Avian Flu in Antarctica, the Elephant Seal’s Tragedy

The first discovery of the highly pathogenic H5N1 avian influenza virus in domestic waterfowl in southern China in 1996 marked the beginning of a series of events that attracted widespread attention. Significant impact on human and animal health worldwide. The virus, designated A/goose/Guangdong/1/1996, soon broke out in poultry in China and Hong Kong in 1997, with disastrous consequences for humans: 18 confirmed cases, 6 die. The mortality rate is greater than 50%.

After a period of relative calm in virus testing, The threat reappeared in 2003, spread throughout Asia with widespread outbreaks among poultry. By 2005, H5N1 had spread from wild birds to poultry in Africa, the Middle East, and Europe, further expanding the global threat. This resurgence is characterized by genetic diversification of viral hemagglutinins into several clades and genotypes.

The situation changed between 2014 and 2016 with the emergence of new virus subtypes, particularly H5N6 and H5N8. Genetic exchange between poultry and wild bird H5 viruses gave rise to these emerging subtypes. During this period, hemagglutinins continued to diversify, especially in clade 2.3.4.4, which is distributed across Asia, Africa, Europe, the Middle East, and North America. at the same time, Several genetic lineages and genotypes were identified, showing the complexity of viral evolution.

Bird flu is approaching humans

Beginning in 2018 and continuing into 2024, the widespread circulation of clade 2.3.4.4b viruses marked a major change in avian influenza epidemiology. The H5N6 and H5N8 subtypes dominate globally, replacing the original H5N1 virus. More than 70 cases of human infection reported in 2022 cases caused by the H5N6 virus, and 7 cases related to the H5N8 virus.

There are two main ways in which avian influenza spreads to humans: Directly from birds or contaminated environments, or through intermediate hosts such as pigs. Those who come into contact with potentially infected birds, such as workers in slaughter operations, or who are in close contact with potentially infected mammals, such as foxes or wild animals, should take appropriate precautions and seek close medical care after exposure. monitor.

Although avian influenza has been shown to be spread through direct contact with birds or their contaminated environments, the disease has not been proven to be spread to humans through the consumption of contaminated poultry products. Safe handling of raw meat and other ingredients, as well as proper cooking and hygiene practices in the kitchen, are effective measures to prevent or reduce the risks associated with these potentially contaminated foods.

The spread of bird flu has reached alarming proportions in Antarctica, with hundreds of elephant seals found dead.People have reason to worry about this highly contagious virus could cause one of the greatest ecological disasters in modern times If it reaches a remote penguin population. Against this backdrop, there have been recent reports of the death of at least one king penguin in Antarctica due to avian influenza.

Bird flu reaches Antarctica, scientists fear mass extinction

Previous data from South Africa, Chile and Argentina indicate Penguin susceptibility to disease, more than 500,000 seabirds died in South America. Penguins, pelicans and boobies are the most affected species.

Initial reports of the virus in Antarctica were traced to Bird Island near South Georgia.Since then, there have been records Mass die-off of elephant sealsDeaths of sea lions, gulls and brown skuas have also increased in other areas, including fulminant bats in the southern Falkland Islands, 1,500 kilometers west of South Georgia.

In Chile and Peru, the virus has wreaked havoc, killing an estimated 20,000 sea lions. The highly contagious H5N1 strain that emerged in 2021 has killed millions of wild birds. The 2.3.4.4b strain has caused significant declines in bird populations in the UK, continental Europe, South Africa and the Americas. Seabird habitats suffered 50% to 60% loss. Although the H5N1 strain has not yet reached Oceania, the current situation poses a significant risk to the region’s ecosystems and wildlife.

December 2023 Bird flu to blame for polar bear deaths in Alaska, pointing to potential threats to poorly controlled remote populations. Unique and fragile polar ecosystems face risks from avian influenza and climate change.

Taken together, the evolution of avian influenza from 1996 to 2024 reflects the complexity of the virus and its impact on human and animal health and global ecosystems. Effective management requires an international effort that addresses human and animal health issues and considers impacts on biodiversity and polar ecosystems.