For the first time, the presence of highly pathogenic avian influenza (otherwise known as bird flu or HPAI) has today (Thursday, January 11) been detected in mammals in the sub-Antarctic.
Experts from the UK’s Animal Planet Health Agency (APHA) identified the disease in elephant and fur seals on the island of South Georgia, which is located in the southern Atlantic ocean – roughly 1,400km east of the Falkland Islands.
The island is a UK overseas territory that is only accessible by ship, and has no permanent residents due to its remote location and lack of infrastructure.
South Georgia is home to 13 mammal species, and it has some of the most closely monitored seabird colonies in the world.
Cases of bird flu were first suspected on Bird Island off the north-west coast of South Georgia in October 2023, following multiple deaths of large sea bird species, the brown skua.
It is believed that the virus likely had been introduced through migratory bird movement from South America, as a result from a sequence analysis of infected birds.
Symptoms of bird flu include:
- Loss of appetite and excessive thirst;
- Respiratory issues;
- Swollen head;
- Extreme fatigue;
- Sudden death.
The virus can affect all bird species and other animals, including cows, horses, and cats.
Leading APHA scientist, Dr. Marco Falchieri of the Influenza and Avian Virology team, spent three weeks in the sub-Antarctic region, visiting the affected islands and collected samples from dead mammals, which included elephant seals and birds.
Following testing, the samples confirmed the presence of the HPAI H5N1 in brown skuas, elephant seals, kelp gulls and fur seals.
To date, there has been no report of a suspiciously high rate of mortality in penguins.
Science manager for Bird Island Research, Ash Bennison, said: “It’s incredibly sad to witness the effects of avian flu on the animal populations we study on South Georgia.
“We are doing everything we can to mitigate the effects of this disease and are working closely with the government of South Georgia, South Sandwich Islands and the APHA to continue our work to monitor and conserve these amazing species.”
Laura Sinclair Willis, chief executive of the government of South Georgia and the South Sandwich islands added:
“The government of South Georgia and the South Sandwich Islands anticipated that HPAI would likely arrive on our shores in the 23/24 austral summer.
“We are grateful for the ongoing support of the APHA, British Antarctic Survey, Ministry of Defence and the Antarctic cruise industry, along with a global community of partners and stakeholders who are helping us to monitor the impacts within the territory.
“The transmission and spread of this disease is primarily a natural phenomenon, and we continue to emphasise the importance of scrupulous biosecurity by all those entering South Georgia and the South Sandwich Islands,” the chief executive said.