were holding their breath at the possibility of it jumping to the virgin Antarctic territory. On February 24, Alcamí himself and his colleague Ángela Vázquez confirmed for the first time the presence of the virus in Antarctica, in two dead skuas found by Argentine scientists and analyzed at the Spanish Antarctic base Gabriel de Castilla, on Decepción Island. .

The sailboat 'Australis', in front of one of the penguin colonies analyzed. Antonio Alcamí

Alcamí spent two months on the national mission and a month ago he jumped on an international expedition, led by Australian scientist Meagan Dewar. The virologist and the biologist Begoña Aguado installed their diagnostic laboratory on the sailboat, to be able to analyze the samples at the time. “This had never been done. “We have shown that it can be done,” Alcamí celebrates. The expedition, made up of 11 people, found some skua carcasses in Esperanza Bay and on Devil's and Paulet Islands, in addition to the fifty observed in the massive outbreak on Beak Island. Researchers tested 10 of the 50 and all of them tested positive. Scientists from the Chilean Antarctic Institute (INACH) also announced on March 14 that they had detected the virus in five skuas on Ross Island.

The sailboat also landed on Heroína Island, inhabited by a colony of Adelie penguins, which owe their name to Adèle Pépin, wife of the French explorer Jules Dumont d'Urville, who discovered these birds in 1840. The Alcamí and Aguado expedition found “a massive mortality” of these penguins. “We counted 500 bodies and stopped counting,” recalls the virologist, who estimates that there could be thousands. His team, however, did not detect highly pathogenic avian flu viruses, despite even analyzing the brains and lungs of dead penguins.

Hundreds of sea lions with bird flu, dead or dying, began to appear on the beaches of Peru in January 2023, triggering fear that the virus would learn to effectively pass from mammal to mammal. That terrifying possibility has not come true, at least for now. The pathogen still jumps easily from bird to bird, but when it reaches a mammal it is usually a dead end. The Indian epidemiologist Vijay Dhanasekaran, from the University of Hong Kong, explained to this newspaper in October that we must remain alert. “There is a perpetual threat of the virus jumping to humans. This is mainly due to the virus's ability to evolve rapidly. It can acquire mutations that help it adhere better to the receptors of human cells, or it can acquire the ability to be transmitted by aerosols,” warned Dhanasekaran. Alcamí and Aguado have analyzed sea lions and elephant seals, without finding any positive cases.

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