Officials have confirmed that bird flu has spread to mainland Antarctica for the first time.

The H5N1 virus was discovered in two dead scavenging birds known as skuas near Primavera Base, an Argentinian scientific research outpost on the Antarctic Peninsula.

Bird flu In Antarctica

According to data from the Scientific Committee on Antarctic Research, further probable cases of brown skua, south polar skua, and kelp gull have been documented in Hope Bay, on the Antarctic peninsula.

"This discovery demonstrates for the first time that the Highly Pathogenic Avian Influenza virus has reached Antarctica despite the distance and natural barriers that separate it from other continents," Spain's Higher Council for Scientific Investigation (CSIC) said.

These are the first verified cases on the continent itself, indicating that the virus is spreading throughout the region, most likely via migrating birds.

This H5N1 virus is estimated to have killed millions of wild birds worldwide since 2021, and it has spread to all continents except Oceania.

Avian flu first appeared on sub-Antarctic islands in October of last year, bringing it to the rest of the Antarctic region. The virus was first discovered on the British overseas territory of South Georgia and the South Sandwich Islands, approximately 1,000 miles (1,600 kilometers) from Antarctica. It was also discovered in the Falkland Islands, which are 600 miles northwest of South Georgia.

It was first documented in gulls, skuas, and terns, but it has since been discovered in albatrosses, penguins, and southern fulmars. It has also spread to Antarctic mammals, resulting in the catastrophic deaths of elephants and fur seals.

The virus is also ravaging wildlife populations in the Arctic. In December, it was determined that the first polar bear perished from H5N1.

Argentine scientists discovered dead birds on mainland Antarctica and transferred them to Madrid's Centro de Biología Molecular Severo Ochoa, which was operating at the Spanish Antarctic base on Deception Island.

Read Also: Bird Flu Detected in Antarctica for the First Time Raises Risk of Catastrophic Breeding Failure Among Isolated Penguins

Threats To Penguin

Experts expressed concern that it would probably spread to penguins. The skuas reside rather close, so there are numerous potentials for transmission.

"The problem is how long is it going to take before it transmits to other species like penguins. We need to monitor that," said Antonio Alcamí, a researcher from the Spanish National Research Council who works at the Centro de Biología Molecular Severo Ochoa CSIC, who is based at the Spanish Antarctic base and tested the carcasses.

Previous outbreaks in South Africa, Chile, and Argentina demonstrated that penguins are susceptible to the virus. Since H5N1 arrived in South America, more than 500,000 seabirds have died from the disease, with penguins, pelicans, and boobies being among the most severely impacted.

Researchers noted in a pre-print study report in November last year that if the virus begins to cause widespread death events across penguin colonies, it might indicate one of the worst ecological disasters of recent times.

Diana Bell, an emeritus professor of conservation biology at the University of East Anglia, said the revelation was "sadly not surprising, given its previously reported presence on Antarctic islands in birds and elephant seals." It seemed doubtful that the penguins there would be uninfected.

"Biosecurity is important so that humans are not exposed to the virus. HPAI can rarely infect humans but close, prolonged contact is required," she added.

Related Article: Bird Flu Reaches Antarctica, Results in Mass Elephant Seal Deaths