A new study published in the journal Nature warns about the pandemic potential of the influenza A (H5N1) virus, better known as bird flu. The investigation considers the latest North American outbreaks in both poultry and ferrets and the impact reflected in the deaths of millions of animals.

The research, led by WCO virologist Richard Webby, traced the spread routes of bird flu since the large wave of the virus arrived in 2021. Webby reported that at some point that year, Ethat the A(H5N1) virus has become more contagious And the speed of its transmission increased both in North America and in Europe, Asia and Africa.

Richard Webby, who is also the director of the World Health Organisation’s Center for Research on Avian Pathology, assured that we are witnessing “the biggest strain of bird flu we have ever seen” and that there is no end in sight.

The current wave of bird flu not only spreads rapidly, but also mixes and evolves in the same way. This fact is one of the behaviors that worries virologists the most. Today’s strains of the A(H5N1) virus appear to cause more severe effects than in the past, as evidenced by carcasses of dead birds where “huge” amounts of the virus were found. Avian influenza, as its name indicates, is an endemic disease of birds, but due to its recent mutation, it started infecting mammals such as sea lions, foxes, rats, dogs, cats, ferrets and humans. Is. The most virulent strains, for example, infect ferrets that have severe necrotizing lesions in the upper respiratory tract.

So far, the A(H5N1) virus has not mutated to become a flu that largely affects humans. Officials follow up on confirmed cases of avian flu in people, but in each case the virus has not developed properties that allow human-to-human transmission. According to the WHO, there have been 26 cases of avian flu infection in humans in the last two years. Of those, 25 came from China and one case developed in the United Kingdom. All those affected worked directly with poultry.

Virologists and epidemiologists are concerned about a possible resurgence of A(H5N1) in humans. Of the registered cases, he calculated a mortality rate of 50%. By comparison, the fatality rate of Covid-19 was only 3%.

The highly pathogenic and infectious version of the virus that causes bird flu, which has already spread to 16 Latin American countries, has managed to adapt to some mammals and may start infecting humans at any time. warns an expert who has been following for years the pathogen’s trail in the wetlands of central Mexico.

At the moment, avian flu is a major challenge facing the world poultry industry that disrupts production chains and has the effect of increasing prices for basic basket products such as eggs or chicken meat. But, as scientists and virologists warn, given the current rate at which bird flu is spreading around the world, and the way it is evolving, the A(H5N1) virus has the potential to become a new human virus. There is clear potential, as was the case with SARS-CoV-2 in 2021.

“Only a few amino acid changes between different influenza proteins are needed to change these properties during adaptation in mammals,” warns Nature study on zoonoses risk in avian influenza now affecting other animals

To reduce the risk of the mutation affecting humans, the leader of the research says the best option currently exists is vaccination of poultry and replacement of invasive strains.