Scientists from Erasmus MC are going to Antarctica to research bird flu. At the end of February it was announced that the virus had reached the mainland there and experts are very concerned. Before winter sets in, they want to determine the impact on wild birds and marine mammals."We have seen the virus spread through South America like wild fire," says veterinary pathologist Lineke Begeman of Erasmus MC, who is on her way to the South Pole by boat.
Between October 2022 and November 2023, more than half a million wild birds and around 50,000 marine mammals were reported as bird flu victims, she wrote with colleagues. This concerns, for example, 17,000 southern elephant seals, 262,000 cormorants of various species and 4,000 Humboldt penguins.
Millions of birds
Many millions of birds breed in Antarctica. In addition to all kinds of penguin species, this also includes the Antarctic tern, Antarctic skua and Antarctic chicken. "It would be horrible if the virus also spreads so wildly across Antarctica because so many birds and mammals live there," says Begeman. On Wednesday evening, she and eight colleagues boarded a boat in Ushuaia, Argentina, towards the Weddell Sea near the Antarctic Peninsula.Researcher Hans Verdaat of Wageningen Marine Research is heading to the South Pole at the end of this month and is also concerned. "In the Netherlands we saw major mortality in species that breed in colonies, such as the black-headed gull. In Antarctica, almost all birds breed in colonies. Emperor penguins, for example, stand on top of each other for hundreds of months. But the impact cannot yet be predicted."
A fewcases of bird flu have been confirmed on the Antarctic mainland so far. On Tuesday it was announced that the virus had been diagnosed in Adélie penguins and Antarctic cormorants. The virus was first found in so-called 'hunters', carnivorous seabirds. Because the area is very remote, visibility of the virus is limited.
Poop with virus
After about three days of sailing, Begeman and her colleagues can go onto land. "We want to land on land in various places with a small boat and carefully approach and observe colonies. How many healthy animals do we see? And do the experts in this area see more carcasses than normal?" They have ten days for field work. The expedition is largely paid for by tourism organization IAATO, which often supports scientific expeditions in the area.The researchers take samples of the feces from healthy animals. In dead animals, they take swabs from the pharynx and cloaca (the body opening for feces, urine and eggs). The ship has equipment that can determine whether there is bird flu within roughly 8 hours.
Begeman wants to take pieces of tissue from animals that have probably died of bird flu to examine under a microscope in Rotterdam. "You can then see whether the virus has destroyed cells in, for example, the lungs, intestines or pancreas. This provides information about the cause of death and about the way in which the virus spreads: through the air or through feces."
Unknown
Virologist and bird flu researcher Thijs Kuiken is closely following developments from Erasmus MC. "I'm worried because I expect that the animals in Antarctica are all susceptible to the virus because they are related to species that have died from the virus."He calls this virus unprecedented. "We have never seen a virus that infects so many different animal species before. If one seal species in the North Sea is hit hard, it is already bad, but this virus affects hundreds of species of birds and dozens of species of mammals. We have never experienced that before."
In the Netherlands, the current variant of bird flu has been causing infections in poultry and wild birds all year round since 2021. It is relatively quiet at the moment, but previously the sandwich tern and the black-headed gull, for example, were hit hard here. No outbreaks have been identified in the poultry sector since December 2.
According to Kuiken, the risk of a bird flu virus that can cause a pandemic in humans is not much greater now that the virus has reached the Antarctic mainland. "The chance that a virus will emerge that can be transmitted from person to person will continue to increase as long as the virus continues to circulate, but the chance of this remains very small."
