Avian flu confirmed on Marion Island

The department of forestry, fisheries and the environment has confirmed the presence of the high-pathogenicity avian influenza (HPAI) H5N1 virus on South Africa's sub-Antarctic territory of Marion Island.

- Sheree Bega

Samples collected from last September to December were shipped back to mainland South Africa on the SA Agulhas II in February, according to the department. In March, polymerase chain reaction testing confirmed infection in six bird species: the wandering albatross, king penguin, brown skua, southern giant petrel, northern giant petrel and the sooty albatross.

"Following an initial suspected HPAI case in a brown skua at Marion Island a bird showing clinical signs of HPAI infection including twitching and tremors in mid-September 2024, more similar cases were reported in early November and mortalities in multiple species have continued into March 2025, though the overall death rate slowed significantly in January," it said.

The department noted that the reduced mortality rate is "promising". But 31 bird species breed on Marion Island and because the bird species and age composition varies throughout the year, "it is difficult to predict how the outbreak will progress".