Bird flu continues to spread: a study published this Tuesday in the journal Nature Communications reports the detection of H5N1 virus in several species of birds and mammals in the Antarctic and subantarctic regions of the Falklands and South Georgia (southwest of those islands).
The researchers, from the United Kingdom, have carried out extensive sampling and monitoring of the fauna of the aforementioned regions during the summers of 2022 and 2023.
Their analysis has revealed the presence of the H5N1 virus in multiple species of birds, such as the brown skua, the black-browed albatross, the South Georgia cormorant and the Antarctic tern; and in marine mammals, such as the elephant seal and Antarctic fur seals.
Scientists have conducted a genetic study of the infected samples to obtain information on how the virus reached these remote islands, and their conclusions indicate that it was via migratory species arriving from South America.
The two most emblematic penguin species in these areas, the king penguin and the southern rock penguin, were not infected by the virus at the time of sampling for this study.
According to the researchers, the findings “demonstrate the expansion of the geographic distribution area of this disease and highlight the potential ecological impact and threat it poses to wildlife living in this remote location.”
End of isolation
“Antarctica, known for its unique ecosystems, has remained isolated from many infectious diseases that affect wildlife in other regions of the world, but recent findings indicate that the H5N1 virus has broken this isolation, affecting several animal species,” the authors conclude.
The first reliable evidence of the spread of the virus on the Antarctic continent itself was reported last February, when two scientists from the Spanish Scientific Research Council (CSIC), Antonio Alcami and Angela Vazquezfound the infection in samples of skuas collected near the Antarctic base Primavera.
Last March, an international expedition was organised aboard the Australis sailboat (HPAI Australis Expedition) with the participation of CSIC researchers Begoña Aguado and Antonio Alcamí to track the presence of the virus in the region of the Antarctic Peninsula and the northern area of the Weddell Sea.
The samples obtained have been analysed in Spain and last July the presence of the virus was reported in the carcass of an elephant seal on the Coppermine Peninsula of Robert Island.
Weeks later, after reanalysing animal samples collected during the Australis Expedition, Spanish researchers have reported 14 new cases of fauna species infected with the avian flu virus, indicating that the spread of the pathogen in the southern region is greater than expected.
These include penguins, skuas, snowy pigeons and fur seals.