According to modelling by Airfinity, a health data analytics company, the risk of H5N1 reassorting this winter will increase by five-fold compared with the summer months.
While no human cases of H5N1 have been reported in Europe, more than 50 have been detected in the US this year, raising concerns the virus may be better adapted to infecting humans.
Since 2020, hundreds of thousands of H5N1 cases have been reported in animals – like poultry, foxes, mink, seals, and even dolphins, across Europe, providing ample opportunities for spillover into humans.
As recently as September, thousands of wild and domestic birds located on the coasts of the Atlantic Ocean, North Sea, and Baltic Sea have tested positive for H5N1.
The ECDC’s updated guidance points to symptoms seen in recent North American cases, including milder cases where the only symptoms are conjunctivitis.
“We’ve updated our guidance to include milder symptoms in individuals exposed to birds or other animals,” Dr Melidou said. “The priority is to strengthen surveillance and ensure we monitor and follow up with exposed individuals.”
Healthcare workers across Europe are now advised to ask patients with flu-like symptoms about recent contact with birds or other animals – a shift from standard influenza protocols.
The threshold for H5N1 testing has also been lowered to include individuals without known animal exposure, following cases in the US and Canada where infections occurred with no clear link to farmed animals.
