Bird flu found in Antarctic seals could pose significant threat to 'fragile ecosystem'
Bird flu has been found in seals near Antarctica in what are the region’s first cases of infected mammals.
The UK’s Animal Plant Health Agency (Apha) said it has been testing for the H5N1 virus on the island of South Georgia since several brown skuas were found dead there in October.
The virus is most likely to have been introduced through birds migrating from South America and it has since passed on to seals and other bird species on the island.
Scientists said the risk to human health remains very low but that H5N1 endangers the delicate and unique ecosystems of the Antarctic.
“Given Antarctica is such a unique and special biodiversity hotspot, it is sad and concerning to see the disease spread to mammals in the region," Professor Ian Brown, Apha’s director of scientific services, said.
“If avian influenza continues to spread throughout the sub-Antarctic region this could significantly threaten the fragile ecosystem, and potentially put a number of very large populations of seabirds and sea mammals at risk.”
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Apha scientists found positive bird flu samples from elephant and fur seals, brown skuas, kelp gulls and Antarctic terns.
They also tested albatross and giant petrels from Bird Island but these tested negative, while there have so far been no reports of above-average rates of death in penguins.
Bird flu has spread to mammals before. It has been found in seals around Europe and the Americas as well as in mink in northern Spain and foxes and otters in England.
Positive samples have been found as far north as the Arctic, in Alaskan polar bears, with the strain now reaching to the other end of the Earth.
Dr Ed Hutchinson, a virologist at the University of Glasgow who was not involved in the Apha testing, said that influenza viruses are particularly common in "waterfowl and shorebirds, which can carry the viruses long distances as they migrate."
“The fact that this virus has now started infecting mammals in the region is, sadly, also not surprising – viruses are usually extremely picky about which animal they infect, but influenza viruses are unusually good at infecting new host species," he added.
“Importantly, there is a difference between isolated infections of a new species and a virus spreading efficiently within that species.
“It requires a lot of changes for a bird virus to become a mammalian virus, and at the current time there is no sign that this H5N1 virus has changed from being a dangerous virus of birds to a virus that can spread easily within any mammal species.”
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