Deadly bird flu found on sub-Antarctic islands for first time

By Steven Mew, the Australian Science Media Centre

The Animal and Plant Health Agency in the UK has confirmed that High Pathogenicity Avian Influenza (HPAI), otherwise known as bird flu, has been detected in elephant seals and fur seals on the sub-Antarctic island of South Georgia.

Researchers first suspected this strain of bird flu was in the region in 2023 after the deaths of several large sea birds known as brown skuas, with subsequent testing of dead mammals including elephant and fur seals, finding that they had also been infected with avian influenza.

Dr Ed Hutchinson from the University of Glasgow said this harmful strain of avian influenza, known as H5N1, has been spreading around the world.

“Influenza viruses are particularly common in waterfowl and shorebirds, which can carry the viruses long distances as they migrate,” Hutchinson says.

“Although the Antarctic is extremely remote, it was inevitable that eventually the highly pathogenic H5N1 strain of influenza would reach the region.”

Scientists are concerned by this discovery because bird flu may threaten the unique biodiversity of birds in Antarctica if it continues to spread.

Dr Alastair Ward from the University of Leeds said the greatest concern from this discovery is for bird conservation.

“South Georgia, and Bird Island in particular, is renowned for being home to large colonies of southern giant petrels, several species of albatross and two species of penguin.”

“Declines of bird populations on these islands would constitute a great loss to local ecosystem functioning and also to the world’s biodiversity,” he added.

Prof Michael Ward from the University of Sydney told the AusSMC last year that while this highly pathogenic strain is also a major cause of sickness and death in the world’s poultry industry, it has only rarely been transmitted to humans.

“It does infect people and does kill people. But for the past few decades, such outcomes have been relatively rare,” he said.

Professor Raina MacIntyre from the Kirby Institute and the University of New South Wales says in the past, the method of preventing the spread of high pathogenic avian influenza was to cull birds, but this method is no longer sustainable due to the sheer scale of the global spread of the disease.

Bird flu first found 9 years ago in Antarctica

“Many countries have switched to vaccination of birds, which may drive further mutation of the virus,” she says.

According to MacIntyre, the spread of avian influenza to mammals is especially concerning, as this may signal adaptation to mammalian transmission and pandemic potential.

“There has never been a time in the history of HPAI where the risk of a human pandemic is more concerning than it is now.”

However, the University of Edinburgh’s Prof Rowland Kao emphasised that in most cases, transmission of this virus to mammals happens as a result of mammals scavenging dead birds, and therefore there is a low risk that the virus would adapt to infect humans.

“Despite this, where there are infected birds and mammals there is a risk, albeit low, so people are advised to avoid direct contact with dead birds and mammals found in the wild, anywhere that avian influenza is a likely cause,” he says.

This article originally appeared in Science Deadline, a weekly newsletter from the AusSMC.