H5N1 bird flu: What to know about the threat of an avian influenza outbreak

The H5N1 aviary virus is already playing havoc in the US. Chickens have been infected and died, or culled to prevent the spread, which has kicked egg prices into overdrive. Tens of millions of the birds have died.

It is not just birds that are pressured by the flu. Despite its name, evidenced has emerged of transmission to mammals, namely minks, and then onwards to other mammals. The spread occured in the northern Spanish state of Galicia, culminating in the killing of 50,000 of the animals.

Though none of the farm workers have been infected, concern remains that a spread could occur in humans in the future.

What is the danger to humans?

Bird flu has been known to infect people, though inter-person transmission is yet to occur. Of the 868 known cases of H5N1 infection in humans worldwide between January 2003 and November 2022, 457 were fatal, according to the World Health Organisation (WHO), a 52% fatality rate.

Timm Harder, an avian influenza expert at the Friedrich Loeffler Institute’s diagnostic virology department in Germany, said there are “numerous hurdles for a more extensive adaptation to humans.”

However, the spread betwen minks could pose a danger for humans in future as bird flu is now proven to transmit between the same species. Scientists weill need to study the infection of minks so we can have the safeguards in place to prevent a pandemic.

“This is incredibly concerning,” said Tom Peacock, a virologist at Imperial College London, in an interview with the scientific journal, Science. “This is a clear mechanism for a H5 pandemic to start.”