From poultry to humans and cows, the deadly avian flu threat looms

The total number of human infections has been relatively small. Nevertheless, the mortality rate among these cases is alarmingly high, with over half of the infected individuals succumbing to the disease.

Since the initial identification of the H5 avian flu strain, billions of poultry have had to be culled. Moreover, millions of wild birds have died. Specifically, in South America, since the start of 2023, around 660,000 birds have been impacted. Additionally, the virus has spread to at least 26 mammal species.

The inaugural case of avian flu in Antarctica was discovered in February 2024. This development is particularly troubling, given Antarctica's rich and diverse bird species.

Scientists are diligently investigating how avian flu spreads and seeking ways to halt its progression.

The avian flu virus, H5N1, was first identified in a domestic goose in China’s Guangdong region in 1996.

Scientists point to human activity as the main issue. The mutation of H5N1, allowing it to transfer to wild birds, has facilitated its global spread. However, the root cause is humanity's growing demand for poultry.

The virus is especially malicious for poultry, such as house finches, parrots, and macaws.

In 2005, there was a notable surge in the virus's spread to wild birds. By 2021, the flu strain had surfaced in North America; by 2022, in South America; and by 2024, it had reached Antarctica.

By the end of 2021, North America reported its first cases in Newfoundland, Canada. A saddleback seagull found ill in a pond was transported to a wildlife rehabilitation center, where it died the following day. Eventually, it was confirmed to have been infected with H5N1. Shortly after, increased mortality rates were reported on poultry farms, with autopsies confirming the virus's presence.

The virus has shown the capability of infecting various mammals—21 species in the United States alone. This has heightened the risk of human exposure and further spread among mammals.

As of April 16, 2024, avian flu has been detected in dairy cows on 26 farms across the USA, from Texas to Michigan. While some infections may be attributed to wild birds, others are believed to be linked to the transportation of cows over long distances.

The silver lining is that, thus far, birds in New Zealand and Australia have remained unaffected.

The first recorded case of a person dying from H5N1 occurred in Hong Kong in 1997. In the first 13 years, only 800 humans were reported infected, with poultry workers and individuals working in slaughterhouses being at the highest risk.

Contact with ill birds, or their droppings, saliva, or feathers, represents the greatest infection risk, although the precise transmission mechanism between species remains a mystery.

In March 2024, a novel form of the virus was identified in cattle. A month later, a Texas farmer became the second American to contract the H5N1 virus from another mammal.

Whether avian flu will evolve into the next major global pandemic is uncertain. However, the risk escalates with each interspecies transmission.

How can we help prevent the spread of avian flu? Avoid contact with dead wild birds and report any discoveries to the local authorities. Furthermore, farms are advised to implement proper safety protocols, including vaccinating poultry, as the World Organisation for Animal Health recommends.