There are concerns about bird flu outbreaks in cattle in the US. How prepared is Europe for the threat of bird flu?

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A strain of bird flu that infected dairy cows and then farm workers in the United States this spring could pose a global health risk, but the extent of the threat is unclear and could catch authorities in Europe and elsewhere off guard if it spreads.

The U.S. cases are the latest increase in highly pathogenic avian influenza (H5N1), which is circulating among migratory and avian birds. mammalian In recent years, it has mainly occurred in Europe and the Americas.

Since March, the strain has been found in 145 cattle herds in 12 states in the United States. Four dairy farmersAll have since recovered from the illness.

There is no evidence of human-to-human transmission – a key indicator of a pandemic threat – and no cases of human infection with this strain have been reported in Europe, according to the European Centre for Disease Prevention and Control (ECDC): general citizen The risk of infection is low.

Still, experts say there are enough warning signs that European countries should be monitoring the virus already and preparing to act quickly if the situation changes.

Waiting until the virus emerges among people on this side of the Atlantic would allow H5N1 to spread unchecked for a long period of time, making it difficult, if not impossible, to contain.

Cattle-to-human transmission

“It's difficult to put a precise timeline on this as the situation can change rapidly and it depends on what the development process is,” Colin Russell, an evolutionary biologist at the University Medical Center Amsterdam and chair of the European Scientific Working Group on Influenza and other Respiratory Viruses (ESWI), told Euronews Health.

“If you don't know what you're missing, you could already be in trouble,” Russell said.

The US outbreak marks the first time the H5N1 virus has been identified in cattle, worrying scientists because the risk of it jumping to humans is much higher and the strain has been deadly in the past.

Between 2003 and 2024, H5N1 caused 889 illnesses and 463 deaths in 23 countries, with a case fatality rate of 52%. World Health Organization (WHO).

The U.S. strain has not yet mutated to allow rapid person-to-person spread, The researchers This week, researchers announced that the inflection point may be closer than previously thought after laboratory tests found signs of transmission between small animals.

“This is a bit worrying because it means that this virus has a greater ability to spread from mammal to mammal via the air than typical highly pathogenic avian influenza viruses,” Thijs Kuijken, professor of comparative pathology at Erasmus University Medical Centre, told Euronews Health.

His research focuses on avian influenza and other emerging viral diseases, but he was not involved in the recent study.

Measures against H5N1

Kuiken and other experts say the risk from H5N1 to people around the world is only slightly higher than it was before the U.S. cattle outbreak, but even that slight increase in risk is enough to cause concern.

“The most likely [outcome] “The concern is that it will die out rather than causing a big change or enough of a change to actually spread to other countries,” Munir Iqbal, head of the Avian Influenza and Newcastle Disease Group at the Pirbright Institute, told Euronews Health.

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But in places where H5N1 is already present, “the virus is invisible, so [should be] It's being treated like an infectious disease.”

Whether or not the U.S. dairy strain poses the ultimate threat to Europe, some countries are taking their own steps to prepare for H5N1.

For example, Finland, Vaccines are being provided to 10,000 workers at high risk of exposure to avian influenza; and Monitoring fur farms All summer long, preparing for potential cases.

meanwhile, German and Italian researcher Tests on samples taken from cows and goats in areas where the virus has been circulating among birds in recent years have found no evidence of infection.

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Kuijken said other European countries, including the Netherlands, Spain, Norway, Sweden, France and Belgium, will soon be launching their own studies.

“When you suddenly realize that a species that you haven't paid much attention to before may have been infected, you want to go back in time to see if that happened,” Kuiken said.

“Looking to the future, many laboratories are now considering that the possibility of such an unusual epidemiological event occurring also in Europe cannot be excluded.”

The European Commission is also stockpiling 665,000 doses It has purchased large quantities of pre-pandemic vaccines to help protect against flu strains that could cause a pandemic, and can buy another 40 million doses if needed.

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Spread of infection in other parts of the world

The International Vaccine Consortium Coalition for Epidemic Preparedness Innovations (CEPI) Expert Group Support global access to H5N1 vaccines if the situation worsens.

But for now, surveillance for H5N1 is key in Europe, Dr Ruth Harvey, deputy director of the Francis Crick Institute's World Influenza Centre, told Euronews Health.

“If we carry out a risk assessment we can respond accordingly,” Mr Harvey said.

Experts aren't just concerned about the spread of the virus in the United States.

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Causes of bird flu Different lineages There have been reported cases in India, China, Australia and Mexico where infected people had no history of contact with animals but ultimately died from the disease.

Beyond the dairy cow crisis, Russell said all countries should develop reporting infrastructure to track the potential for animal pathogens to jump to humans and quickly share that information with the international community.

“This unique situation provides an opportunity to call for increased vigilance against these viruses around the world,” Russell said.