Despite one death from bird flu in the US, the risk of another human pandemic is currently low, according to public health agencies and experts.
The person, who died in November 2025, was the first human case in the US since January. He did not appear to have passed the disease to anyone else, which experts say keeps the risk of spreading a new and major human disease remains minimal. The same is true for other human bird flu cases in 2025.
But the disease has been devastating for animals.
“This is no longer just an impact on the poultry sector or wild birds,” Gregorio Torres, head of science at the World Organization for Animal Health (WOAH), told DW.
Data obtained by DW shows that nearly nine million poultry birds have been culled worldwide since October, mainly in the US, Canada and Germany, as both North America and Europe grapple with the outbreak on farms and in forests.
And its influence has spread beyond birds. The current wave, predominantly of the H5N1 subtype, has also infected cattle, pigs, cats and dogs, and wild mammals.
Bird flu: disease and death
Highly pathogenic avian influenza – HPAI – refers to bird flu viruses that cause serious infections in poultry.
Although these viruses are named based on how they affect chickens, ducks, turkeys and other poultry, the effects of infection are usually the same as for wild birds – illness and then death.
WOAH, an intergovernmental organization responsible for coordinating and monitoring animal health worldwide, views viruses – particularly the 2.3.4.4b clade of H5N1 bird flu that is causing the most infections in animal species – as a major threat to biodiversity.
Managing disease outbreaks is an intensive task. Collaboration between animal monitors such as WOAH, veterinary and wildlife scientists, and human public health agencies is considered critical to controlling the spread.
At present there is less danger to humans, more impact to animals
HPAI has been found on every continent in 2025, both on land and in the ocean.
This scale was highlighted by Australian authorities on 25 November Confirmed Bird flu has reached its remote, sub-Antarctic, Indian Ocean territory Heard Island – about 4,300 kilometers (2,600 miles) southwest of the mainland – where it has infected elephant seals.
Bird flu has previously caused mass death in similar populations in coastal areas of South America. Researchers also have discovered Infection in dolphins.
But bird flu is troubling the agricultural sector the most.
In the fall of 2025, German poultry farmers faced the unpleasant start of the bird flu season, with the disease being spread for the first time by migratory cranes from Sweden. Due to this, more than one million chickens were killed in Germany.
Migratory birds are the main reason for the spread of bird flu across continents.
When they flee the Northern Hemisphere when winter arrives, these birds stop near wetlands to rest and recuperate. These stops can bring them into contact with local bird populations.
Mutation makes bird flu easier to spread
If infected with HPAI, there is a high probability that migratory birds will transmit the pathogen to other wild or farmed birds, triggering chain reactions of transmission. recent research Mutations in the 2.3.4.4b clade of H5N1 suggest that infection has become easier in all wild birds.
This means that a drop of disease among local duck, swan or geese populations can effectively bring it to an area, where it can continue to spread even without the help of migratory birds.
Experts told DW that part of the solution lies in “strong biosecurity” measures, This means that governments must put in place strict protocols to ensure that agricultural sectors reduce the risk of bird flu at their local level.
Justin Bahl, an epidemiologist and evolutionary biologist at the University of Georgia in the US, said strong biosecurity is essential to contain outbreaks, prevent transmission and reduce the risk of future episodes.
“As long as we have biosecurity and we’re cautious, I think we’re in a good place right now,” Bahl told DW. “The lack of biosecurity is probably the bigger risk.”
Controlling the spread of the virus between animals reduces the risk of a worse case scenario – a mutation that makes transmission into and potentially between humans easier.
This is the same view expressed by Amira Royes, a global health epidemiologist at George Mason University in the US. Roes told DW that active surveillance and disease testing helps prevent bird flu from spreading in bird flocks, but also reduces the risk of mutations that could make transmission to humans easier.
“Whenever we see an increase in influenza-related deaths in poultry or wild birds, we need to take notice and activate robust surveillance so we can identify important mutations,” Ross said via email. “The fact that we have not seen serious human cases indicates that the strain circulating so far does not pose any significant threat to human health.”
The experts DW spoke to for this article also stressed the importance of cooperation between countries, because wild birds do not recognize borders and, as the COVID-19 pandemic shows, neither does the virus.
“This is a global problem,” Torres said. “We need to be transparent, and share information for the benefit of everyone, including human and animal health.”
Edited by: Zulfikar Abbani