After receiving reports of several potentially symptomatic birds and unexplained deaths, British Antarctic Survey (BAS) staff collected samples for analysis on Bird Island. The swabs were sent back to the UK and tested by the Animal and Plant Health Service laboratory in Weybridge, where they came back positive.
Natural route is the main transmission route of highly pathogenic avian influenza The spread of the disease is likely caused by the return of birds that migrate to South America., where there are a large number of HPAI cases. BAS and the Government of South Georgia and South Sandwich Islands (GSGSSI) remain alert to new cases and scientific and visitor programs are currently continuing under enhanced biosecurity measures.
recent, Elisa Perez RamirezA veterinary doctor in virology from the Department of Infectious Diseases and Global Health at the INIA-CSIC Animal Health Research Center stressed that the disease has not yet spread to Australia and Antarctica. “This is particularly important because there are now infected wild birds in the far south of Argentina, very close to Antarctica, Virus could reach Antarctica during migration this fall We don’t know what impact this might have on wild birds there. “
BAS has two research stations in South Georgia, including one on Bird Island, where the confirmed case was discovered. Most field work related to animal management has been suspended due to confirmed cases of highly pathogenic avian influenza.. Biosecurity measures continue, including enhanced cleaning of clothing and site equipment, and observation of high-density wildlife areas.
Key elements of Bird Island’s wider science program remain cautious, including long-term monitoring of marine predators such as wandering albatrosses, black-browed and grey-headed albatrosses, northern and southern giant petrels, Macaroni penguins and gentoo penguins. These observations make Bird Island one of the best-monitored seabird habitats in the world, providing scientists and conservationists with indicators of species change.
The impact of highly pathogenic avian influenza in South Georgia cannot be predicted due to highly variable transmission and mortality patterns in Europe and the Americas.Experts Efforts will continue to monitor the impact of wildlife on Bird Island and possible spread to other areas.
background
Avian influenza is a viral disease that primarily affects birds. Low-pathogenic avian influenza viruses are common in wild birds and usually cause no symptoms of illness. However, some strains of the virus, including H5 and H7, are highly pathogenic to poultry and may cause high mortality if they escape into wild bird populations. These are called highly pathogenic avian influenza (HPAI).
The current HPAI H5N1 outbreak began in 2022 and has caused Massive seabird deaths in the Northern Hemisphere, southern Africa, around the Atlantic and Pacific Oceans, and throughout South America. While it is still primarily a virus that affects birds, some mammals have become infected during the current outbreak.This is usually due to predators and scavengers consuming infected birds or carcasses, but can also Cases in which this mode of transmission does not apply have been observed in some marine mammals.
Although it is primarily a virus that spreads among birds, the World Health Organization (WHO) notes that while the number of cases in humans is extremely rare, an increasing number of H5N1 strains are currently being detected in mammals Raising concerns about viruses adapting and infecting humans more easily.
The main mode of transmission of highly pathogenic avian influenza is through natural routes, and the presence of the disease has been confirmed on the South American continent, making it likely to reach South Georgia during the 2023-24 season.
While the source of the disease on Bird Island is unknown, it was likely introduced via skuas migrating back from Argentina, where a large number of cases are known to occur.
The presence of highly pathogenic avian influenza could have severe impacts on rich seabird populations.