PARIS, May 23, 2025 (BSS/AFP) - Outbreaks of bird flu in mammals more than doubled across the world last year, raising the risk that the virus could potentially spread between humans, an international agency warned on Friday.

Avian influenza has spread across the world like never before in the last few years, leading to the mass culling of poultry, sending egg prices soaring and causing the deaths of several people in contact with infected animals.

While the overall risk of human infection remains low, bird flu outbreaks among mammals such as cattle, dogs and cats increase the possibility that the virus could eventually adapt to transmit between humans, the World Organisation for Animal Health (WOAH) said in a new report.

The number of mammal outbreaks soared to 1,022 across 55 countries last year, compared to 459 in 2023, according to the Paris-based agency, which monitors animal diseases worldwide.

"It is concerning because it is a change in the pattern of the epidemiology of the virus," WOAH's director general Emmanuelle Soubeyran told AFP.

Health experts have been sounding the alarm about the potential pandemic threat posed by bird flu, which has shown signs of mutating as it spreads in particular among dairy cows in the United States.

The new report comes as the budgets of US health and science agencies have been slashed by the Trump administration.

This included the sacking earlier this year of the staff of an epidemiology programme known as the "disease detectives".

- 'Global emergency' -

Bird flu "is more than an animal health crisis -- it is a global emergency destabilising agriculture, food security, trade and ecosystems," the report warned.

More than 630 million birds have either died from avian influenza or been culled due to it over the last two decades, according to the agency's first annual State of the World's Animal Health report.

Wild birds have also suffered mass die-offs, although the exact number is difficult to estimate.

The report highlighted the role that vaccination can play in stemming outbreaks among birds -- which in turn decreases the risk to mammals and humans.

It cited the example of France, which started vaccinating poultry ducks against bird flu in 2023.

Modelling from the Toulouse Veterinary School estimated there would be 700 outbreaks in France that year. In the end, there were just 10, the report said.

Soubeyran said this was a "win-win" because it reduced exposure to humans -- and meant there were more poultry products available for export.

However, she emphasised that vaccines were not a "magic wand" and did not suit every situation.

Biosecurity, surveillance, increased transparency and global collaboration are also important tools to fight off the threat of bird flu, Soubeyran added, calling for more investment in these areas.

- Antibiotic use falls -

Last month Mexico reported its first human death from bird flu, a three-year-old girl.

The US recorded its first death in January, while there have been two deaths in Cambodia this year.

Nearly 50 percent of bird flu infections have historically proved fatal, according to the World Health Organization.

It says the human cases detected so far are mostly linked to people who had close contact with infected birds and other animals, or contaminated environments.

The WOAH report also warned more broadly about the rising danger of animal diseases crossing over into humans as climate change pushes species into new areas.

Nearly 70 percent of the emerging diseases notified to the agency over the last 20 years were considered to have the potential to pose a threat to human health, it said.

Another danger is the increasing resistance some diseases are having to antibiotics, which is "one of the greatest threats to global health, food security and economic stability", the report said.

In positive news, use of antibiotics in animals fell by five percent between 2020 and 2022.

Europe saw the biggest decline -- 23 percent, it added, calling for further reductions.