From Antarctica to cows, avian flu is a rising global threat

The number of infected humans has been relatively small. However, the death rate among these individuals is frighteningly high, with over half of the infected people dying.

Since the discovery of the H5 avian flu strain, the number of poultry that have had to be culled is in the billions. Millions of wild birds have perished. Since the start of 2023 alone, South America has seen around 660,000 birds affected. The virus has also infected at least 26 mammal species.

The avian flu was first detected in Antarctica in February 2024, marking a concerning development given the area’s rich diversity in bird species.

Scientists are diligently researching the transmission methods of avian flu and strategies to halt its spread.

The avian flu virus H5N1 was initially identified in a domestic goose in the Guangdong region of China in 1996.

According to scientists, the core issue is human activity. Human demand for poultry meat has facilitated the mutation of H5N1 and its spread to wild birds, causing global proliferation.

The virus is deadly to birds such as house finches but also affects parrots and macaws.

In 2005, there was a notable increase in virus transmission to wild birds. It appeared in North America in 2021, South America in 2022, and Antarctica in 2024.

By the end of 2021, North America detected the virus in Newfoundland, Canada. A saddleback seagull found ill in a pond was taken to a wildlife rehabilitation centre, where it died the next day. It was confirmed to have H5N1. Subsequently, poultry farms reported higher mortality, with autopsies confirming the virus's presence.

The virus has been confirmed in dairy cows on 26 farms across the USA, from Texas to Michigan, as of April 16, 2024. Some cases were linked to wild birds, while others were due to long-distance transportation of cows.

The good news is that, so far, birds in New Zealand and Australia have been unaffected.

In 1997, in Hong Kong, the first human infected with H5N1 died. Over the first 13 years, around 800 people were reported infected, predominantly those working in poultry farming and slaughterhouses.

Contact with sick birds or their droppings, saliva, or feathers is the most significant risk factor for contracting the virus, although the exact transmission mechanism between species remains unknown.

In March 2024, a new variant of the virus was found in cattle, and a month later, a farmer in Texas became the second person in the USA to contract the H5N1 virus from another mammal.

Scientists cannot yet predict whether avian flu will become the next global human pandemic. Nonetheless, each instance of cross-species transmission heightens the risk.

How can we help prevent the spread of avian flu? Avoid touching dead wild birds and report any findings to local authorities. As the World Organisation for Animal Health recommends, farms need to implement proper safety measures, including vaccinating poultry.