HPAI detected in mammals in the sub-antarctic for the first time

In a groundbreaking development, the presence of high pathogenicity avian influenza (HPAI) has been officially confirmed in mammals in the sub-Antarctic. Expert teams from the UK’s Animal Plant Health Agency (APHA) made the discovery on the island of South Georgia, with elephant and fur seals found to be infected.

APHA, in collaboration with the Government of South Georgia and South Sandwich Islands (GSGSSI) and the British Antarctic Survey (BAS), has been actively testing for bird flu in mammals since suspicions arose last year. South Georgia, a UK Overseas Territory situated in the Southern Atlantic Ocean, is approximately 1,000km southeast of the Falkland Islands and is accessible only by ship.

The outbreak was initially suspected on Bird Island off the northwest coast of South Georgia in October 2023, following the deaths of brown skuas. Sequence analysis indicates that the virus likely entered the region through migratory bird movement from South America.

Dr. Marco Falchieri, a leading APHA scientist, spent three weeks in the sub-Antarctic region collecting samples from dead mammals and birds aboard the Royal Navy vessel HMS Forth. Testing at APHA’s laboratory in Weybridge confirmed the presence of HPAI H5N1 in elephant seals, fur seals, brown skuas, kelp gulls, and Antarctic terns.

While samples from albatross and giant petrel colonies on Bird Island tested negative, no above-average mortality has been reported in any penguin species to date. Genomic surveillance data suggests no widespread mammalian adaptation of the virus, and the risk to human health remains very low.

Professor Ian Brown, APHA’s Director of Scientific Services, expressed concern about the disease’s impact on the unique biodiversity hotspot of Antarctica. He emphasized the need for global cooperation to tackle the disease and mitigate potential threats to seabird and sea mammal populations.

BAS, which operates research stations on South Georgia, has suspended most fieldwork involving animal contact due to the confirmed cases of HPAI. Despite challenges, essential components of the science program continue cautiously, including monitoring various bird populations.

Ash Bennison, science manager for Bird Island Research Station, lamented the effects of avian flu on the studied animal populations, while Laura Sinclair Willis, Chief Executive of the Government of South Georgia & the South Sandwich Islands, highlighted the global efforts to monitor the impacts within the Territory.

This discovery coincides with the announcement of an additional £3.3 million funding for the FluMap project from UK Research and Innovation (UKRI) and the Department for Environment, Food and Rural Affairs (Defra). The new project, FluTrailMap, aims to enhance understanding of avian influenza transmission, biosecurity gaps, immunity in wild birds, and the potential impact of vaccination on outbreaks.

APHA Weybridge, a world leader in avian influenza study, continues to provide scientific expertise and policy development, emphasizing global collaboration in addressing emerging threats.